Investigation of pharmaceutical residues and polybrominated diphenyl ethers in selected river estuaries and canal in Eastern Cape Province, South Africa
- Ohoro, Chinemerem Ruth https://orcid.org/ 0000-0002-8167-6314
- Authors: Ohoro, Chinemerem Ruth https://orcid.org/ 0000-0002-8167-6314
- Date: 2021-09
- Subjects: Marine pharmacology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21545 , vital:48878
- Description: The increasing global pollution by contaminants of emerging concern due to industrialization, development, and improper handling of industrial and domestic waste is alarming. Some of these emerging contaminants are endocrine disruptors and persistent organic pollutants. Two groups of compounds (pharmaceuticals and polybrominated diphenyl ethers (PBDEs)) were considered for this study. Pharmaceuticals are drugs which we take to cure and nourish human and animal bodies, ranging from antibiotics, stimulants, psychiatric, to hormonal recipes among others. They are potentially toxic and comprise chemicals or active ingredients capable of disrupting hormones. They have been related to human and aquatic organisms' ecological risks, such as feminization and masculinization of fish, cancer, and disruption of the immune system. In recent times, pharmaceuticals are being tested in the Rivers of South Africa. PBDEs are human influential chemicals usually incorporated into products such as flame retardants, which can travel over a long distance. They are hydrophobic, lipophilic, environmentally persistent, and easily absorbed by aquatic organisms. About 209 congeners exist, and BDE- 17, 47, 66, 100, 153, 154, and 183 are frequently detected in the environment. The higher brominated congeners can debrominate to more toxic and lower congeners. Though they have low acute toxicity, their effect of interfering with the thyroid gland is long-term. They pose a risk such as immunological, neurological, carcinogenicity, and reproductive disruption. Water and sediment samples considered for investigation were collected from five different sites (Buffalo River Estuary, Sundays River Estuary, Swartkops River Estuary, Nahoon River Estuary, and Markman Canal stormwater). These sites are located in the two major cities hosting the two major Ports (East London and Port Elizabeth) in the Eastern Cape Province of South Africa. Five sampling points were chosen for the collection of both water and sediment samples across three seasons that span from August to December in each of the mentioned sites. Nahoon River Estuary that was not sampled in winter seasons due to logistics and the global pandemic of year 2020; sediment sample was not collected at point NH5 for the spring season because of inaccessibility and topography of the sampling point. Ultrasonic extraction was utilized for sediment samples while SPE method with C-18 cartridges, was used to extract pharmaceuticals in water samples and for the purification of sediment extracts. A chromatographic column was employed for sediment purification. Analytes considered in this study were carbamazepine, caffeine, trimethoprim, sulfamethoxazole, and testosterone. Nahoon River Estuary and Markman canal were considered for investigation of water and sediments for PBDEs. The samples were processed for analysis immediately on arrival to the laboratory after being stored in an ice chest at 4 oC. Physicochemical properties of water samples were taken on site. The temperature ranges from 15.5-24.5 oC for Markman and 24.5- 26.6 oC. Nahoon River Estuary. There was a correlation among the congeners except for BDE-153, which do not correlate with BDE- 17, 47, and 183 in Markman. However, BDE- 153 correlated with BDE-66 in Markman. The Ʃ5PBDE for water and Ʃ6PBDE sediment for all seasons were BDL – 1357 ng/L and BDL – 408.14 ng/g, respectively. The PBDEs mean concentrations in Nahoon water samples ranges from BDL-247 ng/L (spring). The dominant congeners in Nahoon Estuary and Markman Canal samples were BDE- 17 and BDE – 66. The temperature and pH of Swartkops River Estuary range from 16.66 – 25.15 oC, and 8.1 – 10.4, respectively. The pH of the Estuary was higher than that of the Markman Canal. The concentrations of pharmaceuticals in water samples were below detection limit. However, carbamazepine gave the highest concentration in sediment samples (23.86 μg/kg). SLF was not detected in sediment samples. The range of temperature for Buffalo River Estuary was lower than the other sites (18.10 – 20.22 oC); however, the pH showed no difference. Human and ecotoxicological risks were estimated for Markman Canal, Nahoon, Swartkops, Buffalo and Sundays River estuaries. The concentrations obtained for the two classes of contaminants in this study showed that PBDEs in Markman Canal sediment could pose a potential risk to humans, while Nahoon River Estuary poses no risk from PBDEs. Furthermore, the concentrations of caffeine in surface water of Sundays Estuary indicates low ecotoxicological risk to aquatic organisms (fish). Also, carbamazepine and trimethoprim levels (BDL – 9.50 and 1.39-2.00 μg/kg, respectively) suggest a high risk to aquatic organisms (bacteria, invertebrate, algae) in sediment of Buffalo, Sundays, and Swartkops estuaries, as well as Markman Canal. The situation report shows that the estuaries and canal in East London and Port Elizabeth are polluted by organic pollutants such as pharmaceuticals and polybrominated diphenyl ethers. Measures has to be taken to monitor the pollution of these rivers that are of economic value to South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Ohoro, Chinemerem Ruth https://orcid.org/ 0000-0002-8167-6314
- Date: 2021-09
- Subjects: Marine pharmacology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21545 , vital:48878
- Description: The increasing global pollution by contaminants of emerging concern due to industrialization, development, and improper handling of industrial and domestic waste is alarming. Some of these emerging contaminants are endocrine disruptors and persistent organic pollutants. Two groups of compounds (pharmaceuticals and polybrominated diphenyl ethers (PBDEs)) were considered for this study. Pharmaceuticals are drugs which we take to cure and nourish human and animal bodies, ranging from antibiotics, stimulants, psychiatric, to hormonal recipes among others. They are potentially toxic and comprise chemicals or active ingredients capable of disrupting hormones. They have been related to human and aquatic organisms' ecological risks, such as feminization and masculinization of fish, cancer, and disruption of the immune system. In recent times, pharmaceuticals are being tested in the Rivers of South Africa. PBDEs are human influential chemicals usually incorporated into products such as flame retardants, which can travel over a long distance. They are hydrophobic, lipophilic, environmentally persistent, and easily absorbed by aquatic organisms. About 209 congeners exist, and BDE- 17, 47, 66, 100, 153, 154, and 183 are frequently detected in the environment. The higher brominated congeners can debrominate to more toxic and lower congeners. Though they have low acute toxicity, their effect of interfering with the thyroid gland is long-term. They pose a risk such as immunological, neurological, carcinogenicity, and reproductive disruption. Water and sediment samples considered for investigation were collected from five different sites (Buffalo River Estuary, Sundays River Estuary, Swartkops River Estuary, Nahoon River Estuary, and Markman Canal stormwater). These sites are located in the two major cities hosting the two major Ports (East London and Port Elizabeth) in the Eastern Cape Province of South Africa. Five sampling points were chosen for the collection of both water and sediment samples across three seasons that span from August to December in each of the mentioned sites. Nahoon River Estuary that was not sampled in winter seasons due to logistics and the global pandemic of year 2020; sediment sample was not collected at point NH5 for the spring season because of inaccessibility and topography of the sampling point. Ultrasonic extraction was utilized for sediment samples while SPE method with C-18 cartridges, was used to extract pharmaceuticals in water samples and for the purification of sediment extracts. A chromatographic column was employed for sediment purification. Analytes considered in this study were carbamazepine, caffeine, trimethoprim, sulfamethoxazole, and testosterone. Nahoon River Estuary and Markman canal were considered for investigation of water and sediments for PBDEs. The samples were processed for analysis immediately on arrival to the laboratory after being stored in an ice chest at 4 oC. Physicochemical properties of water samples were taken on site. The temperature ranges from 15.5-24.5 oC for Markman and 24.5- 26.6 oC. Nahoon River Estuary. There was a correlation among the congeners except for BDE-153, which do not correlate with BDE- 17, 47, and 183 in Markman. However, BDE- 153 correlated with BDE-66 in Markman. The Ʃ5PBDE for water and Ʃ6PBDE sediment for all seasons were BDL – 1357 ng/L and BDL – 408.14 ng/g, respectively. The PBDEs mean concentrations in Nahoon water samples ranges from BDL-247 ng/L (spring). The dominant congeners in Nahoon Estuary and Markman Canal samples were BDE- 17 and BDE – 66. The temperature and pH of Swartkops River Estuary range from 16.66 – 25.15 oC, and 8.1 – 10.4, respectively. The pH of the Estuary was higher than that of the Markman Canal. The concentrations of pharmaceuticals in water samples were below detection limit. However, carbamazepine gave the highest concentration in sediment samples (23.86 μg/kg). SLF was not detected in sediment samples. The range of temperature for Buffalo River Estuary was lower than the other sites (18.10 – 20.22 oC); however, the pH showed no difference. Human and ecotoxicological risks were estimated for Markman Canal, Nahoon, Swartkops, Buffalo and Sundays River estuaries. The concentrations obtained for the two classes of contaminants in this study showed that PBDEs in Markman Canal sediment could pose a potential risk to humans, while Nahoon River Estuary poses no risk from PBDEs. Furthermore, the concentrations of caffeine in surface water of Sundays Estuary indicates low ecotoxicological risk to aquatic organisms (fish). Also, carbamazepine and trimethoprim levels (BDL – 9.50 and 1.39-2.00 μg/kg, respectively) suggest a high risk to aquatic organisms (bacteria, invertebrate, algae) in sediment of Buffalo, Sundays, and Swartkops estuaries, as well as Markman Canal. The situation report shows that the estuaries and canal in East London and Port Elizabeth are polluted by organic pollutants such as pharmaceuticals and polybrominated diphenyl ethers. Measures has to be taken to monitor the pollution of these rivers that are of economic value to South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Knowledge and attitude towards mastitis, culling and mortality among dairy farmworkers, and factors associated with culling and mortality among dairy cattle in the Eastern Cape Province, South Africa
- Authors: Diniso, Yanga Simamkele
- Date: 2021-09
- Subjects: Food security , Dairying--Economic aspects , Milking
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20686 , vital:46425
- Description: Globally, food security is under threat from escalating population growth, new variants of diseases, climate change and livestock loss. Africa is vulnerable to food insecurity, with majority of the estimated 800 million suffering from hunger based in Africa. Intensification of production is a common strategy to counter the increasing demand for nutritional food to maintain and improve food security. The dairy industry is one of the leading agriculture sectors that has adopted intensification of production. The current study had two specific objectives; the first objective was to evaluate the dairy farmworkers’ knowledge and attitude towards mastitis, culling, and mortality in the southern part of the Eastern Cape Province. The data was collected from 106 dairy farm workers of different farm hierarchy in 5 out of 6 districts using questionnaire. In cases whereby a majority correctly answered a question, a point was awarded and a zero for incorrectly answered questions by the majority. A less than 50 percent pass rate was considered a poor level of knowledge, 51-69 percent pass rate was considered an average level of knowledge, and anything higher than that considered a good level of knowledge. The majority of the participants (64.2 percent) indicated that they consume unpasteurised milk even though they know its risks. There was no association (P>0.05) between workplace position, educational level, work experience, and consumption of unpasteurised milk. This study found that participants had a deficient level of knowledge of mastitis causing pathogens by attaining a pass mark of 1.60 out of a possible 10 (16 percent), and educational level was significantly associated with knowledge of Escherichia coli, Staphylococcus aureus, and Streptococcus spp. However, the participants (64.9 percent) showed good knowledge of clinical signs of mastitis, and this was attributed to the regular mastitis detection with California Mastitis Test (CMT, 60.4 percent) and a strip cup (83.0 percent). The participants had varying perceptions and limited knowledge (28.3 percent pass rate) about the major contributing factors of culling and mortality. The lack of dairy training courses and minimal use of other sources of information such as the internet might contribute to this poor knowledge and perceptions. The second objective involved identifying and describing the factors responsible for culling and mortality in dairy farms in the Eastern Cape province, South Africa. The factors were grouped into seven (7) major factors namely lameness and poor growth (2.33 percent), reproduction problems (35.86 percent), health factors (6.72 percent), production factors (7.11 percent), udder-related factors (3.42 percent), voluntary culls (4.86 percent) and miscellaneous factors (26.03 percent). The most frequent reason for culling dairy cows was reproduction problems which was mainly made up of infertility (7.9 percent), reproductive failure (89.9 percent), and dystocia (1 percent). Miscellaneous factors which mainly consisted of indigenous breeds (8.2 percent), and age (2.7 percent) accounted for the second most prevalent factors for the culling of dairy cows. All the farms recorded stock-theft as part of involuntary culling and accounted for 3.6 percent dairy cows that were culled. Poor milk yield and health-related factors such as red-water (33.8 percent), milk-fever (23.3 percent), and heart-water (6.8 percent) were amongst the major factors responsible for the culling of dairy cows. There were 1774 (13.67 percent) dairy cows that died in the study farms from 2015 to 2019 and causes of death were not specified except for drowning (0.01 percent) and snake bite (1 percent). This study exposed a gap in knowledge about the causes of mastitis, culling and mortality among dairy farmworkers in the southern part of the Eastern Cape Province. Furthermore, this study provided with a baseline information on the leading causes of culling and mortality. There is a need for further research on strategies of enhancing the knowledge of dairy farmworkers about pathogens of mastitis and specific causes of culling and mortality to mitigate the challenge they pose to food security. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Diniso, Yanga Simamkele
- Date: 2021-09
- Subjects: Food security , Dairying--Economic aspects , Milking
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20686 , vital:46425
- Description: Globally, food security is under threat from escalating population growth, new variants of diseases, climate change and livestock loss. Africa is vulnerable to food insecurity, with majority of the estimated 800 million suffering from hunger based in Africa. Intensification of production is a common strategy to counter the increasing demand for nutritional food to maintain and improve food security. The dairy industry is one of the leading agriculture sectors that has adopted intensification of production. The current study had two specific objectives; the first objective was to evaluate the dairy farmworkers’ knowledge and attitude towards mastitis, culling, and mortality in the southern part of the Eastern Cape Province. The data was collected from 106 dairy farm workers of different farm hierarchy in 5 out of 6 districts using questionnaire. In cases whereby a majority correctly answered a question, a point was awarded and a zero for incorrectly answered questions by the majority. A less than 50 percent pass rate was considered a poor level of knowledge, 51-69 percent pass rate was considered an average level of knowledge, and anything higher than that considered a good level of knowledge. The majority of the participants (64.2 percent) indicated that they consume unpasteurised milk even though they know its risks. There was no association (P>0.05) between workplace position, educational level, work experience, and consumption of unpasteurised milk. This study found that participants had a deficient level of knowledge of mastitis causing pathogens by attaining a pass mark of 1.60 out of a possible 10 (16 percent), and educational level was significantly associated with knowledge of Escherichia coli, Staphylococcus aureus, and Streptococcus spp. However, the participants (64.9 percent) showed good knowledge of clinical signs of mastitis, and this was attributed to the regular mastitis detection with California Mastitis Test (CMT, 60.4 percent) and a strip cup (83.0 percent). The participants had varying perceptions and limited knowledge (28.3 percent pass rate) about the major contributing factors of culling and mortality. The lack of dairy training courses and minimal use of other sources of information such as the internet might contribute to this poor knowledge and perceptions. The second objective involved identifying and describing the factors responsible for culling and mortality in dairy farms in the Eastern Cape province, South Africa. The factors were grouped into seven (7) major factors namely lameness and poor growth (2.33 percent), reproduction problems (35.86 percent), health factors (6.72 percent), production factors (7.11 percent), udder-related factors (3.42 percent), voluntary culls (4.86 percent) and miscellaneous factors (26.03 percent). The most frequent reason for culling dairy cows was reproduction problems which was mainly made up of infertility (7.9 percent), reproductive failure (89.9 percent), and dystocia (1 percent). Miscellaneous factors which mainly consisted of indigenous breeds (8.2 percent), and age (2.7 percent) accounted for the second most prevalent factors for the culling of dairy cows. All the farms recorded stock-theft as part of involuntary culling and accounted for 3.6 percent dairy cows that were culled. Poor milk yield and health-related factors such as red-water (33.8 percent), milk-fever (23.3 percent), and heart-water (6.8 percent) were amongst the major factors responsible for the culling of dairy cows. There were 1774 (13.67 percent) dairy cows that died in the study farms from 2015 to 2019 and causes of death were not specified except for drowning (0.01 percent) and snake bite (1 percent). This study exposed a gap in knowledge about the causes of mastitis, culling and mortality among dairy farmworkers in the southern part of the Eastern Cape Province. Furthermore, this study provided with a baseline information on the leading causes of culling and mortality. There is a need for further research on strategies of enhancing the knowledge of dairy farmworkers about pathogens of mastitis and specific causes of culling and mortality to mitigate the challenge they pose to food security. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
Participation of smallholder farmers in the production of high-value commodities: The case of smallholder tobacco farmers in
- Authors: Mugande, Unity
- Date: 2021-09
- Subjects: Farms, Small -- Zimbabwe , Sustainable development -- Zimbabwe
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21533 , vital:48864
