An overview of research on agricultural non-point source pollution modelling in China

Abstract With the development of technology for controlling point source pollution, non-point source (NPS) pollution issues have become increasingly prominent worldwide. Because of the wide range, difficult control and complex uncertainties involved in simulation processes, NPS pollution control has become a hotspot in the area of water pollution control. In China, NPS pollution control will be one of the most important issues in water environmental protection in the next several decades. To control NPS pollution, it is important to know how much there is. In this paper, the authors provide an overview of the current NPS pollution modelling technology in China. We first compared several methods used for estimation of the NPS pollution load in China. We next discussed the advantages and disadvantages of these methods in detail, both from the method itself and the simulation results. We found that most of these methods are derived directly from models developed by several developed countries, especially the USA. Although these models may be suitable to the situation of the country they were designed in, they may not be suitable to the actual situation of China. Other methods have been developed by scholars in China, but these are all very simple and may not provide a good estimation. Finally, we point out that we can only determine if a NPS model is good or bad according to the actual conditions of the study area and the available data for this area. Overall, the results of this study indicated that digesting and absorbing foreign NPS models, modifying the related processes and using related key parameters with Chinese characteristics are the future research direction for NPS pollution modelling in China.