河道整治对洪水情势影响的初步分析——以松阳县松阴溪干流为例

河道整治特别是两岸堤防的新建、加高和加固等措施是提高河道防洪能力的主要工程手段,但是河道堤防在满足设计标准后,在发生设计频率洪水时,原来的洪水漫滩现象大大减少,这将增加下游的洪峰流量,洪峰时间也将提前,对下游的防洪有一定的不利影响。以松阳县松阴溪干流为例,通过河道非恒定流模型计算发现,松阴溪流域遭遇20年一遇洪水时,河道堤防整治后靖居口水文站处洪峰流量将增大5.3%,峰现时间提前0.9 h。

Primary Performance of the River Regulation to Flood Events ---Take Songyinxi River in Songyang County as an Example

The river regulation, especially for the heightening and strengthening measures on both sides of the river embankments, are the major means to improve the flood control capacity of the riv-er.After the river embankments meets the design criteria, when the flood events of design frequency occur the previous floodplain phenomenon greatly reduces, the peak discharge downstream increases, and the flood peak time appears earlier.These will result in disbenefit of flood control.In this paper, the main stream of Songyinxi at Songyang county is selected for study.The results of the river un-steady flow model indicate when Songyinxi river basin experienced 20 -year frequency flood, the peak discharge of Jingjukou hydrological station will increase by 5.3%, and the flood peak time oc-cur 0.9 hour ahead of time after the accomplishment of river embankments regulation project.