基于EFDC模型的长江江苏段水流输运时间研究  

Study on transport timescale in Jiangsu reach of Yangtze River based on EFDC model

作　　者：王文才[1,2] 杜薇 范中亚 姜龙 许益新 李一平 WANG Wencai;DU Wei;FAN Zhongya;JIANG Long;XU Yixin;LI Yiping(Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes and Ministry of Education,Hohai University,Nanjing 210098,China;South China Institute of Environmental Sciences,Ministry of Ecology and Environment,Guangzhou 510655,China;Nanjing Institute of Environmental Sciences,Ministry of Ecology and Environment,Nanjing 210042,China)

机构地区：[1]河海大学浅水湖泊综合治理与资源开发教育部重点实验室,江苏南京210098 [2]生态环境部华南环境科学研究所,广东广州510655 [3]生态环境部南京环境科学研究所,江苏南京210042

出　　处：《人民长江》2019年第5期70-75,共6页Yangtze River

基　　金：国家重点研发计划项目(2016YFC0401703);中央级公益性科研院所基本科研业务专项(PM-zx703-201701-005);国家水体污染控制与治理重大专项(2014ZX07206-005)

摘　　要：水流动力过程是水体中物质迁移转化的基础和前置条件,某一段特定的水体中水流的输运速度会影响其水体交换程度和污染物自净能力。基于EFDC(环境流体动力学模型)中的水龄(WA)和拉格朗日粒子示踪模块,以周边经济较发达、污染负荷排放量较大的长江江苏段(南京至徐六泾)为研究对象,模拟在上游不同设计流量及特定下边界潮位条件下的江段水龄分布及拉格朗日粒子输移时间的规律,分析上游径流对江段水体输运的影响。研究结果表明:受下游潮汐的影响,越靠近下游水体输运越慢;水体输运时间在相对较小的径流量下受流量影响较大;拉格朗日粒子示踪的方法相较于水龄计算的方法,下游水流的输运计算结果受下游开边界条件影响较小;水流沿程的输运时间与径流量可以采用二次函数进行回归分析,水流从入口输运到达或完全通过特定站点的时间以及相应站点的水龄均可以采用幂函数进行回归计算,都有较好的效果。模型模拟的方法可以很好地反映和刻画研究区域内水体的输运特征,模拟研究可以增加对感潮河流中物质输移过程的认识,为河流中突发污染事故的预警和管理措施提供新的思路。Water transport process is the basic condition of pollutants transformation, the flowing velocity of the process has a significant influence on water exchange and pollutants degradation. Based on the water age and Lagrangian particle tracer module of Environmental Fluid Dynamic Code (EFDC), we analyzed the effect of upstream Yangtze River runoff on water transport in Jiangsu reach under different designed discharge and specific lower boundary tide level. The specific study reaches was from Nanjing to Xuliujing, where the surrounding economy is well developed and pollution load discharge is large. The results showed that the transport time was slower in the lower reaches due to the effect of tide and much more significant influence by discharge under the small flow. Comparing the transport time given by the two calculating methods, the Lagrangian particle tracer method is much more stable because the water age method can be influenced by downstream open boundary condition. The relationship between the transport time and runoff along the flow path could be calculated by quadratic function. The relationship between the transport time of the water flow reaching the inlet to or completely passing through the specific site and the water age of the corresponding site can be calculated by the power function, and both the fitting effects were very good. The numerical model simulation method can reflect and characterize the water transport characteristic in the study area. This study can increase our understanding of the process of material transport in tidal rivers, and provide new ideas for early warning and management measures of sudden polluted accidents in rivers.

关 键 词：水流输运 水龄 拉格朗日粒子 感潮河流 长江江苏段 

分 类 号：P33[天文地球—水文科学]