GIS-BASED ASSESSMENT OF MICRO TO SMALL SCALE HYDROPOWER POTENTIAL (CASE STUDY ON WESTERN SELECTED SUB-BASINS OF ABAYA-CHAMO LAKES, ETHIOPIA)

Abstract

Hydropower is a clean, renewable and reliable energy source that serves as an environmental and energy policy objectives. It is, therefore, necessary to assess these renewable energy sources in addition to other alternative energies in Ethiopia. The utilization of renewable energy resources may reduce the dependency on traditional energy sources of the country and that may lead to power generation. The searching and formulation of information about the assessment, accessibility and identifying feasible potential sites is an input for planning, drafting policies and strategies for hydropower projects. The objective of this study is to assess the micro to small scale hydropower potentials of Western selected sub-basins of Abaya-Chamo Lakes using geospatial data and techniques. Western selected sub-basins of Abaya-Chamo Lakes is located in the Abaya-Chamo sub-catchment in the Southern part of Ethiopia. The consistency of seven gauged rainfall data has been checked using the double mass curve. The quality flow data of Kulfo and Hare Rivers were screened using the methods of Spearman’s rank correlation and stability of variance and mean tests. Geographical Information System tools are used for processing the satellite images, delineation of watershed and stream network, developing of hydropower modeling, discharge and head raster maps and identification of potential sites for hydropower projects. Twenty-five (25) suitable hydropower potential sites were selected in Western selected sub-basins of Abaya-Chamo Lakes. The individual and total amount of theoretical power of all sites were estimated at each 30%, 40%, 50%, 60%, and 90% flow exceedance. The total annual energy output of 64.75GWh was obtained from the selected hydropower potential sites. The suitable sites were ranked based on the priority weights which calculated using AHP and WLC methods. Sites-2 (S2) were ranked first for both Kulfo and Hare Rivers among the suitable sites. This study will aid the concerning bodies in the energy sector to optimize the available resources in selecting suitable sites for hydropower plants with higher power potential. The proposed approach can further be utilized to assess overall hydropower potential of the country.