Characteristics of the geological hazard distribution and the control measures in Yiliang county, Yunnan

Situated in the northeastern of Yunnan province, Yiliang county belongs to geological hazards pivot prevention and control region of Yongshan-Yiliang landslides and debris flows and one of the seven geological hazards pivot prevention and control regions in Yunnan. The geological hazard investigation in 2003 showed that there were 236 geological hazards, including 181 landslides, 9 unstable slopes and 34 debris flows as well as 12 collapses. Moreover, the landslides and debris flows were dominant disasters in this research area. The results from comprehensive analysis indicated the geological hazard mainly resulted from not only geological and geographic environment factors, such as landform and relief, rainstorms and karst as well as neo-tectonic movement, but also slop-cutting and huge goafs in mining areas by human activity. On the basis of the intensity of several influences, three types of geological hazard region are divided, including high susceptible area in Luoze River-Xiaomixi River, middle susceptible area in Fada-Luowang and low suscepti- ble area in Xiaocaoba and Longjie-Kuixiang. Furthermore, the authors put forward some constructive suggestions for the prevention, control and management as well as publicity and education on geological hazard.