滑坡灾害区划系统研究

本文系统地介绍了滑坡灾害区划研究的国内外研究现状，提出减灾的关键在于从区域上做好预防研究的观点，并阐述了滑坡灾害与风险术语统一化的重要性，由此提出滑坡灾害区划的核心是灾害、易损性和风险三要素的综合分析。文章进一步提出了灾害区划研究的两种基本途径，破坏概率法和信息分析法，把传统的滑坡单体稳定性分析延伸到以Monte-     

浙江省永嘉县滑坡灾害危险性区划

永嘉县是浙江省滑坡灾害发生频繁的区县之一,其滑坡受地质、地形和人类工程活动等因素的影响.本文根据永嘉县滑坡灾害分布情况,选择了影响滑坡分布的主要因素,将各种因子归一化处理后转换成相同分辨率的定量数据,选择了逻辑回归分析模型和信息量模型进行滑坡灾害危险性评价.在逻辑回归模型中,利用SPSS软件,通过逐步回归分析筛选出影响滑坡的最直接的因子,计算出各个因子的回归系数,得到逻辑回归方程,据此编制了危险性预测分区图.在信息量模型中,通过MAPGIS软件及其二次开发的信息量模型,对永嘉县滑坡灾害进行了危险性区划,并依信息量法的结果编制了该区的危险性预测分区图.两种方法所编制的危险性分区图中高危险区和中危险区重合率达到了87%,具有很高的一致性,起到了相互验证的作用,为滑坡的有效防治提供了依据.最后根据"云娜"台风期间永嘉县实际灾害发生情况的资料分析,新灾害点绝大部分落在危险性预测区中的高危险区,表明模型的预测准确率很高.     

降雨诱发区域性滑坡预报预警方法研究

论文以四川省雅安市雨城区为研究区,将逻辑回归模型引入区域降雨型滑坡预警预报,建立了同时考虑降雨强度和降雨过程的降雨临界值表达式.在滑坡危险性区划的基础上,研究提出了区域降雨型滑坡预警预报指标,包括临界值降雨指数R和滑坡发生指数L,并利用20台自动遥测雨量计和地质灾害群测群防网络,采用历史记录雨量和预报雨量,建立了区域降雨型滑坡预报预警体系.     

滑坡危险度区划方法及其应用

在滑坡研究的基础上总结了滑坡危险度区划的研究方法。建立了综合因素分析和本底因素评价的指标体系,提出了综合因素叠加法、本底因素贡献权重叠加法和本底因素模糊判别推理法的区划模型,介绍了这些方法的应用及试验结果。还对滑坡危险度区划研究中存在的3个主要问题进行了讨论：评价指标数量选择、最佳权重确定方法和危险性等级划分的标准。     

基于当日和累计降雨量的区域降雨型滑坡预警研究*

选择合适的降雨型滑坡气象因子有利于提高预测精度,详细研究了四川省雅安市雨城区滑坡和降雨数据,利用不同组的数据进行回归分析,发现前期几日降雨量与滑坡的相关性不大,确定气象因子选取为当日降雨量和累积降雨量,讨论了累积降雨量中衰减系数的选取,确定为0.9。然后利用样本数据中的120组数据进行二元逻辑回归,得到了研究区的滑坡灾害概率预测方程。在此基础上制作了当日降雨量与累计降雨量关系散点图,得到了研究区降雨滑坡的临界表达式。最后选用5个降雨事件滑坡和5个未降雨事件滑坡进行验证,结果完全符合要求,说明此模型的准确性较高。综合表明这种以当日和累计降雨量为自变量的回归模型是一种行之有效的预测方法,可为降雨型滑坡预测提供科学依据。     

基于逻辑回归模型和确定性系数的崩滑流危险性区划

崩滑流是崩塌、滑坡和泥石流地质灾害的总称。本文根据逻辑回归模型和贵州省崩滑流地质灾害发生的确定性系数CF,统计贵州省内崩滑流发生概率与其影响因子之间的函数关系; 并利用GIS技术编制贵州省崩滑流地质灾害危险性区划图。首先根据影响因子子集中已发崩滑流灾害面积和影响因子子集面积来计算崩滑流地质灾害发生的确定性系数CF; 其次将灾害是否发生作为因变量,影响因子子集发生崩滑流地质灾害的确定性系数CF作为自变量,应用逻辑回归模型统计分析它们之间的函数关系; 然后利用GIS技术计算研究区内各独立属性单元发生崩滑流地质灾害的概率p,按p值10等分标准将研究区划分为10个危险性等级区,并绘制贵州省崩滑流地质灾害危险性区划图; 最后用已发崩滑流地质灾害的分布数据来检验危险性区划的效果。研究结果表明:本文根据逻辑回归模型和崩滑流地质灾害发生的确定性系数CF,将贵州省分为Ⅰ～Ⅹ的10个崩滑流地质灾害危险性等级区与实际情况基本符合,能够良好地反映贵州省境内发生崩滑流地质灾害的难易程度。     

