Structural and geomorphological features of landslides in the Bhutan Himalaya derived from Terrestrial Laser Scanning

This study presents data on landslides affecting the main west–east transport corridor in the Himalaya of eastern Bhutan close to the Main Central Thrust. The study focuses on the extraction of structural and geometrical information from Terrestrial Laser Scanning (TLS) data utilising a case study landslide, the Namling Landslide. Analyses of the TLS data allow extraction of slide geometry, discontinuity orientations and identification of the mode of failure. The TLS results are compared to a traditional engineering geological survey and prove to yield considerable added value and should form the basis of new approaches to geomorphological studies and site assessment.Macro-scale geomorphological reconnaissance findings are outlined and interpreted within a conceptual model of the evolution of landslide features, here termed hierarchical landsliding. It is concluded that the Nam Ling Landslide is indicative of deeper seated deformation and is not purely a function of road construction.