Identification of groundwater potential zones for sustainable groundwater resource management using an integrated approach in Sirkole watershed, Western Ethiopia

Abstract

The increasing population in the Sirkole watershed has led to a higher demand for groundwater resources essential for socio-economic development. To ensure sustainable groundwater management, accurate quantitative assessments are necessary, which can be achieved by utilizing scientific principles and modern techniques. This article discusses the use of RS and GIS techniques to evaluate Groundwater Potential Zones in a section of the Sirkole watershed in Western Ethiopia. The study analyzed various spatial data layers involving drainage density, land use, lineaments, slope, lithology, rainfall, geomorphology, and soil type to understand the factors influencing groundwater occurrence and movement. The eight thematic layers were weighted according to their significance. Additionally, a hierarchical ranking was performed using a pairwise comparison matrix (PCM) within the analytic hierarchy process (AHP) to determine the final normalized weights of these layers. Lineaments were extracted using PCI Geomatica and Rockwork software, and their orientations were determined. The sub-basin was divided into five zones based on the resulting GWPZ map: very high, high, moderate, low, and very low. The watershed was divided into two categories: high to very high potential for 22.8% of the area and very low to low potential for 45.4% of it. Validation against existing pumping wells showed a prediction accuracy of 75.9%, affirming the reliability of the GIS and RS techniques have been utilized for the identification of potential zones in the research area. The findings of this study can be utilized for the sustainable development of groundwater resources by pinpointing areas with high groundwater potential.