The Study Of Geo-hazard Of Potential Distributions In Liaoning Province

Natural disaster, especially the geologic hazard, is a great challenge in the processes of sustainable development of human being. The geologic hazards in China are is in a great variety, wide distribution and with great damage. In the flood season, driven by the climatic factors, avalanche, landslip, debris flow etc. are occurred frequently. These kinds of geologic hazard occupying above 80% of entire geologic hazard. According to the records of statistic data from 1995 to 2002, the geologic hazard would result in the death of more than 1 thousand people and losing of decades of billion Yuan per year, which would also have bad influence on all enterprise.Liaoning province is located in the south of Northeastern China, and is in the tectonic units between China-Korea paraplatform and Tianshan-Xingmeng geosyncline. There are complex geologic environment, high heterogeneity and various geologic hazard with wide distribution and big impaction. Since 1998 to 2002, there are 62 geologic hazards, which occurred in 13 cities. These had threaten the safety of people's life and property. Thus, it is very important to study the potential distribution of geologic hazard in Liaoning Province. This dissertation analysed the potential distribution of geologic hazard using geostatistic, Yamamoto detection, Weight of Evidence and Random Forest on the GIS platform, and drew these conclusions:(1) Geostatistic, Yamamoto detection, climate tendency rate and tendency coefficient were used to explore the spatial and temporal changes of the climate in last 40 years. The CGCM2 model, brought forward by Canadian Centre for Climate Modelling and Analysis was used to supply the future climate scinarios. The research showed that there are warming and drying tendency of Liaoning province in last 40 years. The warming tendency is obvious in spring and winter and drying tendency is obvious in summer and winter. Yamamoto detection showed that there are break in the temperature, especially in summer. There are no break in the precipitation. The spatial analysis showed that, the mean annual temperature have the tendency of degressive from southwest to northeast, and the annual precipitation have the dendency of degressive from east to west. There are spatial variability of the tendency coefficient of temperature and precipitation. In future 100 years, the precipitation and temperature would both increase.(2) Spatial overlap and Butter analysis were used to study the relationships of stratum lithology, geological structure, magma rock, vegetation and soil and geologic hazard, aiming to explore the driven factors of geologic hazard. Research showed that there are intimate spatial relationship between geologic structure and geologic hazards. Liaodong Rift and the fracture structures in the rift supplied a lot of relax and chipping material for debreis flow. Beizheng heave, controlled by geologic structure, also supplied the condition for geologic hazard. At the same time, vegetation and soil factors also have relation to the landslide and debris flow of Liaoning Province.(3) Weight of Evidence was used to study the sensitivity of geologic hazard of Liaoning Province. Resutls showed that, magma rock, stratum lithology and vegetation are the most three important factors controlling the geologic hazard. Weight index map showed that Liaodong Mountains were the highly sensitive area of Liaoning Province, Liaoxi Mountains were next, while the middle plain was the lowly sensitive area. In addition, there are a small highly sensitive area near shenyang city.(4) On the basis of sensitive assessment analysis, we use earthquake, precipitation and temperature as the main factos to assess the fatalness of the geologic hazard by weight of evidence. At the same time, based on the future climate scenarios supplied by CGCM2, we assess the fatalness of the geologic hazard in future 50 and 100 years, then we compared the fatalness of the geologic hazard in three periods. The results showed that Liaodong Mountain is the area with highest fatalness and there are also a small area near shenyang city with higher fatalness. Other area with higher fatalness were Liaoxi Mountains and the northeast part of Liaoning Province. The high fatalness area in future would increase, the area with high fatalness in Liaoxi Mountain would decrease, but the area with high fatalness in Liaodong mountian and northeastern part would increase in 2050 year. The area with high fatalness in northeastern part of Liaoning Province would increase in 2100 year.(5) On the basis of analysis the fatalness assessment, fengchen city, with higher fatalness was chosen as the study are in small scale. The TM image, elevation, day precipitation data (from 1971 to 2000), geologic data and soil data of this area were collected to predict the relationship between precipitation and occurrence rate of geologic hazard by Random Forest technique. The results showed that 1 day and 2 day cummulative precipitation have a directive meaning for geologic hazard. In total area, the cutoff value in northwest part is small, while it is big in southeast part of the area.