A Modeling Approach to Diagnose the Impacts of Global Changes on Discharge and Suspended Sediment Concentration within the Red River Basin

Xi Wei (1) , Sabine Sauvage (1) , Thi Phuong Quynh Le (2) , Sylvain Ouillon (2, 3, 4) , Didier Orange (5) , Vu Duy Vinh (6) , Jose-Miguel Sanchez-Perez (1)

1 LEFE - Laboratoire Ecologie Fonctionnelle et Environnement
2 VAST - Vietnam Academy of Science and Technology
3 USTH - University of Science and Technology of Hanoi
4 LEGOS - Laboratoire d'études en Géophysique et océanographie spatiales
5 UMR Eco&Sols - Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes
6 IMER - Institute of Marine Environment and Resources

The Red River basin is a typical Asian river system affected by climate and anthropogenicchanges. The purpose of this study is to build a tool to separate the effect of climate variability andanthropogenic influences on hydrology and suspended sediments. A modeling method combiningin situ and climatic satellite data was used to analyze the discharge (Q) and suspended sedimentconcentration (SSC) at a daily time scale from 2000 to 2014. Scenarios of natural and actual conditionswere implemented to quantify the impacts of climate variability and dams. The modeling gainedsatisfactory simulation results of water regime and SSC compared to the observations. Under naturalconditions, the Q and SSC show decreasing tendencies, and climate variability is the main influencefactor reducing the Q. Under actual conditions, SSC is mainly reduced by dams. At the outlet, annualmean Q got reduced by 13% (9% by climate and 4% by dams), and annual mean SSC got reducedto 89% (13% due to climate and 76% due to dams) of that under natural conditions. The climatetendencies are mainly explained by a decrease of 9% on precipitation and 5% on evapotranspiration,which results in a 13% decrease of available water for the whole basin.

Mots clés: climate; dam impacts; SWAT model; suspended sediment; Red River

Mots clés: hydrology

Domaines: Ingénierie de l'environnement

Xi Wei, Sabine Sauvage, Thi Phuong Quynh Le, Sylvain Ouillon, Didier Orange, et al.. A Modeling Approach to Diagnose the Impacts of Global Changes on Discharge and Suspended Sediment Concentration within the Red River Basin. Water, 2019, 11 (5), pp.958. ⟨10.3390/w11050958⟩. ⟨hal-02367848⟩