Flood Inundation Depth Estimation from SAR-Based Flood Extent and DEM

Remote sensing has been used extensively to identify the extent of floods. However, few studies have addressed the estimation of inundation depth, which would provide a deeper understanding of the affected areas. This paper reports a step-by-step application of a novel method to estimate inundation depths during a flood in Mabi town, Okayama Prefecture, Japan 2018. The method is based on the solution of a nonlinear programming problem, in which the flood extent, computed from SAR imagery, is represented as a sparse linear combination of water bodies calculated from a digital elevation model. The results show a good agreement with observations on the field survey and can be implemented in a fully automatic framework.