Simulation of the River Nevezis Upstream Hydrological Regime

This paper deals with the results of HBV model calibration and runoff calculations for the River Nevezis upstream. Under different hydrological conditions the HBV model was applied to 2 catchments in the Nevezis basin. These two catchments were selected as a modelling area: the Susve River, upstream for the period of 1970-1978 and the River Nevezis upstream for the period of 1958-1964. The both catchment areas close to 1100 km(2). The best results of the runoff simulation were received in the sub-basin of the River Susve (R-2-0,815). The River Nevezis above Panevezys showed less good correspondence with the observations (R-2-0,713) and bad result of low flows (R-log(2)-0,28-0,51). The author relates these error uncertainties by discreet precipitation distribution in basin or they can be solved by splitting the catchment to smaller sub-basins. The results show that some enhancements should be done, but HBV model could be successfully applied for further runoff analysis (risk under different anthropogenic conditions).