FLOOD FREQUENCY MODELLING OF THE KOPACKI RIT NATURE PARK

Kopacki rit Nature Park, as a valuable wetland area in the Republic of Croatia, was very often the subject of different investigations. Most of them were dealing with biodiversity and its biological values. There is only a small number of investigations on the Kopacki rit water regime, basis of the existing ecosystem, and its flooding impacts on the variety and existence of its species. This paper gives a contribution to the hydrological research of Kopacki rit by the analysis of its flooding frequency depending on the Danube River water level in the upstream section from 1380 rkm to 1433 rkm. Also, it pays attention to the importance of the flooding regime for the survival of its biological communities. Fluctuations of discharges cause changes in water velocities and shear stress which have influence on processes of erosion and sedimentation. Results obtained in the paper are the magnitude of flooded areas and the volume of water spread in the floodplain and the Nature Park for the floods of 5, 10, 25, 50 and 100 years return periods.