Extreme weather happened frequently in recent years

in which “7·21” rainstorm in 2012 and “23·7”catastrophic flood in the drainage area had made a huge loss in Beijing. In order to promote the standardized management of river course

to strengthen the management and supervision on basin area

and to understand the effects of trees in river course on the flood discharge

this article uses HEC-RAS and MIKE 21FM hydrodynamic software to build a one-dimensional and two-dimensional mathematical model of the Chaobai River in sections. By simulating the inundation of floods with different frequencies

the impact of existing trees in different sections of the Chaobai River on flood level

flow velocity

and flow pattern is studied and analyzed. Furthermore

the article proposes suggestions for tree planting and removal in the river

providing references for river management and “clearing the four chaotic behaviors”(rectifying the illegal occupation

exploitation

rubbish piling-up

and construction on river courses).