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On 15 May 1991, a landslide occurred at Gacharage Village in the Murang'a District of Kenya; it buried a house near the toe of a cliff, killing all eight residents in their sleep. The principal determining factors of the slide were a high, mechanically unstable slope of deeply weathered volcanic soil and a high sorption capacity of the surface soil layer. The slide was triggered by rapid saturation of the soil following a heavy downpour. Based on field investigations and laboratory studies, this paper discusses the physical properties and environmental factors that affected slope stability at Murang'a. It also points out the economic and social impact of landslides in the region and suggests remedial measures. 相似文献
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Data compiled from monitoring the displacement resulting from the Xintan landslide in China was analyzed. The stability of
the demonstrated colluvial slope has a close correlation with two parameters, the velocity of the displacement and the angle
of the surface vector. The stability trend can be described and evaluated by both the velocity of the displacement and the
vector angles. The displacement vector angle, for which there is no substitute, serves as an explicit criterion for the stability
of the slope, hence it is significant in the prediction of the catastrophic movement of landslides. A systematic analysis
of the features of the vector angles of the surface displacement space and time was performed. The evolving mechanism of space-time
and the characteristics of the displacement vector angles were deduced. On the basis of these deductions and by using principles
of statistics, the double-parameter threshold for forecasting the stability of the colluvial slopes was established. According
to the double-parameter threshold, a calculation and evaluation of stability was completed in terms of the monitoring data
of the F-series of points on the Xintan slope. The forecast results coincided with the destabilized timetable, thus demonstrating
that the double-parameter criterion has, to a certain extent, precision and practical application for forecasting of landslides. 相似文献
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袁炳华 《中国地质灾害与防治学报》2000,11(4):48-52
由于黔江河床大量开采巨型块石作建材,河流急速下切滑坡体下卧湖相粘土层,形成新的临空面,观音岩老滑坡体失稳复活.文章从恢复自然环境的思路入手,提出了采用"多级多期谷坊坝及防冲抗滑挡墙”为主体的治理工程方案.该方案发挥谷坊坝阻流降速作用,利用河流的淤积功能,使观音岩段河床逐步恢复到滑坡活动前的状态,有效地遏止河流下切,消除粘土层临空面,真正起到防灾减灾的作用. 相似文献
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Evaluation of potential landslide damming: Case study of Urni landslide,Kinnaur, Satluj valley,India
This work aims to understand the process of potential landslide damming using slope failure mechanism,dam dimension and dam stability evaluation. The Urni landslide, situated on the right bank of the Satluj River, Himachal Pradesh(India) is taken as the case study. The Urni landslide has evolved into a complex landslide in the last two decade(2000-2016) and has dammed the Satluj River partially since year 2013,damaging ～200 m stretch of the National Highway(NH-05). The crown of the landslide exists at an altitude of ～2180-2190 m above msl, close to the Urni village that has a human population of about 500.The high resolution imagery shows ～50 m long landslide scarp and ～100 m long transverse cracks in the detached mass that implies potential for further slope failure movement. Further analysis shows that the landslide has attained an areal increase of 103,900 ± 1142 m^2 during year 2004-2016. About 86% of this areal increase occurred since year 2013. Abrupt increase in the annual mean rainfall is also observed since the year 2013. The extreme rainfall in the June, 2013; 11 June(～100 mm) and 16 June(～115 mm),are considered to be responsible for the slope failure in the Urni landslide that has partially dammed the river. The finite element modelling(FEM) based slope stability analysis revealed the shear strain in the order of 0.0-0.16 with 0.0-0.6 m total displacement in the detachment zone. Further, kinematic analysis indicated planar and wedge failure condition in the jointed rockmass. The debris flow runout simulation of the detached mass in the landslide showed a velocity of ～25 m/s with a flow height of ～15 m while it(debris flow) reaches the valley floor. Finally, it is also estimated that further slope failure may detach as much as 0.80 ±0.32 million m^3 mass that will completely dam the river to a height of 76±30 m above the river bed. 相似文献
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Ice, moraine, and landslide dams in mountainous terrain 总被引：4，自引：0，他引：4
