Design And Simulation Selection Of Prevention And Control Mode For Watershed Agricultural Non-point Source Pollution

With the improvement of the control of the point source pollution,the non-point source pollution has become an important source of water pollution.In the study of agricultural non-point source pollution,domestic scholars have carried out a number of projects and achieved certain effects.However,those projects are relatively decentralized and failed to form an integrated solution.Learning from the management experience of the control of the agricultural non-point source pollution in foreign countries,the study chose the best management to manage the non-point source pollution in watershed scale.Take the Ashe River for example,the study collected the engineering measures of non-point source pollution in northeast area,and recorded the efficiency of these measures.According to mechanism of the non-point source pollution,these engineering measures were divided into three categories: measures from the source,measures in the process,and measures on the bank.According to the production and living conditions of local residents,the study chose some of the engineering measures and developed six governance programs and they are Commonly Used Type,Policy Oriented Type,Farmers' Active Participation,Scientific Type,High Efficiency and Source Control type.Agricultural non-point source pollution is mainly nitrogen and phosphorus,and the reduction effect of nitrogen and phosphorus in each measure is different.In this study,the effect of nitrogen and phosphorus reduction of each model will be calculated separately.For convenient application,the study generated a software model named Calculation System of the Prevention and Control to Agricultural Non-point Source Pollution.The model took the efficiency of the engineering measures as the input parameters,and took the output parameters as the efficiency of the governance programs.The effect of reduction of the nitrogen in the six models is 82.94%,67.65%,75.27%,72.50%,45.21% and 90.34%;and the effect of reduction of the phosphorusim the six models is80.31%,56.56%,73.55%,81.06%,44.54% and 86.80%.By comparing the optimization results of each model,the study selected two best management plans for the management of the agricultural non-point source pollution,one is the Policyoriented,and the other is the High Efficiency.These two sets are adapted to the northeast region.The research method in this study is meaningful to the agricultural non-point source pollution control of the other places in China.