为保证漯河市西城区防洪安全，减小澧河城区段防洪压力，规划在沙河和澧河弯道相距最近的大楼魏村附近新开挖一条导洪河道，将澧河洪水提前分流入沙河。本文选取9种洪水流量组合，分别建立数学模型和物理模型，对改道前后的沙河、澧河的水力特性进行研究，确定工程对两河河势的影响程度和范围，为工程设计提供依据。模拟结果表明：各组合流量情况下，研究范围内沙河水位、流速等均无明显变化；澧河改道段上游河道流速略有增大、水位因流量组合工况不同而产生壅高和降低。可见，改道工程的实施主要对改道段出口沙河弯道段有一定影响，该段河道需承受上游沙、澧河双向水流，流态紊乱，两侧岸坡均迎流顶冲，应做好岸坡防护工程。

In order to ensure the flood control safety in the Xicheng district of Luohe City and reduce the flood control pressure at the urban section of the Lihe River, a new river channel was planned to be excavated in the Dalouwei village where the Shahe River and Lihe River are the closest, and thus the flood in the Lihe River can be diverted into the Shahe River. In this paper, nine scenarios of flood discharge were selected to develop the three-dimensional numerical models and physical models. In order to provide the basis for project design, hydraulic characteristics in the Lihe River and Shahe River before and after the reconstruction project were investigated, and the effects of the reconstruction project on the river regime were analyzed. The results showed that the water level and flow velocity in the Shahe River have insignificant changes under different scenarios of flood discharge, and the flow velocity in the upstream of the Lihe River reconstruction section increases slightly and the water level in the upstream of the Lihe River reconstruction section can increase or decrease under different scenarios of flood discharge. Therefore, the implementation of the Lihe River reconstruction project has impacts on the river bend section of the Shahe River at the outlet of reconstruction section. The section needs to bear the two-way river flow in the upstream of Shahe River and Lihe River, which can have turbid flow field, and thus the slope protection engineering is needed.