Regional design storm of Greece within the flood risk management framework

Abstract

This paper deals with the concept of regional design storm over Greece, which constitutes part of the flood risk estimation component within the risk management framework. The method includes analysis of rainfall depth, duration, frequency and their relationships in each climatic region of Greece. The design storm is accomplished through the development of rainfall depth-duration-frequency (DDF) relationships for each station. For the estimation of DDFs, daily rainfall data from 24 stations over Greece for the period 1950 to 1981 are used. The Extreme Value I (Gumbel) distribution has the best fit and it is fitted to the maximum annual rainfall depths for various durations and return periods. The analysis has indicated that the rainfall of various durations and return periods represents a certain percentage of the mean annual precipitation of hydrologically homogeneous areas of Greece. Finally, isohyetal frequency mapping of extreme rainfall over Greece is conducted based of DDF relationships. The results can be used for the estimation of areal rainfall at ungauged watersheds, as well as for regional design storm over Greece as the risk estimation component of flood risk assessment and management. © 2016 Inderscience Enterprises Ltd.