【作者】 张雪峰；

【导师】 孙传敏； 何政伟；

【作者基本信息】 成都理工大学 ， 第四纪地质学， 2011， 博士

【摘要】 人类的生存史上从未曾间断过与地质灾害的斗争。在全球板块构造活跃、气象条件异常和人类不断拓展生存空间的今天,地质灾害对人类造成的威胁仅次于地震,成为第二大自然灾害。地质灾害往往具有突发性、多发性和连续性的特点,为了提高对地质灾害的防御能力,需要掌握地质灾害的发育特征和发展规律,估算灾害造成的损失大小,这就是地质灾害风险评价研究的范畴。地质灾害风险的研究已开展多年,虽然对于其研究方法和技术体系等重要问题的看法仍有分歧,但各国学者均认同地质灾害风险评价是防灾减灾的重要一环,是风险管理和制定区域发展规划的前提和基础。对于区域地质灾害风险评价,评价结果是否合理,能否用于指导防灾减灾,主要决定于3个方面:首先是否建立了能够全面、系统地体现区域地质灾害风险特征的评价指标体系;其次,是否建立了合理的风险评价模型;第三,能否将指标因子和评价模型整合于一套平台以实现快速、准确地分析和决策。本文紧紧围绕区域地质灾害风险评价中的关键问题,立足于以“评价手段信息化、评价过程可视化、评价结果定量化、评价目的服务化”为趋势的国内外最新的研究动态,选择位于中国西部山区地质环境脆弱、地质灾害发育、社会经济落后的甘孜藏族自治州作为研究区,以地质灾害风险评价方法论为指导,针对风险评价中两大核心问题——概率和损失,分别以地质灾害危险性评估和易损性评估进行量化,通过构建的风险评估模型进行风险的量化分级。整个过程将专家知识经验融入风险评价的理论和方法,特别注重遥感技术在风险识别和信息提取、信息技术在空间分析与数据管理中的应用,取得的主要成果有:(1)较为全面地对地质灾害风险评价方法论进行了论述。方法论包括地质灾害风险评价研究中涉及的术语基本概念的详解;风险评价中常用的概率分布与统计方法的说明和对风险评价基本内容的论述。(2)初步建立了立足于GIS平台的地质灾害风险评价的技术体系。地质灾害风险评价中数据管理、获取和分析的复杂性使GIS的运用成为必然。文章论述了通过GIS进行地质灾害风险评价可遵循“建库→分析→开发→应用”这一流程。其中基础数据库包括区域地质环境数据、灾害体数据、社会经济数据和实时监测数据等;分析过程可采用空间叠加分析和邻域统计分析等方式;开发过程可针对需求在基于不同平台进行,方便灾害管理和数据更新。(3)根据致灾机理,选定13个对灾害形成和分布、发育具有重要“贡献率”的要素构建评价指标体系,采用适用于大区域评价的信息量法进行甘孜州的地质灾害危险性评价。通过风险识别和地质灾害危险性分析,初步掌握了甘孜州现阶段地质灾害的数量、类型、分布和发育特征,初步揭示了并依据地质灾害易发程度将甘孜州地质灾害危险性分为4个等级。(4)尝试在数据资料不完备的条件下进行区域地质灾害易损性评价。易损性评价的难点就在于评价数据难于获得,一是由于承灾体众多无法完全统计,二是因为某些承灾体无法进行量化,三是因为研究区工作基础薄弱,许多重要指标无数据记录。对于这一问题,一是利用已有数据对无法获取信息的单元通过插值的办法进行推导,或如本文采用定性分析结合定量评估的方法:对于无法获取的数据,选用具有相关性的可以获取的数据代替;对于无法量化的数据,采用定性的方式参与评价,很好地克服了空间尺度地质灾害系统的复杂性和对于信息获取的局限性,使在不完备信息条件下的易损性评价成为可能。(5)甘孜州地质灾害风险与分区评价。在现有风险评价模型的基础上,将区域防灾减灾能力作为一项因子参与评价,构建甘孜州地质灾害风险评价模型。风险分析的结果显示,甘孜州地灾风险具有东高西低,南高北低的总体特征。最高的风险源位于区域的东部和东南部等地质条件易于灾害发生、人口密集、社会经济条件相对较好的高山峡谷地区,而西部和西北部高平原和丘状高原则为低风险区。(6)通过“投资-收益”分析,以地质灾害风险分级管理为原则构建“治理、监测、搬迁”的综合风险管理方案。对具有高风险、对重要设施和大量人员构成威胁的灾害点投入资金进行工程治理;在具有中等风险的地区构建“群策群防”体系,在高风险设立地质灾害专业监测设施;对于风险级别较高且难于治理的灾害,建议以搬迁的方式规避风险。更多还原

