Inspecting Unattended Irrigation Canals of Dujiangyan in Mountainous Area with UAV Remote Sensing Technology

The irrigation system of Dujiangyan takes charge of irrigating about 1 million hectare farmland in the Midwest of Sichuan Basin. It costs huge manpower and financial resources to periodically conduct manual inspection on the full range of irrigation canals, especially in mountainous area. With the advantages of low cost, flexible taking-off and landing, and hyperspatial image resolution, Unmanned Aerial Vehicles (UAVs) are very suitable for obtaining photographs along the irrigation canals. In this paper, two test sites of the Renmin Canal were chosen for UAV operations. The UAV system and its major components were introduced along with the planned flight routes, acquired UAV images, and photographing parameters. Aerial triangulation, generation of DSM and DOM, and textured 3D scenery were described followed by confidence-based edge detection and mean shift image segmentation on DOM. Then the ancillary buildings of the two test sites were identified and the current status of the irrigation canal was assessed on the resulting DOMs and DSMs. Results proved the feasibility and potential of applying the UAV system to rapidly inspecting unattended irrigation canals in mountainous area.