Risk evaluation of urban seismogeology and geological hazards in Kangding,western Sichuan

The Kangding city is situated within the Kangding fault in the southeastern part of the Xianshuihe fault, where the developed second faults and fractured rock masses may be liable to bring about abundant geological hazards triggered by rainfalls and human's economic activities. 25 sites of geological hazards have been determined, including 14 landslides, 3 collapses, 5 debris flows and 3 potential unstable slopes within the city proper. These geological hazards tend to be scattered along the slopes of the rivers and gullies in the urban districts, and are highly threatening the safety of life and properties. As long as severe earthquakes and resulting second geological hazards take place, the city proper will be subjected to disastrous consequences. The risks of urban safety are constantly increasing due to the speeding up of the pace of urbanization construction and the increase of the fault activities in recent years. Therefore, it is imperative to put forward the rational planning of urban scales, scientific investigation of urban environments and effective steps of prevention countermeasures.