Anshan Xiuyan County Mudflows Risk Assessment Research

Mud flow as one of the most common geologic hazards has been largely noticed and paid much attention around the whole world. With the continuous enhance of society development and economy activities, both excessive demand of resource and persistent damage of environment make the mud flow to be worse. As a result, we must do effort to strengthen certain investigation, estimate, early warning, forecast and disaster reduction management in reference to mud flow, organizing economical and effective preventive measures for the precaution against occurrence and reducing the loss by mud flow as far as possible.Mud flow is a non-linear complex system going with uncertainty. On account of the differences of application conditions and fields, extant hazard assessment model shows powerlessness when it's used in the terms of certain problems such as mud flow uncertainty, the relationship among evaluating indicator conditions and the like. For promoting further development of mud flow hazard assessment model system, solving extant parts of problems, this thesis takes Xiuyan country as an example and will have a try to utilize extenics theory based on rough sets evaluation formula and to do detailed research.Take a major growth place-Manchu autonomous country of Yanyou in the city of Anshan in Liaoning province as a research area, with natural valleies of mud flow growth as units, using formation conditions and other factors as the context to do research to mud flow damage and to estimate its hazard in Xiuyan country in particular. Study the following aspects in details:(1) Analyse mud flow space time distribution and influence factors:the mud flow distributes obviously and regularly though the distribution range of mud flow in Xiuyan country is quite broad. At first, analyse the distribution regular of space and time of mud flow in research area, then taking statistical analysis to the influence factors of formation. And the analysis results which are not only good for recognizing geological process of mud flow formation, but also supply reference evidence to establish mud flow hazard assessment index system in research area.(2) Mud flow hazard assessment:with small valleies of mud flow gully as units, depending on field survey, distinguishing severity of mud flow gullies, by choosing 11 evaluating indicators from both historical risk and potential risk to estimate 39 branches of mud flow gullies's risk, then utilizing rough sets evaluation formula to classify gullies into four grades, they are advanced risk of mud flow gully, moderate risk of mud flow gully, low risk of mud flow gully and minute risk of mud flow gully.(3) Analyse land use and vegetation coverage changes during 20 years in mud flow gully area:according to remote sensing interpretation results from there periods(1985, 1995,2005), by contrasting and analysing the changing trend of land use and changing rate of vegetation coverage of each mud flow gully, sequentially to reveal the influence intensity of natural environment by human activities doing research influences caused by land use and vegetation coverage in reference to mud flow's formation and development.(4) Prediction for changing trend of mud flow:to analyse the influence of mud flow disaster from many points like geological evolution, hydro-meteorology, vegetation variation and the changing and development trend for engineering economics and activities by human and to forecast the development trend of mud flow in future.