基于GIS的福建省流域单元滑坡敏感性研究

发布时间：2018-04-08 15:13

本文选题：滑坡　切入点：流域单元　出处：《福建师范大学》2016年硕士论文

【摘要】：近年来,频发的滑坡事件给人们的生命财产安全带来了极大的威胁,严重制约了社会经济的发展。福建省作为我国滑坡发生的重灾区之一,研究其滑坡空间分布规律及其易发性情况对于滑坡的防治具有重要意义。本文在基于野外调查和已有福建省滑坡研究案例的基础上,归纳总结了福建省滑坡的成因；接着选取了11个环境因子,运用频率和密度统计方法,从定量角度分析了滑坡与环境因子的关系；最后,提出了用滑坡环境因子基尼系数计算评价因子对滑坡贡献权重的方法,构建了流域单元的滑坡敏感性识别模型,对福建省7492个子流域的滑坡敏感性进行了评估,主要得到以下结论：(].)基于野外调研结果和已有的福建省滑坡研究案例,总结了福建省滑坡成因。滑坡作为福建省最严重的地质灾害之一,受区域人类活动、降雨情况、地形地貌、地质构造、植被等综合作用。就其诱因来讲,主要是人类活动,如削坡建房、陡坡开垦、大型工程建设、矿山开采等破坏生态环境稳定性,在降雨作用下诱发滑坡的发生。(2)在总结福建省滑坡成因的基础上,选择高程、坡度、地形起伏度、坡向、地形曲率、平均年降雨量、植被覆盖度、地形湿度指数(Topographic Wetness Index,TWI)、水流强度指数(Stream Power Index, SPI)、土地利用、土壤类型11个环境因子,基于福建省5166个滑坡样本点,统计了上述各因子区间上滑坡发生的频率和密度。从滑坡与单因子的关系来看：福建省滑坡多发生在1500-1800mm降水带内；植被覆盖度在50～80%时为滑坡高易发区：在100-800m高程区间带上滑坡发生的可能性最大；坡度在10～25°之间为滑坡易发区,尤其坡度在15°左右时,滑坡密度最大；起伏度在100-200m之间为滑坡易发区,即滑坡多发生在丘陵地带；从坡向来看,滑坡主要分布在南向和西南向坡地上,北向和西北向坡地则分布较少:从滑坡分布的坡型来看,在凹型和凸型坡上都有分布,但凸型坡上分布密度高于凹型坡；滑坡多集中于红壤与水稻土；耕地中最易发生滑坡,其次是建设用地和园地。从滑坡与复合地形因子关系来看：在高程0-100m区间上,坡度大于10°时滑坡发生的敏感性高于10°以下；在100-800m高程区间,坡度在0-20°区域比20°以上,滑坡更为易发；在800m以上高程区间,0-25°坡度范围滑坡比较集中；福建省滑坡多发于丘陵地带,在中起伏山地不易发；同时从滑坡与复合地形因子的关系可以间接推导出人类活动是福建省滑坡的诱因之一。(3)基于福建省30m分辨率的ASTER GDEM数据,运用ArcGIS中的水文分析模型,通过提取河网水系,进行水系分级,对福建省2级水系所对应的流域进行划分,经制图综合,得到7492个福建省子流域单元。结合滑坡与环境因子的定量统计结果,选取高程、坡度、起伏度、平均年降雨量、TWI、植被覆盖度、土地利用和土壤类型8个环境因子,基于上述因子各子区间上的滑坡密度与区域滑坡平均密度之比,计算得到滑坡在因子各子区间上的易发性值；同时,提出了用滑坡环境因子基尼系数计算评价因子对滑坡贡献权重的方法,构建了流域单元滑坡敏感性评价模型,对福建省7492个子流域单元的滑坡敏感性进行定量识别,结果精度达到75%。本方法可以为大区域的滑坡敏感性评价提供参考,同时研究得到的福建省流域单元滑坡敏感性等级图可以为相关部门的滑坡防范、土地利用规划等提供借鉴。
[Abstract]:In recent years, landslide incidents poses a great threat to the safety of people's lives and property, seriously restricts the development of society and economy. Fujian province is one of China's landslide disaster area, study the landslide spatial distribution and susceptibility for landslide prevention has important significance. Based on the field Fujian Province Survey and the existing landslide case studies, summarized the causes of landslides in Fujian province; then we select 11 environmental factors, using the frequency and density of statistical methods, quantitative analysis of the relationship between landslides and environmental factors; finally, proposes a method of evaluating factors of landslide contribution weight calculation of landslide environment the Gene factor coefficient, construct the landslide susceptibility recognition model of watershed unit, 7492 sub basin of landslide susceptibility in Fujian province was evaluated, the main conclusions as follows : (.) study on landslide cases in Fujian province and based on the results of field investigation, summed up Fujian province. One of the causes of landslide Landslide Geological Disasters in Fujian Province as the most serious, regional human activities, rainfall, topography, geological structure, the effect of vegetation. Their causes, mainly human activities. Such as cut slopebuildings, steep slope reclamation, large-scale construction, mining and other damage to the ecological environment stability under rainfall induced landslides occurred. (2) in Fujian province were summarized on the basis of the cause of landslide, elevation, slope, terrain, slope, terrain curvature, mean annual rainfall, vegetation cover the degree of Topographic Wetness Index (Topographic, Wetness, Index, TWI) (Stream Power Index flow intensity index, SPI), land