SWAT Soil Moisture Assessment under Mediterranean Conditions: an Intercomparison Analysis in the Henares Basin (Spain)

Study region: The Henares River Basin, central part of SpainStudy focus: An assessment of SWAT soil moisture in a basin under Mediterranean conditions was carried out for the first time. Intercomparison analysis was performed using modeling (LISFLOOD model) and remote sensing (Soil Moisture and Ocean Salinity, SMOS; and Soil Moisture Active Passive, SMAP) products as references, both in the topsoil and in the root zone layers. The analysis was carried out considering both the temporal and the spatial domains.New hydrological insights for the region: The evaluation results, despite being slightly better for the root zone layer, were very good overall in terms of the correlation coefficient, centered root mean square difference, and bias. The SWAT soil moisture product obtained in a basin under Medi-terranean conditions gave satisfactory performances, similar to those of the modelling and sat-ellite products with which it has been compared. When analyzing whether these assessment results were determined by factors such as land cover, soil characteristics (texture), topography (slope and altitude) and climate (precipitation), no pattern was observed. There was also no temporal pattern in the quality of the SWAT soil moisture estimation under Mediterranean conditions. Producing reliable SWAT soil moisture databases for different environments around the world, offers the possibility of increasing the availability of suitable soil moisture series, for which there is great interest.