基于危险度区划的县级区域降雨引发滑坡的风险预警方法——以四川省米易县降雨滑坡为例

降雨滑坡预警在世界上开展广泛,但对小区域的降雨滑坡风险进行预警尚不多见。以通用的风险定义为基础,首先对目标区域——四川省米易县的地质灾害进行调查,以典型滑坡进行反演,获得灾害的本底因素,按贡献率权重叠加法进行危险度分区;通过对承灾体的调查确定承灾对象,并将各承灾对象按密度由行政界限向1km×1km的网格单元转化后叠加形成易损度分区。二者相乘完成风险分区。对研究区域近5年逐日降雨数据与172条地质灾害记录进行分析,按前期日降雨量模型得到降雨阈值,根据滑坡空间概率和降雨引发滑坡的时间概率叠加的结果,得到研究区域的降雨滑坡概率,对照风险分区,完成风险预警。     

基于聚类分析的滑坡灾害危险性区划研究

滑坡灾害危险性区划研究在城市规划决策方面具有重要的现实意义。聚类分析以统计学的形式将具有相似特征的数据进行归类,能够实现滑坡灾害危险性空间分布情况的定量评价。根据湖北省巴东县滑坡灾害统计资料,选择具有代表性的滑坡灾害影响因素作为危险性区划评价指标,采用熵权法和层次分析法相结合,综合评判各指标权重。并在此基础上,以MapGIS为操作平台,以C#语言编程实现了快速聚类算法,对研究区86216个单元进行了滑坡灾害属性分类及危险性等级自动识别,预测结果较好。本研究将综合权重评判方法与聚类模型结合,同时克服了聚类结果不能自动排序的困难,对处理大批量,多属性数据具有一定的创新性和实用价值。     

基于危险度区划的县级区域降雨引发滑坡的风险预警方法——以四川省米易县降雨滑坡为例

降雨滑坡预警在世界上开展广泛,但对小区域的降雨滑坡风险进行预警尚不多见。以通用的风险定义为基础,首先对目标区域——四川省米易县的地质灾害进行调查,以典型滑坡进行反演,获得灾害的本底因素,按贡献率权重叠加法进行危险度分区;通过对承灾体的调查确定承灾对象,并将各承灾对象按密度由行政界限向1km×1km的网格单元转化后叠加形成易损度分区。二者相乘完成风险分区。对研究区域近5年逐日降雨数据与172条地质灾害记录进行分析,按前期日降雨量模型得到降雨阈值,根据滑坡空间概率和降雨引发滑坡的时间概率叠加的结果,得到研究区域的降雨滑坡概率,对照风险分区,完成风险预警。     

基于逻辑回归的四川青川县区域滑坡灾害预警模型

四川省青川县滑坡灾害群发,点多面广,区域滑坡灾害预警是有效防灾减灾的重要手段,预警模型是成功预警的核心。由于研究区滑坡诱发机理复杂、调查监测大数据及分析方法不足等原因,传统区域地质灾害预警模型存在预警精度有限、精细化不足等问题。文章在青川县地质灾害调查监测和降水监测成果集成整理与数据清洗基础上,构建了青川县区域滑坡灾害训练样本集,样本集包括地质环境、降雨等27个输入特征属性和1个输出特征属性,涵盖了青川县近9年（2010—2018年）全部样本,数量达1 826个（其中,正样本613个,负样本1 213个）。基于逻辑回归算法,对样本集进行5折交叉验证学习训练,采用贝叶斯优化算法进行模型优化,采用精确度、ROC曲线和AUC值等指标校验模型准确度和模型泛化能力。其中,ROC曲线也称为“受试者工作特征”曲线;AUC值表示ROC曲线下的面积。校验结果显示,基于逻辑回归算法的模型训练结果准确率和泛化能力均较好（准确率94.3%,AUC为0.980）。开展区域滑坡实际预警时,按训练样本特征属性格式,输入研究区各预警单元27个特征属性,调用预先学习训练好的模型,输出滑坡灾害发生概率,根据输出概率分段确定滑坡灾害预警等级。当输出概率P≥40%且P<60%时,发布黄色预警;当输出概率P≥60%且P<80%时,发布橙色预警;当输出概率P≥80%时,发布红色预警。     

