Identification of unstable bedrock promontory on steep slope based on UAV photogrammetry.

Conventional, manual methods of surveying unstable bedrock promontories on high and steep slopes are very risky and time-consuming due to problems regarding steep terrain and traffic inconvenience. This paper describes an unmanned aerial vehicle (UAV)-based method for the identification of unstable bedrock promontories. The first step is the spatial position identification of bedrock promontories, which is implemented by processing point cloud models with the one-class support vector machine (OC-SVM) and clustering algorithm. The next step is the preliminary stability assessment of bedrock promontories. Kinematic analysis by mapping the orientations of penetrative discontinuities within bedrock promontories is used to evaluate the stability. The applicability of the method is assessed using the point cloud model of the bank slopes of the Lianghekou Hydropower Project. The results show that effective identification, and preliminary stability assessment of bedrock promontories can be carried out using UAV photogrammetry. [ABSTRACT FROM AUTHOR]