基于随机过程的南通市西山河水质超标风险分析

以南通市西山河为研究对象，通过现场采样、实验室检测获取了氨氮、总磷、六价铬、挥发酚及COD等水质指标的监测数据．采用基于复合泊松过程建立的天然水体水质超标的随机风险模型．估算了监测水质指标的超标风险率，并通过拟合优度检验，证明该模型的合理有效性．通过超标风险率的分析，得出在未来时间内，除六价铬较为安全外，氨氮、总磷的超标随机风险率均为100％，COD为99．95％，挥发酚为99．01％．西山河水质超标的风险性极大．应及时预防．

An Excessive Risk Analysis of Water Quality in Xishan River of Nantong Based on Stochastic Process

The study obtained water quality data of Xishan River by such indicators like ammonia nitrogen, total phosphorus, Cr6＋, volatile phenol and COD. This study analyzed the risk rate of water quality change exceeding the standard values by the clustering stochastic point process model, based on theory of compound Poisson process. Meanwhile a goodness of fit test was performed after a stochastic process analysis. The result showed that the model is reasonable and effective. According to the analysis, except Cr＋, the rest quality index are at high risks. Among them, the risk rate exceeding water quality standard of ammonia nitrogen and total phosphorus are 100%, COD is 99.95%, volatile phenol is 99.01%. It is urgent to take more effective precautions to prevent.