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1.
Gravitational spreading of mountain ridges displays primary disequilibrium of flysch mountain areas of the Czech Carpathians.
The progression of various types of mass movements is a product of long-term ridge disintegration and is predisposed by the
geological structure of the area and the upper Tertiary-Quaternary morphogenesis of the mountain area. Deep-seated slope deformations
are spatially interconnected by the occurrence of some other types of slope deformations (e.g. debris flows, debris slides,
slumps, rock avalanches, etc.), which pose a considerable risk for the existence of human society. An important causative
factor in these dynamically developing hazardous processes is, among other factors, the way in which land has been used in
the last three centuries. Therefore, the occurrence of various types of slope deformations is studied in terms of their relation
to deep-seated gravitational deformations and in terms of other limiting factors (structural geological, morphological and
climatic factors, manmade impacts, etc.). The paper presents several case studies of slope deformations (Velká Čantoryje Mt,
Lysá hora Mt, Ropice Mt and Smrk Mt) in the area of the Outer Carpathians within the territory of the Czech Republic and also
adverts to some consequences in terms of the socioeconomic structure of the landscape. 相似文献
2.
Landslide susceptibility and hazard assessment in San Ramón Ravine, Santiago de Chile, from an engineering geological approach 总被引：1，自引：1，他引：0
Debris flows and soil and rock slides are among the main geological hazards in the mountain foothills of Central Chile. Geological risk associated with the development of landslides, especially debris flows triggered in the basins of ravines that drain into the capital city, Santiago, has increased in time due to accelerated urban expansion. A landslide hazard evaluation in the San Ramón Ravine, located within the foothills of Santiago is presented. Hazard evaluation is based on a methodology that combines the determination of landslide susceptibility calculated by integration of conditioning factors, with the assessment of slope failure and runout probabilities incorporating geotechnical engineering approaches. The methodology is appropriate for medium or subregional scale studies with limited data. The results show that in San Ramón Ravine the landslide hazard consists mainly of debris flows, rock block slides, rock falls and shallow soil slides. Among these, debris flows are the most important due to the urban area that can be affected. Other case studies show that the method can be used in other regions with minor adaptations for territorial planning or for engineering and environmental purposes. 相似文献
3.
Apip Kaoru Takara Yosuke Yamashiki Kyoji Sassa Agung Bagiawan Ibrahim Hiroshi Fukuoka 《Landslides》2010,7(3):237-258
This paper describes the potential applicability of a hydrological–geotechnical modeling system using satellite-based rainfall
estimates for a shallow landslide prediction system. The physically based distributed model has been developed by integrating
a grid-based distributed kinematic wave rainfall-runoff model with an infinite slope stability approach. The model was forced
by the satellite-based near real-time half-hourly CMORPH global rainfall product prepared by NOAA-CPC. The method combines
the following two model outputs necessary for identifying where and when shallow landslides may potentially occur in the catchment:
(1) the time-invariant spatial distribution of areas susceptible to slope instability map, for which the river catchment is
divided into stability classes according to the critical relative soil saturation; this output is designed to portray the
effect of quasi-static land surface variables and soil strength properties on slope instability and (2) a produced map linked
with spatiotemporally varying hydrologic properties to provide a time-varying estimate of susceptibility to slope movement
in response to rainfall. The proposed hydrological model predicts the dynamic of soil saturation in each grid element. The
stored water in each grid element is then used for updating the relative soil saturation and analyzing the slope stability.
A grid of slope is defined to be unstable when the relative soil saturation becomes higher than the critical level and is
the basis for issuing a shallow landslide warning. The method was applied to past landslides in the upper Citarum River catchment
(2,310 km2), Indonesia; the resulting time-invariant landslide susceptibility map shows good agreement with the spatial patterns of
documented historical landslides (1985–2008). Application of the model to two recent shallow landslides shows that the model
can successfully predict the effect of rainfall movement and intensity on the spatiotemporal dynamic of hydrological variables
that trigger shallow landslides. Several hours before the landslides, the model predicted unstable conditions in some grids
over and near the grids at which the actual shallow landslides occurred. Overall, the results demonstrate the potential applicability
of the modeling system for shallow landslide disaster predictions and warnings. 相似文献
4.
