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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/3017

Title: GIS-Based Conservation Priority Area Identification in Mojo River Watershed On the Basis of Erosion Risk
Authors: Kiflu, Gudeta
Advisors: Dr. Mekuria Argaw (PhD)
Keywords: GIS, Remote Sensing, Priority area
Mojo River watershed.
RUSLE, MCA,
Copyright: Jun-2010
Date Added: 11-May-2012
Publisher: AAU
Abstract: The identification of priority areas for the establishment of control measures is one of the first objectives of conservation plans. Since it is not possible to launch watershed management projects all over the watershed at the same time, it is very important to use some method to prioritize micro-watersheds. A particular sub-watershed may get top priority due to various reasons but often, the intensity of land degradation is taken as the basis. In this study, prioritization of micro-watersheds has been done on the basis of soil erosion risk. A methodology, based on Revised Universal Soil Loss Equation (RUSLE) and Multi-criteria Analysis (MCA), has been applied using remotely sensed data, together with other ancillary data in a GIS environment. The analysis shows that RUSLE and MCA help to categorize landscape units into different levels of erosion risk and identify areas that require priority in conservation measures in relative to others. Based on the RUSLE model, the potential average annual soil loss of each parcel of land in the watersheds ranges from 8.57 to 134.46t/ha/year with a mean annual soil loss of 21.2t/ha/year. The result showed that very high soil loss (82.6­ 134.5/ha/yr) is observed in MW6 and Six MWs (7, 9, 12, 14, 20, and 25) fell under high soil erosion classes (59.9 ­ 82.6t/ha/yr). About 40% of the micro-watersheds fall in below the annual average soil loss of the entire watershed. Based on the MCA approach, micro-watershedwise Composite Erosion Index (CEI) indicates that only MW 6 is under ‘Very high’ category with mean CEI above 2.11. The area covered under this category is 60.75 Km2 (3.69%). ‘High’ category is represented by 9 MWs (29.09%) covering 478.77 Km2 area. The landscape positions where steep slope, poor surface cover, erodible soil and gully erosion coincided show high erosion risk compared to others. As a result the critical micro- watersheds which are under very high and high category were selected and recommended to be intervened for conservation measures to reduce on-site soil loss and their off-site effects.
URI: http://hdl.handle.net/123456789/3017
Appears in:Thesis - Earth Sciences

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