彝良县地质灾害分布特征及防治建议

彝良县位于云南省东北部,为云南省七个地质灾害重点防治区的一部分。2003年的地质灾害调查显示,县域内有地质灾害236处,其中滑坡181处,不稳定斜坡9处,泥石流34处,地面塌陷12处,以滑坡和泥石流为主。综合研究分析结果表明,地质灾害的主要诱因除地质地理环境（地形地貌、降雨集中、岩溶作用、新构造运动强烈）等自然因素外,人类工程活动中的切坡过陡和采矿活动形成的巨大采空区也是主要诱发因素。在此基础上,根据各种影响因素的作用强度把彝良县划分为洛泽河—小米溪河高易发区、发达—洛旺中等易发区和低易发区（含小草坝亚区和龙街-奎香亚区）三个地质灾害区,并在灾害防治、协调管理、宣传教育等方面提出了一些有益的建议。      

5.12汶川8级地震次生地质灾害的基本特征及其形成机制浅析

5.12汶川8级大地震沿龙门山断裂带形成长350多km,宽约50 km的地表破裂带,触发了1万多处崩塌、滑坡、泥石流(碎屑流)地质灾害,其中巨型灾害体87处、大型灾害体606处,形成了136个较大规模的堰塞湖。地震地质灾害的链生特征显著,形成地震-崩塌、地震-滑坡-碎屑流-堰塞湖-堰塞坝溃决-泥石流等典型地质灾害链。地震次生地质灾害具有分布范围广、数量多、种类全、密度大、强度高、致灾重的特点。在部分地区,崩塌、滑坡和碎屑流的分布面积占地震极重灾区面积的30%~58％,甚至高达80％。据初步统计,崩塌、滑坡和碎屑流共导致大约2万人死亡,其中北川县老县城滑坡导致1 600多人死亡。地震次生地质灾害主要沿断裂带、河谷和交通线分布。崩塌、滑坡的破裂源主要位于河流拐弯处靠近侵蚀岸一侧、山脊两侧及坡肩部位,这与上述部位对地震动峰值加速度的放大作用直接相关。地震次生地质灾害主要受地震动峰值加速度和地形控制,其次为岩性、斜坡结构、活动断裂、人类工程活动。许多大型崩塌、滑坡还具有高速远程的特征,部分崩塌、滑坡 碎屑流位移达数km,速度高达100~300 m/s,其运动轨迹复杂多变,常常导致多处人员伤亡,是高山峡谷地区地质灾害风险评估和减灾防灾必须面临的新课题。根据上述情况,文中对汶川地震次生地质灾害的基本特征、分布规律和主要影响因素进行了初步总结,并对地震滑坡的形成机制和运动模式进行了初步探讨。首次提出高山峡谷地区单一斜坡上呈阶梯状多级滑动的群发性地震滑坡的形成模式:强烈地震往往引起剧烈的地面震动,而高陡的山脊及其坡肩部位对地震波具有明显的放大作用,因此,上述部位往往是地震滑坡的高易发地段,当地震动峰值加速度超过不稳定性斜坡的临界峰值加速度时,斜坡失稳破坏形成一系列的群发性滑坡,从上到下往往形成阶梯状多级滑动的滑坡群,此种模式适用于残坡积层、风化层地震滑坡和主滑面较缓的地震基岩滑坡。最后,指出了今后应重点研究的科学问题,并对防灾减灾措施提出了一些建议。     

兰州黄河阶地演变过程对滑坡活动的控制效应

为探索特殊地质环境-河流阶地孕育滑坡的相关性, 更深入地认识这类河流岸坡的变形破坏过程, 在广泛分析区域工程地质资料的基础上, 从第四系地貌学与工程地质学相结合的角度, 研究了兰州市黄河河谷演化发育的阶段性特征和黄河阶地演化对滑坡的控制效应及其诱发模式.研究表明: (1)黄河河谷的演化对兰州地区滑坡发育的控制作用具有时间上的阶段性和空间上的分带性, 在河谷演化不同阶段滑坡有着不同的发育模式和形成机理; (2)阶地型滑坡主要诱发因素为新构造运动的强烈抬升、黄河强烈下切以及阶地形成期相对湿润的古气候.第三系泥岩地层间形成的软弱夹层可诱发大型黄土泥岩滑坡, 而黄土层内多发中小型崩滑.河谷演化期间, 滑坡的发生可能导致部分阶地的缺失.      

