Monitoring flood and drought events - earth observation for multiscale assessment of water-related hazards and exposed elements

Disaster management is dependent on comprehensive information about the hazard’s nature and the elements exposed – independent of the location and extent of the hazard. This work explores methods to monitor water-related hazards and identify exposed elements based on multisensorial earth observation (EO) and auxiliary data in southern Africa. For the hazard-related perspective, we present methods to monitor fl oods based on radar data (Sentinel-1, TerraSAR-X) and droughts based on time series MODIS satellite data. For the exposure-related perspective, we classify exposed settlements from TerraSAR-X (TSX) and TanDEM-X (TDX) data. We assess people at risk and their respective locations, combining
earth observation and census-based geoinformation. The datasets and methods are explored in two case studies investigating
a flood in northern Namibia in 2011 and drought events in South Africa and Botswana in 2015 and 2016. The case studies show that the methods developed are crucial tools for hazard and exposure identification, assessment, and monitoring.