Rapid debris flows, a mixture of unconsolidated sediments and water travelling at speeds > 10 m/s are the most destructive water related mass movements that affect hill and mountain regions. The predisposing factors setting the stage for the event are the availability of materials, type of materials, stream power, slope gradient, aspect and curvature, lithology, land use and land cover, lineament density, and drainage. Rainfall is the most common triggering factor that causes debris flow in the Palar subwatershed and seismicity is not considered as it is a stable continental region and moderate seismic zone. Also, there are no records of major seismic activities in the past. In this study, one of the less explored heuristic methods known as the analytical network process (ANP) is used to map the spatial propensity of debris flow. This method is based on top-down decision model and is a multi-criteria, decision-making tool that translates subjective assessment of relative importance to weights or scores and is implemented in the Palar subwatershed which is part of the Western Ghats in southern India. The results suggest that the factors influencing debris flow susceptibility in this region are the availability of material on the slope, peak flow, gradient of the slope, land use and land cover, and proximity to streams. Among all, peak discharge is identified as the chief factor causing debris flow. The use of micro-scale watersheds demonstrated in this study to develop the susceptibility map can be very effective for local level planning and land management. 相似文献
5.
The Afternoon Creek rockslide near Newhalem, Washington 总被引：1，自引：0，他引：1
A series of mass wasting events occurred above a Washington, USA, highway in the Cascade Mountains in November and December 2003. The largest event was a rockslide involving approximately 750,000 m3 that occurred on November 9, 2003. The source zone for this event was located at the crest of a ridge. Most of the debris fell to the east of the sharp ridge and was deposited in the relatively shallow sloping Afternoon Creek without causing damage to the highway. Lesser amounts of debris fell to the west of the ridge, sliding 600 m down the steeper Falls Creek and impacting the road. There is an evidence of one or more historical rock avalanches at this location. Displacement of reference points, ground vibration, crack extension, and tilting are being monitored due to concerns that future slope failures or remobilization of debris might again damage or block the highway. 相似文献
6.
Modeling regional initiation of rainfall-induced shallow landslides in the eastern Umbria Region of central Italy 总被引：3，自引：6，他引：3
Diana Salciarini Jonathan W. Godt William Z. Savage Pietro Conversini Rex L. Baum John A. Michael 《Landslides》2006,3(3):181-194
We model the rainfall-induced initiation of shallow landslides over a broad region using a deterministic approach, the Transient Rainfall Infiltration and Grid-based Slope-stability (TRIGRS) model that couples an infinite-slope stability analysis with a one-dimensional analytical solution for transient pore pressure response to rainfall infiltration. This model permits the evaluation of regional shallow landslide susceptibility in a Geographic Information System framework, and we use it to analyze susceptibility to shallow landslides in an area in the eastern Umbria Region of central Italy. As shown on a landslide inventory map produced by the Italian National Research Council, the area has been affected in the past by shallow landslides, many of which have transformed into debris flows. Input data for the TRIGRS model include time-varying rainfall, topographic slope, colluvial thickness, initial water table depth, and material strength and hydraulic properties. Because of a paucity of input data, we focus on parametric analyses to calibrate and test the model and show the effect of variation in material properties and initial water table conditions on the distribution of simulated instability in the study area in response to realistic rainfall. Comparing the results with the shallow landslide inventory map, we find more than 80% agreement between predicted shallow landslide susceptibility and the inventory, despite the paucity of input data. 相似文献
7.
Various controlling factors such as lithology, slope angle, slope aspect, landuse, channel proximity etc. are generally considered for the landslide hazard assessment. Although outer dependence of these parameters to a landslide is inevitably taken into account, inter-dependence among the factors is seldom addressed. Analytic Network Process (ANP) is the multi-criteria decision making (MCDM) tool which takes into account such a complex relationship among parameters. In this research, an ANP model for landslide susceptibility is proposed, priority weights for each parameter controlling the landslide were determined, and a hazard map was prepared of an area in a fragile mountainous terrain in the eastern part of Nepal. The data used in the example were derived from published sources, aerial photographs and a topographic map. However, the procedures developed can readily incorporate additional information from more detailed investigations. 相似文献
8.
A rainfall-induced shallow landslide is a major hazard in mountainous terrain, but a time-space based approach is still an unsettled issue for mapping rainfall-induced shallow landslide hazards. Rain induces a rise of the groundwater level and an increase in pore water pressure that results in slope failures. In this study, an integrated infinite slope analysis model has been developed to evaluate the influence of infiltration on surficial stability of slopes by the limit equilibrium method. Based on this new integrated infinite slope analysis model, a time-space based approach has been implemented to map the distributed landslide hazard in a GIS (Geographic Information Systems) and to evaluate the shallow slope failure induced by a particular rainfall event that accounts for the rainfall intensity and duration. The case study results in a comprehensive time-space landslide hazard map that illustrates the change of the safety factor and the depth of the wetting front over time. 相似文献
9.
