https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:27797 Wed 31 May 2023 14:45:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:44806 Wed 13 Apr 2022 14:16:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:31218 Wed 12 May 2021 23:04:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6045 Wed 12 May 2021 22:42:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6038 Wed 12 May 2021 22:18:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:20721 Wed 12 May 2021 20:31:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29196 Wed 12 May 2021 20:28:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28491 Wed 12 May 2021 20:11:03 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:31223 Wed 12 May 2021 20:10:33 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:31045 Wed 12 May 2021 20:01:04 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6035 Wed 12 May 2021 19:59:48 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:21334 Wed 12 May 2021 19:58:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6049 Wed 12 May 2021 19:15:57 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6039 Wed 12 May 2021 18:26:52 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6048 Wed 12 May 2021 17:56:06 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:37907 20-40mm), swimmers, flattened body shape, a preference for temporary attachment, crawling, respiration with aerial/vegetation, possession of breathing tubes, possession of strap or other apparatus for respiration, streamlined body, and a high sensitivity to oxygen depletion. Permanent attachment as an ecological preference associated with LIS was also positively correlated with increasing dissolved oxygen (DO) and was deemed a pollution sensitive ecological preference. The possession of very small body size (<5mm), associated with HIS, was deemed a pollution-tolerant trait and was negatively correlated with DO, confirming the deteriorating state of the urban and urban-agricultural rivers. The impact of urban-forestry pollution on the distribution pattern of macroinvertebrate traits and ecological preferences was also explored in the selected rivers. Traits and ecological preferences such as possession of hard-shell, large body size, and grazing as a feeding preference which were significantly positively associated with the LIS, were also either significantly positively correlated with DO, or significantly negatively correlated with increasing any two of flow velocity, water temperature, BOD5 and nutrient. These traits and ecological preferences were deemed sensitive in forested rivers receiving urban pollution. Further, burrowing, the pupa aquatic stage, and predation which were significantly positively associated with HIS on the RLQ ordination, were also significantly negatively associated with DO. These traits were deemed tolerant of forested systems receiving urban pollution. Multimetric indices (MMI) were developed, validated and applied for urban, urban-agriculture and urban-forested (MMI-urban, MMI-urban-agric and urban-forest) areas. Of the 26 metrics that satisfactorily discriminated between the LIS, the MIS, and the HIS for MMI-urban, only five metric were retained for integration into MMI-urban, they are log VeL, Hemiptera abundance, % Coleoptera + Hemiptera, % Chironomidae + Oligochaeta and Evenness index. Further, of the 18 metrics that satisfactorily discriminated between the LIS, the MIS, and the HIS for MMI-urban-agric, only 12 metrics were retained and nine proved to be redundant. The nine metrics represent different measures; two of them were retained in addition to Chironomidae/Diptera abundance, % Odonata and Oligochaeta richness. The two metrics selected in addition to the hironomidae/Diptera abundance, % Odonata and Oligochaeta richness were the Margalef index and the logarithm of relative abundance of sprawler. For the MMI-urban-forest, 14 metrics satisfactorily discriminated between the LIS, the MIS, and the HIS, and 12 metrics were retained and 11 proved to be redundant. The non-redundant metric was Trichoptera abundance. Three metrics were further selected in addition to the Trichoptera abundance which include % Chironomidae + Oligochaeta, Coleoptera + Hemiptera richness and Shannon diversity. The MMI-urban and MMI-urban-agric indices performed better for LIS designated stations compared to the MIS and HIS deignated stations. The developed indices proved effective as biomonitoring tools for assessing the ecological health of rivers in the urban and urban-agriculture catchments within the Niger Delta. Overall, the results of the macroinvertebrate traits and ecological preferences, and taxonomic approaches showed the strength in the complementarity of both approaches in developing biomonitoring tools for assessing levels of deterioration in riverine systems. The study contributes significantly to understanding the ecology of riverine systems in the Niger Delta, particularly those subject to urban stresses, agricultural activities and urban pollution in forested systems, and thus makes an important contribution to the science and practice of biomonitoring in Nigeria where such studies are sparse.]]> Wed 12 May 2021 17:31:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6047 Wed 12 May 2021 17:17:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6040 Wed 12 May 2021 17:09:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:26617 Wed 12 May 2021 16:53:37 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:34270 Wed 12 May 2021 16:50:37 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6027 Wed 12 May 2021 16:40:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6023 Wed 12 May 2021 15:59:29 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6052 Wed 12 May 2021 15:55:13 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42934 0.5). The model also performed generally well compared to established models that had been previously applied in some of the study catchments. The highest sediment yields recorded per country were 153 t km-2 year-1 (Tsitsa River; South Africa), 90 t km-2 year-1 (Odzi River; Zimbabwe) and 340 t km-2 year-1 (Rio Tanama; Puerto Rico). The results also displayed consistent underestimations of peak sediment yield events, partly attributed to sediment emanating from gullies that are not explicitly accounted for in the WQSED model structure. Furthermore, the calibration process revealed that the WQSED storage model is generally challenging to calibrate. An alternative simpler version of the storage model was easier to calibrate, but the model may still be challenging to apply to catchments where calibration data are not available. The additional