Abstract

Water resources from Kôn and Hà Thanh river basin, upstream areas of Thi Nai lagoon plays a very essential role on hydrological in economic – social development of Binh Dinh province. Assessment of potential water resources in the region can be servered for water resources planning toward sustainable development. In this paper, the SWAT model was applied in this study to evaluate river flow in the rivers. The simulation data were used with with the length of meteorological input data up to 36 years. The parameters of model were calibrated by SWAT-CUP with Sufi-2 algorithm (Semi Automated Sequential Uncertainty Fitting) using data of Binh Tuong discharge station(1980-1995), that also used to analyze parameter sensitivity. The coefficient of determination (R2), NSE values and PBIAS index for the daily runoff were obtained as 0,54; 0,51 and 15,01 % .The average input flow to Thi Nai lagoon were 105,16 m3/s (from Kon river) and 19,77 m3/s (from Ha Thanh river). The results of this study can be used for others research such as water balance calculation in the river basin or it can be used as inputs of water quality and sediment transport model in Thi Nai lagoon.