Assessment of Ground Water Potential Zone based on Multi-Criteria Decision making model and Geospatial Techniques: The case of Lemo Woreda and Hossana town, Hadiya Zone, Southern Nation Nationalities

The objective of this paper is to assess and map groundwater potential zone in Lemo woreda and Hosana town by the integrating approach of Geospatial Techniques. For this purpose both primary and secondary data were used. Ground Control Points (GCP) were collected from Google earth; Digital Elevation Model (DEM) and Landsat 8 down loaded, besides, secondary data such as, soil data, rainfall, and Lithology were collected from different governmental institutions. Ground water controlling factors, namely, lithology, Geomorphology, slope, land use land cover (LULC), rainfall, lineaments, soil, and drainage density were generated. In order to map ground water potential area, Geographic Information System (GIS), Remote Sensing and Analytical Hierarchy Process (AHP) were used. AHP was used for computing weight for the parameters by comparing eight factors. The consistency ratio was less than 0.1(CR -0.03) which is acceptable weight to compute weighted overlay analysis in GIS environment .The weight derived for Rainfall, slope, Geomorphology, Soil type, lineaments density, drainage density , land use land cover (LULC) and lithology are:27%, 17%, 16%, 12 %, 9%, 8%, 6% and 5%, respectively, and the groundwater prospective of the area is qualitatively classified into five classes, namely, very high, High, moderate, low, and very low which account for 14.04%, 20.34%, 26.68%, 28.51%, and 10.44 % the study area, respectively. The cross-validation of the resultant model was carefully carried out using spring, and water well data. The result tells most of spring and water well overlaying high and very high groundwater potential zones. As a result, the map generated using this platform could be used as a preliminary reference in selecting potential area for groundwater exploitation.