Abstract
Flood disaster is the most
devastating hydro-meteorological event in the Lacs District, Togo.
Communities in the Lower Mono River Basin experience flooding almost
every two years. In light of this, the study focused on assessment and
mapping of flood disaster risk in six selected communities in the Lacs
District. Specifically, the study examined the pattern of rainfall in
the basin, estimated and predicted flood return periods and the
associated magnitude of river flow and, also mapped the nature of flood
risk in the area. The study combined GIS and Remote Sensing, and
statistical methods in risk mapping and analysis. Weighted overlay tool
in ArcGIS was used for flood risk mapping, while statistical methods
were employed in trend and flood frequency predictions. The study
considered the pattern of rainfall in the entire Mono Basin due to the
fact that the cause of flooding at the downstream is partly due to high
rainfall in the upstream (Mono River).
Significant decreasing
trend in rainfall was found at the station of Sokode (upstream), while
an insignificant increase in rainfall was observed at Atakpame,
Sotouboua, Aklakou and Tabligbo. Flood return periods for each 2 years
and 5 years are 567.4 m3/s and 847.1 m3/s respectively. The resultant
risk map shows that all the communities are exposed to flood disaster
risk but Agbanakin, Azime Dossou and Togbavi communities are found in
areas with high risk levels. Positive attitude towards early warning
systems, collaboration among disaster relief institutions and
appropriate building codes were recommended towards reducing flood
disaster risk.