基于GIS的秦州区地质灾害危险性分区与评价

发布时间：2018-11-24 11:16

【摘要】：进入21世纪以来，因自然灾害尤其是地质灾害造成人员伤亡及财产损失事件越来越频繁，所以人类要从科学的意义上认识这些灾害的发生、发展以尽可能减小它们所造成的危害，这已是国际社会的一个共同主题。本论文以甘肃省秦州区为研究对象，进行了地质灾害危险性区划研究。本论文在充分搜集秦州区气象水文、自然地理和区域地质环境等资料的基础上，结合地质灾害点的实际调查资料，对秦州区地质灾害的类型、发育特征及形成机理进行了详细的分析，并以基于GIS的综合评判法和模糊综合评判法对秦州区进行地质灾害的危险性区划，得出秦州区的危险性分区图，并对两种方法得出的结果进行分析和对比。通过研究得出以下几点认识：（1）查明了秦州区地质灾害的类型、分布规律、发育特征及形成条件。秦州区发育的地质灾害类型主要包括滑坡、崩塌、泥石流与不稳定斜坡；受地形条件、气象水文条件及人类工程活动的影响，研究区内地质灾害具有高中山区灾害少、低中山河谷区灾害发育集中以及各乡镇分布极不均匀的特征；发育特征呈现出群发性、突发性和链生性。地质灾害形成的条件包括地形条件、地层岩性、水文条件、地质构造和地震，诱发因素为降雨和人类工程活动。（2）采用三级评价体系，选取地质灾害点密度、植被指数（NDVI）、地貌、水系、工程地质岩组、降雨量和人类工程活动共7个具体评价因子构成秦州区地质灾害的危险性区划评价指标，并采用层次分析法确定各指标的权重。（3）利用基于GIS的综合评判法，在ARCGIS平台下，以秦州区1:100000比例尺数字地质灾害防治规划图及地质灾害详细调查数据为依据，将利用DEM数据划分出的斜坡单元作为评价单元，在提取7个评价指标图层的基础上进行加权叠置分析，绘制出秦州区危险性分区图。（4）利用模糊综合评判法，以1km×lkm的规则网格单元作为评价单元，用梯形函数确定隶属度，对各个指标进行危险性等级划分，采用模糊综合评判法对提取的7个评价指标图层进行计算，得出秦州区地质灾害的危险性分区图。（5）利用ARCGIS的重分类功能把秦州区划分为地质灾害高危险性区域、中危险性区域和低危险性区域，通过对两种区划结果对比分析，得出两种危险性区划方法的结果比较接近，且与实际地质灾害的发生情况基本吻合。最后，，提出了秦州区地质灾害的防治措施及建议。
[Abstract]:Since the beginning of the 21st century, the casualties and property losses caused by natural disasters, especially geological disasters, have become more and more frequent. Therefore, human beings should understand the occurrence of these disasters in a scientific sense. Development to minimize their harm has become a common theme for the international community. Taking Qinzhou District of Gansu Province as the research object, the geological hazard zoning is studied in this paper. On the basis of collecting the data of meteorology, hydrology, natural geography and regional geological environment in Qinzhou District, combined with the actual investigation data of geological hazard sites, the types of geological hazards in Qinzhou District are analyzed in this paper. The development characteristics and formation mechanism are analyzed in detail, and the hazard zoning of geological hazards in Qinzhou district is obtained by comprehensive evaluation method based on GIS and fuzzy comprehensive evaluation method, and the hazard zoning map of Qinzhou district is obtained. The results obtained by the two methods are analyzed and compared. The main conclusions are as follows: (1) the types, distribution, developmental characteristics and forming conditions of geological disasters in Qinzhou district are found out. The types of geological hazards developed in Qinzhou include landslide, collapse, debris flow and unstable slope. Under the influence of topography, meteorological and hydrological conditions and human engineering activities, the geological hazards in the study area are characterized by less disasters in high and middle mountain areas, concentrated disasters in low mountain valleys, and extremely uneven distribution of villages and towns. The developmental characteristics are group, sudden and chain. The conditions for the formation of geological hazards include topography, stratigraphic lithology, hydrological conditions, geological structures and earthquakes, and the induced factors are rainfall and human engineering activities. (2) adopting the three-level evaluation system, selecting the geological hazard point density, the vegetation index (NDVI), geomorphology, the water system, the engineering geological rock formation, There are seven evaluation factors including rainfall and human engineering activities, which constitute the evaluation index of geological hazard risk regionalization in Qinzhou district, and the weight of each index is determined by analytic hierarchy process (AHP). (3) based on the comprehensive evaluation method based on GIS, and based on the 1: 100000 scale digital geological hazard prevention planning map and detailed geological hazard investigation data of Qinzhou District under the ARCGIS platform, The slope unit which is divided by DEM data is used as the evaluation unit. On the basis of extracting seven evaluation index layers, the weighted overlay analysis is carried out, and the dangerous zoning map of Qinzhou district is drawn. (4) using fuzzy comprehensive evaluation method, taking 1km 脳 lkm regular grid unit as evaluation unit, using trapezoidal function to determine membership degree and dividing each index into dangerous grades. The fuzzy comprehensive evaluation method is used to calculate the seven evaluation index layers extracted and the hazard zoning map of geological hazards in Qinzhou district is obtained. (5) the Qinzhou district is divided into high risk area, middle risk area and low risk area by using the reclassification function of ARCGIS. Through the comparison and analysis of the two zoning results, it is concluded that the results of the two dangerous regionalization methods are close to each other. It is consistent with the actual occurrence of geological disasters. Finally, the prevention measures and suggestions of geological hazards in Qinzhou district are put forward.
【学位授予单位】：西北师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P694;P208

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