evaluation of the WQSED simulated sediment yield rates against observed reservoir sediment rates showed a broad range of differences between the simulated and observed sediment yield rates. Differences between WQSED simulated sediment and observed reservoir sediment ranges from a low of 30% to a high of > 40 times. The large differences were partly attributed to WQSED being limited to simulating suspended sediment from sheet and rill processes, whereas reservoir sediment is generated from more sources that include bedload, channel and gully processes. Nevertheless, the model simulations replicated some of the regional sediment yield patterns and are assumed to represent sheet and rill contributions to reservoir sediment in selected catchments. The outcome of this study is an improved WQSED model that has successfully undergone preliminary testing and evaluation. Therefore, the model is sufficiently complete to be used by independent researchers and water resources managers to simulate erosion and sediment transport. However, the model is best applicable to areas where some observed data or regional information are available to calibrate the storage components and constrain model outputs. The report on potential MUSLE scale dependencies is relevant globally to all studies applying the MUSLE model and, therefore, can improve MUSLE application in future studies. The WQSED model offers a relatively simple, effective and applicable tool that is set to provide information to enhance catchment, land and water resources management in catchments of Africa.]]> Wed 12 May 2021 14:47:01 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42897 Wed 12 May 2021 13:50:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:44959 Wed 02 Mar 2022 15:26:29 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:57245 Tue 25 Oct 2022 15:19:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:46470 50%) of each EI category is stable, but there are areas showing signs of degradation, including 43% of grasslands degraded and 39% of wetlands, cultivated lands, and riparian zones also degraded. Degradation is dominant in the upper (T35B and T3C) and lower (T35K, T35L and T35M) parts of the catchments. The three criteria used by the stakeholders in the prioritisation process of the key EI were assigned 12 spatial attributes (the catchment characteristics about the study area in relation to the criteria) to indicate relevant information needed for selecting suitable restoration areas to enhance flow regulation. The AHP analysis results identified approximately 63% (17,703 ha) of wetlands, 88% (235,829 ha) of grasslands, 78% (13,608 ha) of abandoned cultivated fields and 93% (3,791 ha) of the riparian zones as suitable areas for restoration to mitigate drought impact through flow regulation. Also, the suitability results showed 63% (17,703 ha) of wetlands, 58% (2,203 ha) of riparian zones, 68% (11,745 ha) of abandoned cultivated fields and 46% (122,285 ha) of grasslands as suitable restoration areas for improving ecosystem services for community livelihoods. The AHP analysis identified more than 39-43% (of the degraded EI indicated by the Trends.Earth analysis) areas that are suitable for restoration, because key EI plays a significant role in flow regulation and people’s livelihoods, especially when they are managed, maintained, and restored to good health conditions. Therefore, the prioritized EI areas should be either maintained, managed, rehabilitated or restored. The major distinct causes of land degradation are woody encroachment in grasslands, invasion of alien plants on abandoned cultivated fields and soil erosion in the catchment. The most suitable EI areas recommended for restoration are those natural resources near local communities, which provide essential ecosystem services to sustain their livelihood. Therefore, degraded EI in the T35 catchments should be restored and maintained to improve livelihood and mitigate drought impacts. The study pointed out how the key selected ecological infrastructure can help mitigate the impacts of droughts and improve human livelihood. The study contributes towards the important concept of investing in ecological infrastructure to improve the social, environmental, and economic benefits.]]> Thu 22 Sep 2022 12:27:12 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6042 Thu 15 Jul 2021 20:34:36 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:21328 Thu 13 May 2021 08:20:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6032 Thu 13 May 2021 08:11:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6037 Thu 13 May 2021 07:39:03 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6044 Thu 13 May 2021 06:55:18 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6053 Thu 13 May 2021 06:50:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:31220 Thu 13 May 2021 06:48:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6055 Thu 13 May 2021 06:37:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:19958 Thu 13 May 2021 06:16:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6041 Thu 13 May 2021 06:03:25 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6030 Thu 13 May 2021 05:37:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6056 Thu 13 May 2021 05:14:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6033 Thu 13 May 2021 05:00:58 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6051 Thu 13 May 2021 04:55:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6043 Thu 13 May 2021 04:31:00 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6029 Thu 13 May 2021 04:30:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6054 Thu 13 May 2021 03:19:11 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:38554 Thu 13 May 2021 03:02:27 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35424 Thu 13 May 2021 02:53:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6050 Thu 13 May 2021 01:12:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6046 Thu 13 May 2021 01:12:38 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:38100 Thu 13 May 2021 01:12:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:6024 Thu 13 May 2021 00:27:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45070 Thu 07 Jul 2022 15:33:25 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49971 Sat 01 Jul 2023 15:28:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28417 Mon 22 May 2023 15:47:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28389 Mon 19 Jul 2021 12:03:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28388 Fri 17 Sep 2021 12:45:46 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28490 Fri 06 Aug 2021 11:00:38 SAST ]]>