Abstract

Ho Chi Minh city is located in the lower Sai Gon - Dong Nai river basin, with a relatively low topography compared to sea level and a dense network of rivers. Therefore, this area is very vulnerable to complex developments of saltwater intrusion, especially under the impact of climate change. The study assessed the impacts of saltwater intrusion on raw water supply stations of Ho Chi Minh city by modeling method, specifically the MIKE 21FM model. The results indicated that the water level calibrations had high reliability whose both NSE and R2 were above 0.85, and the salinity calibrations for PBIAS were about 10%. Then, the study simulated the current situation and sea-level rise scenarios for the flow velocity and salinity at the three raw water supply stations, namely Hoa Phu (on the Saigon river), Phu An, and Binh An (on the Dong Nai river). The results showed that the salinity concentrations at these three pumping stations were unsatisfied with QCVN 08- MT:2015/BTNMT under the impacts of both prolonged drought in 2016 and sea-level rise due to climate change, in which Hoa Phu and Binh An stations were affected the most by the sea-level rise.