- Description: Participation in the production of high-value export commodities is important in increasing incomes and in enhancing smallholder farmers’ livelihoods. However, the level of their participation may be limited by several factors. Despite the limiting factors, smallholder tobacco farming has gained popularity, especially for the Zimbabwean tobacco industry. Since the Fast Track Land Reform Programme (FTLRP), the tobacco industry in Zimbabwe has seen an influx of smallholder farmers who have since dominated the industry producing over half of the national total tobacco output. The participation by smallholder farmers in tobacco production can be influenced by many factors, the main being income realisation. However, for farmers to realise reasonable incomes, they should be able to produce reasonable levels of good quality tobacco otherwise their farming would be in vain. It has been shown in the literature that smallholder farmers can be constrained by several factors to produce high levels of produce and these factors may include one or more of the following; lack of capital, lack of productive assets, lack of tobacco production skills, lack of financial resources to finance productive activities properly, lack of access to land to expand production among others. Given this background, this study sought to assess the participation of smallholder farmers in tobacco production in terms of quantities and qualities produced given the differences in their productive capacities. The study utilised both primary and secondary data for analysis. Primary data were collected from individual farmers and contract firms’ representatives. The unit of analysis was the smallholder farmer. Primary data were collected through structured questionnaires and a semi-structured interview guide for the contract representatives. Secondary data for the 2018 season were obtained from TIMB. Descriptive statistics, binary logistic regression analysis and multiple linear regression analysis were used to analyse the data. The descriptive statistics results showed that; the majority of the tobacco farmers had low levels of education and they relied mainly on farm incomes for survival. Concerning farm assets, the results showed that; on average, farmers own at least one of the following traditional assets; plough, scotch cart, cattle, storage facility, tobacco curing barn, (athough among the farmers some had indicated that they do not own curing facilities but used hired facilities to cure tobacco). Modern assets like tractors, ox-drawn ridgers and truck motor vehicles were owned by only a few farmers. The results further showed that contracted farmers were more productive and produced better quality tobacco than independent tobacco producers. The binary regression results showed that Ox-drawn ridgers, ploughs, having had a contract before, pricing, distance to the market, age of the farmer, type of curing facility, number of extension visits, number of bales produced and access to credit were significant factors influencing farmers’ participation in contract farming. However, four of the tested factors; tractors, cattle, number of hectares utilised for tobacco farming and number of years in tobacco farming were insignificant in influencing participation in contract farming. The results from the multiple linear regression analysis showed that the number of hectares utilised, the number of bales produced, market preferred, household size, tobacco production training, tractors, and type of curing facility were significant factors influencing the quality of tobacco produce. The other four variables that were tested; farmer category, type of energy used, being a member of a peer group and the number of years in tobacco farming; had no significant effect on the quality of tobacco produced by smallholder farmers. The study recommended that farmers should try and invest in commercial assets such as tractors, modern curing facilities, irrigation systems and other modern equipment that have potential to highly boost production rather than traditional assets like ox-drawn ploughs. The study also recommended that farmers should aim at maximising quantity per hectare of tobacco planted rather than planting larger crop areas they are unable to finance properly. Finally, it is recommended that farmers should get training on tobacco grading to avoid product quality loses that come with improper grading. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Mugande, Unity
- Date: 2021-09
- Subjects: Farms, Small -- Zimbabwe , Sustainable development -- Zimbabwe
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21533 , vital:48864
- Description: Participation in the production of high-value export commodities is important in increasing incomes and in enhancing smallholder farmers’ livelihoods. However, the level of their participation may be limited by several factors. Despite the limiting factors, smallholder tobacco farming has gained popularity, especially for the Zimbabwean tobacco industry. Since the Fast Track Land Reform Programme (FTLRP), the tobacco industry in Zimbabwe has seen an influx of smallholder farmers who have since dominated the industry producing over half of the national total tobacco output. The participation by smallholder farmers in tobacco production can be influenced by many factors, the main being income realisation. However, for farmers to realise reasonable incomes, they should be able to produce reasonable levels of good quality tobacco otherwise their farming would be in vain. It has been shown in the literature that smallholder farmers can be constrained by several factors to produce high levels of produce and these factors may include one or more of the following; lack of capital, lack of productive assets, lack of tobacco production skills, lack of financial resources to finance productive activities properly, lack of access to land to expand production among others. Given this background, this study sought to assess the participation of smallholder farmers in tobacco production in terms of quantities and qualities produced given the differences in their productive capacities. The study utilised both primary and secondary data for analysis. Primary data were collected from individual farmers and contract firms’ representatives. The unit of analysis was the smallholder farmer. Primary data were collected through structured questionnaires and a semi-structured interview guide for the contract representatives. Secondary data for the 2018 season were obtained from TIMB. Descriptive statistics, binary logistic regression analysis and multiple linear regression analysis were used to analyse the data. The descriptive statistics results showed that; the majority of the tobacco farmers had low levels of education and they relied mainly on farm incomes for survival. Concerning farm assets, the results showed that; on average, farmers own at least one of the following traditional assets; plough, scotch cart, cattle, storage facility, tobacco curing barn, (athough among the farmers some had indicated that they do not own curing facilities but used hired facilities to cure tobacco). Modern assets like tractors, ox-drawn ridgers and truck motor vehicles were owned by only a few farmers. The results further showed that contracted farmers were more productive and produced better quality tobacco than independent tobacco producers. The binary regression results showed that Ox-drawn ridgers, ploughs, having had a contract before, pricing, distance to the market, age of the farmer, type of curing facility, number of extension visits, number of bales produced and access to credit were significant factors influencing farmers’ participation in contract farming. However, four of the tested factors; tractors, cattle, number of hectares utilised for tobacco farming and number of years in tobacco farming were insignificant in influencing participation in contract farming. The results from the multiple linear regression analysis showed that the number of hectares utilised, the number of bales produced, market preferred, household size, tobacco production training, tractors, and type of curing facility were significant factors influencing the quality of tobacco produce. The other four variables that were tested; farmer category, type of energy used, being a member of a peer group and the number of years in tobacco farming; had no significant effect on the quality of tobacco produced by smallholder farmers. The study recommended that farmers should try and invest in commercial assets such as tractors, modern curing facilities, irrigation systems and other modern equipment that have potential to highly boost production rather than traditional assets like ox-drawn ploughs. The study also recommended that farmers should aim at maximising quantity per hectare of tobacco planted rather than planting larger crop areas they are unable to finance properly. Finally, it is recommended that farmers should get training on tobacco grading to avoid product quality loses that come with improper grading. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Prevalence and geo-mapping of livestock disease in the Eastern Cape Province, South Africa
- Phingilili, Wanga-Ungeviwa (https://orcid.org/ 0000-0001-7227-6813)
- Authors: Phingilili, Wanga-Ungeviwa (https://orcid.org/ 0000-0001-7227-6813)
- Date: 2021-09
- Subjects: Parasitology , Veterinary medicine , Veterinary tropical medicine
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20959 , vital:46865
- Description: Livestock disease poses a threat to the livestock production industry due to ban on the exportation of live animals and animal by-products. Information on disease surveillance and mapping of disease prevalence and distribution in the Eastern Cape is very scarce. Therefore, two objectives were set to determine the prevalence and distribution of livestock disease in the Eastern Cape Province (ECP) through retrospective investigation. A retrospective data of animal diseases in the ECP from 2013-2018 was obtained from the veterinary unit of the Department of Rural and Agrarian Reform (DrDAR) database, decoded, analysed, and interpreted. The first objective was to determine the prevalence and seasonal distribution of viral and bacterial diseases in ECP from 2013-2018. The second objective was to conduct a spatio-temporal analysis of parasitic diseases of livestock in ECP from 2013-2018. Significant associations (P< 0.05) were found between local municipality, season, year, and livestock species. The highest prevalence of viral disease was found in the Lukhanji (29.4 percent) and Mbhashe (17.5 percent), while bacterial diseases were found in Nelson Mandela Bay (27.7 percent) and Raymond Mhlaba (34.9 percent) municipalities. Viral infections were more common in autumn (53.8 percent), while bacterial infections were more in spring (58. 5 percent). The highest proportions of bacterial and viral diseases were in caprine (97.2 percent) and bovine (41.4 percent) species. Odds of disease occurrence were highest in Intsika yethu local municipality (OR= 3.279; 95 percent CI= 0.043-263.6; P<0.05) in autumn (OR = 2.131; 95 percent CI= 0.815-5.569; P<0.05) and in bovine (OR= 58.825; 95 percent CI= 16.283-205.591; P<0.05). Internal parasites (75 percent) were the highest reported in the year 2015), whereas external parasites (38.1 percent), and fly parasites (30.4 percent) were mostly reported in the year 2016. The highest prevalence of fly parasites and internal parasites was found in autumn (87 percent) and spring (75 percent), respectively. The Local municipality with the highest prevalence was Amahlathi (fly parasites, 91.3 percent), Dr Beyers Naude (external 3 parasite, 43.6 percent), Intsika yethu (internal parasite, 75 percent), Makana (protozoa, 5.8 percent), Mbhashe (haemoparasite, 40 percent percent), Raymond Mhlaba municipality (haemoparasite, 12.5 percent), and Lukhanji (fly parasite, 8.7 percent). Parasitic diseases with the highest prevalence in the province between 2013 to 2018 were babesiosis, anaplasmosis, cowdriosis, Bovine malignant catarrhal fever, and sheep scab. Livestock diseases are prevalent and unevenly distributed in the Eastern Cape Province. The diseases were mostly diagnosed in autumn and spring. , Thesis (MSc) (Animal Production Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Phingilili, Wanga-Ungeviwa (https://orcid.org/ 0000-0001-7227-6813)
- Date: 2021-09
- Subjects: Parasitology , Veterinary medicine , Veterinary tropical medicine
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20959 , vital:46865
- Description: Livestock disease poses a threat to the livestock production industry due to ban on the exportation of live animals and animal by-products. Information on disease surveillance and mapping of disease prevalence and distribution in the Eastern Cape is very scarce. Therefore, two objectives were set to determine the prevalence and distribution of livestock disease in the Eastern Cape Province (ECP) through retrospective investigation. A retrospective data of animal diseases in the ECP from 2013-2018 was obtained from the veterinary unit of the Department of Rural and Agrarian Reform (DrDAR) database, decoded, analysed, and interpreted. The first objective was to determine the prevalence and seasonal distribution of viral and bacterial diseases in ECP from 2013-2018. The second objective was to conduct a spatio-temporal analysis of parasitic diseases of livestock in ECP from 2013-2018. Significant associations (P< 0.05) were found between local municipality, season, year, and livestock species. The highest prevalence of viral disease was found in the Lukhanji (29.4 percent) and Mbhashe (17.5 percent), while bacterial diseases were found in Nelson Mandela Bay (27.7 percent) and Raymond Mhlaba (34.9 percent) municipalities. Viral infections were more common in autumn (53.8 percent), while bacterial infections were more in spring (58. 5 percent). The highest proportions of bacterial and viral diseases were in caprine (97.2 percent) and bovine (41.4 percent) species. Odds of disease occurrence were highest in Intsika yethu local municipality (OR= 3.279; 95 percent CI= 0.043-263.6; P<0.05) in autumn (OR = 2.131; 95 percent CI= 0.815-5.569; P<0.05) and in bovine (OR= 58.825; 95 percent CI= 16.283-205.591; P<0.05). Internal parasites (75 percent) were the highest reported in the year 2015), whereas external parasites (38.1 percent), and fly parasites (30.4 percent) were mostly reported in the year 2016. The highest prevalence of fly parasites and internal parasites was found in autumn (87 percent) and spring (75 percent), respectively. The Local municipality with the highest prevalence was Amahlathi (fly parasites, 91.3 percent), Dr Beyers Naude (external 3 parasite, 43.6 percent), Intsika yethu (internal parasite, 75 percent), Makana (protozoa, 5.8 percent), Mbhashe (haemoparasite, 40 percent percent), Raymond Mhlaba municipality (haemoparasite, 12.5 percent), and Lukhanji (fly parasite, 8.7 percent). Parasitic diseases with the highest prevalence in the province between 2013 to 2018 were babesiosis, anaplasmosis, cowdriosis, Bovine malignant catarrhal fever, and sheep scab. Livestock diseases are prevalent and unevenly distributed in the Eastern Cape Province. The diseases were mostly diagnosed in autumn and spring. , Thesis (MSc) (Animal Production Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
The effects of household agricultural income on the adoption of electrical appliances and energy security among rural households in Mnquma Local Municipality
- Ntonjane, P https://orcid.org/0000-0001-9432-9031
- Authors: Ntonjane, P https://orcid.org/0000-0001-9432-9031
- Date: 2021-09
- Subjects: Energy security , Sustainable development -- South Africa , Economic development -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22655 , vital:52617
- Description: Energy security is critical to global economic development and agricultural activities. Electricity is one of the most beneficial types of energy for rural household livelihoods and smallholder producers in South Africa. This study aims to examine the effects of household agricultural income on the adoption of electrical appliances and energy security among agricultural households in Mnquma Local Municipality. The study employed primary data obtained from 224 households using simple random sampling technique across three electrification stages. Descriptive statistics, and binary logistic regression was used to determine the relationship between socio-economic and demographic characteristics of the household and the household agricultural income on the adoption of new electrical appliances and energy security across the three electrification stages. Descriptive statistics results indicated that non-electrified (67.1percent) and recently electrified (54.3percent) villages are dominated by female-headed households, while in electrified households there are more male head households (58.3percent). The results also show that among the households that have the highest total monthly income (greater than R15000), 34.5percent were electrified, 17.1 percent were recently electrified, and 4.3percent were non-electrified. The Binary logistic regression model's findings for the second objective revealed that household head factors such as age, monthly total household income, household size, and household agricultural income have significant effects on energy security. The study's findings revealed that household agricultural income has a significant impact at a 5 percent significant level on the adoption of electrical appliances. Binary logistic regression findings for the third objective revealed that on new electrical appliance adoption there was a significant effect of gender (at 5percent level), household size, energy security, and household agricultural income at a 1percent significance level. Binary logistic regression revealed that the coefficient of household size variable is positive and significant at a 1percent significant level on energy security and electrical appliance adoption. In this study, household agricultural income on the adoption of electrical appliances has been found to be the most critical factor influencing the energy security status of households among the selected rural households in Mnquma Local Municipality. As a result, policies must be put in place to facilitate access to electrical appliances through electrification programs, invention of affordable electric appliances, encourage participation in agricultural production and agricultural market access, that will provide households with social benefits. To improve energy security, electrical appliances should be simple to use and aid in the transition from biomass to electricity. , Thesis (MAgric) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Ntonjane, P https://orcid.org/0000-0001-9432-9031
- Date: 2021-09
- Subjects: Energy security , Sustainable development -- South Africa , Economic development -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22655 , vital:52617
- Description: Energy security is critical to global economic development and agricultural activities. Electricity is one of the most beneficial types of energy for rural household livelihoods and smallholder producers in South Africa. This study aims to examine the effects of household agricultural income on the adoption of electrical appliances and energy security among agricultural households in Mnquma Local Municipality. The study employed primary data obtained from 224 households using simple random sampling technique across three electrification stages. Descriptive statistics, and binary logistic regression was used to determine the relationship between socio-economic and demographic characteristics of the household and the household agricultural income on the adoption of new electrical appliances and energy security across the three electrification stages. Descriptive statistics results indicated that non-electrified (67.1percent) and recently electrified (54.3percent) villages are dominated by female-headed households, while in electrified households there are more male head households (58.3percent). The results also show that among the households that have the highest total monthly income (greater than R15000), 34.5percent were electrified, 17.1 percent were recently electrified, and 4.3percent were non-electrified. The Binary logistic regression model's findings for the second objective revealed that household head factors such as age, monthly total household income, household size, and household agricultural income have significant effects on energy security. The study's findings revealed that household agricultural income has a significant impact at a 5 percent significant level on the adoption of electrical appliances. Binary logistic regression findings for the third objective revealed that on new electrical appliance adoption there was a significant effect of gender (at 5percent level), household size, energy security, and household agricultural income at a 1percent significance level. Binary logistic regression revealed that the coefficient of household size variable is positive and significant at a 1percent significant level on energy security and electrical appliance adoption. In this study, household agricultural income on the adoption of electrical appliances has been found to be the most critical factor influencing the energy security status of households among the selected rural households in Mnquma Local Municipality. As a result, policies must be put in place to facilitate access to electrical appliances through electrification programs, invention of affordable electric appliances, encourage participation in agricultural production and agricultural market access, that will provide households with social benefits. To improve energy security, electrical appliances should be simple to use and aid in the transition from biomass to electricity. , Thesis (MAgric) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
The investigation of groundwater potential zones in the Neotectonic area of Ntabankulu Local Municipality, Eastern Cape Province, South Africa
- Nonkula, Zenande https://orcid.org/0000-0002-3858-7703
- Authors: Nonkula, Zenande https://orcid.org/0000-0002-3858-7703
- Date: 2021-09
- Subjects: Groundwater , Water-supply , Neotectonics
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22875 , vital:53068