We review recent work on ice, moraine, and landslide dams in mountainous terrain, thus complementing several comprehensive summaries on glacier dams in intracontinental and Arctic areas of low relief. We discuss the roles of tectonic and climatic forcing on ice-, moraine-, and landslide-dam formation and sudden drainage, and focus on similarities and differences between their geomorphic impacts on confined valleys drained by steep bedrock and gravel-bed rivers.Despite numerous reported failures of natural dams in mountain belts throughout the world, their relevance to long-term dynamics of mountain rivers remains poorly quantified. All types of dams exert local base-level controls, thus trapping incoming sediment and inhibiting fluvial bedrock incision. Pervasive geomorphic and sedimentary evidence of outburst events is preserved even in areas of high erosion rates, suggesting that sudden dam failures are characterized by processes of catastrophic valley-floor aggradation, active-channel widening, and downstream dispersion of sediment, during which little bedrock erosion seems to be achieved.We find that, in the absence of direct evidence of former dams, a number of similarities among the geomorphic and sedimentologic characteristics of catastrophic outburst flows may give rise to ambiguous inferences on the dam-forming process. This is especially the case for tectonically active mountain belts where there is ample and comparable potential for the formation and failure of ice, moraine, landslide, and polygenetic dams concomitant with climatic oscillations or earthquake disturbance. Hence, the palaeoclimatic implications of erroneously inferring the cause of dam formation may be significant.We recommend that future research on natural dams in mountainous terrain addresses (a) climate- and earthquake-controlled systematics in the pattern of formation and failure; (b) quantification of response of mountain rivers to catastrophic outburst events and their concomitant process sequences; (c) elaboration of a comprehensive classification of natural dams in mountainous terrain with special attention to polygenetic dams; (d) physical-based modelling of dam formation, failure, and routing of water and sediment outbursts; and (e) quantitative controls on the contribution of natural dams to sediment budgets in mountainous terrain. 相似文献
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青藏高原东缘理塘乱石包高速远程滑坡发育特征与形成机理 总被引：2，自引：0，他引：2
青藏高原复杂的地质构造背景,导致该区地震频发,加之该区异常的气候变化,大型乃至巨型地质灾害发育多,危害大。在遥感解译、野外地质调查、物探、槽探和地质测年资料分析的基础上,论述了乱石包滑坡的发育特征,并对其形成机理进行分析探讨。认为乱石包高速远程滑坡具有如下特征:1乱石包滑坡的滑动方向垂直于理塘-德巫断裂的北西段,乱石包滑坡顶部接近于现代雪线;2乱石包滑坡最大滑行距离达3.83km,滑坡后壁与前缘堆积区的高差约820m,滑体方量0.64×108~0.94×108m3,平均滑动速度约53.25m/s;3测年资料表明,乱石包滑坡形成1980±30a BP左右;4组成滑坡体的岩性主要为花岗岩,在长期构造活动和冷冻风化作用下,节理裂隙发育,呈碎裂岩体。分析表明,乱石包滑坡受断裂构造、地形地貌和古气候变化影响较大,形成机理复杂:1理塘-德巫断裂全新世以来活动强烈,具有强震地质背景,由该断裂活动形成的强震可能是乱石包滑坡形成的主要因素之一,在地震作用下,坡顶部地震波放大,垂直加速度大于水平加速度,岩体发生震胀和抛掷,从而形成高速远程滑动;2距今1800~2000a BP左右时,青藏高原地区的温度变化较大,该时期发生的大规模冰川活动可能是乱石包滑坡发生的主要因素之一;3地震、气候变化的组合也是引起乱石包滑坡发生的成因之一,并形成一个完整的地质灾害链:地震→雪崩→岩崩→高速碎屑流。 相似文献
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Guruh Samodra Guangqi Chen Junun Sartohadi Kiyonobu Kasama 《Environmental Earth Sciences》2017,76(4):184
There are different approaches and techniques for landslide susceptibility mapping. However, no agreement has been reached in both the procedure and the use of specific controlling factors employed in the landslide susceptibility mapping. Each model has its own assumption, and the result may differ from place to place. Different landslide controlling factors and the completeness of landslide inventory may also affect the different result. Incomplete landslide inventory may produce significance error in the interpretation of the relationship between landslide and controlling factor. Comparing landslide susceptibility models using complete inventory is essential in order to identify the most realistic landslide susceptibility approach applied typically in the tropical region Indonesia. Purwosari area, Java, which has total 182 landslides occurred from 1979 to 2011, was selected as study area to evaluate three data-driven landslide susceptibility models, i.e., weight of evidence, logistic regression, and artificial neural network. Landslide in the study area is usually affected by rainfall and anthropogenic activities. The landslide typology consists of shallow translational and rotational slide. The elevation, slope, aspect, plan curvature, profile curvature, stream power index, topographic wetness index, distance to river, land use, and distance to road were selected as landslide controlling factors for the analysis. Considering the accuracy and the precision evaluations, the weight of evidence represents considerably the most realistic prediction capacities (79%) when comparing with the logistic regression (72%) and artificial neural network (71%). The linear model shows more powerful result than the nonlinear models because it fits to the area where complete landslide inventory is available, the landscape is not varied, and the occurence of landslide is evenly distributed to the class of controlling factor. 相似文献
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A landslide in stiff,intact clay 总被引：1，自引：0，他引：1
