Las Tablas de Daimiel National Park - Spain

Las Tablas de Daimiel National Park is among the many freshwater wetlands around the world that experienced strong hydrological alterations since the 1970s decade. Wetland hydrological functioning changed from a groundwater-dependent system to one that is maintained by artificial external water diversions. Both rainfall and water flow variability are the main hydrological patterns in the wetland area, whilst evapotranspiration appeared as the main hydrologic variable controlling the TDNP annual water storage. The historical analysis of the annual inundation patterns at TNDN has allowed discriminating between 4 distinctive hydroperiods, showing the importance of groundwater discharges to sustain the pristine hydroperiod. While drought frequency ?as measured by the Standard Precipitation Index (SPI)? did not increase in the region, groundwater pumping for irrigation appeared as the main cause of groundwater overexploitation and wetland hydrology degradation. Currently, from 2010 and after three consecutive humid years the wetland experience one the best hydrological periods with an extraordinary recovery of groundwater levels (some springs have been observed in the area close to the ancient Ojos del Guadiana area). However, this scenario could be not sustained in the future if the patterns of socioeconomic development do not change do not change and the exploitation of groundwater remains the driving of the regional economy. A hydrological model developed to simulate wetland hydrology and cut-sedge restoration shown that Las Tablas de Daimiel requires an external annual water supply of close to 54 Mm3 to sustain their ecosystem functions and services. Future stream and groundwater flows at the Upper Guadiana basin will depend on the land use management, while climate change effects will be secondary, considering the actual hydrological situation.