基于信息量法的兰州市幅滑坡灾害易发性评价

发布时间：2018-06-04 12:04

本文选题：滑坡 + 易发性评价　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：兰州市位于青藏高原和黄土高原交汇处的黄河河谷地带,地质环境条件复杂,受南北两山地形的限制,土地资源紧缺,人类工程活动强烈,滑坡灾害频繁发生,已成为现阶段制约本地区经济、社会发展的主要制约因素之一。研究开展兰州市幅滑坡灾害易发性评价很有必要,是进行危险性和风险评价的基础。滑坡灾害易发程度预测评价区划结果,可为区域土地利用规划编制以及气象地质灾害预警预报提供数据基础。本研究在已有滑坡空间数据库的基础上,开展滑坡控制性单要素数据的敏感性分析,不断优化易发性评价模型,建立了一套符合该地区地质环境特点的易发性评价模型方法体系及流程,为今后利用GIS技术进行同类研究提供借鉴。根据研究区地质环境条件,对兰州市幅滑坡灾害的发育类型进行大致介绍,并对滑坡发育的主要影响因素进行分析,最终选用地形坡度、地形坡向、地形曲率、地形起伏度、土地利用类型及距道路距离作为研究区6个评价指标,利用信息量法确定各个评价指标的权重,并做线性归一化处理。用ArcGIS的空间分析功能编绘各个影响因子的权重图层,再将这些权重图层进行图层间的栅格计算,利用自然间断点分级法将计算得到的易发性指标图层进行分类,最终得到了兰州市幅2016年滑坡灾害易发性分区图层。基于现有资料用同样的方法绘制2000年和2012年的滑坡灾害易发性分区图,用ROC曲线对三年的易发分区结果进行检验并做对比分析,最终选择最符合实际情况的2016年滑坡灾害易发性分区结果,将研究区分为高易发区、中易发区、低易发区和稳定区四类,其中高易发区主要分布在研究区南部、西北部陡峭山区及灌溉林地地带。本文基于信息量法对兰州市幅进行滑坡灾害易发性评价的同时,打破人们对传统易发性评价的看法,在人类工程活动强烈且频繁的地区,将评价指标的变动和不可忽视的人类工程活动因子考虑进去,寻求破解地质环境条件受人类工程活动严重影响的地区开展地质灾害易发性评价的瓶颈,为人们对易发性评价的认识提供了新的视角。
[Abstract]:Lanzhou is located in the Yellow River valley at the junction of the Qinghai-Tibet Plateau and the Loess Plateau. The geological environment is complex, restricted by the topography of the northern and southern mountains, land resources are scarce, human engineering activities are intense, and landslides occur frequently. It has become one of the main restricting factors of local economy and social development at the present stage. It is necessary to study the vulnerability evaluation of landslide hazard in Lanzhou, which is the basis of hazard and risk assessment. The prediction and evaluation of landslide vulnerability can provide a data basis for regional land use planning and early warning and prediction of meteorological and geological disasters. Based on the existing landslide spatial database, the sensitivity analysis of landslide control single factor data is carried out, and the vulnerability evaluation model is optimized. A method system and flow chart of vulnerability evaluation model in accordance with the characteristics of geological environment in this area is established, which provides a reference for similar research by using GIS technology in the future. According to the geological and environmental conditions of the study area, the development types of landslide hazard in Lanzhou are introduced, and the main influencing factors of landslide development are analyzed. Finally, the slope, direction, curvature and relief of landform are selected. The land use type and the distance from the road are used as six evaluation indexes in the study area. The weight of each evaluation index is determined by the method of information quantity, and the linear normalization is done. Using the spatial analysis function of ArcGIS to draw the weight layer of each influence factor, then calculating the grid between the layers, and classifying the easiness index layer by using the natural discontinuous point classification method. Finally, the map layer of susceptibility to landslide hazard in Lanzhou in 2016 is obtained. Based on the existing data, the susceptibility zoning maps of landslide disasters in 2000 and 2012 were drawn by the same method, and the results of three years' vulnerability zoning were tested and compared with the ROC curve. Finally, according to the actual situation, the results of 2016 landslide disaster susceptibility zoning were selected, and the study was divided into four categories: high, middle, low and stable areas, in which the high risk areas were mainly distributed in the southern part of the study area. Steep mountains and irrigated woodlands in the northwest. Based on the method of information quantity, this paper, while evaluating the vulnerability of landslide hazard in Lanzhou, breaks people's view on traditional vulnerability evaluation, and it is in the area where human engineering activities are strong and frequent. Taking into account the change of evaluation indexes and the factors of human engineering activities which should not be ignored, we seek to solve the bottleneck of geological hazard vulnerability assessment in areas where geological environmental conditions are seriously affected by human engineering activities. It provides a new perspective for people's understanding of vulnerability evaluation.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P694

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