Comparative analysis of intrinsic groundwater vulnerability assessment methods for carbonate aquifers

Abstract : Groundwater from carbonate aquifers in the Cañete Mountain Range constitutes an important water resource that is used to supply a number of local population centres. Intrinsic vulnerability assessment and cartography are some of the most useful tools used to inform groundwater protection strategies. The Cañete Mountain Range area was chosen to carry out a comparative analysis of selected groundwater vulnerability assessment methods, by using spatial analysis tools and technical statistics through a geographical information system. In this study the Reduced DRASTIC, COP and RISK methods were applied and maximum concentration of nitrates is used to validate the results. The results obtained demonstrated how the COP and RISK methods, which were specifically designed for carbonate aquifers, better fit the characteristics of the Cañete Mountain Range than the results obtained with the Reduced DRASTIC method, in which the evaluation of groundwater vulnerability is based solely on unsaturated zone characteristics.