Delineation of groundwater critical zones by integrating GIS and MCDM techniques in the arid region of Sirjan, southeastern Iran

Abstract

In arid regions, the overexploitation of groundwater (GW) has led to the degradation of aquifers. To address this issue, identifying GW critical zones (GWCZs) is more crucial than identifying GW potential zones. This paper delineates GWCZs in the Sirjan district by integrating geographic information system (GIS) and multi-criteria decision-making (MCDM) techniques. Two scientific MCDM models, including the analytic hierarchy process (AHP) and multi-influencing factors (MIF), were employed to create a GWCZs map. Within the GIS platform, the field data were applied to create, classify, and assign weights to thematic layers of Annual GW discharge (AGD), water well density (WWD), aquifer recharge (AR), aquifer lithology (AL), aquifer thickness (AT), and GW quality change (GQC). Subsequently, the GWCZs map was generated by applying the overlay weighted-sum method to the six different layers. Using AHP, 10.04, 23.62, 32.8, and 33.54 %; and using MIF, 10.13, 23.36, 40.59, and 25.92 % of the study area were classified into critical, sub-critical, semi-balanced, and balanced zones, respectively. The regression analysis and receiver operating curve (ROC) techniques were utilized to assess the reliability of the models. The comparison revealed that both models have acceptable results. However, the MIF method, with an R² of 0.88 and Area Under Curve (AUC) of 0.83, was more reliable than the AHP method, with an R² of 0.86 and AUC of 0.81. The findings of this research can provide valuable assistance for local and government authorities to ensure the sustainable management and development of GW resources.