Un workflow per la valutazione delle soglie empiriche di generazione del runoff

Reliable rainfall and soil moisture data is crucial to investigate hydrogeological processes at the catchment scale (runoff, soil erosion, infiltration, etc.). The present study aims to evaluate the performance of several high resolution satellite products (IMERG GPM, SM2RAIN, Copernicus Sentinel-1 SSM1km, and SMAP L2_SM_SP) and define a workflow for the definition of empirical runoff generation threshold at catchment scale. The analysis was carried out in a small low permeability catchment in Central Italy (Tatarena Creek basin), equipped with three-gauge stations. The basin is scarcely anthropized and can be considered representative of many catchments with different soil cover, from forest to farming. The satellite rainfall products were analysed using the double mass method, statistical tests and three categorical scores. Satellite soil moisture data were tested with the Hydrological Consistency Index, aiming to verify the consistency between soil moisture satellite data and rainfall. The results show that the IMERG GPM rainfall dataset performs better than SM2RAIN at different time scales. Despite some uncertainties, the Copernicus Sentinel-1 SSM1km proved to be the best-performing soil moisture satellite dataset. Results may be useful for the utilisation of satellite data to understand processes in poorly instrumented basins and apply the workflow presented for the definition of empirical runoff generation threshold at catchment scale.