A seismic landslide hazard analysis with topographic effect,a case study in the 99 Peaks region,Central Taiwan     

Wen-Fei Peng  Chein-Lee Wang  Shih-Tsu Chen  Shing-Tsz Lee 《Environmental Geology》2009,57(3):537-549

It has been known that ground motion amplitude will be amplified at mountaintops; however, such topographic effects are not included in conventional landslide hazard models. In this study, a modified procedure that considers the topographic effects is proposed to analyze the seismic landslide hazard. The topographic effect is estimated by back analysis. First, a 3D dynamic numerical model with irregular topography is constructed. The theoretical topographic amplification factors are derived from the dynamic numerical model. The ground motion record is regarded as the reference motion in the plane area. By combining the topographic amplification factors with the reference motions, the amplified acceleration time history and amplified seismic intensity parameters are obtained. Newmark’s displacement model is chosen to perform the seismic landslide hazard analysis. By combining the regression equation and the seismic parameter of peak ground acceleration and Arias intensity, the Newmark’s displacement distribution is generated. Subsequently, the calculated Newmark’s displacement maps are transformed to the hazard maps. The landslide hazard maps of the 99 Peaks region, Central Taiwan are evaluated. The actual landslide inventory maps triggered by the 21 September 1999, Chi-Chi earthquake are compared with the calculated hazard maps. Relative to the conventional procedure, the results show that the proposed procedures, which include the topographic effect can obtain a better result for seismic landslide hazard analysis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

A back-propagation network for the assessment of susceptibility to rock slope failure in the eastern portion of the Southern Cross-Island Highway in Taiwan   总被引：1，自引：0，他引：1  

Chih-Hao Chen  Chien-Chung Ke  Chein-Lee Wang 《Environmental Geology》2009,57(4):723-733

An assessment of the susceptibility to rock slope failure by means of a back-propagation network is proposed for the eastern portion of the Southern Cross-Island Highway in Taiwan. The model was developed on the basis of six influence parameters of rock slope instability, which include the rock type, slope aspect, slope angle, joint set number, joint spacing and bedding–slope relationship. The values of these influence parameters were used as inputs for the network and were classified as nominal scales in terms of binary numbers, while the state of failure/non-failure of a given slope was assumed to be the output variable. Data on a total of 170 slopes along the highway was fed into the network for learning. According to the outputs of the network, the susceptibility to rock slope failure is categorized into four levels, namely low, medium–low, medium and high, which are mapped along the highway. Three highly susceptible regions are found, which can be viewed as hazardous sections requiring cautionary measures. Moreover, the proposed model can be used as a tool for determining the possible state of an unfamiliar rock slope in the context of devising management strategies to be applied to the investigated portion of the highway.  相似文献   

The regional distribution regularity of landslides and their effects on the environments in the Three Gorges Reservoir Region, China   总被引：2，自引：0，他引：2  

He Keqiang  Yu Guangming  Li Xiangran 《Environmental Geology》2009,57(8):1925-1931

On the basis of research and analysis of the landslide system of the Three Gorges Reservoir area, this paper systematically analyzes and studies the temporal–spatial distribution law of landslides of this reservoir area and their impacts on environment of this area. The paper puts forward that the temporal–spatial distribution of this area’s landslides is mainly controlled by lithologic characters of strata, geological structure, valley landscape, and types of bank slope structure; landslide deformation and failure have such characteristics as simultaneity, laggardness, cyclical instability, and stage. Besides, the paper systematically analyzes and studies the main impacts of landslide on environment and points out that landslides and collapses will bring about relatively serious impacts on relocation and layout of cities and towns along the banks. These impacts mainly include the increase of relocation investment, number of migrants, and compensation for losses. Much attention and evaluation should be paid to the impacts of Xintan Landslide and Lianziya Landslide—large landslides near the Dam—on the construction and safety of the Three Gorges Project. However, landslides have relatively small impacts on shipping and reservoir capacity. The above-mentioned research is of great guiding significance for the construction of the Three Georges Project, planning and construction of cities and towns along the banks, and protection of geological environment.  相似文献   

Multiscale analysis of geomorphological and geological features in high resolution digital elevation models using the wavelet transform   总被引：3，自引：0，他引：3  

