The Simulation And Optimization Tool For Awatershed’s Agricultural Non-point Source Pollution Control

It has characteristics of rainfall concentrated，high nutrient content in top layer，strong freezing and thawing of soil and nitrogen and phosphorus loss serious innortheast China.In view ofthese characteristics and by a large number of basicresearch,such as analysis of agricultural non-point source pollution situationinnortheast China and topical regional’s pollution characteristics,theresearchchoseAshiRiver watershed as a typical area of agricultural non-point source pollution innortheast China.A simulation and optimization system for agricultural non-pointsource pollution control in AshiRiver watershed was established. Thesystemrealizedthe function and application with the help of asoftwareplatform.Firstly,according the current characteristic of land use,meteorological and hydrological and agricultural production, the macroscopicanalysis for situation of agricultural non-point source pollutionin northeast china hasbeen carried. Heilongjiang province, as one of the most important grain productionbase,has the largest number of agricultural pollution sources in our nation. In order tofurther study,the research evaluatedthe pollution load of total nitrogen (TN) and totalphosphorus (TP) from agricultural non-point source pollution in Harbin region by theexport load model, and the pollution characteristics were analyzed from theperspective of diagnosing agricultural land use situation. The source of theagricultural non-point pollution was divided into three aspects: land utilization,livestock and poultry breeding and the lives of rural residents. The analysis resultsindicate that the region as a typical intensive form of the Songhua River watershed,the output load（TN and TP）increases year by year.The export load of TN is fargreater than TP, so TNis the main pollutants in research area.The main factor affectingagricultural non-point source pollution in this region is land utilization, and theagricultural land is the biggest contributor to the pollution load of TN and TP, with thelargest contribution from the corn land. That suggests that, intensive farming, singleplanting patterns and blind excessive fertilization are major causes of agriculturalnon-point source pollution. The contributions to pollution load of TN and TP fromLivestock and poultry breeding is rank only second to after land utilization, and non-point source pollution caused by the lives of rural residents should not beneglected.Based onthe above research results, a systemwas conducted forsimulationand optimization of agricultural non-point source pollution controlandanalysis of theinteraction mechanism between watershed agricultural land use and waterenvironment. Based on collection of a large number of data information and fieldmonitoring, a information management systemfor agricultural non-point sourcepollution control, meeting thedata demandof the simulation and optimization systemfor agricultural non-point source pollution control. The study established responsecontact between various influencing factors of agricultural non-point source pollutionand export total load of watershed, and used monitoring data of watershed outletwater quality to validate the reliability of the model.Through input quantitative resultsof improved agricultural management measures to simulation and optimizationsystem, the study achieved evaluation optimization effect, providingfor the basis forload reduction and optimization scheme. In order to make the whole process ofsimulation and optimization more accurate, simple and quick, this study realized theconnection of the data management systems, simulation and optimization of non-pointsource pollution process by computer software, using Java language to writesimulation and optimization system for agricultural non-point source pollutioncontrol.The effect optimization schemeof agricultural non-point source pollutioncontrol in watershed wasobtainedfrom the evaluationofpollution reduction measuresby the simulation and optimization system.It can provide decision support forwatershed agricultural non-point source pollution control. The simulation andoptimization results show that improving fertilizer NPK ratio, increasing organicfertilizer application and balance of corn and soybeans planting structure are effectiveoptimization strategy for agricultural non-point source pollution in this watershed...