Abstract: Tibet, the main part of the QinghaiTibet Plateau, is a hypersensitive terrain for the generation of debris flows and landslides, and is noteworthy for active tectonism, sharp changes in topography, and for cold, dry conditions at high elevations contrasting with intense rainfall in valleys.  Widespread in Tibet, debris flows are triggered by glacial meltwater, glacial lake outburst floods, rainstorms and freezethaw activity.  Thick deposits of large landslides, both modern and ancient, are common.  In general, debris flows and landslides are associated with faults, seismic zones, deeply incised valleys, and road construction. The different types and scales of flows and slope failures occur in valley and highland areas.  Construction activities in areas that are susceptible to debrisflow and landslide formation frequently result in major disasters in Tibet. The mountainous sections of the SichuanTibet Highway along the Polongzangbu valley and of the ChinaNepal Highway from Nielamu to the Friendship Bridge are selected as cases proposed for a hazard monitoring and warning system for highway safety.  A total of 26 towns at risk of debrisflows and landslides have been identified, and a specific plan of risk reduction for the typical Tibetan town of Nielamu, site of a previous debrisflow disaster, has been prepared.  The plan consists of a monitoring and warning system, engineering structures, and specific emergency countermeasures.

Key words: Tibet, debrisflow, landslide, monitoring and warming, disaster prevention, risky management