- Description: Ntabankulu extends from latitude 30° 51' 09"S to 31° 09' 10" S and from longitude 29° 06' 51"E to 29° 23' 49"E in the Eastern Cape Province of South Africa. Ntabankulu Local Municipality has 141 villages with 125 976 population size. About 36% of villages do not have water sources, 38% have partial functional water sources, 6% have non-functional water sources, and 20 % have reliable water sources, primarily rivers (Mnceba, Caba and Mzimvubu). Water is scarce in this area, especially in the dry season when perennial rivers and springs become dry. This research investigates groundwater potential zones and identifies suitable aquifers that can be developed to augment the water resources. The study involved: literature review, remote sensing, borehole and springs data, geological, petrographic and geophysical (gravity, magnetic and electrical resistivity) analyses. Each method has its purpose in finding the potential groundwater zones. Ntabankulu Local Municipality is located on the Karoo Supergroup in Ecca and Beaufort Group, Adelaide Subgroup and Balfour Formation. During field analysis, it was observed that this area consists of sandstone, shale and dolerite sills, dykes and complex rings. Fining up sequences, massive bedding, concretions, and spheroidal weathering were observed in sandstone, shale, and dolerite, respectively. Groundwater seepages are found within these structures. Sandstones are yellow due to the presence of limonite because of the continuous seepage. Red coloured laminated shale reflects that the rock has an iron oxidation state with hematite (Fe2O3) on the sediments. The Geographical Information Systems (GIS) method was used to extract lineaments. Lineaments dominate Ntabankulu with an NW-SE direction. Some of the lineaments are due to Karoo igneous intrusions, and others are due to neotectonic activities. Ntabankulu is located on the eastern and northern neotectonic belts. Geological maps and lineament maps were compared; it was observed that sandstones and shales are found on high liinament density areas. High yielding boreholes and springs coincide with lineaments, and some lineaments are faults. Hence areas that have high lineaments density could be groundwater potential zones. There are geological structures (faults, joints, and fractures) that are present. Systematic and non-systematic joints are found on sandstones which are due to extensional stress. These joints have been reactivated and acted as strike-slip faults. All these geological structures increase the porosity and permeability of the rocks. It was observed that the area of Ntabankulu consists of coarse-grained and medium-grained sandstone with quartz and orthoclase minerals. Dolerite consists of labradorite, clinopyroxene, olivine, oxide minerals with twinning formed during cooling and magma crystallisation. The gravity and magnetic methods were used to study the subsurface rock density contrasts and susceptibilities, respectively. The gravity and magnetic maps were generated in Geosoft Oasis 8.3 software. High gravity zones coincide with some of the mapped Karoo intrusions. Unmapped dolerite intrusions, lineaments and faults were inferred. The magnetic method delineated the subsurface structures (lineaments and faults), which are known to control groundwater accumulation. These structures and inferred dolerite intrusions helped in identifying groundwater potential zones. Groundwater potential zones were inferred in sedimentary rocks between dolerite intrusions and areas where sills and dykes intersect. A total of six vertical electrical soundings (VES) were conducted at Mzalwaneni and Tabankulu town areas using the Schlumberger configuration array with a maximum penetration depth of about 25- 33 m. The VES data were modelled in Winresist and Surfer 9 software to obtain 1D models and geoelectric sections, respectively. These 1D models have three layers with response curves of H-type. The top layer is about 0.4 - 0.7 m thick, with resistivity values from 12.3 – 1885.9 Ωm and is topsoil (sand and clay). The second layer of thickness 5.2 – 13.3 m has low resistivity values from 23.1- 44.9 Ωm. This layer is interpreted to be fractured shales and sandstones possibly containing water. The third layer of high resistivity values of 145.9 – 727.4 Ωm is inferred to be sandstone. The simultaneous interpretation of resistivity and normalised chargeability revealed that groundwater potential zones are characterised by low resistivity values and low normalised chargeability values for layers from 0.7 - 13.3 m depth. The groundwatwer in the area of Ntabankulu can be found on unconfined aquifers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Nonkula, Zenande https://orcid.org/0000-0002-3858-7703
- Date: 2021-09
- Subjects: Groundwater , Water-supply , Neotectonics
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22875 , vital:53068
- Description: Ntabankulu extends from latitude 30° 51' 09"S to 31° 09' 10" S and from longitude 29° 06' 51"E to 29° 23' 49"E in the Eastern Cape Province of South Africa. Ntabankulu Local Municipality has 141 villages with 125 976 population size. About 36% of villages do not have water sources, 38% have partial functional water sources, 6% have non-functional water sources, and 20 % have reliable water sources, primarily rivers (Mnceba, Caba and Mzimvubu). Water is scarce in this area, especially in the dry season when perennial rivers and springs become dry. This research investigates groundwater potential zones and identifies suitable aquifers that can be developed to augment the water resources. The study involved: literature review, remote sensing, borehole and springs data, geological, petrographic and geophysical (gravity, magnetic and electrical resistivity) analyses. Each method has its purpose in finding the potential groundwater zones. Ntabankulu Local Municipality is located on the Karoo Supergroup in Ecca and Beaufort Group, Adelaide Subgroup and Balfour Formation. During field analysis, it was observed that this area consists of sandstone, shale and dolerite sills, dykes and complex rings. Fining up sequences, massive bedding, concretions, and spheroidal weathering were observed in sandstone, shale, and dolerite, respectively. Groundwater seepages are found within these structures. Sandstones are yellow due to the presence of limonite because of the continuous seepage. Red coloured laminated shale reflects that the rock has an iron oxidation state with hematite (Fe2O3) on the sediments. The Geographical Information Systems (GIS) method was used to extract lineaments. Lineaments dominate Ntabankulu with an NW-SE direction. Some of the lineaments are due to Karoo igneous intrusions, and others are due to neotectonic activities. Ntabankulu is located on the eastern and northern neotectonic belts. Geological maps and lineament maps were compared; it was observed that sandstones and shales are found on high liinament density areas. High yielding boreholes and springs coincide with lineaments, and some lineaments are faults. Hence areas that have high lineaments density could be groundwater potential zones. There are geological structures (faults, joints, and fractures) that are present. Systematic and non-systematic joints are found on sandstones which are due to extensional stress. These joints have been reactivated and acted as strike-slip faults. All these geological structures increase the porosity and permeability of the rocks. It was observed that the area of Ntabankulu consists of coarse-grained and medium-grained sandstone with quartz and orthoclase minerals. Dolerite consists of labradorite, clinopyroxene, olivine, oxide minerals with twinning formed during cooling and magma crystallisation. The gravity and magnetic methods were used to study the subsurface rock density contrasts and susceptibilities, respectively. The gravity and magnetic maps were generated in Geosoft Oasis 8.3 software. High gravity zones coincide with some of the mapped Karoo intrusions. Unmapped dolerite intrusions, lineaments and faults were inferred. The magnetic method delineated the subsurface structures (lineaments and faults), which are known to control groundwater accumulation. These structures and inferred dolerite intrusions helped in identifying groundwater potential zones. Groundwater potential zones were inferred in sedimentary rocks between dolerite intrusions and areas where sills and dykes intersect. A total of six vertical electrical soundings (VES) were conducted at Mzalwaneni and Tabankulu town areas using the Schlumberger configuration array with a maximum penetration depth of about 25- 33 m. The VES data were modelled in Winresist and Surfer 9 software to obtain 1D models and geoelectric sections, respectively. These 1D models have three layers with response curves of H-type. The top layer is about 0.4 - 0.7 m thick, with resistivity values from 12.3 – 1885.9 Ωm and is topsoil (sand and clay). The second layer of thickness 5.2 – 13.3 m has low resistivity values from 23.1- 44.9 Ωm. This layer is interpreted to be fractured shales and sandstones possibly containing water. The third layer of high resistivity values of 145.9 – 727.4 Ωm is inferred to be sandstone. The simultaneous interpretation of resistivity and normalised chargeability revealed that groundwater potential zones are characterised by low resistivity values and low normalised chargeability values for layers from 0.7 - 13.3 m depth. The groundwatwer in the area of Ntabankulu can be found on unconfined aquifers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Vulnerability assessment of wetland ecosystems to water demand, climate variability and land-use/cover change: The case of Die Vlei wetland, Eastern Cape province, South Africa
- Gwena, Kudzanai Rosebud https://orcid.org/0000-0002-1032-8937
- Authors: Gwena, Kudzanai Rosebud https://orcid.org/0000-0002-1032-8937
- Date: 2021-09
- Subjects: Water-supply , Climate change mitigation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22688 , vital:52656
- Description: Water scarcity is a major challenge in many different countries, particularly arid and or semi-arid like South Africa. Wetlands are one of the freshwater ecosystems that may assist in alleviating water scarcity because they are valuable not only as a water source for humans but also as an ecosystem of animals and plant species. However, wetlands have been experiencing rapid rates of vulnerability/risk due to alterations by population growth leading to enhanced water demand, climate variability, and human activities leading to land cover/land-use changes. Geographical Information Systems (GIS) and Remote Sensing (RS) are less financially taxing methods useful in studying water scarcity, as shown in this study. The study begins with a literature review presentation based on a desk study from predominantly academic publications and additional municipal and consultancy reports on the wetland ecosystem’s vulnerability/risk and focuses on applying GIS & RS in related studies. After that, the study conducts a vulnerability assessment using the Ramsar Convention’s wetland vulnerability assessment using the theoretical framework stages using GIS and RS technologies. The study hypothesizes that water demand, climate variability, and land-use/cover changes (LULC) are the tri-factor responsible for wetland vulnerability. It begins the assessment by first quantifying wetland water demand using the wetland water budget, ecosystem services and the Penman-Montheith-FAO (ETo) evapotranspiration index. Secondly, objectively representing climate variability on wetland vulnerability using trend analysis to measure rainfall and temperature variability. Thirdly, reconstructing LULC changes from multi-date remotely sensed SPOT imagery over ten years from 2007 to 2017 to identify and monitor impacts of trends. The vulnerability was assessed through a Principle Component Analysis (PCA) that identified relevant variables and Multi-Criteria Evaluation (MCE) to evaluate the wetland’s exposure. The study concludes that there is evidence of a possible increase in water demand whilst climate variability, which is estimated to have a 39% contribution to the wetland dynamics, is characterised by a decrease in precipitation and an increase in temperatures. Lastly, LULC trends showed a marked increase in domestic and commercial farming, and farming has been identified as a wetland stressor of note. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Gwena, Kudzanai Rosebud https://orcid.org/0000-0002-1032-8937
- Date: 2021-09
- Subjects: Water-supply , Climate change mitigation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22688 , vital:52656
- Description: Water scarcity is a major challenge in many different countries, particularly arid and or semi-arid like South Africa. Wetlands are one of the freshwater ecosystems that may assist in alleviating water scarcity because they are valuable not only as a water source for humans but also as an ecosystem of animals and plant species. However, wetlands have been experiencing rapid rates of vulnerability/risk due to alterations by population growth leading to enhanced water demand, climate variability, and human activities leading to land cover/land-use changes. Geographical Information Systems (GIS) and Remote Sensing (RS) are less financially taxing methods useful in studying water scarcity, as shown in this study. The study begins with a literature review presentation based on a desk study from predominantly academic publications and additional municipal and consultancy reports on the wetland ecosystem’s vulnerability/risk and focuses on applying GIS & RS in related studies. After that, the study conducts a vulnerability assessment using the Ramsar Convention’s wetland vulnerability assessment using the theoretical framework stages using GIS and RS technologies. The study hypothesizes that water demand, climate variability, and land-use/cover changes (LULC) are the tri-factor responsible for wetland vulnerability. It begins the assessment by first quantifying wetland water demand using the wetland water budget, ecosystem services and the Penman-Montheith-FAO (ETo) evapotranspiration index. Secondly, objectively representing climate variability on wetland vulnerability using trend analysis to measure rainfall and temperature variability. Thirdly, reconstructing LULC changes from multi-date remotely sensed SPOT imagery over ten years from 2007 to 2017 to identify and monitor impacts of trends. The vulnerability was assessed through a Principle Component Analysis (PCA) that identified relevant variables and Multi-Criteria Evaluation (MCE) to evaluate the wetland’s exposure. The study concludes that there is evidence of a possible increase in water demand whilst climate variability, which is estimated to have a 39% contribution to the wetland dynamics, is characterised by a decrease in precipitation and an increase in temperatures. Lastly, LULC trends showed a marked increase in domestic and commercial farming, and farming has been identified as a wetland stressor of note. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Agro-morphological characterisation, nitrogen use efficiency and combining ability of quality protein maize (zea mays l.) genotypes for low nitrogen tolerance
- AdeOluwa, Olusola Oluyinka https://orcid.org/ 0000-0003-2145-7141
- Authors: AdeOluwa, Olusola Oluyinka https://orcid.org/ 0000-0003-2145-7141
- Date: 2021-08
- Subjects: Corn -- Quality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21501 , vital:48855 , http://id.loc.gov/authorities/subjects/sh85032715
- Description: Low nitrogen stress tolerant Quality Protein Maize (QPM) genotypes will be of great benefit to farmers for increasing productivity in nitrogen depleted soils in the Eastern Cape (EC) Province, South Africa (SA). The current study evaluated: (i) QPM inbred lines for tolerance to low soil nitrogen, (ii) the Nitrogen Use Efficiency (NUE) of different QPM inbred lines, (iii) the combining ability of QPM genotypes for tolerance to low nitrogen, grain yield, and other agro-morphological traits, and (iv) the agro-morphological characteristics and adaptation of QPM hybrids to environments of different production potential in the Eastern Cape, South Africa. Thirty-two white-seeded QPM inbred lines obtained from CIMMYT-Zimbabwe and Quality Seeds (PTY) LTD were evaluated for tolerance to low soil nitrogen stress using two nitrogen (N) treatment levels: 0 kg N ha-1 and 30 kg N ha-1 under both glasshouse and field conditions at the Crop Research farm, University of Fort Hare, in two planting seasons. The study aimed at assessing the response of QPM inbred lines to low N, with a view to identifying low N tolerant types under both glasshouse and field conditions. Shoot length stress tolerance index (SHL STI) indicated lines L23, L29, L27, L13, L16, L17, L31, L14, L18 and L22 to be low soil N tolerant from the glasshouse study. From the field study, low N Stress Tolerance Index (STI) identified inbred lines L23, L31, L26, L28, L25, L29, L32, L4, L6, L3 and L2 as low soil N tolerant. These inbred lines also had high grain yields (GY) in the field under 0 kg N ha-1 (all ranked within the top ten except L2). They also had the potential for stable yields across environments considering their high Yield Stability Index (YSI), Mean Productivity (MP), Geometric Mean Productivity (GMP) and Stress Susceptibility Index (SSI) values. Both the glasshouse and field studies revealed inbred lines L22, L23, L26, L28, L25, L29 and L31 were common to both the glasshouse and field studies as being low soil N tolerant. These thirty-two parental QPM inbred lines were evaluated in the field for their nitrogen use efficiency (NUE) under five different nitrogen levels: 0, 30, 60, 90 and 120 kg N ha-1. The inbred lines studied under 0 kg N ha-1 and 30 kg N ha-1 indicated that N level expressed highly significant differences (P ≤ 0.001) for total nitrogen in biomass (Bio Total N), total nitrogen in grain (G Total N), grain yield (GY), nitrogen use efficiency (NUE) and almost all the indices estimated. The top six nutrient use efficient genotypes were L9, L14, L23, L25, L29 and L32 across N levels. However, the best and highest NUE was obtained from the lowest fertilizer dose, 30 kg N ha-1. Highly significant and positive correlation coefficients were found between Nitrogen Use Efficiency (NUE) and yield (+0.9), NUE and NUtE (+0.9), NUE and HI (Harvest Index) (+0.5), NUtE and yield (+0.99), HI and yield (+0.5) and NUtE and HI (+0.5). Thus, NUE, HI and NUtE could be good predictors of yield potential under low N soil conditions. Sixty-four testcross hybrids were generated from crossing these 32 QPM inbred lines with two QPM open pollinated varieties (OPVs) as testers in a line x tester design and were evaluated under 0 kg N ha-1 and 30 kg N ha-1 in the field. The objectives of the experiment were to: (i) identify high yielding hybrids with tolerance to low soil N in the EC; (ii) determine the combining abilities and mode of gene action for various traits under low and high nitrogen conditions; and (iii) group the inbred lines into heterotic groups for future use in the breeding program. Results revealed that under 30 kg N ha-1 (30N) condition, both additive and non-additive gene effects were observed with less importance of non-additive gene action for grain yield. Based on specific combining ability (SCA) effects, hybrids LNC22, LNC31, LOB22, LNC30, LNC29, LOB11, LNC18, LOB30, LOB19 and LNC24 showed outstanding performance under 0 kg N ha-1 (0N) condition with relatively acceptable SCA under 30N for yield. Inbred lines L6 (1.63), L22 (1.74), L29 (1.83) and L30 (1.24) showed positive and significant GCAs for grain yield under 0N. They were identified as the best combiners for grain yield as they were among the top ten performers for GCA under 0N. They can be very useful sources of low N tolerance genes. Two heterotic groups were formed under 0 kg N ha-1 and 30 kg N ha-1 conditions, and they will be useful for future hybrid development in the breeding program. Furthermore, these thirty-two QPM inbred lines were utilised as parental lines to generate seventy-six single cross hybrids. These single cross hybrids were evaluated across three environments of varying production potential in the Eastern Cape (EC), during the 2016/17 and 2017/18 summer seasons. Non-QPM hybrids namely PAN5Q649R and Phb31MO7BR, as well as QPM OPVs OBATANPA and Nelson's Choice were included in these preliminary variety trials (PVTs) as checks. Twenty-five hybrids expressing high values for the Smith – Hazel selection index were identified across sites over years. Among those hybrids were two checks, namely Q16 (PAN5Q649R) and Q33 (Phb31MO7BR). The top five high – yielding hybrids selected based on the selection index were considered to be the most productive, stable and adaptable based on the GGE biplot and AMMI stability values. None of these single cross hybrids over yielded the best hybrid check (Q16) in the current study. A high potential environment, Centane, was the ideal environments for evaluating genotypes in the present study. The studies showed inbred lines L22, L23, L26, L28, L25, L29 and L31 to be low N stress tolerant at 0 kg N ha-1 based on the low N stress tolerance indices under glasshouse and the field conditions; they were also among the top ten grain-yielders under field conditions at 0 kg N ha-1. Also, in the NUE study, they were found to be among the top ten most N-efficient inbred lines under low N soils, under 30 kg N ha-1, and were among the top twenty-four inbred lines with high NUE values across the N levels in the study. Inbred lines L29 and L22 also produced testcross hybrids that were among the top twenty based on GY under 0 kg N ha-1. The testcross hybrids produced from these inbred lines were also among the top twenty-five with outstanding SCA effects for GY. These inbred lines were also parental lines of some of the top twenty- five best hybrids selected based on the Smith – Hazel selection index in the PVT study. Inbred lines L22, L23, L26, L28, L25, L29 and L31 can therefore further be evaluated and used as sources of N-tolerance genes in QPM breeding programs. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-08
- Authors: AdeOluwa, Olusola Oluyinka https://orcid.org/ 0000-0003-2145-7141
- Date: 2021-08
- Subjects: Corn -- Quality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21501 , vital:48855 , http://id.loc.gov/authorities/subjects/sh85032715