川藏铁路建设面临脆弱地质环境的约束,沿线重大地质灾害的孕灾过程及成灾机理研究能为有效防灾提供技术支撑.基于详细的现场调查,揭示川藏铁路廊道泸定段发育3处大型滑坡及4条泥石流沟.区内大型滑坡的孕灾因素主要有以下3点: (1)康滇古隆起多期强烈东西向挤压,致使近南北向长大结构面发育且与河谷岸坡大致平行; (2)河谷走向与最大主应力方向垂直,谷坡岩体强烈卸荷; (3)鲜水河断裂活动产生震动作用,在三面临空的突出地形、坡折微地貌处地震波放大效应叠加背坡效应,导致地震波被放大3至6倍,使得顺坡向陡缓结构面控制的高位岩体发生大规模失稳,从而导致大型滑坡发生.区内构造破碎,且受强震震裂作用影响,支沟沟谷物源丰富,沟域形态利于汇水及物源启动,受汛期7~9月集中降雨影响,易激发群发性泥石流.泥石流活动影响施工营地安全,边坡地震动放大效应影响桥位区仰坡岩体稳定性. 相似文献
10.
The heavy rains associated with Hurricane Mitch triggered off a number of slope instability processes in several Central American countries. Different instability processes have been acknowledged for the various mountainous regions of Nicaragua. An enormous movement of the Casita Volcano slopes resulted in numerous deaths and some deep movements have been reactivated. On the other hand, numerous shallow mass movements and debris flows have given rise to great material loss throughout a large part of Nicaraguan mountains.Mapping the shallow mass movements in an area of Central Nicaragua clearly reveals the close ties between their distribution and some geomorphological factors. A susceptibility model has been constructed for shallow mass movements based on field mapping of the shallow mass movement distribution, the geomorphological map as well as the digital slope and accumulated flow models. A logistical regression analysis was applied. The study area has been categorized into three classes of relative landslide susceptibility. Given that phenomena of this nature occur much more frequently in the high susceptibility class, 94% of the shallow mass movements that have been used to test the model are in the high and medium susceptibility classes . The geological and geomorphological conditions of the study area are representative of a large sector of the central Nicaraguan region. Consequently, the methodology followed in this paper is deemed to constitute a useful tool, both regarding the design of new infrastructures, and as a guide to the urban development of the area. 相似文献
11.
安徽巢湖二叠系栖霞组碳酸盐岩斜坡沉积 总被引：9，自引：5，他引：9
长期以来,人们均认为下扬子地区广泛发育的栖霞组碳酸盐岩属于浅海碳酸盐岩台地沉积。但以巢湖地区为例研究表明,栖霞组主要为碳酸盐岩斜坡沉积。碳酸盐岩碎屑流沉积物形成了臭灰岩段和顶部灰岩段的层状石灰砾岩,分布于斜坡上部;等深流沉积物形成了上、下硅质层段的砂屑硅质粒泥灰岩,主要分布于斜坡下部。而上、下硅质层段中的钙、硅质页 (泥 )岩属于斜坡远端和盆地沉积;唯有本部灰岩段可能属于浅海碳酸盐岩台地沉积。这一认识不仅突破了传统观念,而且有助于重新认识下扬子板块二叠纪的古地理特征和盆地构造演化。 相似文献
12.
Tianjin coastal plain is flat and its landform is not easy to be divided. The grain size of the sediments is fine, with poor remote sensing interpretation accuracy and field identification, which leads to weak geological map expression effect by the traditional geological survey method. Digital Elevation Model (DEM) is a digital representation of the topographic surface and it has 3D visual information that cannot be expressed by the general topographic map, which can truly reflect the features of the landform. The authors divided the geomorphic units of shallow sediments during the geological mapping process of Tianjin coastal plain based on DEM and the geological survey of the route, the construction of the shallow groove drilling and the sample testing. The shallow sediments can be divided into three sedimentary systems: fluvial sedimentary system, transgression sedimentary systm and deltaic sedimentary system. The fluvial sedimentary system includes several genetic types of point bar, oxbow lake, crevasse splay, natural levee, flood basin and lake marsh. And the transgression sedimentary system can be divided into beach ridge, overland fan, high tide flat, residual lagoon, while the deltaic sedimentary system includes the delta front. DEM can fully make up for the shortage of remote sensing images after the comparative analysis with the results of remote sensing interpretation of different types. Besides, DEM can also be used for the detailed genetic classification of the shallow sediments and improve the cognition about shallow geological process, which will guide the field mapping. The application of high-precision DEM data to the geological mapping on the covered areas of quaternary system can greatly improve the mapping accuracy and efficiency, and provide basic geological support for urban ecological security, territorial space planning and industrial structure layout. 相似文献
13.
