Groundwater protection: A comparative study of four vulnerability mapping methods

The catchment area of the groundwater resources supplying Antalya City consists of travertine rock formations. As a result of the extreme permeability of this formation, the groundwater resources are highly susceptible to pollution. In recent years this resource has been subject to severe human impact. Especially the newly constructed residential centers in this area constitute a severe threat, as the produced wastewater in these areas is mainly disposed via percolating septic tanks. The main task for future development is to protect these karst aquifers from pollution originating from humans. The mapping of groundwater vulnerability to pollution is widely used as a tool for the protection of groundwater resources all over the world. These kinds of maps can also be used by decision makers in the framework of environmental management and in developing land use plans. On the other hand reliability and accuracy of these vulnerability maps are the key issue for their usage. For the determination of the groundwater vulnerability, different methods can be used. In this study, DRASTIC, SINTACS, PI and COP methods are evaluated for their effectiveness in assessing the vulnerability of the groundwater resources to pollution. While PI and COP methods respond the karst characteristics in Antalya better than DRASTIC and SINTACS, the combined use of different methods evaluates the region at a good and acceptable level, as well.