GIS-Based Groundwater Potentiality Mapping Using AHP and FR Models in Central Antalya, Turkey

Abstract

Groundwater is considered one of the essential natural resources stored beneath the earth's surface by infiltration through various rock layers. Groundwater potential supplies almost 30% of fresh water globally, and in general, 65% of groundwater is used for agricultural irrigation, 25% as drinking water, and the remaining 10% is utilized as industrial water. This study aimed to delineate potential groundwater zones in the central Antalya province, Turkey, using the analytical hierarchy process (AHP) and frequency ratio (FR). Seven thematic layers, including lithology, slope, drainage density, landcover/land use, lineament density, rainfall, and soil depth, were considered as influencing factors for these models. The preparation of all geospatial datasets was carried out in the GIS environment and Google Earth Engine. Additionally, some authorized relevant web portals were also tried for obtaining the required spatial data. The findings of analysis by AHP and FR models showed that Muratpasa, Kepez, and eastern Dosemealti in the eastern part of the study area are characterized by a high potentiality of groundwater. In contrast, the regions in the southern and the western parts covered by igneous rocks and other less permeable sediments, also featuring high and steep slopes, were also followed by a low or very low groundwater potential. Consequently, the results from both models were assessed using the receiver operating curve (ROC) and area under the curve (AUC) for validation. The validation in this study confirmed the higher effectivity of the results achieved by FR than the AHP model.