Demonstration Site Construction Plan For Er Yuan Planting Non-point Source Pollution Control Integration

Erhai is the second largest lakes in Yunnan province,regarding as the “morther lake” for local Dali people.However,with the development of economy,the water quality becomes more and more serious,which the eutrophication occurred frequently,such as Blue-green algae and algae bloom.Nitrogen and phosphorus pollution has a close relationship with the non-point source pollution,especially the unreasonable planting structure,excessive fertilizer application,and unreasonable water management in planting industry.Eryuan County is the source of northern Erhai,and accounted for 70% of runoff for Erhai.In Eryuan County,planting industry is pillar industry.However it becomes the main source area of nitrogen and phosphorous input,due to the intensive agriculture and unreasonable production.Therefore the prevention and control of Eryuan planting non-point source pollution is the key to solve the problem of eutrophication in Erhai,which playing a very important role for protection water resources,water ecological environment and the whole of Erhai aquatic ecological environment.Many scholars have done research and prevention measures of non-point source pollution in Erhai area.Although the effects are significant,only a partial or single treatment is unable to control the non-point source pollution from the root formation.The demonstration design is based on the characteristics of planting non-point source pollution,such as low concentration,wide distribution,and difficult to control,applying “4R” technology to achieve comprehensive treatment from source to end,to reduce the nitrogen and phosphorus load from planting industry.The core idea of this project is the combination of technologies such as source reduction,process interruption,nutrient recycling and ecological remediation to control pollutants in the whole system.Focusing on the paddy upland rotation system of planting industry in Eryuan County,the study designed the demonstration project scheme of non-point source pollution control for planting industry,based on the analysis of the characteristics of non-point source pollution in this area.First the source control measures is considered,combining of planting structure adjustment,ecological ridge design,drainage and recharge of paddy field,controlled irrigation for paddy,soil improvement and so on.Then the nitrogen and phosphorus load is further reduced by setting up ecological ditch,purifying pool,blocking and controlling pond,and nutrient cycling technology such as tailrace recharge.Those combined technologies will reduce the formation of non-point source pollution,and achieve the goal of source control,emission reduction,circulation and restoration.This demonstration project is expected to set an example for effectively prevent and control of non-point source pollution in Erhai area,and provides technical support for the improvement of water quality as well.