Assessment of Flood Hazard Areas Using Remote Sensing and Spatial
Information System in Bilate River Basin, Ethiopia
Abstract
Floods are considered as harmful and the most dangerous natural disaster
affecting annually millions of people. This study aimed to present a
geospatial information system based on multi-criteria evaluation
techniques (MCE) methodology for flood hazard areas mapping. The
distance from drainage network, slope, recurrent heavy rainfall, curve
number, normalized difference vegetation index (NDVI), and the
population density are the six factors considered as relevant to the
flood hazard areas mapping of the basin. The final flood hazard areas
map of the basin shows a satisfactory agreement between the spatial
distribution of historical floods that happened in the basin for the
past years and the flood hazard zones. The flood hazard map showed that
Bilate-Humbo area at the very entry of Bilate River to Lake Abaya,
Shashego area at Boyo Lake resulting from Guder River, and Shashego area
at Boyo Lake resulting from Metenchiso River are the areas of very high
flood hazard. These areas are categorized by low NDVI, gentle slope,
high rainfall, high curve number and close to the drainage network. The
proposed methodology of assessing flood hazard areas using spatial
information system delivers a good basis for developing a system of
flood risk management in a river basin