Identification of potential rockfall sources using UAV-derived point cloud

Abstract

Recent advances in remote sensing techniques and computer algorithms allow accurate, abundant, and high-resolution geometric information retrieval for rock mass characterization from 3D point clouds. The automatic application of the extracted information for local scale rockfall susceptibility assessment, where discontinuities characteristics play a major role in rocky slope stability, requires step by step logical procedures. This paper presents a novel methodology to use the extracted discontinuity set characteristics for a local scale rockfall susceptibility assessment, tailored for Uncrewed Aerial Vehicle (UAV) data acquisition. The method consists of 4 steps: (i) 3D slope model reconstruction using UAV digital photogrammetry, (ii) automatic characterization of discontinuity sets, (iii) slope stability analysis, and (iv) susceptibility assessment using a new Rockfall Susceptibility Index. The proposed method was applied to a road cut rocky slope in a mountainous area of the Samaria National Park, in Crete Island, Greece. Visual validation indicates that the areas of higher and moderate rockfall susceptibility on the 3D model of the rocky slope are adjacent to rockfall source areas marked by the presence of fallen blocks on the foot of the slope. The proposed methodological workflow presents novelties related to the use of point clouds for the estimation of the Rock Quality Designation (RQD) index, the visualization of discontinuity set spacing, the evaluation of the persistence and the Slope Mass Rating (SMR) index, as well as the incorporation of the persistence of overhangs into the rockfall susceptibility assessment and visualization.

An Integration of UAV-Based Photogrammetry and 3D Modelling for Rockfall Hazard Assessment: The Cárcavos Case in 2018 (Spain)

“…The high cost and scale of the LiDAR instrumentation itself also motivated the sci-entific community to show interest in alternative techniques such as SfM to develop surface models. In addition, the SfM technique demonstrated its usefulness by generateing 3DPC to identify, delimit and georeference the families of discontinuities in rock outcrops [85,86], and to allow the performance of high-accuracy rockfall simulations [20,87,88]. The contribution of UAVs to rockfalls can have various applications, including recognition, mapping and monitoring.…”

Novel methods for quantitative analysis of kinematic stability and slope mass rating in jointed rock slopes with the aid of a new computer application

“…Several works have been done to assess rock slope stability on the basis of slope mass rating (Singh et al 2014(Singh et al , 2015Sarkar et al 2016;Mahanta et al 2016;Siddique et al 2017;Sardana et al 2019). In addition to the application in rock slopes, recently, SMR classification system has also been applied to check stability in open pit mines (Prasetya et al 2015;Zakaria et al 2016;Morales et al 2019) and detect rockfall hazards in mountainous region (Triana and Hermawan 2020;Albarelli et al 2021). When there is such a wide application of the classification system, the ratings should be determined in a more precise way.…”

The Role of UAS–GIS in Digital Era Governance. A Systematic Literature Review

“…Validating methodology in rocky slopes with different discontinuity characteristics [138][139][140][141][142][143][144][145] Mapping glacial-related landforms…”