Study On Landslide Risk Management Of County Region In Southern Mountainous Area Of Shaanxi Province

Landslide risk management is a research focus in the fields of hazard geology andengineering geology, and it is also an important part of the disaster prevention and mitigationstrategy system. In China, landslide risk management is still at the exploratory stage comparedwith the international popular management, including the technical processes and methods.The mountainous area in the south of Shaanxi Province is one of the severely afflicted areaswith high incidence of geological disasters in China, and the landslide casualties and propertylosses take place almost every year. In view of these reasons, a study on the landslide riskmanagement of county region has an important and practical significance to disasterprevention and mitigation of these areas.A case study was carried out based on the landslide risk investigation in NingqiangCounty, a mountainous area of the southern Shaanxi Province. The indicators, methods,flowcharts and technical guidelines of risk analysis were studied both from the qualitativeanalysis and quantitative evaluation, and from different spatial and temporal scales as well.The risk tolerability criteria for the loss of life was discussed and defined by usingstatistical and comparative analysis method based on the recent year’s casualties caused bylandslides in China and other twelve frequently-occurring provinces of China, that is: theupper limit of the acceptable risk is1×10^-6per annum and the maximum of tolerable risk is1×10^-4per annum for the natural landslides, and for the engineered slopes, the upper limit ofthe acceptable risk is1×10^-7per annum and the maximum of the tolerable risk is1×10^-5perannum. The methods for determine economic risk criteria of county landslide was discussedwith the socio-economic development actual of Ningqiang County. The landslide risk gradingand evaluation matrix was defined by the landslide hazard and harmfulness qualitative analysis.What’s more, the landslide risk treatment methods and flowcharts were also analyzed anddiscussed.Finally, the County Landslide Risk Management Information System （CLRMIS） was developed and achieved on the basis of theoretical research. The system was applied andtested by landslide data in Ningqiang County, and the results show that the CLRMIS is able toprovide an effective support of the landslide risk management, landslide prevention andmitigation for local authorities.