A landslide in a stiff clay formation, interrupting the excavation of a tunnel for a major railway in Sicily, is reported. Limit equilibrium and FEM undrained and drained analyses of the slope before tunnel excavation agree in showing that the slope was stable with a relatively high factor of safety and the critical slip surface is located well above the tunnel. The undrained stability of the tunnel checked both via FEM and via standard analytical solutions for face stability is also verified. The FEM analyses of the slope have been repeated considering the excavation of the tunnel in undrained and drained conditions. The advancement of the tunnel face is simulated in a plane strain analysis by the Panet method. In undrained conditions, the system keeps stable. In drained conditions with a stress release factor of 50 %, the slope is on the verge of failing with a very low safety factor, while with a stress release factor of 80 %, it fails following a complex mechanism that matches the observed failure surface. These findings are discussed and some conclusions attempted. 相似文献
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Development of Taprang landslide,West Nepal 总被引：1，自引：1，他引：0
This paper is about a large landslide located at Taprang, on the right bank of the Madi River in the west Nepal Himalaya. It attempts to reconstruct the evolution of the landslide from its initial state to the present conditions. Many large landslides involve multiple failure incidents in different times to attain their present size and shape. The Taprang landslide has also been active for more than 75 years and experienced many failure episodes. The slide lies in a very complex geological setting characterized by the presence of Main Central Thrust and some other folds as well as several joint sets and shear zones. It is developed on weathered graphitic schists, highly fractured and jointed quartzites, marbles, gneisses, and a few amphibolites. Landslide mapping revealed that the rocks are deformed and fractured. They have also undergone intense weathering. Laboratory analysis of rock and soil samples collected from the landslide and surrounding area shows that the weathered rocks, joint infillings, and shear zones are rich in clay minerals, especially smectite and montmorillonite having swelling properties. Besides, hydrologic, climatic, and anthropogenic factors operating simultaneously since a long time have also contributed significantly to the enlargement of the slide. The study indicates that the landslide has a high potential of future enlargement towards upper slopes. 相似文献
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The Catak landslide (Trabzon Province, Turkey) developed retrogressively upslope through a series of small slips, culminating with the catastrophic rock avalanche of 23rd June, 1988 when at least 66 people were killed. The landslide was caused by prolonged heavy rainfall triggering a failure in a partially supported 25-m high road cutting in colluvium, which progressively removed support for the higher parts of the slope and resulted in the catastrophic slide. Such high-magnitude events are not uncommon in the Black Sea Mountains but the recent disaster highlights the need for systematic landslide hazard assessments in the region. 相似文献
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Modeling landslide recurrence in Seattle, Washington, USA 总被引：5，自引：0，他引：5
Diana Salciarini Jonathan W. Godt William Z. Savage Rex L. Baum Pietro Conversini 《Engineering Geology》2008,102(3-4):227
To manage the hazard associated with shallow landslides, decision makers need an understanding of where and when landslides may occur. A variety of approaches have been used to estimate the hazard from shallow, rainfall-triggered landslides, such as empirical rainfall threshold methods or probabilistic methods based on historical records. The wide availability of Geographic Information Systems (GIS) and digital topographic data has led to the development of analytic methods for landslide hazard estimation that couple steady-state hydrological models with slope stability calculations. Because these methods typically neglect the transient effects of infiltration on slope stability, results cannot be linked with historical or forecasted rainfall sequences. Estimates of the frequency of conditions likely to cause landslides are critical for quantitative risk and hazard assessments. We present results to demonstrate how a transient infiltration model coupled with an infinite slope stability calculation may be used to assess shallow landslide frequency in the City of Seattle, Washington, USA. A module called CRF (Critical RainFall) for estimating deterministic rainfall thresholds has been integrated in the TRIGRS (Transient Rainfall Infiltration and Grid-based Slope-Stability) model that combines a transient, one-dimensional analytic solution for pore-pressure response to rainfall infiltration with an infinite slope stability calculation. Input data for the extended model include topographic slope, colluvial thickness, initial water-table depth, material properties, and rainfall durations. This approach is combined with a statistical treatment of rainfall using a GEV (General Extreme Value) probabilistic distribution to produce maps showing the shallow landslide recurrence induced, on a spatially distributed basis, as a function of rainfall duration and hillslope characteristics. 相似文献
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Regional-scale landslide activity and landslide susceptibility zonation in the Nepal Himalaya 总被引：1，自引：1，他引：0
Ranjan Kumar Dahal 《Environmental Earth Sciences》2014,71(12):5145-5164