牛背至天水高速公路路域环境地质安全性评价方法探讨

天(水)宝(鸡)高速公路牛背至天水段工程通过地区地质构造复杂,岩土种类繁多,岩土工程和环境地质安全如果不加以重视,易造成道路的地质灾害,直接影响到工程建设的质量和安全性,也将给未来运营安全带来严重的隐患和经济损失.在野外地质调查的基础上,探讨了公路路域环境地质安全性评价的影响因素和安全性评估内容,通过遥感技术等方法对地质和岩土工程信息提取并进行安全性评价,对研究区进行了初步评价,并提出了应对措施.     

RS and GIS‐based Statistical Analysis of Secondary Geological Disasters after the 2008 Wenchuan Earthquake

Abstract: Using RS and GIS means, this article analyzes the general geological characteristics and the structural belt distribution features in Wenchuan County, Sichuan province, P.R. China as well as the characteristics of the large-scale landslides, mud-rock flows, earthquake lakes, etc., after the earthquake on May 12, 2008. Based on the above work, comprehensive indoor and outdoor research is launched on disaster distribution characteristics and their relationship with earthquakes, terrains, strata, lithology, and structures. Weights of evidence method is utilized to quantitatively analyze and evaluate the spatial distribution of secondary geological disasters after the earthquake occurred. 3 remedying grades for secondary geological disasters are derived from the results of the weights of Evidence, followed by suggestions given to remedy earthquake secondary disasters.     

构造地质与工程地质的基本关系

构造地质学是研究各种地质构造及其成生演化的基础地质学 ,工程地质学主要是应用地质学理论尤其是构造地质学理论解决人类工程建设活动中与构造现象和构造活动有密切关系的地质问题的应用地质学。二者的研究目的虽然不同 ,但所研究的主要对象是相同的 ,即都是地质构造 ,所研究的又都是地球变化过程中的构造变动及其各类效应。文中讨论了构造地质学与工程地质学之间的基本关系 ,主要包括地质构造对工程地质环境和工程地质条件的控制作用 ;深部构造、浅部构造以及表层构造动力学特征与区域地壳稳定性之间的关系 ;构造结构面、构造应力场与岩土体稳定性的关系 ;活动构造与工程建筑安全性的关系以及地质构造与崩滑流、地裂缝、地面沉降等地质灾害的关系等问题。     

怒江大峡谷“瓦拉亚窟”溶洞景观及地质旅游资源评价

“瓦拉亚窟”洞穴系统地处怒江峡谷，岩溶发育动力条件优越，在滇西北及青藏高原南延区域约4 km2的狭小范围发育了垂向分布超过五、六百米，洞系总长达27 km以上，洞体巨大，岩溶发育演化地史形迹丰富，是滇西北及青藏高原南延区域规模巨大的迷宫式溶洞系统。具有空间上分层、分支及形变复杂多样，溶蚀、沉淀、侵蚀、搬运、沉积形态和物质丰富多彩的景源特征，对“三江并流”区喜山运动以来的地质演化、岩溶作用与水文地质研究等皆有重要的价值。笔者根据前人探洞考察资料，结合新的区域地质、环境地质和旅游地质调查等资料，以及现状考察了解获得的信息，以地质学、自然资源学和美学理论为指导，对“瓦拉亚窟”洞穴系统的形成条件、结构体系和景观、形成及演化历史进行了系统的分析论述，评价了地质旅游资源价值，提出了合理开发和有效保护的策略和建议。     

岩溶山区崩滑灾害变形破坏地质模式分类

岩溶山区特殊的地质结构导致崩塌、滑坡等地质灾害时常发生,带来了严重的人员伤亡和经济社会损失。研究岩溶山区崩滑灾害特征,建立相应的变形破坏地质模式,对于岩溶山区崩滑灾害风险防控与治理工程具有重要理论意义与指导价值。文章以典型地质灾害形成演化过程为例,在系统地分析研究区典型崩滑灾害地质背景、影响因素、动力学与运动学特征的基础上,提出了岩溶山区崩滑灾害变形破坏地质模式,得出以下主要结论:（1）影响崩滑成灾基本因素（崩滑灾害体势能、岩溶结构面、岩组结构、斜坡地貌和斜坡结构）、影响因素（水文地质条件、工程活动、地震、降雨）和变形运动特征（运动形式和变形机制）三个方面,据此建立了岩溶山区崩滑灾害地质分类指标体系。（2）结合研究区特征对模型体系里面的每个要素进行系统分析,崩滑灾害的发生是各个要素相互组合、相互作用的结果。（3）总结了研究区内5种典型崩滑地质模式:高势能反倾降雨型高速远程滑坡—碎屑流模型、高势能斜倾视向采矿型高速远程崩滑灾害模型、超高势能横向陡倾地震型高速远程滑坡、高势能采矿型高速崩塌—碎屑流模型、低势能差异风化崩塌模型。为后续开展物理模拟、数值模拟、稳定性计算和变形破坏预测等工作奠定基础。下一步将更加深入全面地建立研究区的崩滑灾害模式,并进行崩滑灾害的危险性分级工作。      