- Description: Low nitrogen stress tolerant Quality Protein Maize (QPM) genotypes will be of great benefit to farmers for increasing productivity in nitrogen depleted soils in the Eastern Cape (EC) Province, South Africa (SA). The current study evaluated: (i) QPM inbred lines for tolerance to low soil nitrogen, (ii) the Nitrogen Use Efficiency (NUE) of different QPM inbred lines, (iii) the combining ability of QPM genotypes for tolerance to low nitrogen, grain yield, and other agro-morphological traits, and (iv) the agro-morphological characteristics and adaptation of QPM hybrids to environments of different production potential in the Eastern Cape, South Africa. Thirty-two white-seeded QPM inbred lines obtained from CIMMYT-Zimbabwe and Quality Seeds (PTY) LTD were evaluated for tolerance to low soil nitrogen stress using two nitrogen (N) treatment levels: 0 kg N ha-1 and 30 kg N ha-1 under both glasshouse and field conditions at the Crop Research farm, University of Fort Hare, in two planting seasons. The study aimed at assessing the response of QPM inbred lines to low N, with a view to identifying low N tolerant types under both glasshouse and field conditions. Shoot length stress tolerance index (SHL STI) indicated lines L23, L29, L27, L13, L16, L17, L31, L14, L18 and L22 to be low soil N tolerant from the glasshouse study. From the field study, low N Stress Tolerance Index (STI) identified inbred lines L23, L31, L26, L28, L25, L29, L32, L4, L6, L3 and L2 as low soil N tolerant. These inbred lines also had high grain yields (GY) in the field under 0 kg N ha-1 (all ranked within the top ten except L2). They also had the potential for stable yields across environments considering their high Yield Stability Index (YSI), Mean Productivity (MP), Geometric Mean Productivity (GMP) and Stress Susceptibility Index (SSI) values. Both the glasshouse and field studies revealed inbred lines L22, L23, L26, L28, L25, L29 and L31 were common to both the glasshouse and field studies as being low soil N tolerant. These thirty-two parental QPM inbred lines were evaluated in the field for their nitrogen use efficiency (NUE) under five different nitrogen levels: 0, 30, 60, 90 and 120 kg N ha-1. The inbred lines studied under 0 kg N ha-1 and 30 kg N ha-1 indicated that N level expressed highly significant differences (P ≤ 0.001) for total nitrogen in biomass (Bio Total N), total nitrogen in grain (G Total N), grain yield (GY), nitrogen use efficiency (NUE) and almost all the indices estimated. The top six nutrient use efficient genotypes were L9, L14, L23, L25, L29 and L32 across N levels. However, the best and highest NUE was obtained from the lowest fertilizer dose, 30 kg N ha-1. Highly significant and positive correlation coefficients were found between Nitrogen Use Efficiency (NUE) and yield (+0.9), NUE and NUtE (+0.9), NUE and HI (Harvest Index) (+0.5), NUtE and yield (+0.99), HI and yield (+0.5) and NUtE and HI (+0.5). Thus, NUE, HI and NUtE could be good predictors of yield potential under low N soil conditions. Sixty-four testcross hybrids were generated from crossing these 32 QPM inbred lines with two QPM open pollinated varieties (OPVs) as testers in a line x tester design and were evaluated under 0 kg N ha-1 and 30 kg N ha-1 in the field. The objectives of the experiment were to: (i) identify high yielding hybrids with tolerance to low soil N in the EC; (ii) determine the combining abilities and mode of gene action for various traits under low and high nitrogen conditions; and (iii) group the inbred lines into heterotic groups for future use in the breeding program. Results revealed that under 30 kg N ha-1 (30N) condition, both additive and non-additive gene effects were observed with less importance of non-additive gene action for grain yield. Based on specific combining ability (SCA) effects, hybrids LNC22, LNC31, LOB22, LNC30, LNC29, LOB11, LNC18, LOB30, LOB19 and LNC24 showed outstanding performance under 0 kg N ha-1 (0N) condition with relatively acceptable SCA under 30N for yield. Inbred lines L6 (1.63), L22 (1.74), L29 (1.83) and L30 (1.24) showed positive and significant GCAs for grain yield under 0N. They were identified as the best combiners for grain yield as they were among the top ten performers for GCA under 0N. They can be very useful sources of low N tolerance genes. Two heterotic groups were formed under 0 kg N ha-1 and 30 kg N ha-1 conditions, and they will be useful for future hybrid development in the breeding program. Furthermore, these thirty-two QPM inbred lines were utilised as parental lines to generate seventy-six single cross hybrids. These single cross hybrids were evaluated across three environments of varying production potential in the Eastern Cape (EC), during the 2016/17 and 2017/18 summer seasons. Non-QPM hybrids namely PAN5Q649R and Phb31MO7BR, as well as QPM OPVs OBATANPA and Nelson's Choice were included in these preliminary variety trials (PVTs) as checks. Twenty-five hybrids expressing high values for the Smith – Hazel selection index were identified across sites over years. Among those hybrids were two checks, namely Q16 (PAN5Q649R) and Q33 (Phb31MO7BR). The top five high – yielding hybrids selected based on the selection index were considered to be the most productive, stable and adaptable based on the GGE biplot and AMMI stability values. None of these single cross hybrids over yielded the best hybrid check (Q16) in the current study. A high potential environment, Centane, was the ideal environments for evaluating genotypes in the present study. The studies showed inbred lines L22, L23, L26, L28, L25, L29 and L31 to be low N stress tolerant at 0 kg N ha-1 based on the low N stress tolerance indices under glasshouse and the field conditions; they were also among the top ten grain-yielders under field conditions at 0 kg N ha-1. Also, in the NUE study, they were found to be among the top ten most N-efficient inbred lines under low N soils, under 30 kg N ha-1, and were among the top twenty-four inbred lines with high NUE values across the N levels in the study. Inbred lines L29 and L22 also produced testcross hybrids that were among the top twenty based on GY under 0 kg N ha-1. The testcross hybrids produced from these inbred lines were also among the top twenty-five with outstanding SCA effects for GY. These inbred lines were also parental lines of some of the top twenty- five best hybrids selected based on the Smith – Hazel selection index in the PVT study. Inbred lines L22, L23, L26, L28, L25, L29 and L31 can therefore further be evaluated and used as sources of N-tolerance genes in QPM breeding programs. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-08
Comparative performance of 3-kWp ranges Solar Photovoltaic Systems under varying meteorological conditions in Alice, Eastern Cape Province, South Africa
- Apeh, Oliver Okechukwu https://orcid.org/0000-0003-4076-0613
- Authors: Apeh, Oliver Okechukwu https://orcid.org/0000-0003-4076-0613
- Date: 2021-08
- Subjects: Photovoltaic power systems , Solar energy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21567 , vital:48888
- Description: PVsystem has recently emerged in South Africa as a way to curb the country’s persistent shortage of electricity. A wide effort for the past few decades have targeted at study, testing and demonstration of PV power systems which was established all over the country as an appropriate measure to tackle transportation, agriculture, industry, commercial as well as domestic activities. In view of these drives, both off-grid and grid-connected PV systems are being applied. However, operating a building with an off-grid system is one of the means to providing the possibility of energy access to places far away from the national grid. As an off-grid choice, 50 W SHS is being distributed to customers in distant rustic parts of the country where grid option is difficult to access. But the SHS of the stated capacity can barely generate 0.3 to 0.4 kWh of electric energy per day, even at the optimal solar radiations. In view of this, more efforts are directed at expanding the off-grid systems to accommodate large rural households in South Africa. This thesis is dedicated to a study on the various configurations and components of PV power plant as a way to enhance electricity generations in South Africa. To this effect, different power plants were considered at SolarWatt park, University of Fort Hare with the aim to conduct a comparative analysis of the charge controllers with respect to the charge and discharge rates of their respective batteries. The grid-connected PV power generation was classified into hybrid PV and grid-assisted PV, while off-grid is a BIPV. These power plants generations were installed for the purpose of research level with a total capacity of 11.4 kW. The off-grid system is made up of HIT modules, FlexMax80 charge controller, Victron energy inverter and M-Molar battery bank. The hybrid and grid-assisted systems each consist of 15 polycrystalline modules and Microcare charge controllers. In addition, hybrid comprises SMA Sunny Island inverter and Trojan battery bank whereas grid-assisted consist of Microcare inverter and Hoppercke battery bank. The first part of the experimental work was monitored, and the meteorological parameters which are ambient temperature, solar radiation, relative humidity and wind speed, were measured and evaluated while electrical parameters includes PV current and voltage, MPPT current and voltage, battery current and voltage and inverter current and voltage were also measured and evaluated in the second part of the experiment. This lasted for a period of four years, starting from 1st January 2017 to 31st December 2020. Similarly, the second aspect was to monitor the electrical performance of the three systems and was performed for a period of six months, starting from January to June 2019. During the second experiment, hybrid and grid-assisted systems were reconfigured to function as off-grid systems. Moreover, a detailed data acquisition system designed to measure and record both meteorological and electrical parameters affecting the performance of the systems. The electrical parameters include PV current and voltage, MPPT current, battery current and voltage and inverter current and voltage. Other parameters in the measurements are; inverter efficiency, active and apparent power, while meteorological parameters include; solar irradiance, ambient temperature, relative humidity, wind speed and direction. The meteorological results show that the maximum and minimum mean amount of global solar radiation was 7.34 kWh/m2/day in December and 3.03 kWh/m2/day in June, respectively, while the average radiation and temperature for the typical year were 4.98 kWh/m2/day and 16.88 oC respectively. The solar radiations obtained are within the range in major places in South Africa. Similarly, an average wind speed of 2.5 m/s is experienced in Alice in a year and average solar radiation of 606.06 W/m2 in summer and 346.17 W/m2 in winter. The three lead-acid battery systems monitored under the electrical aspect are M-Molar, Trojan and Hoppecke battery systems. It was established that the charging current decreases gradually from 27.7 to 18.5 A for the M-Molar while Hoppecke and Trojan deceased respectively from 15 to 10 A and 23 to 13 A at the end of each phase by charging it at the maximum power point of the PV array. It was equally found that the M-Molar battery current has the highest rate of charging and quickest rate of discharging in comparison to the other two batteries. Finally, from the results gotten from this research, we may propose that the solar PV system contributes significantly to the satisfaction of the needed electricity in South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-08
- Authors: Apeh, Oliver Okechukwu https://orcid.org/0000-0003-4076-0613
- Date: 2021-08
- Subjects: Photovoltaic power systems , Solar energy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21567 , vital:48888
- Description: PVsystem has recently emerged in South Africa as a way to curb the country’s persistent shortage of electricity. A wide effort for the past few decades have targeted at study, testing and demonstration of PV power systems which was established all over the country as an appropriate measure to tackle transportation, agriculture, industry, commercial as well as domestic activities. In view of these drives, both off-grid and grid-connected PV systems are being applied. However, operating a building with an off-grid system is one of the means to providing the possibility of energy access to places far away from the national grid. As an off-grid choice, 50 W SHS is being distributed to customers in distant rustic parts of the country where grid option is difficult to access. But the SHS of the stated capacity can barely generate 0.3 to 0.4 kWh of electric energy per day, even at the optimal solar radiations. In view of this, more efforts are directed at expanding the off-grid systems to accommodate large rural households in South Africa. This thesis is dedicated to a study on the various configurations and components of PV power plant as a way to enhance electricity generations in South Africa. To this effect, different power plants were considered at SolarWatt park, University of Fort Hare with the aim to conduct a comparative analysis of the charge controllers with respect to the charge and discharge rates of their respective batteries. The grid-connected PV power generation was classified into hybrid PV and grid-assisted PV, while off-grid is a BIPV. These power plants generations were installed for the purpose of research level with a total capacity of 11.4 kW. The off-grid system is made up of HIT modules, FlexMax80 charge controller, Victron energy inverter and M-Molar battery bank. The hybrid and grid-assisted systems each consist of 15 polycrystalline modules and Microcare charge controllers. In addition, hybrid comprises SMA Sunny Island inverter and Trojan battery bank whereas grid-assisted consist of Microcare inverter and Hoppercke battery bank. The first part of the experimental work was monitored, and the meteorological parameters which are ambient temperature, solar radiation, relative humidity and wind speed, were measured and evaluated while electrical parameters includes PV current and voltage, MPPT current and voltage, battery current and voltage and inverter current and voltage were also measured and evaluated in the second part of the experiment. This lasted for a period of four years, starting from 1st January 2017 to 31st December 2020. Similarly, the second aspect was to monitor the electrical performance of the three systems and was performed for a period of six months, starting from January to June 2019. During the second experiment, hybrid and grid-assisted systems were reconfigured to function as off-grid systems. Moreover, a detailed data acquisition system designed to measure and record both meteorological and electrical parameters affecting the performance of the systems. The electrical parameters include PV current and voltage, MPPT current, battery current and voltage and inverter current and voltage. Other parameters in the measurements are; inverter efficiency, active and apparent power, while meteorological parameters include; solar irradiance, ambient temperature, relative humidity, wind speed and direction. The meteorological results show that the maximum and minimum mean amount of global solar radiation was 7.34 kWh/m2/day in December and 3.03 kWh/m2/day in June, respectively, while the average radiation and temperature for the typical year were 4.98 kWh/m2/day and 16.88 oC respectively. The solar radiations obtained are within the range in major places in South Africa. Similarly, an average wind speed of 2.5 m/s is experienced in Alice in a year and average solar radiation of 606.06 W/m2 in summer and 346.17 W/m2 in winter. The three lead-acid battery systems monitored under the electrical aspect are M-Molar, Trojan and Hoppecke battery systems. It was established that the charging current decreases gradually from 27.7 to 18.5 A for the M-Molar while Hoppecke and Trojan deceased respectively from 15 to 10 A and 23 to 13 A at the end of each phase by charging it at the maximum power point of the PV array. It was equally found that the M-Molar battery current has the highest rate of charging and quickest rate of discharging in comparison to the other two batteries. Finally, from the results gotten from this research, we may propose that the solar PV system contributes significantly to the satisfaction of the needed electricity in South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-08
Effects of urban expansion on coastal vegetation ecosystems conservation and functioning in Buffalo City Metropolitan Municipality, South Africa
- Olatoye, Tolulope Ayodeji https://orcid.org/0000-0002-2249-9258
- Authors: Olatoye, Tolulope Ayodeji https://orcid.org/0000-0002-2249-9258
- Date: 2021-07
- Subjects: Sustainable development , City planning -- Environmental aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21556 , vital:48885
- Description: Coastal urban expansion is on an upward trajectory, which poses serious threats to ecosystem functioning, human wellbeing and the general environment across the globe. It is on this premise that this study brings to the fore the growing complexity of environmental sustainability problems in a former apartheid space, as characterized by coastal urbanization and the intricacies of vegetation conservation. Consequently, literature utilized for this study reveals that urban expansion has led to an uncontrolled threat to the coastal ecosystem, culminating in soil erosion, environmental pollution through illegal dumping of solid waste, loss of coastal vegetation to other land use types, among others. Therefore, constant monitoring of these spaces is needed due to their fragility, as they are pivotal in the earth-atmosphere processes to the benefit of the entire humanity. To this end, the current study offers critical analysis and insights about the South African coastal ecological space. The essence of using BCMM in its consideration as an ecological space and former apartheid territory brings to the fore a scientific explanation of the spatial configuration and changes in the CVEs of the study area during the post-colonial era. In the course of investigating this study, the Urban Green Sustainability (UGS) theory was adopted in the course of selecting the review of literature, methodological approach and analysis of results. A mixed methodological approach (qualitative, quantitative and geospatial techniques) was explored in data collection and analysis. 254 copies of the questionnaire were returned and analysed for this research. Results generated revealed by the BCMM respondents confirms the occurrence of uncontrolled urbanization, deforestation and crop cultivation as major causes of coastal vegetation loss. In the same vein, the LULC classification results revealed that about 466 km2 of forest vegetation has been lost in BCMM from 1998-2018. Also, LULC classification results were validated by performing the Normalized Difference Built-Up Index (NDBI), Normalized Difference Vegetative Index (NDVI), Kappa’s coefficient (k), coefficient of determination (R2) and Pearson’s Product Moment Correlation (P) tests. The results also revealed that the built-up area had increased from 194 km2 in 1998 to 814 km2 in 2008. Further, all statistical tests revealed very good and highly correlated overall classification accuracies (of R2=0.89 and P=0.86) during the study period (1998 – 2018). This study makes a clarion call towards the rehabilitation of degraded coastal environments and proffers solutions towards the actualization of environmentally sustainable CVEs which offers optimal ecosystem services. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-07
- Authors: Olatoye, Tolulope Ayodeji https://orcid.org/0000-0002-2249-9258
- Date: 2021-07
- Subjects: Sustainable development , City planning -- Environmental aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21556 , vital:48885
- Description: Coastal urban expansion is on an upward trajectory, which poses serious threats to ecosystem functioning, human wellbeing and the general environment across the globe. It is on this premise that this study brings to the fore the growing complexity of environmental sustainability problems in a former apartheid space, as characterized by coastal urbanization and the intricacies of vegetation conservation. Consequently, literature utilized for this study reveals that urban expansion has led to an uncontrolled threat to the coastal ecosystem, culminating in soil erosion, environmental pollution through illegal dumping of solid waste, loss of coastal vegetation to other land use types, among others. Therefore, constant monitoring of these spaces is needed due to their fragility, as they are pivotal in the earth-atmosphere processes to the benefit of the entire humanity. To this end, the current study offers critical analysis and insights about the South African coastal ecological space. The essence of using BCMM in its consideration as an ecological space and former apartheid territory brings to the fore a scientific explanation of the spatial configuration and changes in the CVEs of the study area during the post-colonial era. In the course of investigating this study, the Urban Green Sustainability (UGS) theory was adopted in the course of selecting the review of literature, methodological approach and analysis of results. A mixed methodological approach (qualitative, quantitative and geospatial techniques) was explored in data collection and analysis. 254 copies of the questionnaire were returned and analysed for this research. Results generated revealed by the BCMM respondents confirms the occurrence of uncontrolled urbanization, deforestation and crop cultivation as major causes of coastal vegetation loss. In the same vein, the LULC classification results revealed that about 466 km2 of forest vegetation has been lost in BCMM from 1998-2018. Also, LULC classification results were validated by performing the Normalized Difference Built-Up Index (NDBI), Normalized Difference Vegetative Index (NDVI), Kappa’s coefficient (k), coefficient of determination (R2) and Pearson’s Product Moment Correlation (P) tests. The results also revealed that the built-up area had increased from 194 km2 in 1998 to 814 km2 in 2008. Further, all statistical tests revealed very good and highly correlated overall classification accuracies (of R2=0.89 and P=0.86) during the study period (1998 – 2018). This study makes a clarion call towards the rehabilitation of degraded coastal environments and proffers solutions towards the actualization of environmentally sustainable CVEs which offers optimal ecosystem services. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-07
Groundwater exploration using borehole and geophysical techniques in the east of Raymond Mhlaba Local Municipality (formerly Nkonkobe Local Municipality) in the Eastern Cape Province, South Africa
- Authors: Xanga, Sithule
- Date: 2021-07
- Subjects: Groundwater ecology , Geophysical instruments , Borehole gravimetry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22643 , vital:52616
