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1.
K. S. Sajinkumar S. Anbazhagan A. P. Pradeepkumar V. R. Rani 《Journal of the Geological Society of India》2011,78(3):249-257
The climatic condition of Western Ghats has influenced the process of weathering and landslides in this mountainous tract
along the southwest coast of India. During the monsoon period, landslides are a common in the Western Ghats, and its intensity
depends upon the thickness of the loose unconsolidated soil formed by the process of weathering. Debris landslides with a
combination of saprock, saprolite and soil, indicate the role of weathering in landslide occurrences. This paper reports on
how the weathering in the windward slope of Western Ghats influences the occurrence of landslides and the factors which accelerate
the weathering process. Rock and soil samples were collected from the weathering profile of hornblende gniess and granite
gneiss. The chemical analysis and the calculated Chemical Index of Alteration (CIA) indicate the significant weathering and
its possible influence on landslide occurrences in the study area. Mainly, the CIA value of lateritic soil and forest loam
indicated the extent of high chemical weathering in this region. Rainfall is the dominant parameter influencing the chemical
weathering process. In addition, deforestation, land use practices and soil erosion are some of the other important factors
accelerating the weathering process and landslide occurrences in the region. The locations of the previous landslides superimposed
on geology and soil show that most of the landslide occurrences are associated with the highly weathered zone, particularly
lateritic soil and the ‘severe’ (rock outcrop) erodability zone. 相似文献
2.
History of landslide susceptibility and a chorology of landslide-prone areas in the Western Ghats of Kerala,India 总被引：3，自引：0，他引：3
Kerala is the third most densely populated state in India. It is a narrow strip of land, of which 47% is occupied by the most
prominent orographic feature of peninsular India, The Western Ghats mountain chain. The highlands of Kerala experience several
types of landslides, of which debris flows are the most common. They are called “Urul Pottal” in the local vernacular. The
west-facing Western Ghats scarps that runs the entire extent of the mountain system is the most prone physiographic unit for
landslides. The highlands of the region experience an annual average rainfall as high as 500 cm through the South-West, North-East
and Pre-Monsoon showers. A survey of ancient documents and early news papers indicates a reduced rate of slope instability
in the past. The processes leading to landslides were accelerated by anthropogenic disturbances such as deforestation since
the early 18th century, terracing and obstruction of ephemeral streams and cultivation of crops lacking capability to add
root cohesion in steep slopes. The events have become more destructive given the increasing vulnerability of population and
property. Majority of mass movements have occurred in hill slopes >20° along the Western Ghats scarps, the only exception
being the coastal cliffs. Studies conducted in the state indicates that prolonged and intense rainfall or more particularly
a combination of the two and the resultant pore pressure variations are the most important trigger of landslides. The initiation
zone of most of the landslides was typical hollows generally having degraded natural vegetation. A survey of post-landslide
investigation and news paper reports enabled the identification of 29 major landslide events in the state. All except one
of the 14 districts in the state are prone to landslides. Wayanad and Kozhikode districts are prone to deep seated landslides,
while Idukki and Kottayam are prone to shallow landslides. 相似文献
3.
Lalitha M. Kumar K. S. Anil Nair K. M. Dharumarajan S. Koyal Arti Khandal Shivanand Kaliraj S. Hegde Rajendra 《Natural Hazards》2021,106(1):487-507
Natural Hazards - In the Western Ghats of India, the soil properties, particularly Atterberg limits, are of relevance to the landslides. Pedogenic processes in the Western Ghats and plateaus on it... 相似文献
4.
