Contribution of Sentinel 1 Radar Data to Flood Mapping in the San-Pédro River Basin (South-west Côte d’Ivoire)
Kouakou Hervé Kouassi *
Environmental Sciences and Technologies Laboratory, Jean Lorougnon Guédé University, P.O. Box 150, Daloa, Côte d'Ivoire.
Yao Alexis N’go
Laboratory of Geosciences and Environment, UFR Environmental Science and Management, Nangui Abrogoua University, Abidjan, Côte d’Ivoire.
Kouao Armand Anoh
Environmental Sciences and Technologies Laboratory, Jean Lorougnon Guédé University, P.O. Box 150, Daloa, Côte d'Ivoire.
Tanoh Jean-Jacque Koua
Environmental Sciences and Technologies Laboratory, Jean Lorougnon Guédé University, P.O. Box 150, Daloa, Côte d'Ivoire.
Cristian Constantin Stoleriu
Department of Geography, Faculty of Geography and Geology, Alexandru Ioan Cuza University, Romania.
*Author to whom correspondence should be addressed.
Abstract
Floods result from the overflow of water which submerges the surrounding land. They are frequent on the coast of Côte d'Ivoire during the rainy season and have more or less serious consequences on the populations, property and the environment. The study site is the San Pedro river basin. It is a coastal catchment area characterized by an average annual rainfall of up to 2000 mm and subject to recurrent flooding. The objective of this study is to assess the risk of flooding during the great rainy season of 2017. The study aims to study flood hazard, assess vulnerability and map flood risk areas. The methodological approach is based on the use of C-band (5.6 cm) radar remote sensing data acquired by the Sentinel-1 sensor at 12-day intervals. These data are in GRD (Ground Range Detected) level 1 format and were used to calculate the radar backscatter coefficient. The results obtained allowed to map the extent of the flooded areas and showed that more than 6,000 ha of land is flooded for more than 3 days. Sentinel-1 has enormous potential to identify flooding risky areas and to continuously monitor them.
Keywords: Floods, Radar remote sensing, Sentinel-1, San Pedro.