基于GIS区域边坡失稳灾害预测与评价

 滑坡和泥石流是边坡失稳后两种主要的运动方式,是山区重大的地质灾害。对既往滑坡和泥石流进行研究,以此作为基础来预测和评价本地区潜在的滑坡和泥石流灾害,是防灾减灾的一个重要措施。大多数泥石流是在强降雨的情况下,由滑坡滑入山谷河道而形成的。基于地理信息系统(GIS)和数值模型相结合的方法,采用两步骤方法预测和评价日本熊本县水俣市宝川区集地区的滑坡和泥石流灾害。首先分析该区域可能存在的新滑坡,然后假定这些滑坡在遇到强降雨时形成泥石流,利用数值模拟流动过程分析其在三维复杂地形下的泛滥过程,预测可能受害的房屋和路段。     

基于遗传算法和云模型的公路沿线泥石流灾害危险性区划

 公路沿线泥石流灾害危险性区划可以明确不同地区灾害防治的轻重缓急和设防标准,为宏观政策的制定提供理论基础。从地形地貌、降水、岩土和植被4方面开展公路沿线泥石流灾害危险源辨识,根据潜在公路沿线泥石流灾害调查结果,采用遗传算法提取危险性评价指标,通过云模型改进AHP算法计算各指标权重,基于ArcGIS软件绘制各评价指标的基础图件并进行公路沿线泥石流灾害危险性空间分析,以公路沿线泥石流灾害危险度为主导依据,编制中国公路沿线泥石流灾害危险性区划方案。结果表明：中国公路沿线泥石流灾害危险度为1.000～7.900,危险度较高的区域为浙闽东南山区、台湾山区、昆仑山脉、天山山脉、太行山、黄土高原、横断山脉和青藏高原东部等;中国划分为低度危险、中度危险、重度危险和极重度危险4个等级、14个危险区,其中极重危险区为黄土高原-秦巴山区、武夷山-台湾山区、川滇山区和天山-昆仑山区。     

C4.5算法和GIS技术在波密县滑坡灾害风险评估中的应用

波密县地处西藏东南部,地貌地质环境特殊,滑坡灾害频发。本文选取地层岩性、边坡高度、边坡角度、坡面走向、水系距离和植被覆盖度作为评价因子,通过ArcGIS提取滑坡灾害评价因子相关数据,并利用C4.5算法建立的决策树分类模型对研究区域滑坡灾害的风险性进行了定量评估。结果表明:该模型总体预测精度达到89.7%,有效预测精度高达96.2%。表明该模型具有较高的精度和置信度,为波密县滑坡灾害的预测性分析提供参考。     

A method for quick assessment of earthquake-triggered landslide hazards: a case study of the Mw6.1 2014 Ludian,China earthquake

Rapid assessment of the distribution of earthquake-triggered landslides is an important component of effective disaster mitigation. The effort should be based on both seismic landslide susceptibility and the ground shaking intensity, which is usually measured by peak ground acceleration (PGA). In this paper, we address this issue by analyzing data from the Mw6.1 2014 Ludian, China earthquake. The Newmark method of rigid-block modeling was applied to calculate the critical acceleration of slopes in the study area, which serve as measurement of slope stability under seismic load. The assessment of earthquake-triggered landslide hazard was conducted by comparing these critical accelerations with the distribution of known PGA values. The study area was classified into zones of five levels of landslide hazard: high, moderate high, moderate, light, and very light. Comparison shows that the resulting landslide hazard zones agree with the actual distribution of earthquake-triggered landslides. Nearly 70% of landslides are located in areas of high and moderately high hazard, which occupy only 17% of the study region. This paper demonstrates that using PGA, combined with the analysis of seismic landslide susceptibility, allows a reliable assessment of earthquake-triggered landslides hazards. This easy-operation mapping method is expected to be helpful in emergency preparedness planning, as well as in seismic landslide hazard zoning.