- Description: The study area lies in the eastern portion of Raymond Mhlaba Local Municipality (RMLM), formerly known as Nkonkobe Local Municipality within the Eastern Cape Province of South Africa in the southeastern portion of the main Karoo Basin. Its northen part is mountainous with high altitude of about 1500 m with dense vegetation, whereas the southern part attains low altitude of about 600 m with sparse vegetation. The entire study area is covered on the surface by the Beaufort Group sediments comprised of three geological formations namely Middleton Formation, Balfour Formation members (Oudeberg, Daggaboersnek, Baberskrans, Elandsberg, and Pilangkloof), and the Katberg Formation. Karoo igneous bodies (dolerite dykes and sills) intruded the sediments causing fracturing. The area receives mean annual precipitation of about 54 mm. It is semi-arid to dry with insufficient surface water resources and hence the need for this research to explore for potential groundwater. Many techniques were employed to reveal the surface and subsurface geology, including groundwater potential areas using climate data, vegetation cover, borehole data analysis, geological field mapping, rock samples collection for petrographic analysis, a density-porosity determination, magnetic data analysis, and electrical resistivity tomography. The study area was divided into seven sub-regions, SR1 to SR7. The climate data showed that the area experiences high monthly average temperatures of about 21.6 °C during the summer, and is a semi-arid to dry region. Vegetation cover is dense in the mountainous northern part of the study area. It receives comparatively high rainfall, experiences less evapotranspiration than the southern part the low altitude, receives less rainfall, and has relatively high temperatures and evapotranspiration. A total of 385 boreholes from the Department Water and Sanitation were analysed and these showed that sub-regions SR1 up to SR7 had average borehole depths ranging from 51.9 to 67.7 m, water strike depths from 13.8 to 21.7 m and yields from 0.8 to 1.9 L/s. Sub-regions SR2, SR4, SR5, while SR7 have an average yield ≥ 1.4 L/s up to 1.9 L/s and are classified in this study as having a good or high groundwater yield potential. Fifteen thin sections were studied indicating that the Beaufort Group has mudstone, shale and fine-grained sandstone. The latter was dominant in the studied thin sections with 70 – 80 % quartz, 15 – 20 % groundmass, 5 – 10 % of feldspars, 2 – 5 % biotite, and some had vein like cracks filled with clay cement. Laboratory studies show average dry densities for the formations vary from 2.44 to 2.65 g/cm3, and porosities range from 1.6 to 4.0 %. Magnetic grid data obtained from the Council for Geoscience (CGS) were reduced to the pole, first vertical derivative and analytic signal maps were generated to delineate magnetic sources in the sediments. The magnetic anomalies showed lineaments and ring-shaped patterns that were interpreted to be due to Karoo dykes and sills, respectively. Some of these intrusions are mapped on the geological map and quite a number are not mapped as they are under sediment cover. The intrusions are important in groundwater exploration as they would have caused fracturing of surrounding formations causing increased secondary porosity and permeability. Further, they are groundwater localisers. Electrical resistivity tomography (ERT) was carried out at 12 selected sites using the dipoledipole and Wenner-Schlumberger arrays, with a maximum cable length of 360 m was used with an approximate maximum depth of investigation of 70 m. Most of the sites’ inverted models show a low resistivity top layer of about 10 m thickness, which is inferred to be topsoil with moisture/water and or clayey content. A high resistivity second layer underneath the top layer, and is interpreted to be slightly weathered sandstone at its top grading into compact sandstones at the bottom of the investigation depth. Four site results show models with an intermediate layer between the top and bottom layers consisting of moderate resistivity values due to mudstones. Most of the models have vertical, narrow, low resistivity zones extending from the surface to the bottom layer, interpreted as fracturing. The top layer could be an unconfined aquifer during the wet months but is likely to dry up during the dry, hot months. The inferred fractures that extend deeper from the surface could be good groundwater targets to drill boreholes. Dolerite intrusions can act as natural groundwater barriers depending on their orientation hence such structures are the main targets when searching for groundwater. Vegetation cover observed on satellite images of remote sensing can be used along with other techniques to explore for groundwater. It is recommended that future ERT surveys should measure both electrical resistivity and induced polarization chargeability to discriminate between water and clay influence. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-07
- Authors: Xanga, Sithule
- Date: 2021-07
- Subjects: Groundwater ecology , Geophysical instruments , Borehole gravimetry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22643 , vital:52616
- Description: The study area lies in the eastern portion of Raymond Mhlaba Local Municipality (RMLM), formerly known as Nkonkobe Local Municipality within the Eastern Cape Province of South Africa in the southeastern portion of the main Karoo Basin. Its northen part is mountainous with high altitude of about 1500 m with dense vegetation, whereas the southern part attains low altitude of about 600 m with sparse vegetation. The entire study area is covered on the surface by the Beaufort Group sediments comprised of three geological formations namely Middleton Formation, Balfour Formation members (Oudeberg, Daggaboersnek, Baberskrans, Elandsberg, and Pilangkloof), and the Katberg Formation. Karoo igneous bodies (dolerite dykes and sills) intruded the sediments causing fracturing. The area receives mean annual precipitation of about 54 mm. It is semi-arid to dry with insufficient surface water resources and hence the need for this research to explore for potential groundwater. Many techniques were employed to reveal the surface and subsurface geology, including groundwater potential areas using climate data, vegetation cover, borehole data analysis, geological field mapping, rock samples collection for petrographic analysis, a density-porosity determination, magnetic data analysis, and electrical resistivity tomography. The study area was divided into seven sub-regions, SR1 to SR7. The climate data showed that the area experiences high monthly average temperatures of about 21.6 °C during the summer, and is a semi-arid to dry region. Vegetation cover is dense in the mountainous northern part of the study area. It receives comparatively high rainfall, experiences less evapotranspiration than the southern part the low altitude, receives less rainfall, and has relatively high temperatures and evapotranspiration. A total of 385 boreholes from the Department Water and Sanitation were analysed and these showed that sub-regions SR1 up to SR7 had average borehole depths ranging from 51.9 to 67.7 m, water strike depths from 13.8 to 21.7 m and yields from 0.8 to 1.9 L/s. Sub-regions SR2, SR4, SR5, while SR7 have an average yield ≥ 1.4 L/s up to 1.9 L/s and are classified in this study as having a good or high groundwater yield potential. Fifteen thin sections were studied indicating that the Beaufort Group has mudstone, shale and fine-grained sandstone. The latter was dominant in the studied thin sections with 70 – 80 % quartz, 15 – 20 % groundmass, 5 – 10 % of feldspars, 2 – 5 % biotite, and some had vein like cracks filled with clay cement. Laboratory studies show average dry densities for the formations vary from 2.44 to 2.65 g/cm3, and porosities range from 1.6 to 4.0 %. Magnetic grid data obtained from the Council for Geoscience (CGS) were reduced to the pole, first vertical derivative and analytic signal maps were generated to delineate magnetic sources in the sediments. The magnetic anomalies showed lineaments and ring-shaped patterns that were interpreted to be due to Karoo dykes and sills, respectively. Some of these intrusions are mapped on the geological map and quite a number are not mapped as they are under sediment cover. The intrusions are important in groundwater exploration as they would have caused fracturing of surrounding formations causing increased secondary porosity and permeability. Further, they are groundwater localisers. Electrical resistivity tomography (ERT) was carried out at 12 selected sites using the dipoledipole and Wenner-Schlumberger arrays, with a maximum cable length of 360 m was used with an approximate maximum depth of investigation of 70 m. Most of the sites’ inverted models show a low resistivity top layer of about 10 m thickness, which is inferred to be topsoil with moisture/water and or clayey content. A high resistivity second layer underneath the top layer, and is interpreted to be slightly weathered sandstone at its top grading into compact sandstones at the bottom of the investigation depth. Four site results show models with an intermediate layer between the top and bottom layers consisting of moderate resistivity values due to mudstones. Most of the models have vertical, narrow, low resistivity zones extending from the surface to the bottom layer, interpreted as fracturing. The top layer could be an unconfined aquifer during the wet months but is likely to dry up during the dry, hot months. The inferred fractures that extend deeper from the surface could be good groundwater targets to drill boreholes. Dolerite intrusions can act as natural groundwater barriers depending on their orientation hence such structures are the main targets when searching for groundwater. Vegetation cover observed on satellite images of remote sensing can be used along with other techniques to explore for groundwater. It is recommended that future ERT surveys should measure both electrical resistivity and induced polarization chargeability to discriminate between water and clay influence. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-07
The impact of small-scale farming on food insecurity in rural South Africa over the period 2009 to 2018
- Otunola, Olabisi Benedicta https://orcid.org/0000-0002-5615-1487
- Authors: Otunola, Olabisi Benedicta https://orcid.org/0000-0002-5615-1487
- Date: 2021-07
- Subjects: Sustainable Development Goals , Food supply
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21387 , vital:48517
- Description: The concept of food insecurity has evolved over the years. However, due to the increases in the rate of hunger and food insecurity in many countries of the world, this phenomenon has continued to give both government and private agencies a lot of concern. As it stands now, achieving food security in African countries remain a major task regardless of various efforts made by most of these countries to reduce food insecurity and the household’s welfare by extension. As a result of the importance of this discourse, the issue of food security is number 2 on the United Nations’ Sustainable Development Goals (SDGs). In South Africa, the rate of household food insecurity is still observed to be high, especially in the rural households. One of the most talked about way of combating food insecurity is through household farming. But food insecurity is believed to have affected the household’s level of productivity despite their commitment to improved welfare situation in the country. Consequently, this study sought to assess the impact rural household farming has on food insecurity in South Africa between the year 2009 and 2018. Using the South African General household survey, information on the household socioeconomics and demographic features were retrieved, as well as variables that are believed to impact the rural household agribusiness. In determining this, frequency counts, percentages, the logistic regression model was used. Also, the Household Food Insecurity Access Scale-score (HFIAS-score), multinomial logistic regression as well as the propensity score matching (PSM) was used in achieving the objectives of this research and the data was analysed with Microsoft Excel and STATA version 15. The result of the analysis showed that, the mean age of the household head is 53.96, 55.92, 56.65 for the year 2010, 2014 and 2018 respectively. Adding to that, the range of the households’ size ranged from 1 to 20 in the year 2010, 1 to 46 in the year 2014 and 1 to 20 in the year 2018. From the inferential statistic result, the gender of the household head is significant (p<0.000, 0.011, and 0.006) in determining household participation in agricultural activities for the years under review. The results of the PSM, using different matching methods reveals that the average treatment effect (ATT) of the impact of agricultural participation ranges from -0.121, -0.174, -0.132, and -0.106 in 2015; and -0.076, -0.173, -0.073, and -0.086 in the year 2018. This study therefore recommends that household farming should be encouraged by both private and public agencies as they contribute significantly to reduction in food insecurity. The transportation services in the rural areas should be examined in order to avoid situations that will lead to the increase in cost of transporting agricultural goods and services among the rural inhabitants. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-07
- Authors: Otunola, Olabisi Benedicta https://orcid.org/0000-0002-5615-1487
- Date: 2021-07
- Subjects: Sustainable Development Goals , Food supply
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21387 , vital:48517
- Description: The concept of food insecurity has evolved over the years. However, due to the increases in the rate of hunger and food insecurity in many countries of the world, this phenomenon has continued to give both government and private agencies a lot of concern. As it stands now, achieving food security in African countries remain a major task regardless of various efforts made by most of these countries to reduce food insecurity and the household’s welfare by extension. As a result of the importance of this discourse, the issue of food security is number 2 on the United Nations’ Sustainable Development Goals (SDGs). In South Africa, the rate of household food insecurity is still observed to be high, especially in the rural households. One of the most talked about way of combating food insecurity is through household farming. But food insecurity is believed to have affected the household’s level of productivity despite their commitment to improved welfare situation in the country. Consequently, this study sought to assess the impact rural household farming has on food insecurity in South Africa between the year 2009 and 2018. Using the South African General household survey, information on the household socioeconomics and demographic features were retrieved, as well as variables that are believed to impact the rural household agribusiness. In determining this, frequency counts, percentages, the logistic regression model was used. Also, the Household Food Insecurity Access Scale-score (HFIAS-score), multinomial logistic regression as well as the propensity score matching (PSM) was used in achieving the objectives of this research and the data was analysed with Microsoft Excel and STATA version 15. The result of the analysis showed that, the mean age of the household head is 53.96, 55.92, 56.65 for the year 2010, 2014 and 2018 respectively. Adding to that, the range of the households’ size ranged from 1 to 20 in the year 2010, 1 to 46 in the year 2014 and 1 to 20 in the year 2018. From the inferential statistic result, the gender of the household head is significant (p<0.000, 0.011, and 0.006) in determining household participation in agricultural activities for the years under review. The results of the PSM, using different matching methods reveals that the average treatment effect (ATT) of the impact of agricultural participation ranges from -0.121, -0.174, -0.132, and -0.106 in 2015; and -0.076, -0.173, -0.073, and -0.086 in the year 2018. This study therefore recommends that household farming should be encouraged by both private and public agencies as they contribute significantly to reduction in food insecurity. The transportation services in the rural areas should be examined in order to avoid situations that will lead to the increase in cost of transporting agricultural goods and services among the rural inhabitants. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-07
Characterization of sandstone reservoirs and hydrocarbon generation potential of selected four wells in the Pletmos basin, offshore South Africa
- Moloi, Busiswa https://orcid.org/0000-0001-6815-4901
- Authors: Moloi, Busiswa https://orcid.org/0000-0001-6815-4901
- Date: 2021-06
- Subjects: Hydrocarbon reservoirs
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22512 , vital:52387
- Description: This study focused on the use of data from four wells (Ga-M1, Ga-S1, Ga-Z1, and Gb-J1) comprises of the Late Jurassic to Early Cretaceous shallow marine clastic sandstones consisting of wildcat wells located in Block 11 of the Pletmos Basin, a sub-basin of the Southern Outeniqua Basin, south offshore South Africa. This research evaluates the hydrocarbon potential in the Pletmos Basin by integrating core and well log data to characterize the source and reservoir rock potential. The methods implemented consist of a mineralogical and petrological analysis of about 300 thin section slides from four wells were studied. Stratigraphic profile computation from core logging, geochemistry analysis focusing on total organic carbon (TOC), geophysical wireline logs, conventional core analysis, geological well reports, and petrophysical analysis (water saturation, porosity, permeability, and volume of clay) were done using Interactive Petrophysics software. The different datasets were used to delineate how the mineralogy, total organic carbon content, poro-perm properties, fluid saturation, and volume of clay impact the hydrocarbon production potential. The evaluated sandstones have depths ranging from 2523.9 m to 3397.2 m with varying thickness depending on the position of the well. The results indicate that the study area consists of shallow marine clastic sandstones with sparse siltstones and mudstone that are fine-grained to silty in texture. The sedimentary sequence is characterized by moderate to intense bioturbation. Depositional environment was in a reducing condition indicated by plenty of glauconites. The tight fine-grained sandstones have low porosity values ranging from 4.5% to 13.8% in the selected intervals. The low porosity values may have been caused by the quartz cement that is observed from the thin sections. Low permeability values ranging from 0 mD to 0.16 mD are present throughout the studied wells caused by calcite cement and clay matrix. Source rock in the studied wells have inferior TOC values ranging from 0.31 wt% to 0.51 wt%. The van Krevelen indicates that the analysed samples have very low hydrogen index (HI) values and are consistent with Type III Kerogen (gas prone). A total of six reservoirs were identified. For well Ga-M1, one reservoir interval (2988.2 m – 30281 m) was selected and is located at BCII formation and was classified as a nonproducing reservoir due to its high water saturation content of 94.2%, even though it has an average porosity of 10.6%. Two reservoirs were selected for well Ga-S1, reservoir one (3026.3 m – 3107.7 m) is located within the 13AT1 formation and was classified as a producing reservoir with an average porosity of 11.9%, water saturation of 38.3%, and volume of clay of 29.5%. Reservoir 2 (3380.7 m – 3397.2 m) and the reservoirs (2970.20 m – 2993.0 m and 3006.80 m – 3049.50 m) from well Ga-Z1 located between the 9AT1 – BCVI formations were classified as non-reservoirs. One selected reservoir from well Gb-J1 had promising gas shows with an average porosity of 19%, water saturation value of 34.8%, and volume of shale of 33.1%. However, well Ga-S1 has a large interval with hydrocarbon potential compared to the well Gb-J1. Results indicate that the absence of hydrocarbon accumulation may result from non-effective seals due to the silty texture of the reservoir sandstones. Also, the presence of calcareous cement, clay minerals, and the argillaceous matrix reduce the porosity and permeability characteristics. To better understand the hydrocarbon potential of the Pletmos Basin, 3D seismic data is recommended to perform seismic well tie analysis for correlation between well log and seismic data to understand the basin‟s potential better. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-06
- Authors: Moloi, Busiswa https://orcid.org/0000-0001-6815-4901
- Date: 2021-06
- Subjects: Hydrocarbon reservoirs
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22512 , vital:52387
