#rusle

Authored by Gizaw Tesfaye

Abstract

This study was aimed to estimate soil loss in Gilgel Gibe-1 catchment by GIS-based RUSLE model and prioritize sub-watersheds for soil conservation planning. Both primary and secondary data from different sources were used in this study. The amount of soil loss from the catchment is estimated with GIS-based RUSLE model which uses the rainfall-runoff erosivity, soil erodibility, topographic effect, soil/surface coverage and land management practice of the catchment as an input. The result of the study shows the mean annual soil loss of the catchment is 62.98 t ha-1year-1 which is about 26.56x106 ton year-1. Erosion ‘hotspot’ areas are identified and prioritized on the bases of soil loss. Accordingly, SW4, SW3, SW5, SW6, SW9, SW8, SW7, SW2, and SW1 got 1 to 9 priority level respectively. 35.2% of the catchment area is covered by soil loss class ranging 0-5 t ha-1year-1 and about 56 % of the catchment have soil loss greater than a tolerable level which is 11 t ha-1year-1. The result of this study indicates the catchment and reservoir were under a problem of soil loss and siltation. Therefore, this study recommends immediate action, soil and water conservation measures, should be taken in the catchment according to the priority of sub-watershed and, also a detailed study is appreciated, especially on experimental test plots.

  Introduction

Soil erosion is a serious problem in the Ethiopian highland areas that increased sedimentation of reservoirs and lakes [1]. Rapid population growth, cultivation on steep slopes, clearing of vegetation and overgrazing are the main factors that accelerate soil erosion in Ethiopia. In Ethiopia, soil erosion and nutrient depletion have been one of the most important environmental problems [2]. Rapid land use changes due to intensive agricultural practices in the Ethiopian highlands results in increasing rate of soil erosion [3]. The trans-boundary rivers that originate from the Ethiopian highlands carry about 1.3 billion tons/year of sediment to neighboring countries whereas the Blue Nile alone carries 131 million tons/year [4]. In terms of soil loss due to erosion, estimates vary by locations, which reflects the varying Ethiopian landscape, management practices and soil characteristics within and between sub-basins [5]. measured soil erosion rates on test plots and estimated a loss of 130 to 170 ton ha-1yr-1 on cultivated land. Furthermore, the average annual soil loss in Medego watershed in the north of Ethiopia was estimated at 9.6 t ha-1yr-1 [6].

For more Open Access Journal in Juniper Publishers please click on: https://juniperpublishers.com/

For more articles in Open Access Journal of Environmental Sciences & Natural Resources please click on: https://juniperpublishers.com/ijesnr/

To know more about Peer Review Journal of Environmental Sciences & Natural Resources please click on: https://juniperpublishers.com/ijesnr/index.php

Bchs x stank

Saludos Rusle crew!!