... quality 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 ... contribute 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 ... VNU. JOURNAL OF SCIENCE, nat., Sci., & Tech., T.xxI, N02, 2005 5 PRELIMINARY ASSESSMENT AND SIMULATION OF THE WATER QUALITY OF CAU RIVER, BAC NINH PROVINCE BY MATHEMATICAL MODEL...