Landslide susceptibility zonation mapping is a fundamental procedure for geo-disaster management in tropical and sub-tropical regions. Recently, various landslide susceptibility zonation models have been introduced in Nepal with diverse approaches of assessment. However, validation is still a problem. Additionally, the role of various predisposing causative parameters for landslide activity is still not well understood in the Nepal Himalaya. To address these issues of susceptibility zonation and landslide activity, about 4,000 km2 area of central Nepal was selected for regional-scale assessment of landslide activity and susceptibility zonation mapping. In total, 655 new landslides and 9,229 old landslides were identified with the study area with the help of satellite images, aerial photographs, field data and available reports. The old landslide inventory was “blind landslide database” and could not explain the particular rainfall event responsible for the particular landslide. But considering size of the landslide, blind landslide inventory was reclassified into two databases: short-duration high-intensity rainfall-induced landslide inventory and long-duration low-intensity rainfall-induced landslide inventory. These landslide inventory maps were considered as proxy maps of multiple rainfall event-based landslide inventories. Similarly, all 9,884 landslides were considered for the activity assessment of predisposing causative parameters. For the Nepal Himalaya, slope, slope aspect, geology and road construction activity (anthropogenic cause) were identified as most affective predisposing causative parameters for landslide activity. For susceptibility zonation, multivariate approach was considered and two proxy rainfall event-based landslide databases were used for the logistic regression modelling, while a relatively recent landslide database was used in validation. Two event-based susceptibility zonation maps were merged and rectified to prepare the final susceptibility zonation map and its prediction rate was found to be more than 82 %. From this work, it is concluded that rectification of susceptibility zonation map is very appropriate and reliable. The results of this research contribute to a significant improvement in landslide inventory preparation procedure, susceptibility zonation mapping approaches as well as role of various predisposing causative parameters for the landslide activity. 相似文献
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Jalal Samia Arnaud Temme Arnold K. Bregt Jakob Wallinga John Stuiver Fausto Guzzetti Francesca Ardizzone Mauro Rossi 《Landslides》2018,15(11):2129-2144
Landslide susceptibility modelling—a crucial step towards the assessment of landslide hazard and risk—has hitherto not included the local, transient effects of previous landslides on susceptibility. In this contribution, we implement such transient effects, which we term “landslide path dependency”, for the first time. Two landslide path dependency variables are used to characterise transient effects: a variable reflecting how likely it is that an earlier landslide will have a follow-up landslide and a variable reflecting the decay of transient effects over time. These two landslide path dependency variables are considered in addition to a large set of conditioning attributes conventionally used in landslide susceptibility. Three logistic regression models were trained and tested fitted to landslide occurrence data from a multi-temporal landslide inventory: (1) a model with only conventional variables, (2) a model with conventional plus landslide path dependency variables, and (3) a model with only landslide path dependency variables. We compare the model performances, differences in the number, coefficient and significance of the selected variables, and the differences in the resulting susceptibility maps. Although the landslide path dependency variables are highly significant and have impacts on the importance of other variables, the performance of the models and the susceptibility maps do not substantially differ between conventional and conventional plus path dependent models. The path dependent landslide susceptibility model, with only two explanatory variables, has lower model performance, and differently patterned susceptibility map than the two other models. A simple landslide susceptibility model using only DEM-derived variables and landslide path dependency variables performs better than the path dependent landslide susceptibility model, and almost as well as the model with conventional plus landslide path dependency variables—while avoiding the need for hard-to-measure variables such as land use or lithology. Although the predictive power of landslide path dependency variables is lower than those of the most important conventional variables, our findings provide a clear incentive to further explore landslide path dependency effects and their potential role in landslide susceptibility modelling. 相似文献
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O. Sivrikaya A. M. Kilic M. G. Yalcin A. S. Aykamis M. Sonmez 《Environmental Geology》2008,54(7):1489-1500
The current study deals with a catastrophic landslide that occurred due to heavy rainfall in Adana, Southern Turkey in 2001.