Landslide risk evaluation and hazard zoning for rapid and long-travel landslides in urban development areas

Risk evaluation for earthquake-induced rapid and long-travel landslides in densely populated urban areas is currently the most important disaster mitigation task in landslide-threatened areas throughout the world. The research achievements of the IPL M-101 APERITIF project were applied to two urban areas in megacities of Japan. One site is in the upper slope of the Nikawa landslide site where previous movements were triggered by the 1995 Hyogoken-Nambu earthquake. During detailed investigation, the slope was found to be at risk from a rapid and long-travel landslide induced by sliding surface liquefaction by earthquakes similar in scale to the 1995 event. A new plan to prevent the occurrence of this phenomenon was proposed and the plan was implemented. Another area is the Tama residential area near Tokyo. A set of field and laboratory investigations including laser scanner, geological drilling and ring-shear tests showed that there was a risk of sliding surface liquefaction for both sites. A geotechnical computer simulation (Rapid/LS) using the quantitative data obtained in the study allowed urban landslide hazard zoning to be made at individual street level.     

Seismic landslides hazard zoning based on the modified Newmark model: a case study from the Lushan earthquake,China

Seismically triggered landslides can cause great damage to the road construction in mountainous areas. The permanent displacement analysis based on Newmark sliding-block model can evaluate risk of these landslides from the perspective of deformation damage and overall failure probability of slopes. However, the sliding-block model does not consider the attenuation effect of the shear strength on the sliding surface during earthquake, causing the calculated value of Jibson method to be less than the actual value. Therefore, the Newmark model was modified by adding attenuation coefficients to the effective internal friction angle and the effective cohesion of geologic units. The landslide areal density was proposed for hazard zoning with the Wenchuan earthquake data. The results showed that the predicted values agreed well with the real distribution of the landslides triggered by the Lushan earthquake. The proposed hazard zoning method in this paper can predict the severity of seismic landslides in consideration of the environmental changes in mountainous regions after the earthquake and provide support for the site selection in highly seismic areas.

     

Fatal landslides in Europe

Landslides are a major hazard causing human and large economic losses worldwide. However, the quantification of fatalities and casualties is highly underestimated and incomplete, thus, the estimation of landslide risk is rather ambitious. Hence, a spatio-temporal distribution of deadly landslides is presented for 27 European countries over the last 20  years (1995–2014). Catastrophic landslides are widely distributed throughout Europe, however, with a great concentration in mountainous areas. In the studied period, a total of 1370 deaths and 784 injuries were reported resulting from 476 landslides. Turkey showed the highest fatalities with 335. An increasing trend of fatal landslides is observed, with a pronounced number of fatalities in the latest period from 2008 to 2014. The latter are mostly triggered by natural extreme events such as storms (i.e., heavy rainfall), earthquakes, and floods and only minor by human activities, such as mining and excavation works. Average economic loss per year in Europe is approximately 4.7 billion Euros. This study serves as baseline information for further risk mapping by integrating deadly landslide locations, local land use data, and will therefore help countries to protect human lives and property.     

Fluidization in dry landslides

This paper aims at determining the physical properties affecting the distance travelled by landslides with dry particles, and elucidating the mechanism of the properties affecting landslide fluidization. The procedure is as follows: laboratory landslide experiments were conducted to verify the simulation model which was proposed to represent the movement of landslides. Further, sensitivity analysis for some physical properties affecting the travel distance were conducted using this model. The simulation model could identify the coordinates, velocity and angular velocity for every particle in three-dimensional space, and the kinetic energy of particles consumed by inelastic and frictional collision with each other in the model. The travel distances of landslides simulated by the model were verified by laboratory experiments statistically where the physical properties for the particles and slope angle were changed. Then, sensitivity analysis for the physical properties were conducted using the model to clarify the effect of the properties on the travel distance. It was proven that there were no significant differences between the travel distances represented by the simulation model and those found experimentally using statistical analysis (i.e. the simulation model could represent virtual real landslides). From the sensitivity analysis using the simulation model, the travel distances were positively correlated to volume, or number of particles, and negative correlated to the slope angle, kinetic friction and rolling friction of particles when the initial potential energies were the same. The mass of particles of equal size did not affect the distance travelled. As the number of particles increased, the simulated travel distances tended to be longer compared with theoretical travel distances calculated using the friction between particles and the slope. Consequently, we could determine the distance of the lumped mass model as being critical between fluidized and non-fluidized landslides.     

