为加强突发水污染事件的风险防范和应急处置,保障长江三峡库区水体环境安全,收集重庆市2009—2018年间165起突发环境事件数据,采用统计分析的方法,探讨10 a来突发水污染事件时空分布及发生特征。结果表明:突发水污染事件是重庆市突发环境事件的主要类型,占突发环境事件总数的83.6%,其数量总体呈波动下降趋势;突发水污染事件主要集中在主城九区及周边的区县,渝东南、渝东北各区县发生次数相对较少;在重庆市境内的六大水系中,长江上游干流水系、嘉陵江水系发生突发水污染事件次数占总数的84.8%;突发水污染事件的主要诱因为道路交通事故、设备故障和操作不当,其发生主要形式为有毒有害物质泄漏进入水体;突发水污染事件出现频率较高的污染物为油类、废水类、有机物、酸碱类、液氨和减水剂。研究成果可为加强突发水污染事件的风险防范和保障三峡库区的水环境安全提供参考。

The aim of this research is to enhance the risk prevention and treatment of water pollution emergencies and to ensure the water environment safety in the Three Gorges Reservoir area of the Yangtze River. The spatiotemporal distribution and occurrence characteristics of sudden water pollution incidents in the recent decade are statistically analyzed based on collected data of 165 environmental emergencies in Chongqing from 2009 to 2018. Results reveal that water pollution emergency is the major type of environmental emergencies in Chongqing, accounting for 83.6%. The number of water emergency displays a trend of fluctuation and decline. Water pollution emergencies mainly happened in the nine districts of the main urban area and the surrounding districts/counties of Chongqing, while infrequently in the southeastern and northeastern districts/counties of Chongqing. Among the six major river networks in Chongqing, 84.8% of the total water pollution incidents occurred in the upper reaches of the Yangtze River and Jialing River. The major inducing factors of water pollution emergencies are road traffic accidents, equipment failure and improper operation in the form of toxic and harmful substances leaking into the water. The most frequent pollutants are oils, waste water, organics, acids, alkalis, liquid ammonia and water reducers admixture.