Identi cation of homogeneous regions and regional frequency analysis for Turkey

Wardʹs hierarchical clustering method is applied to classify the annual oods and identify the hydrologic homogeneous regions in Turkey. For this aim, the annual ood data obtained at the 117 gauging stations having data records of 31 years operated by the general directorate of electrical power resources survey and development administration (EIE) throughout Turkey are considered. Discordancy and regional homogeneity measures are applied to test homogeneity of regions identied by Wardʹs cluster method. Flood frequency analyses for seven sub-groups dened by Wardʹs clustering method are carried out using various frequency distributions based on index ood and L-moments approaches. The best t distributions for all sub-regions are identied based on L-moments goodness of t statistic. The accuracy of results of quantile estimates are evaluated by using relative RMSE% and relative BIAS% through the use of Monte Carlo simulation