Every day, up to 750,000 cubic meters of wastewater in Ha Noi metropolitan areas is discharged directly into rivers and lakes, of which only 10 % is treated to the Vietnamese standards. According to the water drainage development master plan for the capital city of Ha Noi until 2030, the government aims at dealing with flood control and improving environmental sanitation for local residents. With respect to the baseline and Master plan implementation scenarios, this study evaluates the future water quality of urban rivers in Ha Noi under the effect of urbanization and climate change using Water Evaluation And Planning tool (WEAP) and take the Cau Bay catchment as the case study. The Cau Bay river is a man-made river system and it has been receiving the untreated wastewater of the Long Bien and Gia Lam districts. The result shows that, without implementation of wastewater treatment plant, the water quality of Cau Bay River will be worse with the DO in dry season is mg/l and BOD is - mg/l. With the implementation of Master plan, the level of DO and BOD would be - mg/l and mg/l respectively in the dry season whereas the values are - mg/l and - mg/l in the wet season. The degradation of wastewater during the wet season is resulted from the combine- overflow sewage system as designed in the master plan when excess wastewater was discharged directly to the river during storm. | Evaluating future water quality of urban rivers in Ha Noi under effect of urbanization and climate change - The application of weap model for Cau bay river
