This goal is achieved through the generation and analysis of an historical archive of water bodies, derived by means of an automatic procedure for the extraction of flooded areas from satellite data. MODIS (Moderate Resolution Imaging Spectroradiometer) Terra and Aqua optical data have been used for this purpose, since they allow: frequent monitoring due to their daily frequency, regional analysis thanks to their global coverage (250 m spatial resolution) and the generation of a 10 years historical archive.
Since the imagery can be affected by the presence of cloud coverage and cloud shadows can be wrongly classified as water bodies because of the spectral response very similar to the one of water, a temporal composite technique has been adopted. The composition algorithm is made by the following steps:
The compositing algorithm allows the creation of an historical archive starting from February 2000.
Different information on flood hazard can be extracted from the archive, such as:
The procedure can be adopted for different regions of the globe. At the moment it is being validated for the countries of Bangladesh and Myanmar.