摘要
This paper focuses on analysis of salinity distribution along Red River and its main branches to determine and limit effects of salinity intrusion under variable scenarios for outlet discharge from upstream reservoirs and the tidal magnitude under global climate change effects. The effect of outlet discharge from upstream reservoirs, which generates flow in droughty months, is considered as upstream input condition for salinity intrusion. The sea level rising phenomenon is represented by scenarios according to prediction of the Intergovernmental Panel on Climate Change （IPCC）. The lateral flow and the rainfall in dry season are neglected in the process of simulation. MIKE 11, ID river model software by DHI （Danish Hydraulic Institute）, is used to simulate the processes of salt water intrusion from the river mouths to the upstream of the river in consideration the effect of the Sea Level Rise phenomenon and the operation of existing reservoirs and those under construction. The results indicate that salinity intrusion length from river mouth depends on the estuary characteristics, discharges from upper reservoirs and tidal phases （low and high tides）. With the safe salinity concentration for agriculture and livestock is 4 psu, the study shows that the length of intruded salt in Red River is about 40km from the river mouth, in otherwise, the effect of salinity intrusion in Thai Binh river is negligible. The Sea Level Rise phenomenon has inconsiderable affects on salinity intrusion processes in Red River System. The influence of outlet discharges from upstream reservoirs has also negligible affects on prevent salinity intrusion from the sea. According to the results of the study, reasonable water resources utilization and appropriate reservoir operation approaches in the drought will be studied to protect the crop and aquaculture from salinity intrusion.