【Abstract】 The war between humans and geological hazards has nenvr interrupted during the long history of the human beings. Nowadays within the abnormal weather condition,the plate movement is activity, and we humans continued expanding our living space, geological hazards, the damage which it made is only a little bit lighter than the earthquake, has become the second serious nature hazards. Geological hazards has a characteristics of emergency, multiple and continuous, in order to enhance the ability of disasters prevention and reduction, it is very necessary to know the development characteristic and to learn the development rule of the geological hazards, foremore, to estimate what kinds of damage would be done by the hazards, that is what’s the risk assessement theories concerned. The geological hazards risk assessment has been studied for many years, though there are different opinions about the research mathods and technical systems, risk assessment is deemed as an importmant step for the hazards prevention and reduction by the scholars all over the world. And also it is been seen as the precondition and the basement of the risk management and make planning for the region.If the risk assessment result is reasonable enough or it could be used to guild the hazards prevention and reduction mainly decisioned by three factors. The first is to build an overall and systemic assessment index system that the characteristics of local geological hazards could be embadyed in it; The second is to build a precise assessment model; The third is to integrate the index and the model into a platform such as GIS in order to take rapid analysis and make correct decision. The paper focuses on the key issues about risk assessment, standing on the lastest research development both domestic and abroad, takes Garze, which has a sensitive geological environment, a number of geological disastersas and a backward social and economic condition region in the mountain area in western China as the instance, takes the Geological Hazards Assessment Methodology as a guide, directed towards the two core issues of the risk assessment– the probability and loss, respectively quantified by geological hazard assessment and vulnerability assessment, constructing a risk assessment model to quantitative risk and classification the risk. Throughout the process inegrate the expert knowledge and experience into the risk assessment theory and the methods, special focus on the application of remote sensing technology in risk identification and information extraction, information technology in spatial analysis and data management, the main results obtained is as follows:(1) More comprehensive methodology for risk assessment of geological hazards are discussed. Disaster risk assessment methodology, including the study of geological terms the basic concepts involved in Detailed; risk assessment and statistical probability distribution commonly used description of the method and the basic content of the discussion of risk assessment.(2) Initially established a platform based on GIS technology of geological disaster risk assessment system. The complexity of geological data management, retrieval and analysis makes the inevitable the use of GIS in the disaster risk assessment. The paper discusses the geological hazards risk assessment based on GIS could follow the way“Build database→Analysis→Redevelopment→Application”. The underlying database includes regional geological environment data, volume data disasters, socio-economic data and real-time monitoring data, etc. Analysis can be overlay analysis and statistical analysis of neighborhood, etc. Demand-driven development process can be carried out based on different platforms to facilitate disaster management, and data updates.(3) Choosing 11 cactors that are considered as have an important“contribution rate”of the disaster development according to disaster-causing mechanism and construction the assessment index system. Using information value model which is very suitable for a large scale to assess the geological hazards risk. By risk identification and hazards analysis, initially understand the quantify, tpyes, distribution and development features of Garze geological hazards. Find out the susceptibility degree of hazards and based on that calssify the hazard into four degree.(4) Try to assess the geological hazards vulnerability under an incomplete data condition. The difficulty of vulnerability assessment lies in the difficult to obtain the evaluation data. First, because there are too many elements at risk to statistics, and second some elements at risk cannot be quantified of their values. For this problem, a method of combining qualitative evaluation and quantitative evaluation is used in this paper, using relativity and available data to instead of unacquirable, using of qualitative methods if the data cannot be quantified of their values.(5) The risk assessment and divisional evaluation of Garze geological hazards. Based on the current risk assessment model, taking the capability of disaster prevention as a factor of the involved in the evaluation, building Ganzi Geological Hazards Assessment Model. The results indicated the geological hazards has a feature that lower in the north and west and higher in the south and east of Garze. The highest risk source located in the high-mountain gorge areas in the east and east-south where there have a feature that prone to hazards, densely populated, a better social and economic conditions, while the high plain and hilly Plateau in the west and west-north are suggested to be the low risk area.(6) By "investment - benefit" analysis and classification management principle, taking the "governance, monitoring, removal" as the geological hazards risk management scheme. The hazards that have a high level of risk and threat of impartment equipment and people are suggested to engineering treatment to eliminate the risk;“mass observation and mass preparedness”system should be constructed in the middle risk area and professional monitoring measures should be took into practice in high risk area; peoples who located in the high risk area and the hazards are difficult to control are suggest to move in order to avoid the risk.更多还原