Groundwater Risk Intensity Assessment. Application to Carbonate Aquifers of the Western Mediterranean (Southern Spain)

Abstract

In this work, the groundwater contamination risk is evaluated as a measure of protection for groundwater bodies intended for human consumption. For this purpose, intrinsic vulnerability maps and hazard maps of anthropogenic activities in the studied region have been taken into account. This region is constituted by carbonate aquifers that supply water to various populations. The methodology employed to determine the contamination risk was adapted from the COST Action 620 which was developed with the aim of protecting karst aquifer water. The vulnerability obtained through the PI method was modified to the COP method for the purpose of this study. The results obtained after evaluating the groundwater contamination risk show a predominance of the very low and low classes that cover more than 80 % of the study area. These areas coincide with outcrops of low permeability materials and an absence of pressures. Only 4 % of the region presents a high to very high risk of contamination which is located in areas of very high vulnerability and low to moderate pressures. These results are supported by chemical analyses of water sampled from a groundwater quality control network. Contamination risk studies are an important tool for the integrated management of groundwater and for designing protection measures. These protection measures should be incorporated into the territorial land use planning; furthermore they should define a possible plan of land uses and activities as well as establish limitations and prohibitions of impacting land uses and activities.