     

Investigation of rockfall-prone road cut slope near Lengpui Airport,Mizoram, India

Rockfall is one of severe natural hazards that are frequently reported in northeast region of India. It carries rock block falling from the cliff with high velocities and energies which can result in damages to vehicles, disruption to transportation, injuries and fatalities. The massive rockfall event which occurred in April 2017 on the highway NH-44A, near Lengpui Airport, blocked the traffic for 1 d, and fortunately, no casualties were reported as the event occurred in the night. This is the only highway connecting the Aizawl city to the airport and the region is highly prone to rockfall events. Hence assessment of rockfall along this highway is necessary. In the current study, rockfall hazard assessment has been carried out on three locations by rockfall hazard rating system (RHRS). During pre-failure analysis, the result shows that most hazardous slopes have RHRS score of 639. The slopes were found to be vulnerable and later on the rockfall activity occurred. Three-dimensional (3D) stability analysis has been carried out using 3DEC software package to analyze the failure behavior and to decide the rockfall-prone zone (unstable blocks) for slope. The total displacement of 2.24 cm and velocity of 2.25 mm/s of the failed block have been observed in the numerical analysis. Further, the rockfall vulnerable zone (unstable blocks) is considered to determine the parameters such as run-out distance, bounce height and energies of the falling rock blocks. The maximum total kinetic energy of 5047 kJ has been observed in the numerical analysis with the maximum run-out distance up to 18 m.     

山区公路边坡病害的防护

针对山区公路边坡灾害的多发性,研究了山区公路边坡的病害类型及形成原因,提出了边坡防护与治理措施,并对边坡综合防护设计要点进行了叙述,从而提高对边坡防护技术的系统研究,减少公路边坡灾害带来的损失.     

基于ArcGIS的四川松新黑水河地区滑坡危险性评价

以松新黑水河地区作为研究区域,基于遥感解译、野外调查统计、地质环境分析、典型滑坡研究的基础上,选取坡度、工程地质岩组、斜坡结构、断裂构造、降雨、人类工程活动等6个与滑坡发生相关的要素作为危险性评价因子。在ArcGIS空间分析模块中,采用自然断点法的数据分类方法,运用频率比——面域模型,对研究区滑坡危险性进行了评价与区划。研究结果表明:松新黑水河地区滑坡危险性分区为:高危险区、中等危险区、低危险区3个区域,所占研究区面积比例分别为32%、50%、18%。     

基于敏感性指数和逻辑回归模型的乐东县地质灾害影响因素敏感性分析

影响因子研究是地质灾害评价的基础,影响因子的敏感性在评价中能直接反应权重大小,敏感性的定量化程度将影响着评价结果的精度。本文以海南乐东县为例,选取断裂、坡度、坡向、岩土体类型、公路、水系作为影响因子,依托GIS平台运用敏感性指数和逻辑回归模型的方法开展了地质灾害影响因素敏感性研究。结果表明:(1)在因子分级中,断裂距离0～1000 m、坡度30°～35°、南向坡、块状坚硬花岗岩岩组、公路范围0~100 m、水系0~200 m是各因子敏感性指数最高的分级区间。(2)影响因子敏感性由大到小依次为坡向>公路>水系>岩土体>坡度>断裂。(3)逻辑回归运算结果AUC值为0.895,预测的准确率满足要求。因此,研究成果可为海南乐东县地质灾害评价及防治提供科学依据。     

一种基于QFD的地铁施工风险评估方法

地铁施工过程中一旦发生事故,会带来严重的经济损失和人员伤亡,而对地铁项目的风险评估和有针对性的预防措施能有效提高施工过程中的抗风险能力。文章以质量功能展开(QFD)为分析工具进行地铁风险评估,通过构建二阶质量屋模型来表达分析对象之间的影响关系,并采用相对具有区域规律性的事故类型的相对风险权重作为输入以及以非归一化处理的方式解决了输入点改变带来的不同作业活动下事故类型的权重求和问题,以获得作业活动和风险因素的相对风险权重。最后将理论应用于钻眼爆破开挖作业下的事故类型与风险因素风险分析,计算结果与实际分析相符。     