- Description: This study focused on the use of data from four wells (Ga-M1, Ga-S1, Ga-Z1, and Gb-J1) comprises of the Late Jurassic to Early Cretaceous shallow marine clastic sandstones consisting of wildcat wells located in Block 11 of the Pletmos Basin, a sub-basin of the Southern Outeniqua Basin, south offshore South Africa. This research evaluates the hydrocarbon potential in the Pletmos Basin by integrating core and well log data to characterize the source and reservoir rock potential. The methods implemented consist of a mineralogical and petrological analysis of about 300 thin section slides from four wells were studied. Stratigraphic profile computation from core logging, geochemistry analysis focusing on total organic carbon (TOC), geophysical wireline logs, conventional core analysis, geological well reports, and petrophysical analysis (water saturation, porosity, permeability, and volume of clay) were done using Interactive Petrophysics software. The different datasets were used to delineate how the mineralogy, total organic carbon content, poro-perm properties, fluid saturation, and volume of clay impact the hydrocarbon production potential. The evaluated sandstones have depths ranging from 2523.9 m to 3397.2 m with varying thickness depending on the position of the well. The results indicate that the study area consists of shallow marine clastic sandstones with sparse siltstones and mudstone that are fine-grained to silty in texture. The sedimentary sequence is characterized by moderate to intense bioturbation. Depositional environment was in a reducing condition indicated by plenty of glauconites. The tight fine-grained sandstones have low porosity values ranging from 4.5% to 13.8% in the selected intervals. The low porosity values may have been caused by the quartz cement that is observed from the thin sections. Low permeability values ranging from 0 mD to 0.16 mD are present throughout the studied wells caused by calcite cement and clay matrix. Source rock in the studied wells have inferior TOC values ranging from 0.31 wt% to 0.51 wt%. The van Krevelen indicates that the analysed samples have very low hydrogen index (HI) values and are consistent with Type III Kerogen (gas prone). A total of six reservoirs were identified. For well Ga-M1, one reservoir interval (2988.2 m – 30281 m) was selected and is located at BCII formation and was classified as a nonproducing reservoir due to its high water saturation content of 94.2%, even though it has an average porosity of 10.6%. Two reservoirs were selected for well Ga-S1, reservoir one (3026.3 m – 3107.7 m) is located within the 13AT1 formation and was classified as a producing reservoir with an average porosity of 11.9%, water saturation of 38.3%, and volume of clay of 29.5%. Reservoir 2 (3380.7 m – 3397.2 m) and the reservoirs (2970.20 m – 2993.0 m and 3006.80 m – 3049.50 m) from well Ga-Z1 located between the 9AT1 – BCVI formations were classified as non-reservoirs. One selected reservoir from well Gb-J1 had promising gas shows with an average porosity of 19%, water saturation value of 34.8%, and volume of shale of 33.1%. However, well Ga-S1 has a large interval with hydrocarbon potential compared to the well Gb-J1. Results indicate that the absence of hydrocarbon accumulation may result from non-effective seals due to the silty texture of the reservoir sandstones. Also, the presence of calcareous cement, clay minerals, and the argillaceous matrix reduce the porosity and permeability characteristics. To better understand the hydrocarbon potential of the Pletmos Basin, 3D seismic data is recommended to perform seismic well tie analysis for correlation between well log and seismic data to understand the basin‟s potential better. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-06
Investigation of the levels of PBDEs and PCNs in the surface water and sediments from selected waterbodies in the Eastern Cape Province, South Africa
- Agunbiade, Idowu Victoria https://orcid.org/0000-0001-5605-0312
- Authors: Agunbiade, Idowu Victoria https://orcid.org/0000-0001-5605-0312
- Date: 2021-06
- Subjects: Persistent pollutants , Water -- Purification -- Organic compounds removal , Organic water pollutants
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22699 , vital:52660
- Description: Studies have revealed that persistent organic pollutants (POPs) are omnipresent in our environment; almost all human beings have definite levels of POPs in their bodies. Even fetus and embryos are not spared; they have been found to bear certain levels of POPs. So far, there are about 28 chemicals listed as POPs among which are polybrominated diphenyl ethers (PBDEs) and polychlorinated naphthalenes (PCNs). PCN and PBDE distributions have been reported from different sources around the world, but studies relating to PCNs occurrence and distribution in Africa, especially South Africa is still minimal. PBDEs have been reported to cause diabetes, cancer, damage to reproductive system, thyroid, liver and other vital organs in the body, while PCNs have been linked to chloracne (severe skin reactions/lesions) and liver disease (yellow atrophy) in humans, chicken oedema and X-disease in cattle. Hence, this study evaluates PCN levels in water and sediment samples from three waterbodies: North End Lake (NEL), Chatty River (CHA) and Makman Canal (MMC), while PBDE levels was reported in NEL and CHA samples. The three sites are located in Port Elizabeth, Eastern Cape Province (ECP) of South Africa. The lake serves as a recreational resort while the latter two waterbodies are tributaries discharging into the Swartkop Estuary, an important estuary in ECP. Water samples were extracted with C18 cartridges (solid phase), while soxhlet was employed for the extraction of sediments. Water and sediment extricates were purified and quantified with gas chromatography-micro electron capture detector (GC-μECD). Forty-seven (47) water samples and 44 sediment samples were collected in August until December 2020 from six sampling points in NEL, five points in each of CHA and MMC. All the samples were evaluated for physicochemical properties, PBDEs and PCNs using validated standard methods. The sampling period covered three South Africa seasons: August (winter), October (spring) and December (summer). The physicochemical parameters (PP) of NEL water samples for the three seasons generally varied as follows: temperature (15.3–23°C), pH (7.9–10.3), oxidation-reduction potential, ORP (23.4-110 mV), atmospheric pressure, AP (14.52-15.56 PSI), turbidity (15.1–167 NTU), electrical conductivity, EC (114–1291 μS/cm), total dissolved solids, TDS (55-645 mg/L), total suspended solids, TSS (20–107 mg/L) and salinity (0.05–0.65 PSU). All the PPs except for turbidity and TSS are within acceptable limits. NEL sediments had moisture content (MC), organic matter (OM) and organic carbon (OC) in the range of 0.04–8.0percent, 0.08–2.2percent and 0.05–1.8percent, respectively. The sum of eight PCN congeners Σ8PCNs and six PBDE congeners Σ6PBDEs in NEL water samples ranged from 0.164–2.934 μg/L and 0.009-1.025 μg/L individually. The values for Σ8PCNs and Σ6PBDEs in NEL sediment samples varied from 0.991–237 μg/kg and 0.354-28.850 μg/kg, respectively. The calculated hazard quotient (HQ) corresponding to the non-carcinogenic health risk associated with PBDEs in NEL water samples was 2.0×10-3-1.4×10-1, while the TEQ values due to PCNs varied from 6.10×10-7- 3.12×10-3 μg/L in NEL water samples and 3.70×10-5-1.96×10-2 μg/kg dw in sediments. The PP values for CHA water samples include temperature (15.4–22.9°C), pH (7.7–10.5), TDS (991–1771 mg/L), TSS (6–41 mg/L), turbidity (1.0–198 NTU), EC (1981–3542 μS/cm), AP (14.60–14.80 PSI), ORP (-339.1-51.3 mV), and salinity (1.02–1.87 PSU). The EC, TDS and salinity exceeded acceptable values at certain points. The sediments of CHA have MC, OM and OC contents ranging from 0.01-10.2percent, 0.2-1.3percent and 0.1-0.8percent in that order. Sum of Σ8PCNs, Σ6PBDEs in CHA water and sediment samples ranged from 0.026–1.054 μg/L, 0.007-0.079 μg/L and 0.429–1888.468 μg/kg, 0.347-6.468 μg/kg individually. The HQ in CHA water samples was 1.6×10-3-7.7×10-3 and the estimated TEQ was 1.0×10-7-6.62×10-5 μg/L and 1.10×10−5-6.40×10−2 μg/kg in water and sediments, respectively. The temperatures for MMC water samples ranged from 15.6-24.5°C, while other PPs recorded were as follows: pH (8.4-10.2), TDS (943–4002 mg/L), TSS (7-491 mg/L), turbidity (2.9-154.2 NTU), EC (1885-8004 μS/cm), AP (14.53–14.82 PSI), ORP (7.8-130 mV) and salinity (0.96-4.47 PSU). MMC’s sediments recorded MC, OM and OC varying as 0.4- 18.9percent, 0.2-4.5percent and 0.1-2.6percent, respectively across the three seasons. The Σ8PCNs for MMC water and sediment samples were 0.035–0.699 μg/L and 0.260–6744 μg/kg. The TEQ values in MMC water and sediment samples were 1.19×10-7-1.47×10-4 μg/L and 4.43×10−5- 4.19×10−1 μg/kg, respectively. The results are all less than one, and this suggests that the selected water is safe. Results showed that NEL water had highest TEQ, PCN and PBDE concentrations, while MMC sediments recorded maximum TEQ and PCN levels in this study. PBDE concentrations in NEL sediments were above the other site. In conclusion, NEL water was most polluted with both pollutants (PCNs and PBDEs), but MMC sediments contained more PCNs. There is need for the immediate remediation of these selected waterbodies. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-06
- Authors: Agunbiade, Idowu Victoria https://orcid.org/0000-0001-5605-0312
- Date: 2021-06
- Subjects: Persistent pollutants , Water -- Purification -- Organic compounds removal , Organic water pollutants
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22699 , vital:52660
- Description: Studies have revealed that persistent organic pollutants (POPs) are omnipresent in our environment; almost all human beings have definite levels of POPs in their bodies. Even fetus and embryos are not spared; they have been found to bear certain levels of POPs. So far, there are about 28 chemicals listed as POPs among which are polybrominated diphenyl ethers (PBDEs) and polychlorinated naphthalenes (PCNs). PCN and PBDE distributions have been reported from different sources around the world, but studies relating to PCNs occurrence and distribution in Africa, especially South Africa is still minimal. PBDEs have been reported to cause diabetes, cancer, damage to reproductive system, thyroid, liver and other vital organs in the body, while PCNs have been linked to chloracne (severe skin reactions/lesions) and liver disease (yellow atrophy) in humans, chicken oedema and X-disease in cattle. Hence, this study evaluates PCN levels in water and sediment samples from three waterbodies: North End Lake (NEL), Chatty River (CHA) and Makman Canal (MMC), while PBDE levels was reported in NEL and CHA samples. The three sites are located in Port Elizabeth, Eastern Cape Province (ECP) of South Africa. The lake serves as a recreational resort while the latter two waterbodies are tributaries discharging into the Swartkop Estuary, an important estuary in ECP. Water samples were extracted with C18 cartridges (solid phase), while soxhlet was employed for the extraction of sediments. Water and sediment extricates were purified and quantified with gas chromatography-micro electron capture detector (GC-μECD). Forty-seven (47) water samples and 44 sediment samples were collected in August until December 2020 from six sampling points in NEL, five points in each of CHA and MMC. All the samples were evaluated for physicochemical properties, PBDEs and PCNs using validated standard methods. The sampling period covered three South Africa seasons: August (winter), October (spring) and December (summer). The physicochemical parameters (PP) of NEL water samples for the three seasons generally varied as follows: temperature (15.3–23°C), pH (7.9–10.3), oxidation-reduction potential, ORP (23.4-110 mV), atmospheric pressure, AP (14.52-15.56 PSI), turbidity (15.1–167 NTU), electrical conductivity, EC (114–1291 μS/cm), total dissolved solids, TDS (55-645 mg/L), total suspended solids, TSS (20–107 mg/L) and salinity (0.05–0.65 PSU). All the PPs except for turbidity and TSS are within acceptable limits. NEL sediments had moisture content (MC), organic matter (OM) and organic carbon (OC) in the range of 0.04–8.0percent, 0.08–2.2percent and 0.05–1.8percent, respectively. The sum of eight PCN congeners Σ8PCNs and six PBDE congeners Σ6PBDEs in NEL water samples ranged from 0.164–2.934 μg/L and 0.009-1.025 μg/L individually. The values for Σ8PCNs and Σ6PBDEs in NEL sediment samples varied from 0.991–237 μg/kg and 0.354-28.850 μg/kg, respectively. The calculated hazard quotient (HQ) corresponding to the non-carcinogenic health risk associated with PBDEs in NEL water samples was 2.0×10-3-1.4×10-1, while the TEQ values due to PCNs varied from 6.10×10-7- 3.12×10-3 μg/L in NEL water samples and 3.70×10-5-1.96×10-2 μg/kg dw in sediments. The PP values for CHA water samples include temperature (15.4–22.9°C), pH (7.7–10.5), TDS (991–1771 mg/L), TSS (6–41 mg/L), turbidity (1.0–198 NTU), EC (1981–3542 μS/cm), AP (14.60–14.80 PSI), ORP (-339.1-51.3 mV), and salinity (1.02–1.87 PSU). The EC, TDS and salinity exceeded acceptable values at certain points. The sediments of CHA have MC, OM and OC contents ranging from 0.01-10.2percent, 0.2-1.3percent and 0.1-0.8percent in that order. Sum of Σ8PCNs, Σ6PBDEs in CHA water and sediment samples ranged from 0.026–1.054 μg/L, 0.007-0.079 μg/L and 0.429–1888.468 μg/kg, 0.347-6.468 μg/kg individually. The HQ in CHA water samples was 1.6×10-3-7.7×10-3 and the estimated TEQ was 1.0×10-7-6.62×10-5 μg/L and 1.10×10−5-6.40×10−2 μg/kg in water and sediments, respectively. The temperatures for MMC water samples ranged from 15.6-24.5°C, while other PPs recorded were as follows: pH (8.4-10.2), TDS (943–4002 mg/L), TSS (7-491 mg/L), turbidity (2.9-154.2 NTU), EC (1885-8004 μS/cm), AP (14.53–14.82 PSI), ORP (7.8-130 mV) and salinity (0.96-4.47 PSU). MMC’s sediments recorded MC, OM and OC varying as 0.4- 18.9percent, 0.2-4.5percent and 0.1-2.6percent, respectively across the three seasons. The Σ8PCNs for MMC water and sediment samples were 0.035–0.699 μg/L and 0.260–6744 μg/kg. The TEQ values in MMC water and sediment samples were 1.19×10-7-1.47×10-4 μg/L and 4.43×10−5- 4.19×10−1 μg/kg, respectively. The results are all less than one, and this suggests that the selected water is safe. Results showed that NEL water had highest TEQ, PCN and PBDE concentrations, while MMC sediments recorded maximum TEQ and PCN levels in this study. PBDE concentrations in NEL sediments were above the other site. In conclusion, NEL water was most polluted with both pollutants (PCNs and PBDEs), but MMC sediments contained more PCNs. There is need for the immediate remediation of these selected waterbodies. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-06
Market participation and welfare of smallholder farmers in the Eastern Cape Province South Africa
- Lesala, Mahali Elizabeth https://orcid.org/0000-0001-9921-2190
- Authors: Lesala, Mahali Elizabeth https://orcid.org/0000-0001-9921-2190
- Date: 2021-06
- Subjects: Farms, Small , Economic development -- South Africa , Agriculture -- Economic aspects -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20916 , vital:46745
- Description: The low market participation of smallholder farmers in markets has received enormous attention from scholars, both in the country and the Eastern Cape Province. However, it is not clear how low their market participation is including its implications on farmer’s welfare. The purpose of the study was to determine the extent to which smallholder farmers in the homelands of the Eastern Cape participate in output markets and assess how their participation in markets has affected wellbeing of their households. This information will have important practical implications for policy regarding appropriate pathways for poverty alleviation and livelihoods improvements in the rural areas of the Eastern Cape Province. Three irrigation schemes; Qamata, Zanyokwe and Tyefu irrigation schemes were selected for this study. A sample of 210 smallholder irrigators were interviewed by means of a close-ended questionnaire. The data were analysed by means of descriptive statistical tools, the multiple-level choice models and the Propensity Score Matching (PSM) technique. SPSS and STATA computer programmes were used to carry out all the estimations. The analysis established that, although agriculture is the primary activity for rural livelihoods, it is not the main contributor to family income. Rather, remittances and social grants were the dominant sources of household income in the Qamata, Zanyokwe and Tyefu areas. From the standpoint of market, maize and potatoes are the most popular crops, but potatoes dominate the market. This result confirms that maize is the staple crop and therefore mostly grown for home consumption while production of potatoes is market-oriented. The Market Participation Index (MPI) revealed that farmers sell at least 55 percent of their farm produce, implying that farmers have made some transition from subsistence to semi-commercial farming. However, farmers’ priority still remains food self-sufficiency and market participation only takes place after satisfying their home food needs. The results revealed that the significant factors influencing the farmers’ decisions and their extent of participation in output markets were the age, gender, marital status of the household head, primary occupation of household head, size of farm cultivated, government financial support, access to extension services and farmer’s membership of cooperatives. Concerning the impact of output market participation on welfare of smallholders, the Average Treatment on the Treated (ATT) as the measure of change revealed that participation in output markets has a positive impact on welfare of the smallholder farmers through increased incomes. Farmers who participated in output market were at least R838.44 better off than those who did not participate in markets although social grants and remittances made significantly higher contribution to household welfare. The study suggests that despite some improvements in income of market participants, the standards of living of the rural households are still far from what would be considered optimal. Crop farming evidently contributes less than desired, hence the persistence of the widespread poverty. It is urgent to focus interventions on improving agricultural productivity while widening strategies for improving rural livelihoods beyond agriculture to diversify the choices open to rural dwellers. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-06
- Authors: Lesala, Mahali Elizabeth https://orcid.org/0000-0001-9921-2190
- Date: 2021-06
- Subjects: Farms, Small , Economic development -- South Africa , Agriculture -- Economic aspects -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20916 , vital:46745
- Description: The low market participation of smallholder farmers in markets has received enormous attention from scholars, both in the country and the Eastern Cape Province. However, it is not clear how low their market participation is including its implications on farmer’s welfare. The purpose of the study was to determine the extent to which smallholder farmers in the homelands of the Eastern Cape participate in output markets and assess how their participation in markets has affected wellbeing of their households. This information will have important practical implications for policy regarding appropriate pathways for poverty alleviation and livelihoods improvements in the rural areas of the Eastern Cape Province. Three irrigation schemes; Qamata, Zanyokwe and Tyefu irrigation schemes were selected for this study. A sample of 210 smallholder irrigators were interviewed by means of a close-ended questionnaire. The data were analysed by means of descriptive statistical tools, the multiple-level choice models and the Propensity Score Matching (PSM) technique. SPSS and STATA computer programmes were used to carry out all the estimations. The analysis established that, although agriculture is the primary activity for rural livelihoods, it is not the main contributor to family income. Rather, remittances and social grants were the dominant sources of household income in the Qamata, Zanyokwe and Tyefu areas. From the standpoint of market, maize and potatoes are the most popular crops, but potatoes dominate the market. This result confirms that maize is the staple crop and therefore mostly grown for home consumption while production of potatoes is market-oriented. The Market Participation Index (MPI) revealed that farmers sell at least 55 percent of their farm produce, implying that farmers have made some transition from subsistence to semi-commercial farming. However, farmers’ priority still remains food self-sufficiency and market participation only takes place after satisfying their home food needs. The results revealed that the significant factors influencing the farmers’ decisions and their extent of participation in output markets were the age, gender, marital status of the household head, primary occupation of household head, size of farm cultivated, government financial support, access to extension services and farmer’s membership of cooperatives. Concerning the impact of output market participation on welfare of smallholders, the Average Treatment on the Treated (ATT) as the measure of change revealed that participation in output markets has a positive impact on welfare of the smallholder farmers through increased incomes. Farmers who participated in output market were at least R838.44 better off than those who did not participate in markets although social grants and remittances made significantly higher contribution to household welfare. The study suggests that despite some improvements in income of market participants, the standards of living of the rural households are still far from what would be considered optimal. Crop farming evidently contributes less than desired, hence the persistence of the widespread poverty. It is urgent to focus interventions on improving agricultural productivity while widening strategies for improving rural livelihoods beyond agriculture to diversify the choices open to rural dwellers. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-06
Movement behaviour and reproductive biology of adult spotted grunter (Pomadasys commersonnii) in the Breede Estuary
- Authors: Ziko, Bantony Alford
- Date: 2021-06
- Subjects: Fishery management , Freshwater fishes , Fishes--Nutrition
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20970 , vital:46870
