UAV photogrammetry for reservoir topography mapping: A case study of Hoa Trung and Phu Vinh reservoirs in central Vietnam

Tóm tắt

Central Vietnam frequently experiences extreme weather, especially floods and droughts, requiring effective water storage regulation from numerous large reservoirs. Topographic surveys are crucial for reservoir design, operation, and safety; however, traditional methods face challenges related to cost, time, accuracy, coverage, and safety, particularly in complex terrain. This study evaluates the effectiveness of Unmanned Aerial Vehicles (UAVs) for detailed 3D topographic reconstruction of the Hoa Trung reservoir in Da Nang city and the Phu Vinh reservoir in Quang Tri province, Central Vietnam. The terrestrial 3D terrains of the reservoirs were generated from 1,825 and 4,160 aerial photographs processed using the Structure-from-Motion (SfM) technique of two different software packages, i.e., Agisoft Metashape and Pix4D. Accuracy assessment using design data across multiple dam cross-sections shows elevation errors of less than 1%, with a maximum absolute error of 0.25 m, satisfying relevant technical requirements for topographic mapping. The results confirm that UAV-based SfM photogrammetry combining image interpretation software provides a cost-effective, accurate, and safe approach for reservoir monitoring and topographic updating. Keywords: 3D reservoir topography, structure from motion, UAV photogrammetry Da Nang, Quang Tri.