Influence of the Bottomland with Dikes on Flood Discharge of Juzhang River
The bottomland with dikes has a great effect on the flood stage of Juzhang River.It should be distinguished whether it has been flooded in different years when water surface profiles were calculated,and its roughness coefficients should differ from main channels.In this paper,the water surface profiles of Juzhang River with frequency of the biggest flood in 20,10 and 5 years were calculated,which came to the conclusion that if the bottomland with dikes was cleaned out,the water level of Herong would fell by 0.43~0.53 m,the water level of Zhangjiakou by 0.60~0.79 m and the Fengtai by 1.00~1.44 m.So cleaning out the bottomland with dikes of Juzhang River contributes to the flood releasing capacity.