Soil moisture and evapotranspiration in four temperate agricultural catchments of Southern Sweden under future climatic conditions

Study region We modelled four agriculturally dominated catchments that represent key agro-climatic production zones in southern Sweden: Tidan (58.37 N, 13.92E), Enköpingsån-Örsundaån (59.83 N, 17.0E), Saxån-Braån (55.96 N, 13.14E) and Gamlebyån-Loftaån (57.96 N, 16.30). These catchments were chosen to represent the typical production systems, land cover and soil conditions, influenced by distinct weather regimes Study focus Our objective was to assess how current and future extreme weather impacts soil moisture availability and evapotranspiration in agricultural catchments. We applied the Soil and Water Assessment Tool to four agriculturally dominated catchments in southern Sweden that represent main crop production regions. A reference period (1991–2023) was simulated and compared with future climate scenarios (CMIP6 SSP2–4.5 and SSP5–8.5, periods 2024–2040 and 2041–2060), generated using the weather generator LARS-WG. The scenarios showed significant temperature increase but non-significant precipitation change. Soil moisture dynamics were evaluated weekly, using the soil moisture deficiency index (SMDI) for topsoil and subsoil, and the evapotranspiration deficiency index (ETDI) in relation to temperature (TX90p) and precipitation (SPI) indices. New Hydrological Insights for the Region Results showed significant drying trends (p < 0.05) in both topsoil and subsoil in three of four catchments, with enhanced drying in the subsoil alongside reduced evapotranspiration in future climate scenarios. This suggests negative implications for biomass and crop management, highlighting increasing needs for improved soil water management and irrigation.