New flow field construction method based on vessel-mounted ADCP data

Abstract

Acquiring flow structure characteristics in specific areas and constructing large-scale flow fields are necessary tasks for analyzing the evolution of river channels and developing water conservancy projects. The Acoustic Doppler Current Profiler (ADCP) is commonly used to observe large-scale flow fields in rivers. However, the conventional method of constructing flow fields has several challenges, including inaccurate estimation of flow velocity, distorted identification of flow structure in specific areas, and inability to explain the sediment transport mechanism. Therefore, it is necessary to explore a new method for large-scale flow field construction. This paper utilizes vessel-mounted ADCP data with dense interval single transects, along with single-beam data, to perform optimal flow velocity estimation based on the actual spatial positions of radial velocities. Experiments demonstrate that the method proposed in this paper is superior to the conventional method in estimating magnitude and direction of flow velocity at different water depths. Furthermore, the flow field analysis using the proposed method successfully identifies flow features such as plunging flow and secondary flow. The maximum difference in grid velocity exceeds 0.2 m/s, while the root-mean-square error is reduced by 50 % compared to the conventional method. Results reveal a significant correlation between eddies and scour holes, providing a novel perspective on understanding the sediment transport mechanism of scour holes and exploring the relationship between vertical structures and localized scour.