A Remote Sensing and GIS Approach for Prioritization of Wadi Shueib Mini-Watersheds (Central Jordan) Based on Morphometric and Soil Erosion Susceptibility Analysis

摘要

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 km2. 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 3rd 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.