HAZARD IDENTIFICATION AND EVALUATION USING UAV PHOTOGRAMMETRY FOR PIPELINE ROUTING

ABSTRACT: The geotechnical engineering aspect of pipeline route selection is a multifaceted process involving detailed studies of ground conditions, natural hazards, and geological history. Assessing ground conditions typically involves preliminary desktop based terrain evaluation tools, boots on the ground field investigations, drilling/sampling/testing, and remote sensing data collection and interpretation. Recent advancements in the field of Structure from Motion (SfM) 3-dimensional (3D) photogrammetry eliminate the onerous requirements of ground control and enable the generation of high resolution digital terrain models at variable resolutions. Photographs can be taken from a variety of aerial platforms or terrestrial locations. In this project we demonstrate the use of Oblique Aerial Photogrammetry from a UAV (OAP-U) for the generation of a detailed terrain models for the evaluation of a pipeline route crossing a deep valley 200 km from Vancouver, British Columbia. The resultant data was used to map slope angles, geological structure, rockmass conditions, thereby allowing for the optimisation of the pipeline route, and to establish a baseline 3D model of the site that could be used for future comparisons to assess ground changes. The incorporation of OAP-U techniques into field mapping projects has greatly increased the information obtained in the field and resulted in a greater understanding of the terrain.