Potential impacts of climate change on groundwater supplies to the Doñana wetlands, Spain

Climate change impacts on natural recharge and groundwater-wetland dynamics are investigated for the Almonte-Marismas aquifer, Spain, situated in the Doñana National Park. Simulations are carried out using outputs from 13 GCMs to assess the impacts of climate change by estimating the reduction in flow from the aquifer to streams and drains flooding the wetland, induced by changes in recharge according to different simulated climates. The results of this modelling study indicate that the change in climate by the 2080s under the SRES A2 emissions scenario will lead to a reduction in groundwater resources. The reduction in recharge ranges from 33% to 70%. The simulations show that there is an impact on hydraulic head in terms of the overall water table configuration with decreases in groundwater level ranging from 0 to 17 m. Most simulations predict lower discharge rates from the aquifer to streams, with the most significant reductions being in the La Rocina (between -57% and -27%) and Marismas (between -50% and -19%) catchments. Water flows from these two basins are critical to maintain aquatic life in the wetland and riparian ecosystems. The results highlight that effective strategies for groundwater resources management in response to future climate change are imperative.Área de Geología Ambiental y Geomatemáticas, Instituto Geológico y Minero de España, EspañaKingsley Dunham Centre, British Geological Survey, Reino Unid