... and improving the water quality model for Cau River, we carried out the research: “Preliminary assessment and simulation of the water quality of Cau River, Bac Ninh province by mathematical model”. ... standard of Vietnam (TCVN 5942/95/B) [4, 9]. The two reasons for this situation are the discharges of cattle waste into channels then to river and the uses of fertilizer. • The concentrations of ... side-effects of economic developments which is greater than ever are environmental problems, especially water pollution. At present, with the pressure of environmental pollution, river water quality...