Recognition of groundwater potential zones using geo-spatial technique: A case study in Thatta Tehsil, Sindh, Pakistan

Abstract

Water is one of the primary requisites for the existence of life. Overutilization of this critical wealth is threatening our ecosystems as well as the life of future generations. To change pressure on this natural resource, there is a need to find out potential sites of groundwater using modern techniques. The aim of this study is to determine groundwater potential zones using consolidation of Remote Sensing and GIS technique. The data used for this study includes 30 meter resolution ASTER GDEM, Landsat 8 imagery and existing Geological and Soil maps. Using these data, different thematic layers were developed i.e. slope, drainage density, lineaments density, geological, soil and land cover maps. Lineaments were carried out by visual interpretation of different band combinations. Weightage are assigned based on their capability to store groundwater. These were then integrated with weighted overlay in ArcGIS to get potential zones of ground water. The groundwater potential zones were then classified into five categories like excellent, good, moderate, poor and very poor. Produced ground water potential zone map were compared and validated by existing hand pumps and well data obtained from different localities of the project area. This study specifically show that Geo-spatial techniques with compounding of field data could be used for the determination of ground water potential zones. It can be considered as a time and cost-efficient practice for depiction and designation of high potential ground water target areas.