Statistical Method for the Depth-Duration-Frequency Curves Estimation Under Changing Climate: Case Study of the Južna Morava River (Serbia)

This paper addresses the influence of climate change on flood occurrence within the Veternica river stream, a tributary of the Južna Morava River. Depth-Duration-Frequency (DDF) curves serve as the indicators of climate change impacts. The Generalized Extreme Value (GEV) distribution is selected as the theoretical distribution function, and the Modified Method proposed by the Indian Meteorological Department (MIMD method) is employed to downscale daily precipitation data to sub-daily levels. DDF curves are established using both the standard and Koutsoyiannis’ methods, respectively. In addition, the HEC-HMS model will be utilized for the computation of flood hydrographs, and a comparative analysis will subsequently be carried out. Under climate change conditions, the hydro-graph peak for a 100-year return period, based on the standard method, exhibits variation ranging from a decrease of 17% to an increase of 2% compared to the reference period. However, the peak based on Koutsoyiannis’ method shows variation from a decrease of 4% to an increase of 12%, thereby indicating it as a more conservative approach.