HIGH-WATER CONDITIONS at the Bolska River Basin – Current State
A hydrological study of the high waters in the area of the Bolska River basin has been created. It includes the “actual” peak flows and flood waves with return periods of 10, 20, 50, 100 and 500 years for individual Bolska River sections and its tributaries.
For the purpose of hydraulic modelling, input hydrographs up to the confluence of the Bolska and the Konjšica were provided and meteorological and hydrological data of the Slovenian Environment Agency was obtained and analysed in order to allow further processing. Precipitation analysis (peak daily precipitation, peak precipitation with varying durations ranging from 5 minutes to 24 hours) took into account 18 rain-gauging stations, of which 2 were ombrographs.
A hydrological model of the surface runoff was created for individual hinterlands using the HEC-HMS 4.0 program. Flood waves were evaluated with the synthetic unit hydrograph method according to the SCS method. Flood routing was performed according to the Muskingum-Cunge method.
It was assumed that precipitation with a return period of N causes runoff with a return period of N.