杭徽高速公路上边坡病害调查与分析

为更好地掌握杭徽高速公路沿线边坡的稳定现状以及可能存在的地质灾害隐患,为制定相应预案提供依据,及时消除安全隐患,对全线138处上边坡进行详细的地质灾害调查,采用综合因子法和工程地质分析法对上边坡病害的成因进行了分析,对边坡的稳定性进行了评价,并提出了相应的防治对策。     

基于信息量层次分析法在海南琼海市地质灾害易发性分区中的应用

琼海市处于华南褶皱系东部,人类工程活动强烈,地质灾害多发。文章采用信息量层次分析法,在琼海市1:5万地质灾害详细调查的基础上,建立评价因子并转化成信息量值,接着由判断矩阵计算出被比较因子的权重值,最后利用ArcGIS的空间分析功能,以综合信息量值为依据,绘制琼海市地质灾害易发性分区图,为琼海市地质灾害防治提供依据。     

路堤震害风险概率评价与管理研究

 路堤震害在破坏性地震中十分普遍,开展路堤震害风险概率评价并提出合理的震害风险管理方法对提高公路抗震能力和区域防灾减灾能力具有重要意义。进行路堤震害等级划分,选取路堤震害损伤参数,建立路堤震害等级与震害损伤参数的对应关系;以连霍高速公路西宝段K1125+470处路堤为例开展基于CPSHA的公路地震危险性评价,基于IDA和PSDA的路堤震害易损性评价以及基于危险性曲线的路堤震害风险概率评价;在明确路堤震害风险可接受度的基础上提出路堤震害风险管理方法,验证挡土墙对提高路堤抗震性能的积极作用。研究结果表明：连霍高速公路西宝段地震危险性评价结果比第四代地震区划图略高,这与目前渭河断陷盆地地震活跃的现实是一致的;PGA(PGA为地震动峰值加速度)达到0.6 g时,路堤超越严重损伤的概率为65.910%,达到0.8 g时,超越严重损伤的概率为99.995%,说明路堤震害易损性较高;路堤未来50 a超越严重损伤的风险概率为36.46%,发生基本完好和轻微损伤的风险概率为28.49%;以路堤未来50 a发生毁坏的风险概率40%为风险可接受度,路堤震害风险管理方法适用于新建路堤的抗震设计和已建路堤的抗震加固;未来50 a有挡土墙路堤超越严重损伤的风险概率比无挡土墙路堤低15.29%,发生基本完好和轻微损伤的风险概率比无挡土墙路堤高15.62%。     

Landslide hazard assessment and judgment of reliability: a geomechanical approach

Landslide hazard maps are often defined as reliable a posteriori, in accordance with the real landslides occurring from the time of the map production. However, to be useful for planning, a reliability judgment concerning the hazard mapping should be a priori, based on data uncertainty characterization, and must be driven by the knowledge of the slope instability mechanisms. The landslide hazard assessment, when based on the deterministic diagnosis of the processes, may really lead to really providing clues about how and why the slope could fail (landslide susceptibility) and, possibly, when (landslide hazard). Such deterministic assessment can be pursued only through the interpretation and the geo-hydro-mechanical modelling of the slope equilibrium. In practice, though, the landslide hazard assessment is still seldom dealt with slope modelling, in particular when it addresses intermediate to regional zoning. The paper firstly offers an overview of the key steps of a methodology called the multiscalar method for landslide mitigation, MMLM, which that is a methodological approach for the intermediate to regional landslide hazard assessment using the hydro-mechanical diagnoses of landsliding. The validation of the MMLM to the geologically complex outer sectors of the Southern Apennines (Daunia-Lucanian mountains; Italy) is also delineated, together with a practical approach to incorporate a reliability judgment in the landslide susceptibility/hazard mapping.     