基于岩质滑坡引发泥石流的影响范围评价模型

降雨滑坡引发泥石流是发生于山区的复杂地质灾害现象。通常与地质、地层岩性、岩土体的力学性质、雨量、地下水和土地使用情况有关。分析滑坡与泥石流之间的内在关联因素不仅为分析滑坡破坏机理提供一个参考依据,而且也可以作为滑坡引发泥石流评估的基础。本文基于质量守恒定律和黏性牛顿流体Navier-Stokes方程的泥石流二维数学模型,进行深度积分后采用有限差分法进行数值求解,引用统计得出的溪流倾斜角正切值与泥石流影响范围的宽度关系表达式。结合GIS,完善了3DslopeGIS系统。对以往记载的山体滑坡引发泥石流案例进行类似地质条件的滑坡灾害再发可能性和影响范围分析。本文模型及系统不仅可用于预测泥石流的影响范围,还可以风险地图来显示可能受泥石流影响的地区。     

Ground deformation monitoring by using the Permanent Scatterers Technique: The example of the Oltrepo Pavese (Lombardia, Italy)

The applicability of the Permanent Scatterers Synthetic Aperture Radar Interferometry (PSInSAR) technique for detecting and monitoring ground displacements was tested in the Oltrepo Pavese territory (Northern Italy, southern Lombardia), which could be representative of similar geological contexts in the Italian Apennines. The study area, which extends for almost 1100 km², is characterized by a complex geological and structural setting and the presence of clay-rich sedimentary formations. These characteristics make the Oltrepo Pavese particularly prone to several geological hazards: shallow and deep landslides, subsidence and swelling/shrinkage of the clayey soils. The PSInSAR technique used in this study overcomes most of the limitations of conventional interferometric approaches by identifying, within the area of interest, a set of “radar benchmarks” (PS), where very precise displacement measurements can be carried out. More than 90,000 PS were identified by processing Synthetic Aperture Radar (SAR) images acquired from 1992 to 2001 by the European Remote Sensing satellites (ERS). The PSInSAR application at a sub-regional scale detected slow ground deformations ranging from + 5 to − 16 mm/year, and resulting from various processes (landslides, swelling/shrinkage of clay soils and water pumping). The PS displacements were analysed by collecting data obtained through geological, geomorphologic field surveys, geotechnical analysis of the soils and the information was integrated within a landslide inventory and the damaged building inventory. Despite the limited number of landslide bodies with PS (7% of the inventoried landslides), the PS data helped to revise the state of activity of several landslides. Furthermore, some previously unknown unstable slopes were detected. Two areas of uplift and two areas of subsidence were identified.     

基于GIS与信息量模型的汶川次生地质灾害危险性评价

5·12汶川大地震诱发了大量滑坡、崩塌、泥石流等次生地质灾害,对人民群众的生命财产和社会经济的发展形成了严重威胁.针对次生地质灾害危险性评价,选取重灾区汶川县作为研究区域,利用遥感与地理信息技术的空间数据管理和空间数据分析平台,获取了研究区的次生地质灾害信息,分析了研究区内次生地质灾害与各影响因子,包括地形地貌、地层岩性、水系、地震断裂之间的相关性特征,并结合信息量法模型进行次生地质灾害危险性评价.高度、中度和轻度危险区的面积分别为1 130.196 km2、1 739.584 km2、1 213.219 km2.本次地震触发次生地质灾害的分布具有集群式分布的特点,即断裂带及其附近地区地质灾害集中发育,而远离断裂带区地质灾害很快衰减,呈零星分布;从灾害发育的区域特征分析,汶川县震后次生地质灾害呈现出北部和东部重、西部和南部轻的特点.所得研究结果与实际情况较吻合,表明地理信息系统结合信息量模型能够快速、有效地对次生地质灾害的空间分布以及危险性作出评价.      

