Application of fuzzy hierarchical analysis process in groundwater potential mapping (Case study: Silakhor plain)

Many groundwater resources have been significantly reduced in quality due to improper harvesting, and in addition to few problems, they have also suffered from quality problems. Hence, the potential mapping and exploration of groundwater resources have become a breakthrough in the field of hydrogeological research. In this study, with the aim of analyzing and evaluating areas with groundwater potential in Silakhor plain and developing a modified method, the process of fuzzy hierarchical analysis and GIS has been used. Eleven thematic layers including layers of lithology, rainfall, vegetation cover, lineament density and distance, elevation, slope, land surface temperature, land use and drainage density and distance were prepared based on satellite image processing and statistical data. Each layer and its classes were assigned a weight based on the fuzzy analytic hierarchy process. Groundwater resource potential map was classified into five classes including high, good, medium, low and poor potential. Accordingly, 56% of the plain area has high to medium potential, mostly located in the central and southwest of the plain, consistent with quaternary alluviums and carbonate hard rocks. Validation was done by the number, location and amount of withdrawals from exploitation wells in the area and it was found that 89% of the wells were located in areas with moderate to high groundwater potential. Therefore, using the fuzzy hierarchical analysis process is an effective and reliable way to identify areas with groundwater potential that can be used to develop and manage groundwater resources.