부산대학교 도서관

Saltwater intrusion is a major concern commonly found in Ho Chi Minh City (HCMC). In recent years, this problem has been increased significantly and serious effects on socio-economic as well as the natural environment. Due to sea level rise and upstream flow decline, salinity intrusion is expanding into upstream areas rising vulnerability of crop, fish and soil productivity, which results in severe degradation of bio-environment and ecology. Therefore, the study was applied HEC-RAS software including hydrodynamic and salinity model to estimate and predict salinity distribution in Sai Gon – Dong Nai rivers belong to HCMC by using observed hydrological data and salinity distribution to calibrating and verifying in 2011 and 2013 year. To implement research’s purpose, a scenario as RCP 8.5 (the representative concentration pathway higher) was used to estimate salinity distribution in 2050 and 2080, respectively. The algorithm results indicated that the correlation coefficients of R2 were over 0.8 for the hydrodynamic model while NSE was approximately 0.5 for salinity model. With high confidence, therefore, the parameters are suitable for simulating the saltwater intrusion. The salinity thresholds are divided into two levels – including a threshold of 1.2 g/l for the rice field and 5 g/l for the aquaculture. In the current situation, the results show that the salt concentration was 1.2 g/l intruded into 52 km in comparison of was 5 g/l intruded into 47 km from downstream to upstream in the main river systems. In conclusion, the predicted results of salinity distribution will increase and move further upstream of the Sai Gon and Dong Nai Rivers, affecting seriously water resources due to either the sea level rises or the upstream flow declines or impacted combination.