ANALYSIS ON THE DEVELOPMENT OF GEOLOGICAL HAZARD AND FAILURE MODE IN YANZI RIVER BASIN

Based on the surveying results of geological hazard investigation, the development characteristics of geological hazard in the Yanzihe river basin were analyzed. Then, the failure modes of landslide and rockfall were studied. Results shows that the geological hazards in the study area are mainly consist of landslides, rockfallsand debris flows. Those disasters are mainly located in the valley slopes especially in the Kangxian County-Yangba town road where human activities are concentrated. Most of the geological hazardsare occurred during the rainy season from July to September. The landslides are mainly in small scale and occurred within shallow cover layers. The main type of rock fall is in small scale and are occurred in low rocky slopes. Then, the majority of debris flowswereoccurred in valley and driven by rainstorms. From the aspect of failure modes:most of the rock could be classified as fracturing-load falling, bending-topping and fracturing-sliding; the landslides could be classified as creep-tension creaking and sliding-tension cracking. The results offers technical support for geological hazard prevention, town planning, landuse and so on.