A holistic approach for determining the hydrology of the mar menor coastal lagoon by combining hydrological & hydrodynamic models

A combination of hydrological and hydrodynamic modelling can be applied to understand the hydrology key water balance components lakes lagoons. In this research, Soil Water Assessment Tool (SWAT) model QGIS Ecosystems (QWET) were for Mar Menor coastal lagoon its watershed known as Campo de Cartagena. First, SWAT was calibrated validated based on remote sensing evapotranspiration data. Results showed an acceptable performance in both calibration (R2 = 0.63, NSE 0.62, PBIAS 2.91%) validation 0.68, 2.47%) periods a monthly basis. The simulated streamflow fed into QWET simulate lagoon. evaluated comparison between observed temperatures also estimated evaporation. Simulated daily good agreement with data by capturing timing inter-annual variations, 0.98, BIAS 2.7%. Our estimation, using reference period 2003–2019, yields mean annual rainfall over lake 301 mm evaporation 1325 mm. average surface runoff groundwater discharge are 49 hm3/year 11 hm3/year, respectively. Extreme storm events cause vary 8 202 hm3/year. closed exchange Mediterranean Sea, resulting overall positive flow from Sea 82 study that during summer months, particular, there is considerable inflow lagoon, whereas some autumn winter months (November, December January) net outflow Mediterranean. This novel approach combining complex provides useful tool understanding may play role decision makers when developing strategies mitigating eutrophication.