The Study on Current Situation of Ecological Environment and Recommendation of Ecological Red Line in Mangshi City: An Example for Non-point Sources Pollution of Mangshi River

For the characteristics of water resources and hydrological inter annual variation in Mangshi city, the monitoring data of Mangshi river were collected all year. Empirical analysis of environmental management, environmental impact assessment, environmental monitoring and ecological red line were conducted to build comprehensive recommendation. The results shows that:(1) Comparing Gazhong section, the water quality of Fengping section was Ⅲ~Ⅳ, and the content of ammonia nitrogen and chemical oxygen demand have reached maximum in May were 2.318 mg/L and 19 mg/L. The CODMn have reached maximum in July was 5.5 mg/L. While the BOD5 have reached two maximum values in March and July were 6 mg/L. (2) The content of total coliform group over 40 000/L, showed the change of S curve in all year. In general, for the one of the most important river in Mangshi, strict the total amount control of pollutants emission, strength monitoring and supervision and improve the current situation of water environment are the key of solving the limitations and problems in Mangshi rivers.