Praveen B. Gawali Sainath P. Aher B. V. Lakshmi Ravindra D. Gaikwad K. Deendayalan Pramod T. Hanamgond J. L. V. Mahesh Babu Sandeep A. Arote Shashikant I. Bairage 《Journal of the Geological Society of India》2017,90(3):301-311
Heavy rainfall triggered landslides are on the rise along the Western Ghats making it a matter of priority to identify landslide-prone areas well in advance. The present effort is aimed at identifying landslide susceptible villages (LSV) around the Kalsubai region of Deccan volcanic province (DVP), Maharashtra, India from 8 weighted landslide parameters- rainfall, slope, lithology, land use and land cover (LULC), soil properties, relative relief, aspect and lineament. These parameters were combined with advanced remote sensing (RS) data and processed in geographical information system (GIS) as well as in image processing software, which are an integral part of geospatial techniques. Out of the total 59 villages, the study identified 9 villages are situated in very high, 13 in high, 12 in moderate, 11 in low and 14 in very low risk zones. Our data reveals incessant heavy rains and steep slopes are the dominant factors in triggering landslides, exacerbated by anthropogenic activity prevalent in the study area. The spatial and non-spatial database created will help to take effective steps in preventing and/or mitigating landslide disasters in the study area. The methodology can be applied to identify other landslide prone areas in a cost effective way. 相似文献
5.
Estimating potential landslide sites of an upland sub-watershed in Western Ghat’s of Kerala (India) through frequency ratio and GIS 总被引：10，自引：0，他引：10
The purpose of this study is to assess the susceptibility of landslides in parts of Western Ghats, Kerala, India, using a
geographical information system (GIS). Landslide inventory of the area was made by detailed field surveys and the analysis
of the topographical maps. The landslide triggering factors are considered to be slope angle, slope aspect, slope curvature,
slope length, distance from drainage, distance from lineaments, lithology, land use and geomorphology. ArcGIS version 8.3
was used to manipulate and analyse all the collected data. Probabilistic-likelihood ratio was used to create a landslide susceptibility
map for the study area. The result was validated using the Area under Curve (AUC) method and temporal data of landslide occurrences.
The validation results showed satisfactory agreement between the susceptibility map and the existing data on landslide locations.
As the result, the success rate of the model was (84.46%) and the prediction rate of the model was (82.38%) shows high prediction
accuracy. In the reclassified final landslide susceptibility zone map, 5.68% of the total area is classified as critical in
nature. The landslide susceptibility map thus produced can be used to reduce hazards associated with landslides and to land
cover planning. 相似文献
6.
7.
Landslide susceptibility analysis using probabilistic likelihood ratio model—a geospatial-based study 总被引：1，自引：1，他引：0
E. Ramani Sujatha Victor Rajamanickam P. Kumaravel E. Saranathan 《Arabian Journal of Geosciences》2013,6(2):429-440
The crucial and difficult task in landslide susceptibility analysis is estimating the probability of occurrence of future landslides in a study area under a specific set of geomorphic and topographic conditions. This task is addressed with a data-driven probabilistic model using likelihood ratio or frequency ratio and is applied to assess the occurrence of landslides in the Tevankarai Ar sub-watershed, Kodaikkanal, South India. The landslides in the study area are triggered by heavy rainfall. Landslide-related factors—relief, slope, aspect, plan curvature, profile curvature, land use, soil, and topographic wetness index proximity to roads and proximity to lineaments—are considered for the study. A geospatial database of the related landslide factors is constructed using Arcmap in GIS environment. Landslide inventory of the area is produced by detailed field investigation and analysis of the topographical maps. The results are validated using temporal data of known landslide locations. The area under the curve shows that the accuracy of the model is 85.83%. In the reclassified final landslide susceptibility map, 14.48% of the area is critical in nature, falling under the very high hazard zone, and 67.86% of the total validation dataset landslides fall in this zone. This landslide susceptibility map is a vital tool for town planning, land use, and land cover planning and to reduce risks caused by landslides. 相似文献
8.
