A simplified model to investigate the hydrological regimes of temporary wetlands: the case study of Doñana marshland (Spain)

Abstract. Natural and pristine ecosystems, such as wetlands, are being either directly or indirectly threatened by a multiplicity of drivers, which include anthropogenic activities and the impacts they have on the use of natural resources. Strategies oriented to a sustainable management of natural resources (in particular, water) are therefore urgently needed, considering also the increasing effects of climate change. Despite their ecological importance, wetlands remain underrepresented in hydrological modelling studies, especially regarding their specific water needs under changing environmental conditions and different scenarios. This study aims to estimate the water requirements of a temporary wetland through a simple hydrological balance model, ultimately facilitating the identification of strategies for its long-term sustainable management. The pilot case study is the Doñana National Park, SW Spain, one of the case studies of the European project LENSES (PRIMA Call 2020). The model ('WetMAT') is calibrated and validated using historical time series of key hydrological variables (Maximum Flooded Area and Hydroperiod) taken from the literature, to describe the hydrological processes in the wetland. The model is then used for a scenario analysis focused on the assessment of climate change impacts on the state of the wetland and for assessing the ecological water demand of the wetland in a dynamic way, helping to quantify the water needs of such a fragile ecosystem. The results highlight the urgency and importance of developing tools that can help integrating environmental needs into water resources planning and management.