Delineation of groundwater potential zones using remote sensing (RS), geographical information system (GIS) and analytic hierarchy process (AHP) techniques: a case study in the Leylia-Keynow watershed, southwest of Iran

In this research, a standard methodology has been applied to delineate groundwater resource potential zonation based on integrated remote sensing (RS), geographic information system (GIS), and analytical hierarchy process (AHP) techniques in Leylia-Keynow watershed, southwest of Iran. A total of five sets of criteria/factors (including lineament density, rainfall, lithology, slope, and drainage density) believed to be influencing groundwater storage potential in the area were selected. Each criterion/factor was assigned appropriate weight based on Saaty's 9-point scale and the weights were normalized through the analytic hierarchy process (AHP). The process was integrated in the GIS environment to produce the groundwater potential prediction map for the area. The fi9-p groundwater prospect map obtained was classified as excellent potential, very good potential, good potential, moderate potential, and poor potential zone. The obtained results indicated that only 21% (122 km(2)) of the study area exhibit poor groundwater potential, whereas most of the regions (326 km(2)) in the research showed good to excellent groundwater potential. Also, about 24% (141 km(2)) was classified as having moderate groundwater potential. The good to excellent potential zones are characterized by the higher lineament density, higher rainfall, and lithology type such as limestone, whereas the poor to moderate groundwater potential zones are characterized by the lesser lineament density, lower rainfall, lithology type of shale and marl as well as shale and limestone. Based on the obtained evidences, the tectonic structures had an important role in fracturing and crushing of limestone units in the area and so are vital for karst and ground water sources development. The demarcation of groundwater potential zones in the Leylia-Keynow watershed will be helpful for future planning, development and management of the groundwater resources.