Michael KalbermattenDimitri Van De Ville  Pascal TurbergDevis Tuia  Stéphane Joost 《Geomorphology》2012,138(1):352-363

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Geology as a control on landslides on the Isle of Wight: an overview     

G.O. Jenkins  C. Foster  P.M. Hopson 《Proceedings of the Geologists' Association. Geologists' Association》2011,122(5):906-922

The Cretaceous and Palaeogene sedimentary rocks that crop out on the Isle of Wight are highly prone to landsliding and the island offers an important field laboratory wherein to investigate a number of the different types of failure. Many of these landslides represent a significant engineering hazard, with several urban areas requiring remedial work and planning constraints (e.g. The Undercliff and Seagrove Bay) to aid development. Previous studies have thoroughly investigated the major landslides in the Undercliff area around Ventnor and presented a mechanism for that massive failure. This overview of the landslides throughout the Isle of Wight by the British Geological Survey was completed as part of the multidisciplinary survey of the surface geology, structure, geophysical response and offshore interpretations of the island between 2007 and 2010. The survey has collected new observational data on the extensive coastal landslides, as well as the distribution, nature and mechanism of failure of the lesser-studied inland examples.  相似文献   

Landslides triggered by the 22 July 2013 Minxian–Zhangxian,China, Mw 5.9 earthquake: Inventory compiling and spatial distribution analysis     

《Journal of Asian Earth Sciences》2014

On July 22, 2013, an earthquake of Ms. 6.6 occurred at the junction area of Minxian and Zhangxian counties, Gansu Province, China. This earthquake triggered many landslides of various types, dominated by small-scale soil falls, slides, and topples on loess scarps. There were also a few deep-seated landslides, large-scale soil avalanches, and fissure-developing slopes. In this paper, an inventory of landslides triggered by this event is prepared based on field investigations and visual interpretation of high-resolution satellite images. The spatial distribution of the landslides is then analyzed. The inventory indicates that at least 2330 landslides were triggered by the earthquake. A correlation statistics of the landslides with topographic, geologic, and earthquake factors is performed based on the GIS platform. The results show that the largest number of landslides and the highest landslide density are at 2400 m–2600 m of absolute elevation, and 200 m–300 m of relative elevation, respectively. The landslide density does not always increase with slope gradient as previously suggested. The slopes most prone to landslides are in S, SW, W, and NW directions. Concave slopes register higher landslide density and larger number of landslides than convex slopes. The largest number of landslides occurs on topographic position with middle slopes, whereas the highest landslide density corresponds to valleys and lower slopes. The underlying bedrocks consisting of conglomerate and sandstone of Lower Paleogene (E^b) register both the largest number and area of landslides and the highest landslide number and area density values. Correlations of landslide number and landslide density with perpendicular- and along-strike distance from the epicenter show an obvious spatial intensifying character of the co-seismic landslides. The spatial pattern of the co-seismic landslides is strongly controlled by a branch of the Lintan-Dangchang fault, which indicates the effect of seismogenic fault on co-seismic landslides. In addition, the area affected by landslides related to the earthquake is compared to the relationship of “area affected by landslides vs. earthquake magnitude” constructed based on earthquakes worldwide, and it is shown that the area affected by landslides triggered by the Minxian–Zhangxian earthquake is larger than that of almost all other events with similar magnitudes.  相似文献   

Geotechnical characterization and strain analyses of sediment in the Mauritania Slide Complex,NW-Africa     