唐山市雷电灾害易损性分析及易损度区划

根据唐山市9个市县1957～2008年的雷暴日资料及2006～2008年的雷电灾害资料,结合唐山市的经济和人口密度特征,提出年平均雷暴日数、雷电灾害频数、生命易损模数及经济易损模数作为唐山市雷电灾害易损性评估指标,并在此基础上,给出唐山市雷电灾害易损性指标的等级标准,利用主成分分析的方法对各市县的雷电灾害易损性等级标准进行综合评估,初步形成了唐山市雷电灾害易损度区划,为区域防雷减灾规划提供科学依据。     

川藏公路南线八宿—林芝段滚石灾害的工程地质调查与评价

对川藏公路南线八宿一林芝段沿线山地灾害的工程地质调查表明，滚石对公路的危害性非常突出，鉴于滚石事件自身的特点应将之作为一个专门的灾种给予高度的重视。通过对滚石灾害的影响因素分析，给出了相应的灾害评价方法，并对19个滚石灾害点进行了灾害评价。针对灾害的相对严重程度，对各段滚石区防护措施的设置提出了初步建议。     

陕西泾阳县地质灾害发育特征及形成条件

泾阳县是咸阳市辖县之一,地质构造复杂,大断裂发育,岩土体结构类型较复杂,人类活动强度大,降水量大且集中,地质灾害发育。该文分析了泾阳县地质灾害的类型、规模、发育特征和分布特征,进而分析了地质灾害的形成条件。分析表明,地质灾害发育的控制因素主要有地形地貌、地质构造、地层和岩土体结构、坡体地质结构等,而地下水和植被是地质灾害的影响因素,人类工程活动、大气降雨和地震是地质灾害的促发因素。     

某大型项目地质灾害危险性评估与建议

地质灾害危险性评估是国家针对工程建设项目强制执行的条款,在一些地质灾害易发区合理避开地质灾害的威胁起到了重要的作用。本文以山西省阳城县阳泰转型产业集聚区建设项目为例,介绍了区域内地质灾害危险性评估的主要内容和方法,调查研究了评估区的地质环境条件、水文地质条件及工程地质条件,对地质灾害危险性进行了现状和预测评估,评估级别确定为一级。     

甘肃临泽县地质灾害类型及特征

甘肃省张掖市临泽县是河西走廊地质灾害最为发育的县区之一。通过实地测量、调查评价和综合研究等手段,在概述县域自然地理条件及地质背景的基础上,县域内已有的地质灾害共30处,其中泥石流沟29条主要集中分布于祁连山和合黎山山前与走廊平原的过渡带,尤其是北部合黎山山前连片分布;崩塌1处为斜坡坡度65°的独山子崩塌。从地形条件、物质条件、降雨条件以及人类日益工程建设活动等方面研究表明,较大的沟床纵坡降比和流域面积、丰富的松散固体物质和短时间聚集的充足水源(多是有暴雨形成)是形成区内泥石流的基本条件。崩塌(不稳定斜坡)于公路沿线的人工开挖坡度大于60°的边坡地带。临泽县地质灾害具有不均匀性、突发性、周期性。该研究为县域地质灾害防灾减灾提供科学依据。     

Hazard assessment in Switzerland – Codes of Practice for mass movements

More than 6% of Switzerland is prone to slope instability. New federal regulations require regional authorities (cantons) to generate natural hazard maps and the zoning of mass movements to restrict development on hazard-prone land. The paper discusses the proposed three-step procedure of hazard identification, hazard assessment and risk management. The Codes of Practice concerning the hazard maps involve the standard use of three colours (red, blue and yellow) to indicate areas of prohibited construction, construction with certain safety requirements and construction without restriction. Electronic Publication     

津围公路北二线K4段滑坡地质灾害产生因素分析

为消除津围公路K4段滑坡次生的地质灾害隐患,保障公路通行车辆和人员的安全,在充分收集并分析已有相关地形、地质资料的基础上,对津围公路北二线(K4+350-K4+460段)滑坡开展现场踏勘、调查,查明滑坡分布、规模及发生发育过程,分析诱发滑坡的主要因素,探讨该滑坡地质灾害的发育机理。研究结果表明:导致该地区滑坡产生的自然因素包括地形、地质条件和大气降水三方面。研究区岩石破碎、构造发育,顺层面产生泥化夹层诱发滑动产生滑坡,为中型、浅层、破碎岩体、牵引式滑坡。研究成果可为下一步深入治理提供相关地质资料和设计参数。