Groundwater recharge in North Rhine-Westphalia projected using the model chain RCP-GCM-RCM-mGROWA

摘要

In order to analyze the impact of climate change on groundwater resources in North Rhine-Westphalia a multi-model ensemble for projecting future groundwater recharge was established. The ensemble consists of 36 members of the model chain RCP-GCM-RCM-mGROWA in total, i.e. combinations of 3 greenhouse gas concentration trajectories, 6 global and 5 regional climate models, and the water balance model mGROWA. The ensemble projections show only a few significant changes of groundwater recharge in the future periods 2011-2040, 2041-2070, and 2071-2100. A robustness test using the two-criteria model agreement and the significance of the individual model projections did not reveal systematic and significant changes of groundwater recharge until 2100. From the statistical point of view, groundwater recharge can be expected to remain at the current level. Hydrometeorological, North Rhine-Westphalia is located in a transition zone in which the impact of the rising winter precipitation on groundwater recharge is counter-balanced by the impact of warming.