CC-PESTO: a novel GIS-based method for assessing the vulnerability of karst groundwater resources to the effects of climate change

Abstract

The new GIS-based CC-PESTO method is shown to successfully assess and map the vulnerability/resilience of karst aquifers to effects of climate change. Karst aquifers were chosen due to their importance at the global level and widespread utilisation in potable water supply and irrigation, but also because of their hydrogeological complexity. The method was developed to assess the intrinsic vulnerability of aquifers, without considering the direct impact of variable climate factors, but considering the adaptive capacity of aquifers in response to expected climate extremes (floods and prolonged droughts). The procedure includes a subdivision of aquifer systems and an assessment of four main attributes: permeability, storativity, the discharge regime and the slope of each of the subdivided segments. CC-PESTO was tested in three study areas located in the highly developed karst of Montenegro and Serbia. In Mt. Durmitor (Montenegro), four out of 21 subunits were found to belong to the category of ‘low vulnerability’ and to have a good prospect for further development. Two subunits in the Babine and Bogovina study areas (Serbia) were defined as less vulnerable than others. The results obtained should help water managers and spatial planners to safeguard and reserve these areas as alternative or supplementary water sources that might be able to reduce the shock on groundwater-dependent ecosystems caused by expected extended droughts. The CC-PESTO method is flexible, and its application is possible in other karstic terrains such as platform or tropical karst. Indexation of the main attributes and their subcomponents could be adapted to local circumstances.