Mapping Flood Risk Using Sentinel-1 Data: A Case Study of Niamey, Niger

Abstract

Flood events are recognized to be one of the most among the most catastrophic disaster in the world, with a consequential loss of lives, goods, and services. Factors such as rapid urbanization, lack of proper infrastructure development, insufficient consideration of the environment, and the effect of climate change have made floods even more destructive, particularly for developing countries that lack the means to respond appropriately during such events. The impacts of flood disasters on people and the local economy are more severe in urban areas than in rural areas. Niamey has experienced frequent devastating flooding events in recent times, particularly in 2020. For this reason, producing a flood map for Niamey is crucial to see which places will be affected. This study aims to map potential flood areas after the 2020 flash flood using unsupervised classified sentinel 1 SAR images from the European Space Agency. For the research purpose, we used the Digital Earth Africa Sandbox platform to get and analyze the result. The inundated area map demonstrates that the flood affected approximately 149.541 km2, the Built-up area highly prone to flooding: 18.325 km2, the cropland area highly prone to flooding: 26.252 km2, the Built-up area medium prone to flooding: 79.318 km2, Cropland area medium prone to flooding: 13.26 km2.