复杂河网地区航道整治工程对防洪的影响分析

Research on influence of navigation improvement project on complex river network area

为了研究芜申运河安徽段航道整治工程(包括青弋江线和水阳江两条线路)对流域河网水系防洪的影响,应用Mike11水动力学模型,模拟遇设计标准洪水和超标准洪水条件下,航道整治工程实施前后水阳江、青弋江、漳河流域关键控制站点的水位变化、水阳江干流中游分洪量变化以及航道整治对流场流态的影响情况。分析表明,航道整治工程实施后,控制站点水位降低或者保持不变,水阳江干流分洪量有所减少,并且航道整治工程对河道进行拓展底宽、疏浚挖深、撇弯切滩及局部河段裁弯、退堤等工程措施,扩大了河道行洪断面,增加了泄流能力,整体上有利于河道行洪,符合流域"上、中、下游兼顾,上游以蓄为主;中游蓄泄兼施;下游在充分利用湖泊调蓄作用的基础上,尽可能将洪水外排"的防洪治理原则,对水阳江、青弋江、漳河流域防洪是有利的。航道整治工程实施后,工程段内近岸流速普遍减小,对局部区域近岸流速增大的情况,建议加强观测,若影响堤防或岸坡稳定,应及时加强防护。

In order to study the influence of the navigation improvement project,including the two routes of Qingyi River and Shuiyang River,on flood control of the complex river network,we simulate the water level variation of the key control stations in Shuiyang,Qingyi and Zhanghe river basins,flood diversion variation of middle reach of Shuiyang stem and flow pattern in the flow field before and after construction of the project using Mike11 model,under the conditions of designed standard flood and excessive standard flood.The results show that after construction of the project,the water levels at the control stations are decreasing or constant and the flood diversion of middle reach of Shuiyang stem decreases.The project follows the principles of flood control,which fully considers the upper,middle and lower reaches,and the treatment as a whole is beneficial to the flood control of Shuiyang,Qingyi and Zhanghe basins.After construction of the project,the flow velocity near the banks in the project area decreases generally.Therefore,it is suggested that we should strengthen the monitoring of the local area near the banks where the flow velocity increases and protection measures should be taken in time if embankment or bank slope is instable.