天津市滨海平原地区地势平坦,地貌类型不易划分,沉积物粒度较细,遥感解译精度及实地可识别性差,按照传统的地质调查方法开展填图,图面表达效果不佳。数字高程模型(Digital Elevation Model, DEM)是地形的数字化表达,具有一般地形图无法表达的三维可视化信息,能够真实反映地形地貌特征。在开展天津滨海平原地质填图过程中,通过建立研究区DEM,并结合路线地质调查、槽型浅钻施工、样品测试分析,进行了地貌单元划分,将浅地表沉积物划分为河流、海侵和三角洲3个沉积体系: 河流沉积体系包含边滩(曲流砂坝)、充填河槽(牛轭湖)、决口扇、天然堤、洪泛盆地和湖沼沉积微相; 海侵沉积体系包含海滩脊、越岸扇、高潮坪和残留潟湖沉积微相; 三角洲沉积体系主要为三角洲前缘沉积。通过与不同类型遥感解译结果进行对比分析可知,DEM可充分弥补遥感影像的不足,对浅地表沉积物进行详细的成因类型划分,提升对浅地表地质作用过程的认知程度,较好地指导野外地质填图。将高精度DEM数据应用于第四系覆盖区地质填图,可以大大提高填图精度及效率,为城市生态安全保障、国土空间规划、产业结构布局等提供基础地质依据。 相似文献
14.
喜马拉雅山地区是世界上最高大的也是最年轻的山脉,这里地处两大板块的碰撞带,地质构造复杂,新构造运动强烈,山地灾害发育,泥石流异常活跃,经常给生命线工程和当地人民生命财产造成威胁。但是由于高寒缺氧,加之技术手段所限,研究程度一直很低。本文在对该区大型、巨型泥石流进行了遥感研究和实地调查资料基础上,发现该区泥石流存在16个泥石流较集中分布区,并且北坡比南坡更为发育。在此基础上,对其发育规律进行细致分析,发现:(1)喜马拉雅山地区泥石流的活动目前正处于活跃期; (2)研究区泥石流沟口主要分布在两个高程段,一个是2800~3400m范围,另一个是4200~4900m范围; (3)研究区衰败期泥石流沟道比降大都小于100,而发育期的泥石流沟道比降一般比较大,大都大于300,旺盛期的泥石流沟道比降则介于100~300之间。另一方面,我们发现本区冰雪融水与雨水型泥石流的沟道比降几乎相同,其动力条件相差不大。这对于该区泥石流灾害的防治、判断泥石流的活动性具有重要意义。 相似文献
15.
降雨诱发坡面型泥石流形成机理 总被引：7，自引：0，他引：7
基于野外调查和室内测试分析,依据岩土体破坏准则理论,结合典型坡面型泥石流进行剖析,从坡面型泥石流形成的影响因素、运动学特征、动力条件、形成与演化过程等方面,探讨了降雨诱发坡面型泥石流的形成机理。研究结果表明:坡面流以平移式滑动方式破坏为主,通常发生于残坡积土层厚度小(≤2.0 m)的陡坡地带(坡度≥40°),降雨是坡面型泥石流的主要触发因素,雨水入渗促使斜坡残坡积岩土体饱和软化,当土体含水率超过28%~30%,粘聚力、内摩擦角与含水率关系曲线都出现了明显的拐点,即饱和度超过75%时,其粘聚力和内摩擦角都发生急剧降低,斜坡土体由稳定状态向破坏状态演化。遇持续降雨(或暴雨)作用,此种残坡积土局部发生失稳下滑——流土,进而在动水压力作用下发生下泻造浆形成坡面泥石流。 相似文献
16.
浙东南山丘区泥石流爆发的临界雨量分析 总被引：2，自引：0，他引：2
首先对浙东南山区泥石流的形成条件（物源、地形和降水条件）进行了研究。随后研究了本区泥石流的基本特征：在形成方式上,以谷坡或沟源地带的土动力启动方式为主;在侵蚀特征方面,主要有面蚀作用和沟谷侵蚀作用;堆积特征方面,在宏观上当规模较大时可形成堆积扇,规模较小时往往以停积于中下游沟道为主;微观上,主要表现为堆积物质结构杂乱,个别具有期次性。对本区泥石流临界雨量组合进行分析,认为采用基于区域临界雨量组合的泥石流预警预报方法较为合理。利用研究区内4次群发泥石流时的降雨特征值确定了本区泥石流爆发的临界雨量组合,并将其应用于研究区泥石流的临灾预警,分为以下步骤：①收集实时降雨资料;②绘制实时雨量组合曲线;③泥石流灾害预警;④泥石流临界雨量基准的修正。 相似文献
17.
