A climate change impact on groundwater recharge assessment method using different analytical methods
Résumé
Assessing the climate change impact on groundwater recharge can represent a challenge due to the generally limited knowledge about infiltration processes, interaction with surface water or between aquifers, available data and pumping impact on it. Using different methods to estimate recharge is recommended in order to integrate uncertainties (Scanlon et al., 2006). Nonetheless, only some of the existing recharge estimation methods (ie. water balance methods) allow exploring the impact of future climate on recharge, as meteorological variables are taken as input data.
A multi-method recharge estimation, combining several analytical recharge estimation methods based on climate data, discharges or piezometric levels depending on the method, has been tested over contrasted aquifers located in France. The comparative analysis of the results proves to be an interesting way to assess the main recharge processes of an aquifer and to illustrate the uncertainties linked to a given estimation method. Based on that assessment, it is possible to explore the climate change impact on direct recharge over a large spatial extent, providing results including the uncertainty associated to the recharge estimation method and to the global recharge processes.