The research area, which is one of the largest populated districts in Adana, and one of the most tropical places between the
Middle East and southern Europe, has about 25,000 people. On the basis of geological and geotechnical surveys, the landslide
phenomena and the effects of landslide are examined. To understand the slide mechanism of the landslide, ground reconnaissance,
laboratory and in situ tests are conducted. It is observed that the clayey and silty layers of the site are heavily saturated
due to extreme rainfall in winter, and consequently sheared. The landslide consists of a block sliding in the upper portions
and a debris flow/soil flow component around the margins of the sliding blocks in the middle parts and at the toe. Although
there was no loss of human life, it has caused significant economic losses. Besides, it is determined that if precautions
are not taken around the landslide area, larger landslides could definitely occur in the future. 相似文献
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Formation and failure of the Tsatichhu landslide dam, Bhutan 总被引：1，自引：1，他引：1
At 00:30 (local time) on the 10th September 2003 a joint and foliation defined wedge of material with an estimated volume of 7–12×106 m3 slid into the narrow Tsatichhu River Valley, in Jarrey Geog, Lhuentse, eastern Bhutan. The Tsatichhu River, a north–easterly flowing tributary of the Kurichuu River, was completely blocked by the landslide. During its movement, the landslide transitioned into a rock avalanche that travelled 580 m across the valley before colliding with the opposite valley wall. The flow then moved down valley, travelling a total distance of some 700 m. The rock avalanche was accompanied by an intense wind blast that caused substantial damage to the heavily forested valley slopes. The resulting geomorphologically-typical rock-avalanche dam deposit created a dam that impounded a water volume of 4–7×106 m3 at lake full level. This lake was released by catastrophic collapse of the landslide, which occurred at 16:20 (local time) on 10th July 2004, after reported smaller failures of the saturated downstream face. The dam failure released a flood wave that had a peak discharge of 5900 m3 s−1 at the Kurichhu Hydropower Plant 35 km downstream. 相似文献
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从易发性、危险性、风险的概念入手,依据国际上流行和通用的滑坡风险评价与管理理论,分析了易发性评价的内容,包括易发性评价到危险性评价需要增加的评价要素,以及从危险性评价到风险评价需要增加的评价要素,阐明了这三种评价之间的联系和区别。并通过延安宝塔区的滑坡易发性、危险性和风险的评价与区划具体说明三者的做法和结果。 相似文献
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Past landslides have been recognized in the Battice area in E-Belgium. In contrast to the other inactive landslides, the Manaihan landslide responded immediately to heavy rainfall events in the last two decades. This study aims to map its spatial extent and the dominant surface features; to measure surface displacement using GPS; to investigate subsurface structure with Cone penetration test (CPT) and corings; and to determine the depth of the shear surface by inclinometers. Results show a partial landslide reactivation. Surface velocities range between 20 and 40 cm/year and are strongly dependent on winter rainfall. CPT results give clear boundaries between the landslide mass and the undisturbed bedrock in the head scarp. Distinct shear surfaces have been determined with displacement rates up to 15.8 mm in 21 days. Further research should apply geophysical methods for two-dimensional information on the ground, investigate geotechnical properties of the landslide mass, model slope instability, and determine the influence of a sewage pipe crossing the central landslide mass as a potential cause for landslide activity. 相似文献