Analysing the impact of hydropower dams on streamflow in the Be river basin

Abstract

The aim of the present study is to assess the effect of hydropower dams on the streamflow in the Be river basin using the Soil and Water Assessment Tool (SWAT). Model calibration and validation of SWAT were conducted using the historical data collected from two stream gauges, namely Phuoc Long and Phuoc Hoa, and the obtained results indicated that SWAT shows a good reliability in reproducing streamflow with R²>0.90 and NSE>0.70 for both periods of calibration (1980-1990) and validation (1991-1993). Considering the results of SWAT’s calibration, the hydrological impact on the streamflow needs to be taken into consideration. The study results show that the separate impact of each hydrological dam (Thac Mo reservoir, Can Don reservoir, and Srok Phu Mieng reservoir) significantly increases streamflow in the dry season (89-101%) and decreases it in the wet season (6-33%). Moreover, there is a considerable rise in the dry season (89%) and a significant decline in the wet season (33%) of streamflow under the combined impact of the three dams.