A. Förster  R.G. Ellis  R. Henrich  S. Krastel  A.J. Kopf 《Marine and Petroleum Geology》2010

Mass wasting processes are a common phenomenon along the continental margin of NW-Africa. Located on the high-upwelling regime off the Mauritanian coastline, the Mauritania Slide Complex (MSC) is one of the largest events known on the Atlantic margin with an affected area of ∼30?000 km². Understanding previous failure events as well as its current hazard potential are crucial for risk assessment with respect to offshore installations and tsunamis. We present the results of geotechnical measurements and strain analyses on sediment cores taken from both the stable and the failed part of the MSC and compare them to previously published geophysical and sedimentological data. The material originates from water depths of 1500–3000 m and consists of detached slide deposits separated by undisturbed hemipelagic sediments. While the hemipelagites are characterized by normal consolidation with a downward increase in bulk density and shear strength (from 1.68 to 1.8 g/cm³, 2–10 kPa), the slid deposits of the uppermost debris flow event preserve constant bulk density values (1.75 and 1.8 g/cm³) with incisions marking different flow events. These slid sediments comprise three different matrix types, with normal consolidation at the base (OCR = 1.04), strong overconsolidation (OCR = 3.96) in the middle and normal consolidation to slight overconsolidation at the top (OCR = 0.91–1.28). However, the hemipelagic sediments underlying the debris flow units, which have been ¹⁴C dated at <24 ka BP, show strong to slight underconsolidation (OCR = 0.65–0.79) with low friction coefficients of μ = 0.18. Fabric analyses show deformation intensities R ≥ 4 (ratio σ₁/σ₃) in several of the remobilized sediments. Such high deformation is also attested by observed disintegrated clasts from the underlying unit in the youngest debrites (¹⁴C-age of 10.5–10.9 ka BP). These clasts show strong consolidation and intense deformation, implying a pre-slide origin and amalgamation into the mass transport deposits. While previous studies propose an emplacement by retrogressive failure for thick slide deposits separated by undisturbed units, our new data on geotechnical properties, strain and age infer at least two different source areas with a sequential failure mechanism as the origin for the different mass wasting events.  相似文献   

SARETL: an expert system for probabilistic displacement-based dynamic 3-D slope stability analysis and remediation of earthquake triggered landslides     

A. S. Al-Homoud  W. W. Tahtamoni 《Environmental Geology》2000,39(8):849-874

 Different models were developed for evaluating the probabilistic three-dimensional (3-D) stability analysis of earth slopes and embankments under earthquake loading using both the safety factor and the displacement criteria of slope failure. In the 3-D analysis, the critical and total slope widths become two new and important parameters. The probabilistic models evaluate the probability of failure under seismic loading and consider the different sources of uncertainties involved in the problem, i.e. uncertainties stemming from the discrepancies between laboratory-measured and in situ values of shear strength parameters, randomness of earthquake occurrence, and earthquake-induced acceleration. The models also take into consideration the spatial variabilities and correlations of soil properties. The developed models are incorporated in a computer program, PTDDSSA (probabilistic three-dimensional dynamic slope stability analysis). These developed analysis/design procedures are incorporated within a code named SARETL (stability analysis and remediation of earthquake-triggered landslides) that was developed in this study for stability analysis and remediation of earthquake-triggered landslides. In addition to the dynamic inertia forces; the developed system takes into consideration the local site effects. The code is capable of: 1. Prediction of permanent deformations that result from landslides under seismic loading using both probabilistic and deterministic approaches. 2. The assessment of landslide hazard that affects major transportation routes in the event of earthquakes, and the preparation of earthquake-induced landslide hazard maps (i.e. maps that show expected displacements and probability of slope/embankments failure) for different earthquakes magnitudes and environmental conditions. 3. Proposing a mitigation strategy against landslides and suggesting guidelines for remedial measures. The developed expert system is applied to a major highway case study. Design maps are developed for the highway under seismic loading. Received: 18 March 1999 · Accepted: 11 October 1999  相似文献   

四川省石棉县科落头滑坡形成机理与治理     

赵国鹏 《山东地质》2013,(10):46-49

由自然产生和人类活动引发的滑坡灾害在世界范围内都较普遍,其对人民的生命和财产安全构成了严重威胁,急需对其进行治理。以四川省石棉县新民乡科落头滑坡为例,在分析滑坡形成机理的基础上,进行了设计与施工探讨,为同类滑坡治理提供借鉴。  相似文献   

气候变化背景下中国滑坡灾害人口风险评估     

王霞  王瑛  林齐根  李宁  张馨仁  周笑影 《气候变化研究进展》2022,18(2):166-176

中国是世界上滑坡灾害造成人口伤亡较严重的国家.受气候变化影响,极端降水频率与强度的增加会提高滑坡灾害的人口风险.文中将不同RCPs情景多个模式的未来降水数据和SSPs情景下的未来人口数据相结合,构建滑坡灾害人口风险评估模型,评估气候变化背景下的中国滑坡灾害人口风险.研究发现,气候变化下中国滑坡灾害的危险性呈上升趋势,预...  相似文献