Chávez-García Francisco J. Natarajan Thulasiraman Cárdenas-Soto Martín Rajendran Kusala 《Natural Hazards》2021,105(2):1623-1642
The unusually intense precipitations of the 2018 monsoon triggered numerous landslides in the Western Ghats region, southwest of India. Although the landslides caused no casualties, significant damage to property and infrastructure was observed. We present, as a case study, the results of active and passive seismic prospecting at two of those landslides with the goal of characterizing them, in a first application of shallow seismic exploration to landslides in the region. Our deployments included both sites perturbed by the landslides and unperturbed slopes adjacent to them with the purpose of identifying possible structural differences between slopes that underwent landsliding from slopes that were not affected. We analyze seismic sections obtained using the multi-channel analysis of surface waves technique and compare the results with seismic noise analyzed using seismic interferometry. We show that different analyses give similar results. The lateral variations observed in the shear-wave velocity distribution below the different profiles are well correlated with dominant frequency determined from seismic noise horizontal-to-vertical spectral ratios. Our measurements were taken after the landslides occurred. In hindsight, our results suggest that soil thickness played a major role in the triggering of landslides.
相似文献9.
开发为地质灾害预测预报所需用的岩土层含水量和渗透力测试仪,并和气候雨量、地质灾害成灾规律联系起来,是我国地质灾害监测预报发展的趋势。岩土层含水量分层监测系统是采用TDR（Time Domain Refiectometry）技术原理、方法研制的仪器,通过波导棒探针发射的电磁波射入岩土层,测量电磁波脉冲从波导棒的起点传播到接收末端的反射电压值,此反射电压值与岩土体本身含水量介电常数有函数关系,经过计算转换为测点岩土体积含水量,实时测量和采集地质灾害岩土层含水量和渗透力参数。介绍了该监测系统的基本原理、主要技术参数、监测工艺技术方法以及现场应用情况。 相似文献
10.
A potential head ward retreat landslide area was identified in Munnar, a hill station in Western Ghats of Kerala, India. This imminent landslide was suspected to be formed in three different stages viz., evolution of plateau region, upliftment of the plateau region and the consequent slope modification which ultimately facilitated landslide occurrence. Geophysical study through vertical electrical sounding reveals that more than 11 m thick soil is still left in an overhanging position in the crown portion of the landslide and the thickness continues to the top of that ridge. In the event of high rainfall, the land can fail as there is no toe support, and the slope angle is >40º. This area is adjacent to a college building and in the event of any further landslide, the consequence will be high. Slope stability analysis using one-dimensional infinite slope stability model reveals that the entire area occupied by the college and the adjacent areas are unstable even in dry conditions. Rainfall threshold analysis shows that the landslide occurred due to very high amount of a 5-day antecedent rainfall rather than a daily rainfall during the monsoon. All these point towards a pressing requirement of landslide management practices in this area. This study also attempts to suggest a few management practices to minimize the effect of landslides. 相似文献
11.
肖进 《地质灾害与环境保护》2011,22(1):16-21,35
为实现对滑坡体进行实时监测和提高滑坡应急处置能力,利用计算机技术、网络技术和无线传输技术,将数字视频实时监控技术引入重大滑坡监测预警,开发滑坡远程监测预警系统.系统对吴家岩滑坡的监测表明,该系统能及时、准确和完整地反映滑坡体的变形及危险,出现异常立即自动报警. 相似文献
12.
根据光纤光栅传感的原理,提出了光纤光栅式封装应变传感器,对其传感特性进行了研究,并进行了室内实验。结合光栅传感监测滑坡的应用实例,探讨了光纤布拉格光栅传感元件在滑坡体上的布设工艺及监测过程。分析初期的监测结果,针对监测系统可能出现的问题提出了解决途径。 相似文献
13.
Landslide susceptibility mapping and spatial prediction have been carried out for the headwater region of Manimala river basin in the Western Ghats of Kerala, India, through geographic information technology and bayesian statistics, Weights of Evidence (WofE) model. The variables such as geomorphology, slope, relative relief, terrain curvature, slope length and steepness, soil type and land use/land cover are considered as factors that translate the terrain susceptible to landsliding. The quantitative relationship between landslides and the causative factors were statistically weighted using the ArcSDM extension of ArcGIS software. The posterior probability map, produced on the basis of predictive weights for each variable by combining the weighted layers in GIS, shows a high posterior probability value of 0.1 (highly possible) with a standard deviation of 0.0025. The discrete susceptibility classes in the reclassified posterior probability map reveals that the high and moderate landslide susceptibility classes cover 0.78 and 14.93% respectively of the total study area. The result was validated using the Area Under Curve (AUC) method with a separate set of landslide locations and the validation demonstrates high prediction accuracy with a prediction rate of 81.32%. 相似文献
14.
