【作者】 陈伟；

【导师】 傅旭东；

【作者基本信息】 武汉大学 ， 岩土工程， 2019， 博士

【摘要】 我国是遭受滑坡灾害影响最为严重的国家之一,尤其是山地村镇地区,由于地形地质条件复杂,加之近年来城镇建设所带来的日益活跃的人类工程活动,滑坡灾害频繁发生。“灾害减缓,预防先行”,滑坡灾害研究的重点就是要探索从单体滑坡灾害防治对策研究到区域滑坡灾害风险评估研究的理论与方法,从而更有效地避免、控制和减少我国山区村镇宏观滑坡灾害损失。滑坡灾害风险评估(Landslide Risk Assessment)是目前国际上倡导和推广的区域滑坡灾害防治最经济有效的工具和手段。针对我国缺乏完善的、满足实际应用的山区村镇滑坡灾害风险评估体系的现状,本文以“十二五”国家科技部支撑计划“村镇区域综合防灾减灾信息系统研究及示范”为依托,对滑坡灾害风险评估研究中单元划分参数取值困难、指标体系构建方法主观性较强,以及评价模型的空间适应性较低等问题开展了深入研究,主要研究成果及结论如下:(1)通过定量分析单元划分参数对单元划分效果的影响,提出了以指标图层图像质量及指标分类为依据的栅格单元尺寸确定方法,以及基于正交分析的斜坡单元划分方法,解决了评价单元划分参数取值困难的问题。(2)针对指标体系构建方法主观性较强的问题,提出了基于循环剔除聚类算法的距离型指标分类方法,以及基于信息熵和相关性分析的指标筛选方法,不仅降低了主观判断和样本数据中异常值对指标体系构建的不确定影响,而且保证了评价指标之间的相互独立性和各指标与滑坡灾害之间的相关性。(3)通过分析各评价指标对滑坡灾害易发性影响的空间差异,建立了基于空间位置的分区线性/逻辑回归模型,解决了评价指标类型或影响规律不同时单一回归方程无法对滑坡灾害易发性作出准确评价的问题,提高了评价模型的空间适应性。(4)研发了山区村镇滑坡灾害易发性评价系统,利用其开展了不同空间尺度条件下,基于多种评价单元(栅格单元、斜坡单元)和模型(分区线性/逻辑回归模型、支持向量机)的滑坡灾害易发性评价研究。分析结果表明:指标数据提取方式的不同是造成不同空间尺度和评价单元条件下易发性评价结果差异的主要原因。(5)建立了考虑承灾体抗灾能力和灾害损失比的滑坡灾害风险评估模型,并将斜坡单元引入承灾体价值分析,以此为基础完成了松柏镇镇域及镇区的滑坡灾害风险评估。分析结果表明:松柏镇滑坡灾害风险主要集中在道路、建筑用地及周边,人类工程活动是影响滑坡灾害风险分布最为主要的原因。更多还原

【Abstract】 China is one of the most seriously affected countries by landslides,especially in mountainous villages and towns.Due to the complex topographical,geological conditions and the increasing engineering activities brought by urbanization,landslides occur frequently.The focus of landslide prevention research should be on exploring a theoretical way to study of regional landslide risk assessment from the case of single landslide prevention,so as to play a more effective and positive role in avoiding,controlling and reducing the macro landslide loss in mountainous villages and towns.Landslide risk assessment is the most economical and effective tool for landslide prevention advocated internationally,which includes landslide susceptibility assessment,vulnerability assessment and value analysis.The problems existing in landslide risk assessment include the difficulty of determining the parameters of unit division,the subjectivity of index system construction and the low spatial adaptability of assessment model.Considering the lack of a desirable system to satisfy the needs of practical application,the mentioned problems are are analyzed depending on the Research and Demonstration of Integrated Disaster Prevention and Mitigation Information System in Villages and Towns supported by National Science and Technology Ministry.The main works and conclusions are as follows:(1)A method for determining the size of grid unit is established based on the image quality of index layers and the classification results.Through analyzing the impacts of flow thresholds of DEM and inversed DEM on slope division,the division method based on orthogonal method is built.Those methods solve the difficulty of determining the parameters of unit division.(2)In consideration of the subjectivities in of index system construction,the loop-rejection clustering algorithm is established to classify the locational indexes under grid condition,and the screening method of index based on information entropy and correlation analysis is built.Those methods could not only eliminate sample data those are less correlated with landslides but also guarantee the independence among assessment indexes and the correlation between each index and landslides.(3)The region-based linear/logical regression model considering the spatial location is obtained by analyzing the impacts of indexes on landslide susceptibility at different locations.This model avoids the problem that a single regression equation cannot make a reasonable assessment while the types and influence patterns of each index are different and improves the spatial adaptability.(4)A landslide susceptibility assessment system for mountainous villages and towns is developed,based on which landslide susceptibility assessments under different units(grid and slope)models(regionalized linear/logical regression model and support vector machine model)are compared.The result shows that the way of data extraction is the main controlling factor that affects the susceptibility assessment at different conditions.(5)A landslide risk assessment considering the resistance to landslides and loss rate of disaster-bearing body is proposed,and the slope division is introduced to the value analysis.On this basis,the landslide risk assessment is completed for Songbai Town.The result shows that landslide risk in Songbai Town is mainly concentrated around road and construction land,and human engineering activity is the dominating factor affecting the distribution of landslide risk.更多还原