Geohazard detection and analysis along an electricity transmission line in Tibet, China

Abstract

To facilitate scientific decision-making and geohazard prevention and mitigation during the construction and operation of an electricity transmission line projects in Tibet, China, this paper used remote sensing (RS) and geographic information system (GIS) technologies to semi-automatically extract potential geohazards along this line which pose threats to the transmission towers from the perspective of drainage basin, especially for the high-speed and long run-out geohazards, such as glacial landslides and debris flows (triggered by glacial lake burst and rainstorm). Spatial analysis tools are used to model the relationships among different geohazards and towers, according to the development and movement laws of each kind of geological disasters and position information of the towers. Using the proposed extraction model, 37 geohazards posing direct threats to 93 towers were automatically filtered. These were corroborated by field investigations and should be monitored during the following construction and line operation stage. The results show that the proposed model based on spatial analysis can quickly filter and locate geohazards and the corresponding towers, especially for the hazards with a long distance to the transmission towers, and effectively reduce the workload of field investigation.