基于河道断面的三维水面构建方法研究

Research on 3D Water Surface Construction Method Based on River Cross-Section

摘要: 三维水面是数字孪生水利重要的可视化元素，可以直观展示洪水演进、洪水淹没过程，为管理提供决策支撑。本文提出了基于河道断面洪水位的三维水面构建方法，首先是基于等值线粗略确定河道水面边界，其次是对分布在河道上下游的断面水位数据进行不规则三角网构网与调整，然后采用栅格模型计算、图像二值化等空间分析方法精确提取河道二维水面线，最后通过高程映射实现河道三维水面构建。以湖北省某水电站下游河段为研究区域，基于沿程断面50年一遇设计洪水位构建了三维水面，并结合该区域实景三维模型构建了数字化场景，验证了三维水面高程精度，最大差值−0.33 m，最小差值0.01 m，结果表明该方法能精准有效表达河道水位的平面与高程变化。

Abstract: The 3D water surface is an important visualization element in digital twin water conservancy, which can intuitively demonstrate flood routing and flood inundation processes, providing decision support for management. This paper proposes a method for constructing a 3D water surface based on flood levels in river cross-sections, Firstly, the boundary of the river water surface is roughly determined based on isoline, Secondly, irregular triangulation and adjustment of cross-sectional water level data are distributed upstream and downstream of the river channel. Then, spatial analysis methods such as raster model calculation and image binarization are used to accurately extract the 2D water surface line of the river. Finally, the 3D water surface is achieved through elevation mapping. Taking the downstream river section of a hydropower station in Hubei Province as the research area, the 3D water surface was constructed based on the 50-year design flood level of cross-sections along the river. A digital scene was also constructed by combining the real-world 3D model of the area. The accuracy of the 3D water surface elevation was validated, with a maximum difference of −0.33 m and a minimum of 0.01 m. The results show that the method can accurately and effectively represent the planar and elevation changes of river water levels.