Abstract:
In the Volta River Basin, flooding has been one of the most damaging natural hazards
during the last few decades. Therefore, flood frequency estimates are important for disaster risk
management. This study aims at improving knowledge of flood frequencies in the Volta River Basin
using regional frequency analysis based on L-moments. Hence, three homogeneous groups have
been identified based on cluster analysis and a homogeneity test. By using L-moment diagrams
and goodness of fit tests, the generalized extreme value and the generalized Pareto distributions are
found suitable to yield accurate flood quantiles in the Volta River Basin. Finally, regression models of
the mean annual flood with the size of the drainage area, mean basin slope and mean annual rainfall
are proposed to enable flood frequency estimation of ungauged sites within the study area.
