Rapid mapping of temporary surface water using Sentinel-1 imagery, case study: Zorn River flooding, Grand-Est, France

Temporary Surface Water (TSW) is defined as waterbody experiencing frequent drying phases (small ponds, puddles, and wetlands) or correspond to surfaces frequently affected by flooding, thus causing hazards to human, settlements, and infrastructures. The Zorn is one of main river in Grand-Est, France which overwhelmed by strong precipitations from the Storm Eleanor (Cyclone Burglind). It caused inundation in Zorn surrounding areas. On 23 January 2018, data reported that floods occurred in Zorn watershed near to the municipalities of Brumath, Hoerdt and Hochfelden. Zorn River lies in the Moselle and Bas-Rhin departments with 580 km of linear streams. Historically, floods are frequently occurred in the Zorn watershed area. The municipalities of Eschbourg, Brumath and Dossenheim-sur-Zinsel are the most affected floods areas. Synthetic Aperture Radar (SAR) is an effective way to detect surface water over large areas. Sentinel-1 is a new available SAR, and its spatial resolution and short temporal baselines have the potential for surface water rapid mapping. Thus, the objective is to perform rapid mapping to produce flood map around the catchment of the Zorn River (next to Brumath).