Integrating C- and L-Band SAR Imagery for Detailed Flood Monitoring of Remote Vegetated Areas

Flood detection and monitoring is increasingly important, especially on remote areas suchas African tropical river basins, where ground investigations are difficult. We present an experimentaimed at integrating multi-temporal and multi-source data from the Sentinel-1 and ALOS 2synthetic aperture radar (SAR) sensors, operating in C band, VV polarization, and L band, HH andHV polarizations, respectively. Information from the globally available CORINE land cover dataset,derived over Africa from the Proba V satellite, and available publicly at the resolution of 100 m, isalso exploited. Integrated multi-frequency, multi-temporal, and multi-polarizations analysis allowshighlighting different drying dynamics for floodwater over various land cover classes, such asherbaceous vegetation, wetlands, and forests. They also enable detection of different scatteringmechanisms, such as double bounce interaction of vegetation stems and trunks with underlyingfloodwater, giving precious information about the distribution of flooded areas among the differentground cover types present on the site. The approach is validated through visual analysis fromGoogle Earth(TM) imagery. This kind of integrated analysis, exploiting multi-source remote sensing topartially make up for the unavailability of reliable ground truth, is expected to assume increasingimportance as constellations of satellites, observing the Earth in different electromagnetic radiationbands, will be available.