IMPACT OF THE RESERVOIRS ON THE POC FLUXES OF THE DA RIVER OVER THE PERIOD 1960 - 2014

Abstract

The Da river with its river basin of 51285 km2 is the largest tributary of the
Red River system. Some previous studies showed the strong retention of
suspended solids in the reservoirs dammed on the Da River. The present paper
introduces the calculation results on the particulate organic carbon POC fluxes
of the Da River over the period 1960 - 2014, under the impact of impoundment
of superposed reservoirs, Hoa Binh and Son La. The results showed that a strong
reduction of the POC fluxes 82% at the outlet of the Da River was observed in
1990s since the completion of the Hoa Binh reservoir. After that, the
impoundment of the Son La reservoir accelerated to result in a substantial
decline7% of the POC fluxes of the Da River.