基于分布式非点源有毒污染物模型的农药输移研究

Simulation of Pesticide Transportation with a Distributed Non-point Pesticide Pollution Model

以山东省临沂流域为研究区,基于分布式非点源有毒污染物模型ESSI-2对当地的农药输移过程进行研究。选取甲基异柳磷为模拟农药种类,基于合理的农药假设数据,对分布式有毒污染物模型ESSI-2进行参数率定,并基于模拟结果,对临沂流域的甲基异柳磷负荷及其输移的空间分布特征进行了分析。结果表明,分布式非点源有毒污染物模型是研究农药输移过程的首选工具。临沂流域在农药施用初期,其空间分布主要与农药的施用相关,随着时间的推移,在水流的作用下,农药逐渐向河道汇聚,从而流向下游流域,在这一阶段中,地表径流是影响农药输移的主要因素。

An increasing number of researchers have been studying pesticide pollution remained in the cultivated fields using the distributed non-point source pesticide model. On the basis of a distributed non-point source pesticide pollution model ESSI-2, this paper studied the process of pesticide transportation in Linyi catchment. Taking Isofenphos methyl as a simulated pesticide, and a reasonable pesticide concentration as an assumption, the ESSI-2 model was calibrated based on the acceptance level of the simulation results. The spatial distribu- tion of pesticide transportation was analyzed by making use of the output of pesticide loading capacity. Study results are drawn as follows ： （ 1 ）The distributed non-point source pollution model is a preferred tool to simulated the process of pesticide transportation in term of simu- lation precision and operational practicality. （2）The spatial distribution of pesticide was highly related to the different stages of its transporta- tion. In the initial stage of pesticide spray in the cultivated fields, the spatial distribution of pesticides is primarily determined by the amount of pesticide usage in various locations. As time elapses, surface water flow palys a more important role in the spatial distribution and transportation of pesticide, resulting in the pesticides conflux to the stream course gradually and then to the downstream watershed. This simulated result provides an important basis for not only studies on water resource management in general, but also further research on pesticide transportation in particular.