Geology, landscape and human interactions: examples from the Isle of Wight

The British Geological Survey has recently re-mapped the Isle of Wight at a scale of 1:10,000. This has added to a wealth of geological research already published. Within this paper, we highlight the importance of geology to the heritage of the Isle of Wight and its impacts on everyday life. There is a growing cultural awareness of the variety of landscapes and resources, the geology that underpins them, and the need to manage and understand them in a sensitive and sustainable way. ‘Geodiversity’, which collectively embraces these themes, is defined as “… the natural range (diversity) of geological (rocks, minerals, fossils), geomorphological (land form, processes) and soil features …” (Gray, 2004). This paper will focus on the geomorphological features; that is, the link between geology, the landscape it influences, and the human interactions with it. Examples from the Isle of Wight of the influences of geology on landscape include the landslides at Ventnor; geotourism at The Needles, Alum Bay and various dinosaur sites; and the artificial landscapes resulting from resource extraction. The geological issues and examples that we have used are some of the most applicable to everyday life, and therefore ones that many people will be able to relate to, such as geohazards (e.g. landslides), water supply, economic value (e.g. quarrying) and tourism. The paper is aimed at the non-specialist and students but also may provide a contextual element to professionals.     

黄河上游地质环境的演化与崩滑体成因探讨

黄河上游水流湍急,水量丰沛。利用水能资源所规划和兴建的梯级电站,大多座落在黄河上游的高山峡谷区。这些区段地势高陡,崩滑体分布广泛,是我国崩滑灾害的多发区段。一旦坝前失稳,将会造成难以弥补的损失。本文从地质环境演化的观点出发,对崩滑体的成因进行了较为深入的探讨,并对其稳定性进行了初步评价。     

Critical shallow and deep hydrologic conditions associated with widespread landslides during a series of storms between February and April 2018 in Pittsburgh and vicinity,western Pennsylvania,USA

The potential for widespread landslides is generally increased when extraordinary wet periods occur during times of elevated subsurface hydrologic conditions. A series of storms in early 2018 in Pittsburgh, Pennsylvania, overlapped with a period of increased shallow soil moisture and rising bedrock groundwater levels resulting from seasonally diminished evapotranspiration and induced widespread landslides in the region. Most of the landslides were shallow slope failures in colluvium, landslide deposits, and/or fill. However, deep-seated landslide activity also occurred and corresponded with record cumulative precipitation from late February to April and bedrock groundwater levels rising to an annual high. Landslides blocked or damaged roads, adversely affected multiple houses, disrupted electrical service, crushed vehicles, and resulted in considerable economic losses. The initial landslides occurred during or immediately after a rare period of three successive days of heavy rain that began on February 14. Subsequent landslides between late February and April were induced by multiday storms with smaller rainfall totals. As shallow soil moisture at a monitoring site rose above a volumetric water content of 32%, the mean rainfall intensities necessary to induce slope failure in colluvium and other surficial deposits decreased. Deep-seated landslide movement occurred in the region mostly when the groundwater level in a bedrock observation well was shallower than 1.7 m. The availability of hydrologic and landslide movement monitoring data during this extraordinary series of storms highlighted the evolution of the landslide hazard with changing moisture conditions and yielded insights into potential hydrologic criteria for anticipating future widespread landslides in the region.

     

西秦岭北缘断裂宝鸡—武山段活动触发滑坡分布规律与成因机制

西秦岭北缘断裂沿"一带一路"交通廊道展布,是南北活动构造带强震丛集发育的节点之一,地震地质灾害风险极高。基于地质调查、测绘与数值分析,查明了断裂在天水地区触发的地震滑坡分布特征,探讨了断裂触发滑坡的形成机制。研究表明:(1)西秦岭北缘活动触发的巨、大型滑坡为断裂地貌过程的一部分,易在断裂的阶区聚集发育,其枢纽部位也有零星的分布;(2)巨大型滑坡集中于历史极震区内,断裂破裂过程中的近场惯性滑移、远场地震动是主要触发因素,二者耦合作用导致巨大型滑坡在断裂带两侧具有对称分布特征,活动强度由近及远而逐渐变弱;(3)断裂水平滑移、破裂引起的斜坡滑动变形以结构面贯通为主要表现形式,具有强烈的方向效应、近直立断层的区域地震动效应及地震波的山体地形放大效应,这些力学效应在滑坡破坏过程产生断裂结构面、次级羽裂结构面与滑动面,它们协同控制了滑坡的运动;(4)极端降雨触发的泥流是巨大型滑坡堆积体复活运动的主要形式,是现今防灾减灾重点。     