Longoni Laura Ivanov Vladislav Ferrario Maddalena Brunero Marco Papini Monica Arosio Diego 《Landslides》2022,19(3):761-772
Optical fibre–based sensors have now established their place in the field of geohazard monitoring due to their sensitivity to strain and temperature changes. Progressive development in the technology leads to the availability of novel, accurate and durable sensors at a relatively limited cost. This creates room for original monitoring applications that have been, so far, impeded by the shortcomings of conventional monitoring tools. In this work, we explore the applicability of an interferometric optical fibre sensor as a vibration sensing tool at laboratory scale. We tested the ability of the sensor to identify precursors of instability in a downscaled model of a rainfall-induced landslide composed of granular material. We carried out four experimental tests which involved different sensor deployments and soil mixtures. The recorded signals were processed by means of a time–frequency analysis and we identified two frequency-domain parameters—the spectral centroid and band power—that could provide information on the development of instability. Their ratio yielded a unique parameter through which a precursory stage could be outlined by defining a threshold value based on the data collected at the beginning of the experiment. In our lab tests, precursors of instability were detected 2–3 min before a crack was observed at the surface. This may upscale to a lead time of about 20–30 min or more in the field, classifying our monitoring approach in between an alarm and a warning system. The work presented here can be considered a first promising step towards an innovative monitoring system and shows the potential of optical fibre sensing as a shallow landslide monitoring technique, encouraging further testing, especially in real-case studies.
相似文献15.
Real-time monitoring and early warning of landslides at relocated Wushan Town,the Three Gorges Reservoir,China 总被引：12，自引：6，他引：6
A special monitoring and warning system has been established and improved in the Three Gorges Reservoir area since 1999. It
is necessary to develop a real-time monitoring system on landslides because there are dense populations centered in the reservoir
area and geo-hazards may be triggered by a 30-m water level fluctuation between 145 and 175 m in elevation during reservoir
operation; the regular monitoring could not be suitable to the early warning on landslides. Since 2003, the authors have carried
out a real-time monitoring and early warning project on landslides at the relocated Wushan town in the Three Gorges Reservoir
area. The monitoring station includes Global Positioning System with high-accuracy double frequency to monitor ground displacement,
time domain reflection technology, and immobile borehole, inclinometer to monitor deep displacement, piezometer to monitor
pore water pressure, and precipitation and reservoir water level monitoring. Compared with traditional methods, the real-time
monitoring is continuous and traceable in the acquisition process, and the cycle of data acquisition is very short, usually
within hours, minutes, or even shorter. Based on the landslide monitoring experience at the Three Gorges Reservoir area, the
early warning criteria on landslide are established in which the critical situation is classified into four levels: blue,
yellow, orange, and red, respectively, expressed by no, slight, moderate, and high risk situation. Comprehensive judgment
from multimonitoring data of Yuhuangge landslide in this area since 2004 suggested that the new Wushan town will be at the
blue early warning level, although some monitoring data of individual displacement at deep borehole showed that the displacement
was increased by 5 mm in 5 months with an average velocity of 1.0 mm/month, and the data of BOTDR also showed an obvious dislocation
along a stairway on the landslide. 相似文献
16.
随着我国西南山区石油天然气常输管道的大规模建设,各类边坡问题将会层出不穷,滑坡检测将成为管道运营检测的重要组成部分。文中对实际滑坡治理工程中的TDR监测成果进行分析,将其与传统的监测手段对比,总结TDR技术在滑坡监测实际应用中的优缺点。同时,提出了TDR技术与长输管道自动化监视和控制体系-SCADA系统相结合的理念,可通过SCADA系统克服TDR技术绝大部分的缺点,在石油天然气常输管道滑坡检测中有着十分广阔的应用前景。 相似文献
17.