Scanning electron microscopy and Raman spectroscopy as combined methods for studying zoning in minerals: The case of spinels from Archean komatiites

Several types of both magmatic and metamorphic spinels have been found in Archean komatiites of the Sovdozero and Kostomuksha greenstone belts in the eastern part of the Fennoscandian Shield. Scanning electron microscopy and Raman spectroscopy revealed relics of cores of primary magmatic chrome-spinels with high Cr and Al contents. In the Sovdozero structure, the relics are better retained than those in the Kostomuksha structure, which is caused by a different degree of metamorphic transformation. The comparable 100 · Cr/(Al + Cr) values of spinel cores from Sovdozero and Kostomuksha reflect similar conditions of partitional melting in the mantle. These data agree with the fact that both komatiite complexes belong to the Al-undepleted petrogenic type. Wide variations in the Cr and Al contents in primary chrome-spinel cores together with a constant Mg/(Fe²⁺ + Mg) ratio correspond to low oxygen fugacity during magma crystallization. In general, the composition of these primary chrome-spinels is similar to that of accessory phases in peridotites from suprasubduction zones and agrees with hypothesis of komatiite complex formation in back-arc basins.     

Geography of alarm zoning in Israel

During the Gulf War Israel was divided into six alarm zones to enable the people to be released gradually from their shelters according to the rate of damage and danger which has been in the different regions. These zones were outlined superficially, neither according to basic geographical elements, nor to the ballistic behaviour of the Iraqi missiles. A modified division into ten alarm zones was announced in September 1992 following the blockade which the USA had laid on military aviation in southern Iraq. A different division of alarm zones, based on ballistic and geographical parameters is proposed should there be missile attacks on the country in the future.     

Earthquake-induced landslides in Central America

Central America is a region of high seismic activity and the impact of destructive earthquakes is often aggravated by the triggering of landslides. Data are presented for earthquake-triggered landslides in the region and their characteristics are compared with global relationships between the area of landsliding and earthquake magnitude. We find that the areas affected by landslides are similar to other parts of the world but in certain parts of Central America, the numbers of slides are disproportionate for the size of the earthquakes. We also find that there are important differences between the characteristics of landslides in different parts of the Central American isthmus, soil falls and slides in steep slopes in volcanic soils predominate in Guatemala and El Salvador, whereas extensive translational slides in lateritic soils on large slopes are the principal hazard in Costa Rica and Panama. Methods for assessing landslide hazards, considering both rainfall and earthquakes as triggering mechanisms, developed in Costa Rica appear not to be suitable for direct application in the northern countries of the isthmus, for which modified approaches are required.     

Trace hydrogen zoning in diopside

Summary ¶The trace hydrogen content of a colourless to light-green zoned diopside single-crystal from Zillertal was investigated by IR microspectroscopy. The light-green part of the crystal reveals pleochroic OH absorption bands centred at 3645, 3463, and 3358cm^–1 which are attributed to structural OH defects. The OH absorptions of the colourless crystal part are characterised by weak bands at 3645 and 3662cm^–1 and by a strong band at 3676cm^–1. The bands at 3662 and 3676cm^–1 are attributed to the presence of amphibole lamellae. The analytical water content due to the structural OH defect concentration of the light-green crystal part amounts to 0.0016wt.%, that of the colourless part is lowered by a factor of about 50. According to optical absorption spectra, the light-green colour of the crystal is essentially caused by an Fe²⁺–Fe³⁺ charge transfer. The relatively high concentration of OH defects in the light-green crystal part associated with higher Al contents relative to the colourless part suggests that OH is incorporated as hydrodiopside component, CaMg(SiAlO₅OH). It is concluded that increasing water activity during the crystallisation process causes the formation of amphibole lamellae under consumption of nearly all of the water available in the fluid phase. It is further concluded that the observed hydrogen content of diopside represents a primary incorporation and not the result of late hydrothermal alteration processes.Received July 11, 2002; accepted October 30, 2002 Published online February 24, 2003     

Mechanisms of large landslides

SummaryMechanisms of Large Landslides The moving components of many large landslides show a remarkable tendency to remain in more or less undisturbed sequential order. In the present study this lack of laminar or turbulent flow is mathematically analyzed and explained. The high energy concentration thus resulting for the zone near the gliding surfaces points to self-lubrication by transformed (fused or dissociated) rock as a fundamental tribological mechanism. The idea is backed by two important facts: the impossibility to explain the observed economy of locomotion (and especially its increase with size) by any of the mechanisms considered hitherto; and a calculation yielding an unexpectedly low amount of energy susceptible to be dissipated far away from the gliding surfaces. Further analysis demonstrates numerically the plausibility of the self-lubrication concept both for primitive and carbonate rock. The development of useful prediction algorithms is not impossible in the future.

