A remote sensing approach for the derivation of numerical modelling input data: insights from the Hope Slide, Canada

In this paper, we describe an integrated remote sensing approach for the collection of geomechanical data to be used as input for continuum, discontinuum, and hybrid numerical analyses. Ground-based and aerial remote sensing techniques, including terrestrial digital photogrammetry (TDP), terrestrial laser scanning (TLS), structure-frommotion photogrammetry (SfM), and terrestrial infrared thermography (IRT) may be used for collecting rock mass data appropriate for input into varied numerical modelling approaches. To demonstrate our suggested approach, we have used the 1965 Hope Slide, British Columbia, Canada. We present the mapping of rock discontinuities for numerical modelling using a hierarchical geological structure order. Large-scale geological structures which were identified and mapped on the pre-failure and present-day topography are used in a preliminary analysis of the rock slope to investigate their influence on kinematic freedom and in bounding keyblocks. Detailed geomechanical mapping is performed on three-dimensional TDP models. IRT data is used to characterize surface water seepage. Unmanned aerial vehicle (UAV) SfM imagery of the landslide debris was used to analyse the block size distribution. Preliminary numerical discontinuum 3D-DEM modelling based on this data and assigned mechanical properties shows that with detailed planning and systematic field data collection techniques, the geological engineer can obtain the data necessary to reduce both model and parameter uncertainty and allow more reliable and realistic numerical slope simulations.