APPLICATION OF HEC-RAS MODEL SIMULATING FLOOD IN LA RIVER BASIN BASING ON THE CONNECTION OF HYDRONAMIC 1-2D

Abstract

This article presents some results of calculations, simulation of flooding in the La river basin using the Hec-Ras model on the basis of hydrodynamics. 1D area are connected to 2D area through the side connection. Input data for the model are data on water levels and flow rates collected from hydro-meteorological stations in the basin. Parameters of model was calibrated and verified with observation water level data in two major floods in October 2010 and 2011 at Linh Cam station. The results of the error estimation using the Nash index for values greater than 0.9 indicate the applicability of the model to flood simulation. The model results also show that the heaviest flooded area is the right bank of the La river with an average flood level of 2m, flooded areas are at least the left bank of the Ngan Pho river with inundation is 0.5m.