use, soil type 11 environmental factors, samples of 5166 landslides in Fujian Province Based on statistics, the area of each factor Between landslide frequency and density occurred. From the relationship between landslide and the single factor of Fujian Province: the landslide occurred in the 1500-1800mm precipitation zone; vegetation coverage in 50 ~ 80% for landslide prone areas: most likely on the 100-800m elevation with landslide occurrence interval; slope at 10~25 degrees between the landslide easily in particular, the slope at about 15 degrees, the maximum density fluctuation in the landslide; between 100-200m landslide prone areas, namely the landslide occurred in the hilly areas; from the aspect of view, the landslide is mainly distributed in the South and southwest slope, to the north and northwest slope is less distributed from slope landslide the distribution, are distributed in the concave and convex slope, but convex slope distribution density is higher than that of the concave slope; landslide are more concentrated in the red soil and paddy soil; the most prone to landslides in farmland, followed by land and garden construction from landslide and complex. Close relationship: the terrain factor on the elevation of 0-100m interval, slope greater than 10 degrees when the landslide sensitivity is higher than that of less than 10 degrees; in 100-800m elevation range, slope area than at 0-20 degrees 20 degrees, more prone to landslide; elevation above 800m interval, 0-25 degree slope landslide concentrated; landslide in Fujian province mainly in the hilly area in mountainous region is not easily; at the same time from the relationship between landslide and composite terrain factor can indirectly derived from human activity is one of the causes of landslides in Fujian province. (3) ASTER GDEM 30m resolution data of Fujian Province Based on the analytical model of hydrological transport in ArcGIS, through the extraction of river network. Water basin classification, corresponding to the 2 level system of Fujian province are divided by comprehensive mapping, 7492 Fujian sub basin unit. Combining quantitative and statistical results of landslide and environmental factors, selection of high slope process, The ups and downs of average annual rainfall, TWI, vegetation coverage, land use and soil type 8 environmental factors, landslide density and area of the factor of each sub interval on the average density of landslide based on the ratio calculated in each sub interval factor of landslide susceptibility value; at the same time, a method is proposed to evaluate the factor of the weight calculated by landslide Landslide with environmental factors of the Gene coefficient, constructed watershed unit landslide susceptibility evaluation model for quantitative identification of landslide susceptibility of 7492 sub units of the basin in Fujian Province, the accuracy of this method can reach 75%. that regional landslide susceptibility assessment to provide a reference, the basin of Fujian, the research unit at the same time the landslide susceptibility rating map you can prevent landslide for the relevant departments, to provide reference for land use planning.

【学位授予单位】：福建师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P642.22

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