Effect of homogeneity on flood estimation at the West Mediterranean region

Abstract

In regional flood frequency analysis, identification of homogeneous sub-regions is a fundamental factor for reliable flood quantile estimation in hydrologic modeling, engineering practice for water structures design and management. In this study, regional flood frequency analysis is carried out for annual maximum flood series of stream gauging stations with Dalrymple and L-moments homogeneity approaches for the West Mediterranean River basins in Turkey. The studied region is divided into three homogeneous sub-regions namely Antalya, Lower West Mediterranean and Upper West Mediterranean based on Dalrymple and L-moment homogeneity tests. Design floods with various recurrence intervals are calculated for stream gauging stations in each homogeneous sub-region. The results showed that the difference between design floods with various recurrence intervals according to the homogeneity tests is not significant at small recurrence intervals but this difference increases at large recurrence periods especially for stations that have high coefficient of variation and skewness.