Application of unmanned aerial vehicle remote sensing technology in hydrological monitoring for water conservancy projects

The article provides a brief introduction to hydrological monitoring and the methods of water body identification and flow velocity estimation based on unmanned aerial vehicle (UAV) remote sensing technology. Then, a case study of hydrological monitoring using UAV remote sensing technology was conducted on Gangnan Reservoir in Hebei Province. The effectiveness of the convolutional neural network (CNN) algorithm was verified, and measurements were made on the reservoir’s water area and average flow velocity in both flood and non-flood periods during 2020, 2021, and 2022. It was found that the CNN algorithm effectively identified water areas in UAV remote sensing images. Compared to non-flood periods, there was a significant increase in the water area of the reservoir during flood periods, as well as a noticeable increase in average flow velocity upstream; however, there was no significant change in average flow velocity downstream of the reservoir.