- Description: Movements of the adult spotted grunter (Pomadasys commersonnii), an overexploited estuary-dependant fishery species, were investigated in relation to its reproduction behaviour and selected environmental influences. The South African P. commersonnii population is known to spawn at sea along the KwaZulu-Natal (KZN) coastline, whereas there no published records on spawning in the Eastern and Western Cape Provinces exist. However, due to the occurrence of ripe running fish that were reported in the Breede Estuary (Western Cape - WC), an investigation into its reproductive behaviour was necessary, as was gaining a greater understanding of its movements between the estuary, the sea, and other connected habitats. Seven adult P. commersonnii (610 – 690 mm fork length, FL) were captured and implanted with long-life acoustic transmitters and their movements were logged on a linear array of 16 acoustic receivers in the Breede Estuary (WC) and six acoustic receivers in the adjacent marine environment. Movements of the tagged fish to other marine and estuary habitats were also determined using data collected by the Acoustic Tracking Array Platform (ATAP) which is an extended network of acoustic receivers along the South African coastline with receivers at sea and in selected estuaries. Furthermore, adult P. commersonnii tagged in the Goukou (n = 6) (WC) and Sundays (n = 8) (Eastern Cape - EC) estuaries, approximately 50 km and 470 km away, respectively, were also monitored to facilitate an improved understanding of inter-habitat connectivity. Fish tagged in Sundays and Goukou estuaries were monitored by the Acoustic Telemetry Array Platform (ATAP). Each individual fish tagged in the Breede Estuary was monitored between 356 and 1166 days and selected environmental parameters, including water temperature, river flow rate and rainfall, were measured during the study period (November 2016 – March 2020) to assess their influence on the movements of the tagged fish. Furthermore, to determine time of spawning and duration, gonads of 112 adult fish (383 – 700 mm FL) were opportunistically collected from recreational anglers in the Breede Estuary to determine the gonadal maturation cycles by using a combination of Gonado-somatic index (GSI) and histology. The tagged adult P. commersonnii spent significantly more time in the estuary (83.5 percent) than the marine (16.5 percent) environment, with all of the tagged P. commersonnii making sea trips of varying frequency and duration. While in the estuary, fish showed a strong preference for the lower reaches of the estuary compared to the middle and upper reaches. Area use varied seasonally, with the mouth area being heavily utilized during winter, then followed by summer. Sea trips in all three tagging estuaries also fluctuated seasonally, with more frequent movements during summer which lasted for longer periods. This coincided with the peak of the spawning period inferred from the gonad developmental cycle of fish captured in the Breede Estuary. Results from a generalized linear mixed model showed that the presence of Breede tagged P. commersonnii in the sea, where the species is known to spawn, was significantly influenced by water temperatures in the estuary and river flow rate with fish more likely to occur at sea during warmer months (summer) and periods of high river flow (winter). Furthermore, circular analysis showed that season (month) had a significant influence on the departure from and arrival in the Breede Estuary, with most departures and arrivals occurring during January. Moreover, P. commersonnii tagged in the Sundays Estuary also showed similar results where both departures and arrivals were influenced by season, mostly taking place in December and January, respectively. The increased frequency of sea trips by adult P. commersonnii in summer suggests regional spawning occurring in the WC. Based on the similar movement behaviour displayed by tagged fish in the Sundays Estuary, it is possible that spawning also occurs in the EC. Most of the P. commersonnii tagged in all the three estuaries never left their tagging estuaries (57 percent Breede, 66 percent Goukou, 38 percent Sundays), only making short sea trips, while others displayed use of multiple habitats. On average, the tagged P. commersonnii that left their tagging estuaries travelled a maximum distance of 377 km (Breede), 63 km (Goukou) and 300 km (Sundays). Tagged fish were more likely to visit nearby estuaries and offshore marine habitats (< 130 km) compared to distant ones (> 130 km). These results suggest that there are high levels of localised connectivity between P. commersonnii populations in different habitats although connectivity between distant habitats appears to be rare. Connectivity will likely occur on habitats located close to the boundaries of the WC, EC and KZN. The findings from this long-term monitoring study have shown that adult P. commersonnii rely heavily on the estuarine environment, undertaking short sea trips, thus demonstrating the importance of estuaries to the adult population. Due to various threats faced by estuaries such as habitat degradation and overexploitation, management of these systems is paramount to conserve such fishery resources. Due to the resident behaviour of the P. commersonnii within estuaries, Marine Protected Areas (MPAs) and area closures, in conjunction with Estuarine Protected Areas (EPAs) will be significant in the recovery and management of P. commersonnii populations. Since P. commersonnii appears to reach peak spawning activity during summer when fishing pressure is usually highest, improved enforcement during this period is necessary to conserve the spawning stock. As connectivity is an important aspect in the life of the P. commersonnii, ensuring such connectivity is maintained by protecting all these habitats is important. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-06
- Authors: Ziko, Bantony Alford
- Date: 2021-06
- Subjects: Fishery management , Freshwater fishes , Fishes--Nutrition
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20970 , vital:46870
- Description: Movements of the adult spotted grunter (Pomadasys commersonnii), an overexploited estuary-dependant fishery species, were investigated in relation to its reproduction behaviour and selected environmental influences. The South African P. commersonnii population is known to spawn at sea along the KwaZulu-Natal (KZN) coastline, whereas there no published records on spawning in the Eastern and Western Cape Provinces exist. However, due to the occurrence of ripe running fish that were reported in the Breede Estuary (Western Cape - WC), an investigation into its reproductive behaviour was necessary, as was gaining a greater understanding of its movements between the estuary, the sea, and other connected habitats. Seven adult P. commersonnii (610 – 690 mm fork length, FL) were captured and implanted with long-life acoustic transmitters and their movements were logged on a linear array of 16 acoustic receivers in the Breede Estuary (WC) and six acoustic receivers in the adjacent marine environment. Movements of the tagged fish to other marine and estuary habitats were also determined using data collected by the Acoustic Tracking Array Platform (ATAP) which is an extended network of acoustic receivers along the South African coastline with receivers at sea and in selected estuaries. Furthermore, adult P. commersonnii tagged in the Goukou (n = 6) (WC) and Sundays (n = 8) (Eastern Cape - EC) estuaries, approximately 50 km and 470 km away, respectively, were also monitored to facilitate an improved understanding of inter-habitat connectivity. Fish tagged in Sundays and Goukou estuaries were monitored by the Acoustic Telemetry Array Platform (ATAP). Each individual fish tagged in the Breede Estuary was monitored between 356 and 1166 days and selected environmental parameters, including water temperature, river flow rate and rainfall, were measured during the study period (November 2016 – March 2020) to assess their influence on the movements of the tagged fish. Furthermore, to determine time of spawning and duration, gonads of 112 adult fish (383 – 700 mm FL) were opportunistically collected from recreational anglers in the Breede Estuary to determine the gonadal maturation cycles by using a combination of Gonado-somatic index (GSI) and histology. The tagged adult P. commersonnii spent significantly more time in the estuary (83.5 percent) than the marine (16.5 percent) environment, with all of the tagged P. commersonnii making sea trips of varying frequency and duration. While in the estuary, fish showed a strong preference for the lower reaches of the estuary compared to the middle and upper reaches. Area use varied seasonally, with the mouth area being heavily utilized during winter, then followed by summer. Sea trips in all three tagging estuaries also fluctuated seasonally, with more frequent movements during summer which lasted for longer periods. This coincided with the peak of the spawning period inferred from the gonad developmental cycle of fish captured in the Breede Estuary. Results from a generalized linear mixed model showed that the presence of Breede tagged P. commersonnii in the sea, where the species is known to spawn, was significantly influenced by water temperatures in the estuary and river flow rate with fish more likely to occur at sea during warmer months (summer) and periods of high river flow (winter). Furthermore, circular analysis showed that season (month) had a significant influence on the departure from and arrival in the Breede Estuary, with most departures and arrivals occurring during January. Moreover, P. commersonnii tagged in the Sundays Estuary also showed similar results where both departures and arrivals were influenced by season, mostly taking place in December and January, respectively. The increased frequency of sea trips by adult P. commersonnii in summer suggests regional spawning occurring in the WC. Based on the similar movement behaviour displayed by tagged fish in the Sundays Estuary, it is possible that spawning also occurs in the EC. Most of the P. commersonnii tagged in all the three estuaries never left their tagging estuaries (57 percent Breede, 66 percent Goukou, 38 percent Sundays), only making short sea trips, while others displayed use of multiple habitats. On average, the tagged P. commersonnii that left their tagging estuaries travelled a maximum distance of 377 km (Breede), 63 km (Goukou) and 300 km (Sundays). Tagged fish were more likely to visit nearby estuaries and offshore marine habitats (< 130 km) compared to distant ones (> 130 km). These results suggest that there are high levels of localised connectivity between P. commersonnii populations in different habitats although connectivity between distant habitats appears to be rare. Connectivity will likely occur on habitats located close to the boundaries of the WC, EC and KZN. The findings from this long-term monitoring study have shown that adult P. commersonnii rely heavily on the estuarine environment, undertaking short sea trips, thus demonstrating the importance of estuaries to the adult population. Due to various threats faced by estuaries such as habitat degradation and overexploitation, management of these systems is paramount to conserve such fishery resources. Due to the resident behaviour of the P. commersonnii within estuaries, Marine Protected Areas (MPAs) and area closures, in conjunction with Estuarine Protected Areas (EPAs) will be significant in the recovery and management of P. commersonnii populations. Since P. commersonnii appears to reach peak spawning activity during summer when fishing pressure is usually highest, improved enforcement during this period is necessary to conserve the spawning stock. As connectivity is an important aspect in the life of the P. commersonnii, ensuring such connectivity is maintained by protecting all these habitats is important. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-06
Application of geophysical methods to investigate the subsurface geology of Kuruman and Kono areas in Griqualand West Basin, South Africa
- Authors: Mthintweni, Sylvia Lwandisa
- Date: 2021-05
- Subjects: Geology , Soil surveys--Geophysical methods
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22555 , vital:52456
- Description: Kono and Kuruman areas belong to the geology of the Campbell Rand and Asbestos Hills Subgroups, Ghaap Group in the Griqualand West Basin. Campbell Rand Subgroup comprises interbedded chert, limestone and dolomite rocks of dominantly the Kogelbeen Formation covered with a thick regolith of red sand and weathered material. The Asbestos Hills Subgroup consists of a banded iron formation (BIF) of the Kuruman Formation overlain by the Kalahari sands. Petrographic and mineralogical analyses and various geophysical methods were utilised to investigate the surface and subsurface conditions of the study areas. This study was done to characterize and understand the geology of Kuruman and Kono and identify the structural lineaments. Rock samples of varying lithology were collected in the field for laboratory analyses that include preparation of thin sections and petrographic analyses and density and porosity determinations. Both the petrographic results and XRF analyses revealed that iron oxide (Fe2O3) and silica (SiO2) are the most abundant minerals in BIF. Iron oxide and silica percentages range between 21.17-39.97 wt % and 59.03-78.01 wt %, respectively. BIF has an average density of 3.0 g/cm3 and porosity of 2.51% and dolomite has an average density of 2.8 g/cm3 and porosity of 0.17%. The Bouguer anomaly values range between - 119.00 mGal and -1 17.29 mGals. High gravity anomalies are attributed to shallow fresh bedrock and this was confirmed by the seismic line that cuts across the map. The gravity high observed in the Kuruman profile coincides with the thick BIF body observed in the field. The gravity analytic signal indicates a width of about 1125 m for the BIF and inferred two normal faults at about 675 m and 1500 m. The high magnetic anomalies in the ground magnetic map correspond to chert rich dolomite ridges in the field and the intermediate to lows correspond to dolomitic terrains. A geological map was superimposed on an aeromagnetic map to correlate the two. The linear magnetic high trending from NW – SE coincide with BIF. Older dykes trending east-west were intruded by younger dykes trending north-south. The total counts channel map for Kono area shows the measured total gamma radiation count in the study area and the concentrations of radioelements range between 51.84 and 94.64 counts/sec. The concentrations of potassium, thorium and uranium range from 0.12 – 0.51%, 0.83 – 5.23 ppm and 0.06 – 2.27 ppm, respectively. A high concentration of radiometric elements cutting through the central part of the map stretching from northwest to southeast was observed in a ternary map and this could be associated with chert rich dolomite outcrops. Seismic refraction tomography (SRT) cross-section for study area 1 in Kono revealed 3 different layers. The topmost layer comprises sand and loose material and has a velocity ranging from 614 – 1194 m/s. It is underlain by highly to slightly weathered dolomite with a velocity that ranges from 1774 – 2354 m/s. Layer 3 is the fresh bedrock dolomite and has a velocity of 2934 m/s. Three layers were observed in study area 2 for Kuruman. Layer 1 had a velocity of 300 – 750 m/s, the second layer had a velocity of 1200 – 2100 m/s and the bottom layer’s velocity was 2500 – 2999 m/s. An inferred fault is indicated on the western side of the seismic section at about 650 m. The dipole-dipole resistivity model for the main survey line in Kono revealed that the area is underlain by fractured bedrock with high resistivity in places. A thick conductive stratum was observed at the beginning of the line. The resistivity models for the sinkhole in Kono were characterized into three resistivity zones. High resistivity values (1000 – 134202 Ωm) are due to slightly weathered to fresh bedrock, intermediate values (24 – 5770 Ωm) are interpreted to be due to highly weathered dolomite and compacted dolomitic soils and very low resistivity zones (4 – 397 Ωm) are inferred to be karstic cavities. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Mthintweni, Sylvia Lwandisa
- Date: 2021-05
- Subjects: Geology , Soil surveys--Geophysical methods
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22555 , vital:52456
- Description: Kono and Kuruman areas belong to the geology of the Campbell Rand and Asbestos Hills Subgroups, Ghaap Group in the Griqualand West Basin. Campbell Rand Subgroup comprises interbedded chert, limestone and dolomite rocks of dominantly the Kogelbeen Formation covered with a thick regolith of red sand and weathered material. The Asbestos Hills Subgroup consists of a banded iron formation (BIF) of the Kuruman Formation overlain by the Kalahari sands. Petrographic and mineralogical analyses and various geophysical methods were utilised to investigate the surface and subsurface conditions of the study areas. This study was done to characterize and understand the geology of Kuruman and Kono and identify the structural lineaments. Rock samples of varying lithology were collected in the field for laboratory analyses that include preparation of thin sections and petrographic analyses and density and porosity determinations. Both the petrographic results and XRF analyses revealed that iron oxide (Fe2O3) and silica (SiO2) are the most abundant minerals in BIF. Iron oxide and silica percentages range between 21.17-39.97 wt % and 59.03-78.01 wt %, respectively. BIF has an average density of 3.0 g/cm3 and porosity of 2.51% and dolomite has an average density of 2.8 g/cm3 and porosity of 0.17%. The Bouguer anomaly values range between - 119.00 mGal and -1 17.29 mGals. High gravity anomalies are attributed to shallow fresh bedrock and this was confirmed by the seismic line that cuts across the map. The gravity high observed in the Kuruman profile coincides with the thick BIF body observed in the field. The gravity analytic signal indicates a width of about 1125 m for the BIF and inferred two normal faults at about 675 m and 1500 m. The high magnetic anomalies in the ground magnetic map correspond to chert rich dolomite ridges in the field and the intermediate to lows correspond to dolomitic terrains. A geological map was superimposed on an aeromagnetic map to correlate the two. The linear magnetic high trending from NW – SE coincide with BIF. Older dykes trending east-west were intruded by younger dykes trending north-south. The total counts channel map for Kono area shows the measured total gamma radiation count in the study area and the concentrations of radioelements range between 51.84 and 94.64 counts/sec. The concentrations of potassium, thorium and uranium range from 0.12 – 0.51%, 0.83 – 5.23 ppm and 0.06 – 2.27 ppm, respectively. A high concentration of radiometric elements cutting through the central part of the map stretching from northwest to southeast was observed in a ternary map and this could be associated with chert rich dolomite outcrops. Seismic refraction tomography (SRT) cross-section for study area 1 in Kono revealed 3 different layers. The topmost layer comprises sand and loose material and has a velocity ranging from 614 – 1194 m/s. It is underlain by highly to slightly weathered dolomite with a velocity that ranges from 1774 – 2354 m/s. Layer 3 is the fresh bedrock dolomite and has a velocity of 2934 m/s. Three layers were observed in study area 2 for Kuruman. Layer 1 had a velocity of 300 – 750 m/s, the second layer had a velocity of 1200 – 2100 m/s and the bottom layer’s velocity was 2500 – 2999 m/s. An inferred fault is indicated on the western side of the seismic section at about 650 m. The dipole-dipole resistivity model for the main survey line in Kono revealed that the area is underlain by fractured bedrock with high resistivity in places. A thick conductive stratum was observed at the beginning of the line. The resistivity models for the sinkhole in Kono were characterized into three resistivity zones. High resistivity values (1000 – 134202 Ωm) are due to slightly weathered to fresh bedrock, intermediate values (24 – 5770 Ωm) are interpreted to be due to highly weathered dolomite and compacted dolomitic soils and very low resistivity zones (4 – 397 Ωm) are inferred to be karstic cavities. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Aspects of the ecology of the estuarine round-herring Gilchristella aestuaria (Pisces: Clupeidae) and its small-scale fishery potential
- Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Authors: Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Date: 2021-05
- Subjects: Small-scale fisheries , Silversides
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22765 , vital:52752
