Time series analysis methods have been used to detect behavioral patterns in a set of nine time series. These series contained information in a 3‐h time step about meteorological, hydrological and tidal data of a sand dune pond area located in Doñana National Park in the southwest of Spain. The methods used, such as wavelet analysis and additive seasonal decomposition, had never been applied before in the types of ecosystems studied. These approaches have improved the current knowledge of the conceptual model of the Santa Olalla pond system, the only system with a permanent hydroperiod located in this protected area. In addition, complex surface water‐groundwater interactions, not visible through descriptive methods, have been distinguished to have a strong seasonal component. Finally, we evaluated the effect of pumping activity in a nearby coastal resort on the water supply of the Santa Olalla pond system. Although direct damage to this sand dune pond has not yet been identified, special attention must be paid in order to maintain groundwater inputs that are integral to maintaining its current status.

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Rainfall is the major contribution for groundwater recharge in arid and semiarid climates, therefore a key factor in water resources estimation. This work presents the results of an in-depth study in Don ˜ana National Park concerning groundwater recharge behavior over a long period . The spatio-temporal kriging algorithm was used as a supportive tool to improve the reconstruction of the spatio-temporal rainfall variability. One of the main findings was that monthly recharge estimations range between 21 and 91% of the maximum rainfall, being overestimated in areas that also demonstrate spatial heterogeneity in rainfall distribution. In the light of these results, for water management purposes in the Mediterranean area, rainfall spatio-temporal scale is a critical aspect and it must be taken into account in groundwater reservoir allocation. Moreover, it is highlighted that local studies of rainfall and recharge, in an area of high ecological fragility, are essential to developing management strategies that prevent climate change effects and guarantee optimal conditions for groundwater resources in the future.

The physical limnology of a shallow pond system was characterized using field measurements of water temperature, pH, and electrical conductivity (EC). We determined the spatial variability in surface and groundwater temperature, pH, and EC along the pond’s shore and along the several pond-shore transects, analyzed the water column temperature gradient and estimated the groundwater discharge rate using a heat transfer model. The fieldwork was conducted in Santa Olalla and Dulce ponds located in Doñana National Park in southwestern Spain during different stages from 2016 to 2018. The results of this study have improved the understanding of the thermal structure and the surface–subsurface heat exchange in the ponds and highlighted the importance of groundwater discharge in the pond water balance. It also showed the heterogeneous nature of groundwater discharge through the bottom sediments of the Santa Olalla pond. These results are consistent with previous studies and strengthen the existing hydrological and limnological knowledge of these ponds located in the protected area which is receiving a great deal of public attention.

This paper aims to determine how both climate and local drivers, such as groundwater withdrawals influence surface watergroundwater interactions in Groundwater Dependent Ecosystems (GDEs). We studied the hydroperiod in eight of the most representative ponds of Doñana 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.