Pollution trend in the tumen river and its influence on regional development

The Tumen River had failed to meet Grade III and IV levels in the environmental quality standard for surface water, and had exceeded Grade V level. Surface water pollution is serious. The major excessive standard pollutants were COD_Mn and SS. After taking effective treatment steps, the worsening trend of water pollution will be basically under control. But the change of runoff in the Tumen River is large in a year, especially during as long as five-month freezing period, smaller flow and lower temperature of river waters led to weak dilution and self-purification capacity. The water quality of the Tumen River will not reach the appoint functional water quality standards, even if sewage meets discharge standard, which will influence water resources utilization in the lower reaches of the Tumen River and regional economic development. Therefore water pollution has become the major restrictive factor of the development of the Tumen River area.