- Description: In the past two decades, there has been increasing pressure for small-scale inland fisheries to play a central role in food and nutrient security for poor communities in South Africa. For decades, South African inland fisheries have focussed on the exploitation of large fish species and generally ignored the exploitation of inland small fish species (SFS). This research aimed to assess the ecology and small-scale fishery potential of the estuarine round-herring, Gilchristella aestuaria. To understand the ecology of G. aestuaria better, morphometric trait analysis and fish condition of populations in relation to environmental variables (salinity, pH, temperature, turbidity and chlorophyll-a) were done. Fish were supplemented with samples acquired from the SAIAB collection facility for 14 sites to cover all the three South African biogeographic regions, stretching from Lake Sibaya (KZN) to the Orange River estuary in the western parts of the country. The morphometric trait analysis showed that G. aestuaria populations can be distinguished based on the trait variation, however there were many overlaps for populations that are interconnected, with distant/ geographically separated populations showing clear differences. Morphometric traits of the G. aestuaria population were significantly different, however there was no strong directional relationship with environmental variables and variation in morphometric traits. However, fish condition as measured by Fulton’s condition (K) and relative weight (Wr) showed variation between populations found in different environments. These differences suggest that these populations must be managed differently if G. aestuaria is to be exploited in managed fisheries. To determine the potential nutrient value of G. aestuaria to the human diet, samples from two freshwater sites and five estuarine sites were analysed for essential macro and micronutrients. The nutrient content of G. aestuaria revealed there is potential for exploitation, as the species has a high macro (protein and fat) and micronutrient composition (calcium, iron and zinc). Mean ± SD of selected nutrients were protein (61.7±5.0 g/100g), fat (20.4±3.7g/ 100g), calcium (3507.5±314.0mg), iron (40.37±14.0mg/ 100g), zinc (22.47±5.6mg/ 100) and vitamin A (37.3±44.4 RAE/ 100g). The nutrient composition of fish collected from freshwater sites was comparable to those collected from estuarine environments. Using the recommended dietary allowances (RDA) from literature, the mass of fish and the number of fish that would provide a minimum amount for each nutrient were calculated. A child would require only 13.4g of dry G. aestuaria or approximately 74 dried fish to meet the daily requirements of zinc. Other minerals such as iron and calcium also showed a similar low weight or number of fish required to meet daily requirements for the different categories. A small number of G. aestuaria are needed to meet RDA for groups (children, adult men, adult women, pregnant women and lactating mothers). A comparison was done for the nutrient composition of G. aestuaria with reference species that are already harvested for human consumption in some African and Asian countries. The protein content of G. aestuaria was comparable to Chisense (Microthrissa moeruensis) and Kapenta Limnothrissa miodon), while the fat composition was more than twice Chisense and Kapenta. Comparing the mineral composition, G. aestuaria had more than three times higher calcium than Mola (Amblypharyngodon mola) and Puti (Puntius sophore). Zinc composition was four times higher than M. moeruensis and L. miodon. Further exploration of the ecology of G. aestuaria was studied using the Sundays River irrigations ponds as a case study that would represent small impoundments across South Africa. Species rank abundance curve and catch per unit effort (CPUE) on the Sundays Irrigation ponds revealed that G. aestuaria dominated numerically and biomass in the Sundays River irrigation ponds. To assess the potential of harvesting G. aestuaria harvesting experiments were conducted using depletion (removal) sampling. Catchweight (kg) ranged from 2.16 (1.03; 3.28) to 61.25 (44.40; 78.09) kg and the estimated biomass from the depletion model ranged from 1.05 to 40.19 kg/ha for September 2019. The depletion model revealed that small impoundments have high biomass per hectare of G. aestuaria ranging from which indicates that the species may not support a commercial fishery but small-scale fisheries. In conclusion, G. aestuaria could become a meaningful contribution to the food and nutrient security of poor communities where available as a food source through small-scale fishery exploitation. The extent of this contribution may depend on its production potential in various regions and environments. More research is however needed to determine the long-term sustainability of harvesting of G aestuaria by looking at how populations respond to harvesting. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Date: 2021-05
- Subjects: Small-scale fisheries , Silversides
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22765 , vital:52752
- Description: In the past two decades, there has been increasing pressure for small-scale inland fisheries to play a central role in food and nutrient security for poor communities in South Africa. For decades, South African inland fisheries have focussed on the exploitation of large fish species and generally ignored the exploitation of inland small fish species (SFS). This research aimed to assess the ecology and small-scale fishery potential of the estuarine round-herring, Gilchristella aestuaria. To understand the ecology of G. aestuaria better, morphometric trait analysis and fish condition of populations in relation to environmental variables (salinity, pH, temperature, turbidity and chlorophyll-a) were done. Fish were supplemented with samples acquired from the SAIAB collection facility for 14 sites to cover all the three South African biogeographic regions, stretching from Lake Sibaya (KZN) to the Orange River estuary in the western parts of the country. The morphometric trait analysis showed that G. aestuaria populations can be distinguished based on the trait variation, however there were many overlaps for populations that are interconnected, with distant/ geographically separated populations showing clear differences. Morphometric traits of the G. aestuaria population were significantly different, however there was no strong directional relationship with environmental variables and variation in morphometric traits. However, fish condition as measured by Fulton’s condition (K) and relative weight (Wr) showed variation between populations found in different environments. These differences suggest that these populations must be managed differently if G. aestuaria is to be exploited in managed fisheries. To determine the potential nutrient value of G. aestuaria to the human diet, samples from two freshwater sites and five estuarine sites were analysed for essential macro and micronutrients. The nutrient content of G. aestuaria revealed there is potential for exploitation, as the species has a high macro (protein and fat) and micronutrient composition (calcium, iron and zinc). Mean ± SD of selected nutrients were protein (61.7±5.0 g/100g), fat (20.4±3.7g/ 100g), calcium (3507.5±314.0mg), iron (40.37±14.0mg/ 100g), zinc (22.47±5.6mg/ 100) and vitamin A (37.3±44.4 RAE/ 100g). The nutrient composition of fish collected from freshwater sites was comparable to those collected from estuarine environments. Using the recommended dietary allowances (RDA) from literature, the mass of fish and the number of fish that would provide a minimum amount for each nutrient were calculated. A child would require only 13.4g of dry G. aestuaria or approximately 74 dried fish to meet the daily requirements of zinc. Other minerals such as iron and calcium also showed a similar low weight or number of fish required to meet daily requirements for the different categories. A small number of G. aestuaria are needed to meet RDA for groups (children, adult men, adult women, pregnant women and lactating mothers). A comparison was done for the nutrient composition of G. aestuaria with reference species that are already harvested for human consumption in some African and Asian countries. The protein content of G. aestuaria was comparable to Chisense (Microthrissa moeruensis) and Kapenta Limnothrissa miodon), while the fat composition was more than twice Chisense and Kapenta. Comparing the mineral composition, G. aestuaria had more than three times higher calcium than Mola (Amblypharyngodon mola) and Puti (Puntius sophore). Zinc composition was four times higher than M. moeruensis and L. miodon. Further exploration of the ecology of G. aestuaria was studied using the Sundays River irrigations ponds as a case study that would represent small impoundments across South Africa. Species rank abundance curve and catch per unit effort (CPUE) on the Sundays Irrigation ponds revealed that G. aestuaria dominated numerically and biomass in the Sundays River irrigation ponds. To assess the potential of harvesting G. aestuaria harvesting experiments were conducted using depletion (removal) sampling. Catchweight (kg) ranged from 2.16 (1.03; 3.28) to 61.25 (44.40; 78.09) kg and the estimated biomass from the depletion model ranged from 1.05 to 40.19 kg/ha for September 2019. The depletion model revealed that small impoundments have high biomass per hectare of G. aestuaria ranging from which indicates that the species may not support a commercial fishery but small-scale fisheries. In conclusion, G. aestuaria could become a meaningful contribution to the food and nutrient security of poor communities where available as a food source through small-scale fishery exploitation. The extent of this contribution may depend on its production potential in various regions and environments. More research is however needed to determine the long-term sustainability of harvesting of G aestuaria by looking at how populations respond to harvesting. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Assessing Drought Conditions using NDVI, Land Surface Temperature and Precipitation in Amathole District Municipality, Eastern Cape, Province, South Africa
- Authors: Dyosi, Masonwabe
- Date: 2021-05
- Subjects: Remote sensing , Earth sciences--Remote sensing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20793 , vital:46570
- Description: The world is faced with unprecedented environmental changes, which can be linked to population growth, and economic development. Several studies have indicated that these changes are likely to accelerate in the future and cause adverse impact on the environment. To this end, the Eastern Cape Province and in particular the Amathole District Municipality (ADM) has recorded high number of climate change related disasters such as prolonged drought conditions witnessed during the winter season of 2008, 2009, 2014 and 2015 among others. To this end, this study aimed to use remote sensing imagery to assess and document drought occurrences in the ADM from 2007 to 2017. To accomplish the aim, the Normalized Difference Vegetation Index, Land Surface Temperature and Precipitation were explored to assess drought spatiotemporal occurrences. To assess the relationship between abovementioned variables, the Pearson’s correlation was used. For the analysis a total of 396 satellite imagery (MODIS NDVI and Land Surface Temperature as well as TRMM precipitation) were used. The study results revealed that different correlations exist between the three variables. The strength of correlations differed by season. Furthermore, it was revealed that the drought conditions in the district differed in the spatial distribution. The study accurately identified the drought episodes which occurred in the ADM in the years 2008, 2009, 2014, 2015 and 2016. The chosen methodology and variables proved to be suitable for analysing drought conditions offering space and temporal variation dimension, which is vital in monitoring disasters such as drought. , Thesis (MSc) (Geography) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Dyosi, Masonwabe
- Date: 2021-05
- Subjects: Remote sensing , Earth sciences--Remote sensing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20793 , vital:46570
- Description: The world is faced with unprecedented environmental changes, which can be linked to population growth, and economic development. Several studies have indicated that these changes are likely to accelerate in the future and cause adverse impact on the environment. To this end, the Eastern Cape Province and in particular the Amathole District Municipality (ADM) has recorded high number of climate change related disasters such as prolonged drought conditions witnessed during the winter season of 2008, 2009, 2014 and 2015 among others. To this end, this study aimed to use remote sensing imagery to assess and document drought occurrences in the ADM from 2007 to 2017. To accomplish the aim, the Normalized Difference Vegetation Index, Land Surface Temperature and Precipitation were explored to assess drought spatiotemporal occurrences. To assess the relationship between abovementioned variables, the Pearson’s correlation was used. For the analysis a total of 396 satellite imagery (MODIS NDVI and Land Surface Temperature as well as TRMM precipitation) were used. The study results revealed that different correlations exist between the three variables. The strength of correlations differed by season. Furthermore, it was revealed that the drought conditions in the district differed in the spatial distribution. The study accurately identified the drought episodes which occurred in the ADM in the years 2008, 2009, 2014, 2015 and 2016. The chosen methodology and variables proved to be suitable for analysing drought conditions offering space and temporal variation dimension, which is vital in monitoring disasters such as drought. , Thesis (MSc) (Geography) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
Coastal urban climate change adaptation and disaster risk reduction assessment: the case of East London city, South Africa
- Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Authors: Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Date: 2021-05
- Subjects: Climate change mitigation , Climatic changes , Emergency management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20938 , vital:46756
- Description: The increasing incidences of climate change and its registered negative effects have disturbed the entire world, with the coastal areas being the worst hit. Given the fact that coastal areas are becoming centres of global population settlement. An attempt to explore climate change-related disasters and risks is an important aspect in building communities' adaptation and resilience, especially for the most vulnerable global south. Consequently, climate change adaptation (CCA) and disaster risk reduction (DRR) have become fundamentally linked to offering sustainable solutions to address climate change and related disaster risk problems witnessed frequently in recent years. However, the assessment of synergy between CCA and DRR for coastal areas remains fragmented, vague and limited, especially for Sub-Saharan Africa and thus the need for exploration. Furthermore, the urban populace and planning stakeholders are grappling with the challenges of seeking ways to integrate adaptation measures into human livelihoods and planning systems. Also, considering complex issues inhibiting sustainable planning, for example, poor communication of climate risks affecting coastal areas, little records of hazards disclosure and disaster history, inundation and/or sea level rise etc warranted further investigation. Accordingly, the synergies between CCA and DRR in addressing various climate change-related disaster risks, especially for the coastal areas and cities was explored in this study. To this end, given the complexity of CCA and DRR, trio-theories were adopted, which included Resilience Theory (RT), Social Vulnerability Theory (SVT) and Protective Motivation Theory (PMT) as the study’s theoretical underpinnings using East London Coastal City as a case study. Consequently, a multi-method approach was employed using a review of literature, bibliometric analysis, field survey, geographic information system (GIS), and remote sensing. The first objective reveals that there is a need for convergence and harmonisation of CCA and DRR policy, programme, and practice to improve sustainable planning outcomes. Accordingly, the study proposed the adoption of a problem analysis model (PAM) for place function sustainability and local or community level resilience building. The second objective revealed that the Sendai framework for disaster risk reduction has not been fully operationalised at the local and global scales. However, in South Africa, there are efforts to streamline DRR across manifold sectors through the Integrated Urban Development Framework (IUDF). Therefore, disaster risk managers and climate change adaptation stakeholders at the local level need to embrace the position of the SFDRR to possibly offer sound and sustainable results to the most vulnerable. In addition, a bibliometric analysis on climate change adaptation from 1996 – 2019 highlights the need for more African countries' engagement and cross-collaboration between developing and developed countries in CCA research to advance sustainable solutions and improve resilience. The third objective revealed the need for more awareness, flexibility, and adaptability among stakeholders at various levels as fundamental ingredients for CCA and DRR sustainable planning outcomes. The fourth objective highlighted that floods were recorded as the most predominant hydro-meteorological hazard (n=118, 81.9percent) in the East London, coastal city. Finally, the fifth objective portrayed that many communities, populace, buildings (types), and areas are exposed to flood disaster risks, especially, communities such as Nahoon Park Valley, Sunrise on Sea, Beacon Bay, Buffalo, Gonubie, and East London are among the most vulnerable. The study recommends that early action and warning systems should be adopted, and allocation proper building codes to boost awareness to reduce the potential flood disaster risks. Moreover, the study reveals the significance of local flood disaster risk mapping in advancing CCA and DRR to ensure the implementation of coherent spatial planning for sustainable planning outcomes. The overall lessons learnt from this study are vital in contributing to the attainment of the sustainable development goals (SDGs) such as goal 11: sustainable cities and communities, and goal 13: climate action, including the seven targets and four priorities for action of the Sendai framework at a local level. The study results are deemed critical in guiding city planners, decision-makers, disaster risk managers, local communities among others towards the development of a more resilient coastal community. In general, the study calls for the integration of CCA and DRR initiatives to be premised on PAM for sustainable planning outcomes to achieve sustainable development goals and reduction of fatalities from climate-related disasters. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Date: 2021-05
- Subjects: Climate change mitigation , Climatic changes , Emergency management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20938 , vital:46756
- Description: The increasing incidences of climate change and its registered negative effects have disturbed the entire world, with the coastal areas being the worst hit. Given the fact that coastal areas are becoming centres of global population settlement. An attempt to explore climate change-related disasters and risks is an important aspect in building communities' adaptation and resilience, especially for the most vulnerable global south. Consequently, climate change adaptation (CCA) and disaster risk reduction (DRR) have become fundamentally linked to offering sustainable solutions to address climate change and related disaster risk problems witnessed frequently in recent years. However, the assessment of synergy between CCA and DRR for coastal areas remains fragmented, vague and limited, especially for Sub-Saharan Africa and thus the need for exploration. Furthermore, the urban populace and planning stakeholders are grappling with the challenges of seeking ways to integrate adaptation measures into human livelihoods and planning systems. Also, considering complex issues inhibiting sustainable planning, for example, poor communication of climate risks affecting coastal areas, little records of hazards disclosure and disaster history, inundation and/or sea level rise etc warranted further investigation. Accordingly, the synergies between CCA and DRR in addressing various climate change-related disaster risks, especially for the coastal areas and cities was explored in this study. To this end, given the complexity of CCA and DRR, trio-theories were adopted, which included Resilience Theory (RT), Social Vulnerability Theory (SVT) and Protective Motivation Theory (PMT) as the study’s theoretical underpinnings using East London Coastal City as a case study. Consequently, a multi-method approach was employed using a review of literature, bibliometric analysis, field survey, geographic information system (GIS), and remote sensing. The first objective reveals that there is a need for convergence and harmonisation of CCA and DRR policy, programme, and practice to improve sustainable planning outcomes. Accordingly, the study proposed the adoption of a problem analysis model (PAM) for place function sustainability and local or community level resilience building. The second objective revealed that the Sendai framework for disaster risk reduction has not been fully operationalised at the local and global scales. However, in South Africa, there are efforts to streamline DRR across manifold sectors through the Integrated Urban Development Framework (IUDF). Therefore, disaster risk managers and climate change adaptation stakeholders at the local level need to embrace the position of the SFDRR to possibly offer sound and sustainable results to the most vulnerable. In addition, a bibliometric analysis on climate change adaptation from 1996 – 2019 highlights the need for more African countries' engagement and cross-collaboration between developing and developed countries in CCA research to advance sustainable solutions and improve resilience. The third objective revealed the need for more awareness, flexibility, and adaptability among stakeholders at various levels as fundamental ingredients for CCA and DRR sustainable planning outcomes. The fourth objective highlighted that floods were recorded as the most predominant hydro-meteorological hazard (n=118, 81.9percent) in the East London, coastal city. Finally, the fifth objective portrayed that many communities, populace, buildings (types), and areas are exposed to flood disaster risks, especially, communities such as Nahoon Park Valley, Sunrise on Sea, Beacon Bay, Buffalo, Gonubie, and East London are among the most vulnerable. The study recommends that early action and warning systems should be adopted, and allocation proper building codes to boost awareness to reduce the potential flood disaster risks. Moreover, the study reveals the significance of local flood disaster risk mapping in advancing CCA and DRR to ensure the implementation of coherent spatial planning for sustainable planning outcomes. The overall lessons learnt from this study are vital in contributing to the attainment of the sustainable development goals (SDGs) such as goal 11: sustainable cities and communities, and goal 13: climate action, including the seven targets and four priorities for action of the Sendai framework at a local level. The study results are deemed critical in guiding city planners, decision-makers, disaster risk managers, local communities among others towards the development of a more resilient coastal community. In general, the study calls for the integration of CCA and DRR initiatives to be premised on PAM for sustainable planning outcomes to achieve sustainable development goals and reduction of fatalities from climate-related disasters. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05