Vulnerability Assessment in Karst Aquifers with EPIK and COP Indices Calibration

One of the most important water resources for extraction and exploitation is karst water resources, which has grown greatly due to the trend of exploitation of aquifers and the decline of these resources. This increase in exploitation has the potential to pollute water resources due to a set of anthropogenic factors. Therefore, recognizing the development potentials should be based on the vulnerability of these resources. This study aims to determine the vulnerability of karst aquifers with two EPIK and COP indices. Accordingly, considering geological studies, the type of karst formations and the karst network in the region, the parameters of each index were extracted and the final index was calculated. After determining each index, the level of vulnerability was calibrated based on the springs available in the region in terms of quality. In order to calibrate the GQI qualitative index with the zoning of the springs in the region, whale optimization algorithms were used. In this calibration, the weights and ranks of the two vulnerability indices were determined. The results showed that the EPIK index had a good accuracy before calibration, but after calibration, the results and the correlation between the vulnerability index and the GQI quality index indicated an increase in the correlation in the COP index. The results showed that the correlation index increased and improved from 0.34 to 0.57 for the COP index.