Abstract:

This paper presents results of the status quo and predictions of saline intrusion of surface water in the southern Red River delta, including the Day River and Ninh Co River, which are heavily impacted by saline intrusion. The scenarios of climate change and sea level rise, which is selected to analyse are RCP 4.5 and RCP 8.5 and time scales are the year of 2020, 2030, 2040, 2050, 2100. The studied results which was obtained from statistic data, field and laboratory testing, and modelling with Mike 11 programme showed that saline intrusion in the Day river is stronger than that in Ninh Co river. Intrusion distance of the salinity of 1.5 g/L in Ninh Co river is 22.5 km. Meanwhile that one in Day river is up to 29 km. At 22km far from the river mouth, the salinity in Day river is 12.7 g/L and in Ninh Co river is only 2.3 g/L. The estimated results of modelling showed that saline boundary of 1.5 g/L moves toward upstream from 300m to 700m in Day river and 200m in Ninh Co river in each decade. The estimation of salinity intrusion under these scenarios is mainly based on natural factors but not on the role of human activities such as regulating upstream reservoirs.