Erosion hotspot mapping using integrated morphometric parameters and Land use/land cover of Jigjiga Watershed, Ethiopia

Abstract

Integration of morphometric parameters (MPs) and Land use/land cover (LU/LC) is crucial to prioritise the sub-watershed for conservation management to control soil erosion. The main objective of this study is to develop erosion hotspot mapping using integrated MPs and the LU/LC of Jigjiga Watershed further precisely to map soil erosion hotspots using MPs, LU/LC types and mapping of erosion hotspots by average weightage of MPs and LU/LC types. The study used the digital elevation model data for MPs analysis to extract the areal, linear and relief aspects to determine erosion risk mapping further using ArcGIS 10.5 software. The Jigjiga watershed was sub-divided into fifteen sub-watersheds and coded as JSW-1 to JSW-15. The MPs and LU/LC types computed values were used to rank and prioritise the sub-watersheds. Jigjiga Sub-watershed, LU/LC types were analysed for erosion risk area mapping using the Compound Priority method. The degree of prioritisation used for this study for the MPs and LU/LC types was very high, high, moderate, low, and very low. Accordingly, the erosion hotspots mapping results showed that the sub-watersheds JSW-15 and JSW-14 were categorised under a high priority based on MPs, whereas the JSW-14 was put under a very high priority by LU/LC. The JSW-1, JSW-5, JSW-9 and JSW-13 need high priority for natural resources conservation, both methods of MPs and mean weightage of LU/LC and MPs. The integration of erosion hotspot mapping from MPs and LU/LC parameters correlated for JSW-2, JSW-3, JSW-10, JSW-11, JSW-13 and JSW-14 common values of final erosion prioritisation. This research has provided information on land degraded areas for watershed managers, urban planners and decision-makers to manage the natural resources for sustainable watershed development.