The Risk Evaluation of Model Nonpoint-source Agricultural Pollution

Abstract

Keywords: the model of risk evaluation; nonpoint-source; agricultural pollution Abstract. It is difficult to measure non-point source pollution. Compared with other models used in the study of non-point source pollution, INVEST risk assessment is available in agricultural non-point source pollution, which will provide a model for further study of non-point source pollution in large scale space. The progress of models to assess nonpoint-source agricultural pollution Nonpoint-source pollution models might be helpful for us to analyze the spatial and temporal characteristics, identify the main sources and paths, forecast generation load of pollution and the impact on water because complex pollution process has been reported in the system of all basins or regions. Also, the assessments on changes in land use and different technical measures of nonpoint-source pollution and water quality will provide a basis for management decision-making(1). Recently, there are two ways to forecast model for nonpoint-source pollution load like nitrogen, phosphorus, pesticides and so on. The first method is called as empirical model, including the output coefficient, Universal Soil Loss Equation estimation, correlation, pollution segmentation, rainfall interpolation. The second one is estimated by the introduction of foreign distribution model. The main applications of the pollution load models include CREAMS model, HSPF model, SWAT model, ANSWERS model, etc. (2-8). These above models mentioned have applied widely on abroad because of high accuracy on simulation. However, there are a lot of parameters in these models, and some of the data are difficult to obtain, for example, we could need long-term monitoring results for water quality and quantity in some models. The lack phenomenon of current basic data, hydrological and meteorological information is serious in China, and the basic investigations on basins are not enough in various cities. The monitoring points of nonpoint-source emissions are set not too much. Thus, the applications and development of models above are restricted.