黄河上游地区地质灾害分布规律与区划

黄河上游地区是中国地质灾害特别发育的地区之一。主要地质灾害有：地震、崩塌、滑坡、泥石流以及水土流失、土地沙漠化、土地盐碱化、黄土湿陷、融冻等，除了直接威胁人民生命财产安全和各种工程设施安全外，还严重破坏国土资源和生态环境，是阻碍西部大开发和可持续发展的重要因素。受地质、地貌以及气候等条件控制，各地区地质灾害发育情况有很大差异，可划分为3个地质灾害类型区：以土地沙漠化、盐碱化和地震为主的北部区；以地震、崩滑流和水土流失灾害为主的中部区和以融冻为主的西南部及西北部区，3个灾害区又可进一步划分为13个亚区。     

四川泸定地区岩土体类型与地质灾害

岩土体为地质灾害的活动主体。地质灾害的孕育、发生和成灾等,都是岩土体的不同活动形式的反映。不同岩土体具有不同的物理、力学及水理性质,其可能产生的地质环境问题也不同。在进行灾害预测评价时,必须充分考虑不同岩土体与地质灾害的关系。     

滑坡演化的基本属性与研究途径

我国是世界上滑坡地质灾害最严重的国家,重大滑坡防治是国家防灾减灾重大而迫切的战略需求.自然界经历了漫长的演化过程,演化是滑坡的基本属性,是滑坡工程地质研究的重要基础.滑坡演化机理、演化特征的正确认识及其定量表征,是滑坡预测预报和防控研究的关键组成部分.在归纳自然界演化共有特征的基础上,系统阐述了滑坡动力来源、演化形式、孕育模式、演化阶段和演化状态等基本属性;提出多场关联监测是揭示滑坡演化特征的有效手段,介绍了近期取得重要技术突破——滑坡柔性大变形监测技术;提出了演化在重大滑坡预测预报和防治中的应用途径,指出了重大滑坡演化进一步研究的方向.      

环境地球科学之滑坡地震地质学

本文提出滑坡地震地质学学科概念,属于环境地球科学学科范畴。滑坡地震地质学是研究地震荷载下滑坡发生机理、分布与演化规律的学科;也是借助地震滑坡解决地震地质问题的学科。它是地质灾害学、地震地质学、工程地质学之间的一门交叉边缘学科。其也与固体地球物理学、构造地质学、构造地貌学、环境地质学、数值计算、地理信息系统、遥感、统计分析等学科密切相关。文章从科研层面与应用层面的分类大体构建了滑坡地震地质学的研究框架与体系。科研层面的目的是探索地震滑坡规律,应用层面的目的是地震滑坡防灾减灾。根据科研与应用层面的研究目的,将其研究内容大体分为两部分:（1）研究地震滑坡发生机制、分布样式、演化规律等;（2）建立地震滑坡与地震、发震构造、地震破裂过程等的关系式,进而利用地震滑坡解决地震地质问题,如地震问题（地震参数、地震动强度、地震烈度）、发震构造问题（性质、破裂过程）、地质问题（震区地貌演化）等。最后,从地震滑坡数据库,全球范围多震例的地震滑坡分析,地震滑坡与地震地质对象关联的机理研究,地震滑坡演化规律等方面对该学科进行了展望。总之,考虑到随着遥感与GIS等技术的发展成熟、地震滑坡防灾减灾的越来越迫切的需求、多学科的融合交叉的发展趋势等方面,滑坡地震地质学势必会受到越来越广泛的关注。     

Compositional tomography of a gold‐bearing sample by Laser‐induced breakdown spectroscopy

This contribution presents the first results of compositional tomography of a geological sample. The volume render of 6 × 8 × 1 mm³ was constructed by assembling 63 compositional maps acquired in 21 min (19.5 s/layer) by laser‐induced breakdown spectroscopy (LIBS), which determines the chemical composition of the analysed spot from the light emitted by a plasma produced by the laser. This technique is, therefore, able to directly reveal the 3D distribution of chemical elements in a sample. As an example, the spatial distribution and 3D geometry of visible gold in an ultramafic schist are presented. Inasmuch as this newly developed portable LIBS instrument is able to the rapidly characterize the 3D geometry of any geological materials, it has a high potential to be useful for the mining industry and for a wide range of geosciences, such as structural geology, petrology, sedimentology and economic geology.