Susceptibility Analysis And Assessment Of The Debris Flow Disaster In Jilin Province

Geological environment of Jilin province is complex, Geological disasterespecially debris flows occur frequently in the annual rainy season, causes hugeeconomic losses. Investigation and regionalization of geological disaster have beencarried in geological disaster area, which provides the basic data for the preventionand control of geological disaster.The paper according to Jilin province county (city) comprehensive research ongeological disaster investigation and regionalization (serial number of theproject: MLR environment [2008]76),uses the results of geological disasterinvestigation and regionalization of county in Jilin province, Sudden geologicalhazard investigation data in recent years, and Jilin province geological disasterprevention and control works, with reference to “the County (city) comprehensivestudy of geological disasters technical requirements” which the Chinese geologicalenvironmental monitoring institute formulates,“1:50000regional hydrologicalengineering geological environment comprehensive geological survey andspecification”（GB/T14158—93）,and geological disaster survey technicalstandards(1:25000-1:50000). The paper collected geology, hydrogeology, engineeringgeology, environmental geology, hydrology, meteorology and related data of socialand economic development, has carried on the comprehensive analysis and summaryabout debris flow disasters, and analyzes the development of debris flow disasterdistribution, development characteristics, the main influence factors and importantpoint distribution and the damage degree of the debris flow hazard. This paperanalyses the debris flow disaster and rainfall, the relation between the factors such asgeological environment conditions, establishes the evaluation model of susceptibilityof debris flow hazards, whole province is divided into four areas. In addition the papercompletes debris flow disaster zoning map of Jilin province. Finally, the paper obtainsthe following results and conclusions:(1) Debris flow is one of general development and frequent activity geologicaldisasters in the eastern mountain area of Jilin Province. There are three kinds of debrisflow in Jilin Province, valley pattern, gully pattern and slope pattern according to theformation conditions, There are mud flow and water flow according to the materialcomposition. There are1407debris flows totally, most is small debris flow.(2) This paper selects the following seven prediction indicators landforms, slope,rock and soil, annual average precipitation, vegetation coverage rate and population density as the main disaster inducing factors for the study of debris flow in JilinProvince, according to the characteristics of geological disasters in Jilin Province andthe result of comprehensive analysis in the platform of ARCGIS.(3) An analysis was carried out to the sensitive factors of debris flow in JilinProvince based on rough set theory. In order to make the evaluation index morereasonable and reliable,after attribute reduction and remove redundant data，sort ofDebris Flow Sensitivity：slope、terrain elevation、population density、vegetation coveragerate、rock and soil type、average annual rainfall、landform, slope、elevation、populationdensity and vegetation coverage rate are sensitive to debris flow. The others are not.(4)We could draw the Sort of importance of7prediction index by the rough settheory, calculated the weight coefficient based on Rough set theory and hierarchyanalysis method. On the basis of the above, the optimal weighting coefficient of theEvaluation index was determined. This method avoided the disadvantages of thetraditional AHP method, making the evaluation results more objective.(5) Evaluation model with extenics theory was established. The study area wasdivided into1km×1km unit grids with ARCGIS. Susceptibility of debris flow wasevaluated in each grid. Based on the criterion, the same in the same region, thedifferent in the different region, debris flow susceptibility of Jilin Province wasdivided into four parts, as the follow, high possibility, possibility, low possibility,impossibility.(6) Based on the analysis of data for debris flow indicators, analysis andevaluation system of Jilin province debris flow was established on the ARCGISplatform. The system could be used to predict the susceptibility of debris flow. Sevenindicators, such as, landforms, slope, etc., were selected to analyze and evaluate thedebris flow susceptibility in Jilin Province with extenics theory on ARCGIS platform.