Delineation of Groundwater Potential Zones in Nangarhar Province, Using RS, GIS, and Analytical Hierarchy Process (AHP)

Abstract

Groundwater is the main sources of water supply in Afghanistan, especially that areas where access to surface water is hard and difficult. Nangarhar Province has significant surface and groundwater resources and depend extensively on these resources for domestic and agricultural usage, including orange orchards, vegetable cultivation & sugarcanes production. Therefore, detecting areas with suitable groundwater potential is essential for sustainable SGRM (groundwater resource management) and well siting. The present study aimed to identify GPZ in Nangarhar Province using RS, GIS, and the AHP. The research of study is in terms of purpose and employed a quantitative, analytical, and spatial methodology. 7 layers, includes precipitation, slope, lithology, soil type, Dd, LD, and LULC, were analyzed in ArcGIS 10.8. The criteria were weighted through MCDA using AHP model and weighted overlay method. Results showed that the central, southern, and southeastern parts of mention area predominantly fall within the high and very high GP classes, whereas the northern and northeastern parts are mainly characterized by low to moderate potential. Validation using 20 observation wells showed that 80% agreement is between the GP map and observed well locations. Simultaneously, Sensitivity analysis also indicated that limited changes in criterion weights did not importantly affect the all-spatial pattern of the GP map. The findings can support SGRM, well siting, agricultural planning, and improved groundwater development and management in the study area, especially in areas expose to increasing water demand and future needs.