Partitioning and sourcing of evapotranspiration using coupled MARMITES-MODFLOW model, La Mata catchment (Spain)

The new, two-way coupled, distributed and transient MARMITES-MODFLOW (MM-MF) model, coupling land surface soil zone domains with groundwater, is presented. It implements model-based partitioning sourcing of subsurface evapotranspiration ( ET ss ) as part spatio-temporal water balance (WB). involves its separation into evaporation E transpiration T ), while the each two groundwater g components. objective that development was to understand system dynamics a catchment shallow table, through quantification fluxes evaluation their importance in balances, focusing on components . While computed using formulation from published study, obtained novel phenomenological function, based moisture availability demand driven by climatic conditions. MM-MF model applied small La Mata (~4.8 km 2 , Salamanca Province, Spain), characterized semi-arid climate, granitic bedrock, table sparse oak woodland. main characteristics were remote sensing, non-invasive hydrogeophysics classical field data acquisition. calibrated transient, daily five hydrological years, between 1 st October 2008 30 th September 2013. WB confirmed dependence exfiltration gross recharge. These fluxes, together infiltration constituted largest fluxes. higher than which explained low tree coverage (~7%). Considering seasonal variability, larger dry seasons wet season, when solar radiation most depleted. A relevant observation respect during seasons, decline associated moisture, compensated increase despite continuously declining table. However, far below atmospheric evaporative demand, indicating uptake species this study survival strategy not mechanism for continued plant growth. presented allowed analyze detail, accounting separately impacts processes resources. With unique capability particularly suitable mapping dependent ecosystems, but also analyzing climate cover changes