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ZusammenfassungMechanismen groer Bergstürze Die Trümmerströme vieler großer Bergstürze zeigen eine bemerkenswerte Tendenz zum Verbleiben in mehr oder weniger undurchmischtem Verband. In der vorliegenden Arbeit wird dieses Fehlen laminarer oder turbulenter Strömung auf Grund einer mathematischen Untersuchung erklärt. Die dabei resultierende hohe Energiedichte in der Nähe der Gleitflächen deutet auf Selbstschmierung durch transformiertes (geschmolzenes oder dissoziiertes) Gestein als entscheidenden tribologischen Mechanismus. Zwei wesentliche Tatsachen sprechen für diese Idee: das Versagen aller bisher vorgeschlagenen Mechanismen bei der Erklärung der beobachteten Bewegungsökonomie, speziell im Hinblick auf deren Steigerung in Funktion der Größe; und der rechnerisch ermittelte überraschend niedrige Energieanteil, der in größerer Entfernung von den Gleitflächen umgesetzt werden kann. Eine weitere Rechnung demonstriert zahlenmäßig die Plausibilität der Selbstschmierung sowohl für Urgesteine wie für Kalke. Die Entwicklung brauchbarer Vorhersage-Algorithmen rückt damit in den Bereich des Möglichen.

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RésuméLes mécanismes de gros éboulements Les composantes de gros éboulements montrent une tendance remarquable à se déplacer dans un ordre plus ou moins invariable. L'étude explique mathématiquement cette absence d'écoulements laminaire ou turbulant. La haute concentration d'énergie aux environs immédiats des surfaces de glissement implique la possibilité d'une auto-lubrification par le rocher métamorphosé (soit fondu, soit dissocié) en tant que mécanisme tribologique fondamental. Deux faits importants appuient cette hypothèse: d'une part l'impossibilité jusqu'à maintenant d'expliquer l'économie d'énergie observée (et spécialement en corrélation avec la grandeur de l'évènement) par un mécanisme quelconque; d'autre part la fraction d'énergie déterminée par calcul, étonnament basse, susceptible d'être métamorphosée à grande distance des surfaces de glissement. En outre le calcul démontre la possibilité du mécanisme d'auto-lubrification pour les plus importants types de rochers (primitifs et sédimentaires). Le développement futur d'algorithmes de prédiction utilisables entre de ce fait dans le domaine du possible.

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Notation a acceleration (m/s²) - A area (m²) - c specific heat (J/kg °C) - C transformation heat (J/kg) - d distance between two narrow passages (m) - e base of natural logarithms = 2.72 - e thickness of layer (m) - g gravitational acceleration = 9.81 m/s² - h thickness of mass (m) - k resistance coefficient - L global coefficient describing tribological quality (m/s⁴) - m mass (kg) - M lubrication quality factor - p pressure (Pa) - P power (W) - r wave amplitude (m) - s air cushion or gap thickness (m) - t time (s) - v velocity, speed (m/s) - V volume (m³) - W specific energy (J/kg) - x distance travelled (m) - z height (m) - Z height of center of gravity (m) - slope angle - relative portion of volume occupied by voids - dissipation coefficient - difference - relative fraction of A acting as narrow passage - depth (m) - viscosity (kg/ms) - temperature (°C) - adiabatic constant of air = 1.4 - wavelength (m) - µ coefficient of friction (solid state) - average coefficient of friction - Ludolf's number = 3.14 - density (kg/m³) - fidelity coefficient - jet contraction factor Indices a primitive rock - A air cushion - b feldspar - c quartz - d lubricant generated from primitive rock - d dissipation - e sedimentary rock - E air escape gap - f CaO - g CO₂ - h lubricant generated from sedimentary rock - i ordinal number - L lubricant - M total area - R rock - o initial, basic, 30 = after 30 s With 12 Figures     

Paleofloristic zoning of the Carboniferous in USSR

The author presents an excellent, objective review of Radchenko's phytogeographic zoning, proposed for the Carboniferous of the USSR. Whereas Radchenko has recognized several phytogeographic zones and provinces for the Carboniferous of the USSR, Meyen points out that anatomical and morphological features of the plants concerned do not support the climatic conclusions drawn by Radchenko. A major point of criticism also lies in the fact that many undescribed taxa are used to support Radchenko's views, and floristic boundaries are confidently drawn with no supporting basis. Meyen advises general caution in considering Radchenko's overall conclusions. -- S. H. Mamay.