Abdolhossein Khalilnejad Faisal Hj. Ali Normaniza Osman 《Geotechnical and Geological Engineering》2012,30(2):277-288
Land sliding is a geotechnical event that includes a wide range of ground movements such as rockfalls, deep failure of slopes
and shallow debris flows, and it can cause various problems in varied civil fields such as roads and dams. Since most conventional
methods are neither inexpensive nor applicable everywhere, attention has nowadays been drawn to soil bioengineering using
vegetation as the environment-friendly method for slope stabilization. Soil bioengineering or using vegetation in civil engineering
design is mostly applicable to shallow slope stabilization projects characterized by unstable slopes with surface movement.
Vegetation has both a silent effect on soil improvement to predict the landslide and a mechanical role to increase shear and
pulling-out stress on the soil. During the last decade, many researches have been carried out to clarify the effect of vegetation
on slope stability, but many questions still remain to be answered. 相似文献
18.
The existence of a small population of ‘relict rock glaciers’ scattered across the main British mountain areas has previously been inferred from published cases of individual sites or local clusters. Discrete debris accumulations (DDAs) of widely differing character have been identified as ice‐debris landforms (whether ‘rock glaciers’ or ‘protalus lobes’) partly from morphological, sedimentological and topo‐locational evidence, but principally by analogy with both active and relict examples in present‐day arctic/alpine environments, with consequent palaeoclimate inferences. However, re‐interpretation of several supposed rock glaciers as rock slope failures has cast doubt on both the palaeoclimatic reconstructions and the origin of the remaining features. Issues of polygenesis and mimicry/equifinality have contributed to some previous misidentifications. We re‐evaluate the 28 candidate cases based on new field and image‐analysis evidence and place them on a continuum from no ice presence through passive ice presence and glacial shaping to emplacement onto glacier ice with consequent melt‐out topography. A null hypothesis approach (that there are no relict rock glaciers in the British mountains) is pursued, and the evidence indicates that none of the 28 cases clearly warrants classification as a relict rock glacier; their characteristics can be explained without recourse to any significant forward debris movement controlled or facilitated by incorporated or underlying ice as it deforms and melts out. However, only one‐third of the candidate DDAs are attributed in whole or part to rock slope failure (sensu stricto), with other debris sources including incremental rockfall, bedrock knolls with coarse debris veneer, protalus rampart and moraine. A few cases deserve more detailed investigation of their structure, morphology and sediments within a broader local glaciological/topographical context, with multitemporal/polygenetic evolution in mind. But it is for future researchers to demonstrate that deforming ice played an incontestable part in shaping these often enigmatic DDAs, given that other causes are simpler and commoner. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
19.
Hazard Zoning for Landslides Connected to Torrential Floods in the Jerte Valley (Spain) by using GIS Techniques 总被引：2，自引：0，他引：2
Carrasco R.M. Pedraza J. Martin-Duque J.F. Mattera M. Sanz M.A. Bodoque J.M. 《Natural Hazards》2003,30(3):361-381
The Jerte Valley is anortheast-southwest tending graben located in the mountainous region of west central Spain (Spanish Central System). Mass movements have been a predominant shaping process on the Valley slopes during the Quaternary. Present day activity is characterized as either `first-time failure' (shallow debris slides and debris flows) or `reactivations' of pre-existing landslides deposits.A delineation of landslide hazard zoningwithin the Valley has been carried out by using the detailed documentation of a particular event (a debris slide and a sequel torrential flood, which occurred on the Jubaguerra stream gorge), and GIS techniques. The procedure has had four stages, which are: (1) the elaboration of a susceptibility map (spatial prediction) of landslides; (2) the elaboration of a map of `restricted susceptibility' in the particular case of slopes that are connected to streams and torrents (gorges); (3) the elaboration of a digital model which relates the altitude to the occurrence probability of those particular precipitation conditions which characterized the Jubaguerra event and (4) the combination of the probability model with the `restricted susceptibility map', to establish `critical zones' or areas which are more prone to the occurrence of phenomena that have same typology as this one. 相似文献
20.
2011年3月13日至4月13日哥斯达黎加地震起源计划IODP334航次在中美洲哥斯达黎加俯冲带大陆边缘斜坡带实施。该航次的主要科学目标是研究俯冲剥蚀控制的俯冲带大地震的聚集和破裂过程。在1个月的钻探时间内,总共在4个站位、8个钻孔中获得1492．88m的岩芯,获得许多中新世到现代的火山灰层,初步确定上覆板块内沉积物和... 相似文献