Recently watershed prioritization has become a pragmatic approach for watershed management and natural resources development. Wadi Shueib is a Jordan Rift valley and covers an area of 177.8 km<sup>2</sup>....Recently watershed prioritization has become a pragmatic approach for watershed management and natural resources development. Wadi Shueib is a Jordan Rift valley and covers an area of 177.8 km<sup>2</sup>. The upper catchment is of dry Mediterranean climate, whereas the lower part is arid. The drainage network is sub-dendritic pattern, with a trellis pattern developed due to the influence of W. Shueib structure. Fourteen mini-watersheds were delineated and designated as (MW 1 to MW 14) for prioritization purposes. Morphometric analysis, and soil erosion susceptibility analysis were conducted, and their values were calculated for each mini-watersheds. Based on value/relationship with erodibility, different prioritization ranks were ascribed following the computation of compound factors. Based on morphometric and soil erosion susceptibility analysis, and the resultant ranks, the mini-watersheds have been classified into four categories in relation to their priority for soil conservation measures: very high, high, moderate, and low. It is found that 64.3% of the 3<sup>rd</sup> order mini-watersheds are classified in the categories of very high and high priority. Based on soil erosion susceptibility analysis, three mini-watersheds are of very high priority and three are of high priority. The integration of morphometric and soil erosion susceptibility methods shows that mini-watersheds no.2 and no.3 are common mini-watersheds, and can be classified in the class of moderate and low priority respectively. By contrast, two mini-watersheds (no.8 and no.13) are categorized in the class of high priority based on morphometric analysis, and are classified in the category of very high priority based on soil erosion susceptibility analysis. Similarly, mini-watershed no.14 can be placed in the category of very high priority based on morphometric analysis, and ranks in the category of high priority based on soil erosion susceptibility analysis. With reference to the integration of the two methods of prioritization, it can be concluded that most of the mini-watersheds can be categorized in the classes moderate, high, and very high priority. Consequently, the entire W. Shueib watershed must be prioritized for soil and water conservation to ensure future sustainable agriculture and development of natural resources.展开更多
The study is aimed at analyzing the risk of Taita Hills region of harmful runoff and soil erosion by employing morphometric analysis and change detection in a GIS environment to prioritize the Taita Hills in Taita Tav...The study is aimed at analyzing the risk of Taita Hills region of harmful runoff and soil erosion by employing morphometric analysis and change detection in a GIS environment to prioritize the Taita Hills in Taita Taveta County. The objective of the study was to characterize and give hierarchy in which the region should be conserved. The methodology adopted hydrological modeling, morphometric computation, Weighted Sum Analysis (WSA) and change detection. Hydrological modeling was vital in delineating the sub-watersheds and stream network. Morphometric computation and WSA was applicable in coming up with parameters and weighting the parameters for each sub-watershed’s prioritization. Change detection is related to how human activity is important for conservation as the effect of land forms and dimensions are compounded. Twenty-one fourth order streamed sub-watersheds were generated and prioritized using morphometry and change detection. Every sub-watershed is given a hierarchy based on the calculated compound parameter from the WSA equation developed and shows the risk of runoff and soil erosion. The morphometric prioritization shows 47% of the watersheds are in the high and very highly susceptible areas and there are two sub-watersheds with the highest land cover change. As well six sub-watersheds are risky with both land cover change and morphometry.展开更多
文摘Recently watershed prioritization has become a pragmatic approach for watershed management and natural resources development. Wadi Shueib is a Jordan Rift valley and covers an area of 177.8 km<sup>2</sup>. The upper catchment is of dry Mediterranean climate, whereas the lower part is arid. The drainage network is sub-dendritic pattern, with a trellis pattern developed due to the influence of W. Shueib structure. Fourteen mini-watersheds were delineated and designated as (MW 1 to MW 14) for prioritization purposes. Morphometric analysis, and soil erosion susceptibility analysis were conducted, and their values were calculated for each mini-watersheds. Based on value/relationship with erodibility, different prioritization ranks were ascribed following the computation of compound factors. Based on morphometric and soil erosion susceptibility analysis, and the resultant ranks, the mini-watersheds have been classified into four categories in relation to their priority for soil conservation measures: very high, high, moderate, and low. It is found that 64.3% of the 3<sup>rd</sup> order mini-watersheds are classified in the categories of very high and high priority. Based on soil erosion susceptibility analysis, three mini-watersheds are of very high priority and three are of high priority. The integration of morphometric and soil erosion susceptibility methods shows that mini-watersheds no.2 and no.3 are common mini-watersheds, and can be classified in the class of moderate and low priority respectively. By contrast, two mini-watersheds (no.8 and no.13) are categorized in the class of high priority based on morphometric analysis, and are classified in the category of very high priority based on soil erosion susceptibility analysis. Similarly, mini-watershed no.14 can be placed in the category of very high priority based on morphometric analysis, and ranks in the category of high priority based on soil erosion susceptibility analysis. With reference to the integration of the two methods of prioritization, it can be concluded that most of the mini-watersheds can be categorized in the classes moderate, high, and very high priority. Consequently, the entire W. Shueib watershed must be prioritized for soil and water conservation to ensure future sustainable agriculture and development of natural resources.
文摘The study is aimed at analyzing the risk of Taita Hills region of harmful runoff and soil erosion by employing morphometric analysis and change detection in a GIS environment to prioritize the Taita Hills in Taita Taveta County. The objective of the study was to characterize and give hierarchy in which the region should be conserved. The methodology adopted hydrological modeling, morphometric computation, Weighted Sum Analysis (WSA) and change detection. Hydrological modeling was vital in delineating the sub-watersheds and stream network. Morphometric computation and WSA was applicable in coming up with parameters and weighting the parameters for each sub-watershed’s prioritization. Change detection is related to how human activity is important for conservation as the effect of land forms and dimensions are compounded. Twenty-one fourth order streamed sub-watersheds were generated and prioritized using morphometry and change detection. Every sub-watershed is given a hierarchy based on the calculated compound parameter from the WSA equation developed and shows the risk of runoff and soil erosion. The morphometric prioritization shows 47% of the watersheds are in the high and very highly susceptible areas and there are two sub-watersheds with the highest land cover change. As well six sub-watersheds are risky with both land cover change and morphometry.
