基于GIS的青川县滑坡灾害易发性评价与区划

发布时间：2017-12-27 04:03

本文关键词：基于GIS的青川县滑坡灾害易发性评价与区划　出处：《西南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：青川县位于川、甘、陕交界处,地势西北高南东低,地质环境复杂,是我国受滑坡灾害影响最为严重的地区之一,已经严重制约着当地社会的经济发展。本文依托四川省青川县地质灾害详细调查项目,根据收集的资料及野外实地调查的数据,分析了研究区的自然地理条件和地质环境背景,探讨了滑坡灾害的形成条件、发育机理、分布特征及影响因素。在此基础上,选取坡度、相对高差、地质岩性、距断层、公路、水系等的距离以及年平均降雨量作为评价指标,利用ARCGIS软件,提取了相关图层的数据,建立了信息量评价模型,实现了对青川县滑坡灾害易发性的分区评价。同时选取了典型滑坡点对评价结果进行了验证,最后提出了滑坡灾害防治对策。取得了以下研究成果:1、在较为详细的分析研究区自然地理环境及区域地质环境条件的基础上,对研究区的滑坡灾害的发育特征,形成机理及影响因素进行分析。研究区内的滑坡灾害主要表现为数量多、分布广,在时空上、行政区域分布不均匀,但在地段上分布较为集中。2、对研究区滑坡灾害的分布特征进行分析,在地形地貌上,滑坡主要分布在低山地貌区,这一区域地形高差变化大,切割强烈,而且为人类聚居区,容易诱发滑坡灾害。在时间上,滑坡主要发生在6-8月,雨季是滑坡灾害的易发期。3、在对研究区滑坡灾害的影响因素的分析基础上,构建了坡度、相对高差、地层岩性、分别距断层、公路、水系的距离及年平均降雨量等7个因素的评价指标体系,利用GIS软件,采用信息量模型进行了滑坡灾害易发性评价。研究结果表明:青川县滑坡灾害高易发区面积为688.72km2,占全县总面积的21.41%;滑坡灾害中易发区面积为1455.24km2,占全县总面积的45.25%;滑坡灾害低、微易发区面积为1072.27km2,占全县总面积的33.34%。评价结果与实际调查情况相吻合。4、选取了典型滑坡点,经过现场勘查、室内试验,然后对滑体、滑床、滑动面及滑坡变形破坏特征进行分析,利用传递系数法进行了稳定性评价。得出典型滑坡点在天然均处于稳定状态,在暴雨工况下,滑坡整体处于基本稳定,安全储备较低,易再次在强降雨或者持续降雨下发生更大规模的变形。5、根据研究区滑坡灾害易发性分区及典型灾害点的稳定性分析结果,提出了群策群防、搬迁避让和工程治理等措施。
[Abstract]:Qingchuan county is located in Sichuan, Gansu and Shaanxi at the junction of the high terrain in the northwest, southeast low, complex geological environment, the landslide disaster is our country by one of the worst affected areas, has seriously restricted the local social and economic development. Based on the detailed investigation of geological disasters in Sichuan County of Qingchuan Province, according to the collected data and field survey data, analyzes the natural geographical conditions and geological environment of the study area, discusses the landslide formation condition, development mechanism, distribution characteristics and influencing factors. On this basis, the selection of slope, relative elevation, lithology, distance from the fault, highway, water distance and average annual rainfall as the evaluation index, using ARCGIS software, extract the relevant data layer, established information quantity evaluation model, to achieve the partition evaluation of landslide hazards in Qingchuan County of susceptibility. At the same time, the typical landslide points are selected to verify the evaluation results. Finally, the Countermeasures of landslide disaster prevention and control are put forward. The following research results have been achieved: 1. Based on the detailed analysis of the natural geographical environment and regional geological environment, the development characteristics, formation mechanism and influencing factors of landslide in the study area are analyzed. The landslide disaster in the study area is mainly characterized by large quantity and wide distribution, and the distribution of the administrative region is uneven in time and space, but the distribution is more concentrated in the area. 2, the distribution characteristics of landslide hazard in the study area are analyzed. In terms of topography and landform, landslides are mainly distributed in low mountain geomorphic area, where the terrain height difference is large and cutting is intense, and it is easy to induce landslide hazard for human settlements. In time, the landslide occurred mainly in 6-8 months, and the rainy season is the easy period of landslide disaster. 3, based on the analysis on Influencing Factors of landslide disasters in the study area, the construction of slope, relative elevation, lithology, fault, highway, water from the distance and the average annual rainfall of 7 factors of the evaluation index system, using the GIS software, the information model of landslide susceptibility assessment. The results show that: Qingchuan County landslide disaster prone areas of high area of 688.72km2, accounting for 21.41% of the total area of the county; landslide prone area is 1455.24km2, accounting for 45.25% of the total area of the county; landslide prone areas of low and micro area of 1072.27km2, accounting for 33.34% of the total area of the county. The results of the evaluation coincide with the actual survey. 4, select the typical landslide point, after field investigation and laboratory test, then analyze the characteristics of landslide, sliding bed, sliding surface and landslide deformation and failure, and use the transfer coefficient method to evaluate the stability. It is concluded that the typical landslide sites are all in a stable state. Under the rainstorm condition, the landslide is basically stable, and the safety reserve is low. It is easy to occur more large-scale deformation under heavy rainfall or continuous rainfall. 5, according to the results of stability analysis of landslide prone areas and typical disaster points in the study area, measures for group decision making prevention, relocation, avoidance and engineering management are put forward.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22

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