Geospatial based groundwater resources susceptibility and contamination risk mapping for Yeşilköy aquifer, Cyprus

Abstract

In rural areas where the goals of sustainable agriculture are intertwined with the availability and supply of groundwater resources, it becomes imperative to perceive and search the status of groundwater resource’s susceptibility to contamination. A well-known overlay & index method, the DRASTIC model that assesses the state of susceptibility to contamination using vulnerability index map has been applied to the Yeşilköy aquifer. The seven different hydro-geologic parameters; aquifer media, vadose zone, and soil media, surface topography, recharge capacity, water table depth, and the hydraulic conductivity maps were overlaid to find the vulnerability of the aquifer. Results depicted that the aquifer is categorized into two vulnerability zones; low and moderate. The available susceptibility of the aquifer due to ongoing anthropogenic activities like agriculture was also studied by implementing the Weighted Arithmetic Water Quality Index (WQI) method. The aquifer’s overall water quality was “poor water quality”. Hence, there was no significant relationship between WQI and the vulnerability of the aquifer. A modification of the DRASTIC to enhance the relationship with WQI is proposed by utilizing the Analytic Hierarchy Process (AHP), as one of the successful multi-criteria decision-making models. The modification of the DRASTIC model with AHP revealed that the performance of the DRASTIC model was improved and the correlation between WQI and the DRASTIC vulnerability index was significantly enhanced. The results also show that the effective contributing parameters for groundwater vulnerability in the Yeşilköy aquifer were the aquifer media and the vadose zone. On the other hand, the water table’s depth and topography were almost independent of the aquifer’s vulnerability.