Quantifying the importance of vegetation in water fluxes partitioning over Mediterranean mountain areas: a study case in Cardeña-Montoro Natural Park (Spain)

Abstract

<p>Mediterranean mountain areas are hotspots when evaluating vulnerability towards global warming. Future hydro-climatic scenarios present a probable situation of high alteration of these systems, mainly conditioned by an increase of extreme events frequency (e.g., heatwaves and droughts). Dehesas are one of these characteristic landscapes. They result from the co-evolution of autochthonous ecosystems and human settlement in a sustainable balance, with high relevance from the environmental (biodiversity) and socioeconomic (livestock farming, including the Iberian pork food industry) view. They have a complex vegetation cover structure formed by isolated trees, mainly holm oak, cork oak, and oak, Mediterranean shrubs, and pastures, with specific phenological cycles. This complexity conditions the partitioning of water fluxes, shifting their importance along the year. </p><p>This work proposes to quantify the actual role of the vegetation in the water fluxes partitioning over mountain Mediterranean areas. Specifically, this study is conducted in the Martin Gonzalo watershed upstream of the Martin Gonzalo dam, located within the Cardeña-Montoro Natural Park (southern Spain). The vegetation role is assessed by comparing three different hydrological model simulations conducted using the distributed and physically-based hydrological model WiMMed (Watershed Integrated Model for Mediterranean Areas): i) non-vegetation, in which no vegetation is included in the modelling; ii) static vegetation, in which vegetation is defined in the model using the official land cover maps from the regional authorities; and iii) dynamical vegetation, in which vegetation information is provided by a dynamical spectral mixture analysis using Sentinel-2. All water fluxes in the water balance are quantified and compared between the three simulations. Results highlight, on the one hand, the key role of vegetation in controlling water partitioning and, on the other hand, the importance of considering the yearly phenological changes to model water partitioning accurately.  </p><p> </p><p> </p><p>This work has been funded by project SIERRA Seguimiento hIdrológico de la vEgetación en montaña mediteRránea mediante fusión de sensores Remotos en Andalucía, with the economic collaboration of the European Funding for Rural Development (FEDER) and the Office for Economy, Knowledge, Enterprises and University of the Andalusian Regional Government.</p>