Flood Mapping Using Synthetic Aperture Radar Sensors From Local to Global Scales

Abstract

Flooding involves large inundated regions, which are often inaccessible or ungauged. Remote sensing (RS) data provide an elegant and practicable solution to assess spatiotemporal flood evolution. RS‐based flood map­ ping has witnessed significant research breakthroughs over the last decade. In addition to providing stakeholders with timely and spatially distributed information for crisis response [Schumann et al., 2016], RS‐based flood maps are now utilized for hydrodynamic model calibra­ tion and evaluation and to improve forecasts through assimilation [Schumann and Domeneghetti, 2016]. The cost of high resolution (>4 and ≤ 10 m) imagery and sparse temporal coverage previously acted as a deter­ rent to unlocking the full potential of RS for flood management. In 1999, the International Charter “Space and Major Disasters” was initiated to provide a unified system of rapid satellite data acquisition and delivery in the face of major disasters [Martinis et al., 2015b]. Floods are so frequently occurring and globally pervasive, that more than 50% of all satellite data requests through the charter were flood related in the past decade, as illus­ trated in Figure 4.1. The launch of several high‐resolu­ tion SAR missions has also contributed to improvements in the spatial and temporal resolutions and global cov­ erage, making their use in flood mapping more practical. A summary of currently operational, historical, and planned SAR missions is presented in Figure 4.2, with Table 4.1 providing details of the sensor characteristics. Sensors operating in the visible region of the electro­ magnetic (EM) spectrum offer the most straightforward ABSTRACT