Kinematic-based landslide risk management for the Sichuan-Tibet Grid Interconnection Project (STGIP) in China

Abstract

Landslides are major threats to the construction and operation of electric towers of the Sichuan–Tibet Grid Interconnection Project (STGIP). The long, narrow project corridor is vulnerable to different types of landslides, making risk management a difficult task. In this study, a kinematic-based, landslide risk management framework that includes hazard analysis, risk estimation, risk evaluation, and risk control is proposed and implemented. The spatial density of historical landslides and the spatial distribution of landslide kinematics are used to analyze landslide hazard. Kinetic energy derived from the landslide physical process model is employed to analyze the vulnerability of the towers in the risk estimation step. Then, the landslide hazard and tower vulnerability are used to comprehensively evaluate the landslide risk level of the electric towers. Electric towers with high risk are mainly situated in areas near rivers and faults, with fragile steep slopes. Fragmented rock masses and a thick regolith cover provide abundant materials for landslides, and steep slopes supply the initial conditions and energy that make them a risk. Risk-control strategies are provided based on site-specific risk. The safe construction and operation of the STGIP in the past 10 years show the effectiveness and reliability of the proposed framework. We suggest that the workflow and guidelines for landslide risk management used in this study can be adopted for large engineering projects in complex environments.