Research on water flow resistance characteristics in a vegetation environment is a hotspot in environmental fluid research, which is primarily concentrated on the calculation of the vegetation drag coefficient C_d. At present, relatively few studies exist on the resistance characteristics of vegetation under non-uniform flow conditions, resulting in few general expressions for the research of C_d for this type of condition. In response to these scientific problems, this study selects shrub vegetation as the research object and generalised it as cylinders for the simulation study. This study adopts quadratic and Gaussian functions to change the coordinate expression of cylindrical vegetation C_d and then proposes the drag formulas of cylindrical vegetation in non-uniform flow for non-rainfall and heavy rainfall conditions based on regression analysis. Finally, this study substitutes the proposed C_d formula into the Saint-Venant equation to calculate the depth of channel flow. The newly proposed equations are verified by comparing the measured flow depth data with the calculation results. This study provides technical support for refined hydrodynamic simulations of vegetated flow regions.

植被环境中水流阻力特性的研究是环境流体研究的热点，主要集中在植被阻力系数C _d的计算上。目前，针对非均匀流条件下植被阻力特性的研究相对较少，导致针对该类条件的C _d研究缺乏通用表达式。针对这些科学问题，本研究选择灌木植被作为研究对象，将其概括为圆柱体进行模拟研究。本研究采用二次函数 和高斯函数改变圆柱植被C _{d的坐标表达}然后基于回归分析提出了非均匀流下圆柱形植被在非降雨和强降雨条件下的阻力公式。最后，本研究将提出的C _d公式代入圣维南方程来计算河道水流深度。通过将测量的流深数据与计算结果进行比较，验证了新提出的方程。该研究为植被流动区域的精细水动力模拟提供了技术支持。