Estimating the change in groundwater quality resulting from changes to land use and groundwater recharge

Abstract

Global change will change the quantity and quality of groundwater resources and subsequently the prerequisites for the supply of safe drinking water. Quite often, attempts are made to simply express the status of groundwater resources by stating changes in groundwater level or concentrations. However, such results require further interpretation by experts before they can be used in decision making. This chapter presents the approach chosen in GLOWA-Danube to translate the results of model simulations of land use changes calculated by the agricultural model Farming into an index that expresses the changes of the quality status of groundwater resources in one single value. The chosen approach is based on the intrinsic groundwater vulnerability index (DRASTIC) and a predefined typical pollution load associated with different land uses. This chapter describes the methodology chosen and the main assumption underlying the approach. Results are shown for selected districts of the UDC for a variety of climatic and societal scenarios.