Assessing the impact of resolution and soil datasets on flash-flood modelling

Abstract

Abstract. The present study assesses the impacts of the grid resolution and the descriptors of soil texture and land cover on flash-flood modelling at local and basin scales. The ISBA-TOP coupled system, which is dedicated to Mediterranean flash-flood simulations, is used with two grid-cell sizes (300 m and 1000 m) and various soil datasets to model 12 past flash-flood events in southeastern France. The skill of the hydrological simulations is assessed using conventional data (discharge measurements from operational networks) and proxy data such as post-event surveys and high-water marks. The results show significant 5 differences between the experiments in terms of both the simulated river discharge and the spatial runoff, whether at the catchment scale or at the local scale. The spatial resolution has the largest impact on the hydrological simulations. In this study, it is also shown that the soil texture has a larger impact on the results than the land cover.

Hydrometeorological evaluation of two nowcasting systems for Mediterranean heavy precipitation events with operational considerations

“…The ISBA-TOP configuration used in this study is the one suggested by Lovat et al (2019) for flash-flood simulations, based on SRTM data for orography, Land use/cover area frame statistical survey topsoil data (Ballabio et al, 2016) for soil texture, ECOCLIMAP-II (Masson et al, 2003;Faroux et al, 2013) data for land cover, and a spatial resolution of 300m for ISBA.…”

“…ISBA-TOP is used in operations in the National Institute of Meteorology and Hydrology of Bulgaria for the Arda river flood forecasting (Artinyan et al, 2016). In addition to simulating river discharges during flash floods, ISBA-TOP is also able to simulate intense runoff phenomena (Vincendon et al, 2016;Lovat et al, 2019).…”