Monitoring soil moisture dynamics in multilayered Fluvisols

Abstract The identification of drought-sensitive areas (DSAs) in floodplain Fluvisols of high textural pedodiversity is crucial for sustainable land management purposes. During extended drought periods moisture replenishment is only available by capillary rise from the groundwater. However, moisture flux is often hindered by capillary barriers in the interface between layers of contrasting textures. The results of HYDRUS-1D simulations run on multilayered soil profiles were integrated into textural maps to determine the spatial distribution of water dynamics on the floodplain of the Drava River (SW Hungary). Model runs and field data revealed limited moisture replenishment by capillary rise when both contrasting textural interfaces and sandy layers are present in the profile. By implementing these textural and hydraulic relations, a drought vulnerability map (DSA map) of the operational area of the Old Drava Programme (ODP) was developed. According to the spatial distribution of soils of reduced capillary rise, 52% of the ODP area is likely threatened by droughts. Our model results are adaptable for optimisation of land- and water-management practices along the floodplains of low-energy and medium-sized rivers under humid continental and maritime climates.