基于MIKE21模型的汉江中下游水环境影响风险研究  

Study on Water Environment Impact Risk in the Middle and Lower Reaches of Han River by MIKE21 Model

作　　者：赵晓磊 Zhao Xiaolei(Shanghai Investigation Design&Research Institute Company,Shanghai 200335,China)

机构地区：[1]上海勘测设计研究院有限公司,上海200335

出　　处：《绿色科技》2022年第10期54-61,74,共9页Journal of Green Science and Technology

基　　金：中国长江三峡集团有限公司科研项目(编号:202003134)。

摘　　要：汉江是长江中游最长的一级支流,汉江流域是实施全国最严格水资源保护制度的试点流域,在经济和社会的发展中有不可替代的战略作用。然而近年来汉江中下游水污染事件频发,导致水环境质量下降,甚至严重影响沿江用水安全。为进一步增强流域预警预报能力,为流域水生态环境风险管控提供理论支撑,基于汉江中下游干流和入汇支流多年水质数据,建立了MIKE21二维水动力水质耦合模型,对汉江中下游水量水质动态变化过程进行了模拟,并对模型进行了率定验证。同时在该模型基础上模拟4种不同流量设计值工况下突发水污染事故对下游水质的影响,研究分析了污染物动态扩散变化过程,结果显示:当流量设计为3926.63 m^(3)/s和1787.68 m^(3)/s时,下游河段仍为Ⅱ类水,突发事故并未对河道造成污染;当流量设计为816.05 m^(3)/s时,下游部分河段被污染为Ⅲ类水,并历经约55h后污染河道基本恢复为Ⅱ类水;当流量设计为387.23 m^(3)/s时,下游很长一段河道被污染为Ⅳ类水,并历经97 h后污染带基本恢复为Ⅱ类水。As the longest primary tributary of the middle reaches of the Yangtze River,Han River Basin is also the pilot basin for the implementation of the strictest water resources protection system in China.It plays an irreplaceable strategic role in economic and social development.However,in recent years,water pollution events in the middle and lower reaches of Han River occur frequently,which not only reduces the water environment quality,but also affects the water safety along the river seriously.In order to further enhance the early warning and forecasting ability of the basin and provide theoretical support for watershed water ecological environment risk management and control,based on the multi-year water environment data of the main stream and tributaries in the middle and lower reaches of Han River,this study establishes MIKE21 two-dimensional hydrodynamic and water quality coupling model to simulate the dynamic change process of water quantity and quality,and calibrates and tests the model.After model validation,this paper simulates the impact of sudden water pollution accidents on water quality of main stream under four different flow design values and analyses the dynamic change process of pollutant diffusion.The results show that the downstream section is still classⅡwater and sudden accident doesn't pollute the river when the flow design values are 3926.63 m^(3)/s and 1787.68 m^(3)/s.When the flow design value is 816.05 m^(3)/s,part of the downstream section is contaminated to classⅢwater.After about 55 hours,the polluted river channel is basically recovered to classⅡwater.When the flow design value is 387.23 m^(3)/s,a long section of river downstream is contaminated to classⅣwater.And after 97 hours,the polluted zone is basically recovered to classⅡwater.

关 键 词：MIKE21模型 汉江中下游 水动力水质耦合模型 突发水污染事故 污染物扩散影响研究 

分 类 号：X321[环境科学与工程—环境工程]