UAV-based tri-spatial monitoring of environmental resources in southwestern China’s complex terrain

Steep relief and dense vegetation in Southwest China constrain ground surveys through poor sight lines, uneven sampling, and higher operational risk. We propose a UAV (Unmanned Aerial Vehicle) based approach for complex terrain: with a tri-spatial (Air-Sidewall-Ground) observation structure coupled with a “Point-Line-Area” design tying sampling points, flight paths, and sample plots. Multi-platform drone operations generated regional terrain, 3D models, and target identification outputs. In representative mountain plots, the method withstood vegetation occlusion, sharp relief, and fragmented surfaces. Overall, it increases data completeness and object detectability and offers a replicable workflow for ecological monitoring, geological surveying, and resource assessment in rugged mountains.