Climate Influence Vs. Local Drivers in Surface Water-Ground water Interactions in Eight Ponds of Donana National Park (Southern Spain)

摘要

This paper aims to determine how both climate and local drivers, such as groundwater withdrawals influence surface water - groundwater interactions in Groundwater Dependent Ecosystems (GDEs). We studied the hydroperiod in eight of the most representative ponds of Donana National Park (southern Spain) during a 21-year period. We analyzed the average flooded phase of each pond as well as the average depth of the piezometric level in nearby piezometers. In addition, we used the average precipitation as a proxy of the water inputs onto the ponds. The average flooded surface was taken by a previous analysis of satellite images and the depth to the piezometric level was field measured at a monthly time step. We found out that the average precipitation was slightly lower during the second decade (675 mm/y vs. 552 mm/y). Nonetheless, 5/8 of the ponds showed a much higher shrinking of the flooded surface that could not be explained only by a reduction in the precipitation events. Local drivers were found to be decisive in the degradation of 3/8 of the ponds: those closer to a pumping facility and located at a higher altitude.