Evaluación de la alteración del hidroperiodo en la laguna del Taraje (Parque Nacional de Doñana) mediante monitorización continua y modelización numérica

Abstract

The Taraje pond (Doñana National Park) is a shallow wetland, whose average flooded area has been drastically reduced in recent years. The daily hydrological modelling of the evolution of the water level has been carried out, through the precise measurement of the water balance components and its evolution, thanks to continuous level monitoring. The study period covers from March 2016 to October 2019 of hourly water level and water temperature measurements and daily registers of precipitation, air temperature and potential evapotranspiration. The modelling results suggest that, in natural regime, during the studied period the Taraje pond should have been flooded about 80% of that time (1083 days). The current hydroperiod has been 875 days, which means a theoretical average reduction of the hydroperiod of 208 days (58 days a year on average). Moreover, the median depth of the water level in natural regime would be 64 cm, but the recorded median level was 34 cm. The most probable cause of this reduction in both the hydroperiod and the water level in the pond is the extraction of groundwater for urban supply in a close touristic resort. The effect of the water pumping has been detected in piezometers installed very close to the Taraje pond.