Simulation of the river Nevėžis upstream hydrological regime

Abstract

This paper deals with the results of HBV model calibration and runoff calculations for the River Neve˛is upstream. Under different hydrological conditions the HBV model was applied to 2 catchments in the Neve˛is basin. These two catchments were selected as a modelling area: the u ve River, upstream for the period of 1970-1978 and the River Neve˛is upstream for the period of 1958-1964. The both catchment areas close to 1100 km2. The best results of the runoff simulation were received in the sub-basin of the River u ve (R2-0,815). The River Neve˛is above Paneve˛ys showed less good correspondence with the observations (R2-0,713) and bad result of low flows (R2 log-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).