Monitoring of post-failure landslide deformation by the PS-InSAR technique at Lubietova in Central Slovakia 总被引：1，自引：1，他引：0
Interferometric synthetic aperture radar data from ERS and ENVISAT sensors were utilized in the analysis of the post-failure
deformations in the area of Lubietova town in Central Slovakia. The catastrophic landslide of 1977 together with surrounding
landslides in the Lubietova area were analysed with the help of persistent scatterers (PS) technique in order to evaluate
recent and past deformations of the unstable slopes. Although long-term precise geodetic monitoring of the 1977 landslide
revealed differential deformations inside the sliding mass, due to the lack of the PS located inside the landside caused by
temporal decorrelation, unfortunately, these records could not be directly compared. The adjacent landslides with sufficient
number of PS were analysed by transformation of the line of sight displacements recorded by the sensors to the slope vector
direction. This procedure allowed identification of the precise boundaries of the actively moving landslide parts and the
updating of the landslide inventory for the Lubietova area. 相似文献
18.
滑坡监测预警国内外研究现状及评述 总被引：11，自引：0，他引：11
本文从降雨临界值研究、监测技术方法、区域性监测预警系统三个方面对滑坡监测预警的国内外研究现状进行了回顾和总结。首先归纳了国内外28个国家或地区的滑坡降雨临界值及统计方法,三个模型——日降雨量模型、前期降雨量模型和前期土体含水状态模型,基本概括了当前降雨诱发滑坡临界值的确定方法;但由于降雨入渗触发滑坡的复杂性,不同机理的滑坡"需要"不同的降雨临界值;目前的研究趋势是对雨量雨强雨时—土体渗流场动态变化—土体抗剪强度变化的耦合关系进行研究。按监测对象的不同,滑坡监测可分为四大类,即位移监测、物理场监测、地下水监测和外部诱发因素监测;按监测手段的不同,则可分为人工监测、简易监测、专业监测三大类;目前国内外在滑坡监测技术、方法、手段上并无太大差距,专业仪器已成为常规设备,只是由于价格因素得不到普及;一些新技术如InSAR、三维激光扫描等能很快应用到滑坡监测领域;监测数据的采集和传输也都实现了自动化和远程化;监测和预警系统有向Web—GIS发展的趋势。利用一个地区的滑坡易发区划或危险区划,结合降雨临界值,可以设定不同的预警级别,在区内布设一定数量的雨量站,监测雨量加上预报雨量,就可进行滑坡预警预报,国内外的区域性降雨型滑坡监测预警大体都是这个思路和做法,该方法在对公众进行警示方面起到了良好效果,但由于预警的范围太大,在具体的单点防治上,难以做到有效。我国在近10年开展了大量的监测预警工作,并取得了丰硕的成果,但根据统计数据,其成功预警率却并不理想,这一方面表现在成功预警实例中专业预警所占比例过低,另一方面同时表现在发生的大量的地质灾害在已有的预警点之外。制约目前工作有效性的主要问题是滑坡隐患点的排查和识别问题,因为只有识别出了隐患点才能进行下一步的监测和预警,它是一切工作的基础。而解决这一问题的重要途径是分析区域上的滑坡发育规律,找到有效的隐患点识别技术方法,以及引进风险管理的概念,进行监测资源的合理分配和有效预警。 相似文献
19.
GPS RTK技术用于滑坡动态实时变形监测的研究 总被引：2，自引：0，他引：2
为了研究GPS RTK技术用于滑坡动态变形监测的精度和可靠性,本文结合某类滑坡的大型物理模型试验,在滑坡体上布设了若干监测点,并用GPS RTK技术、全站仪三维测量技术和GPS单历元定位技术实时跟踪监测了该滑坡在自然状态下从稳定到产生破坏的全部过程。通过对监测数据的处理和分析,获得了RTK技术用于滑坡变形监测的可靠性和精度等技术参数,即在基准站和流动站同步观测到的卫星数在7颗以上且RTK系统的数据链能够正常工作的情况下,RTK测量的平面和高程精度就能分别控制在15mm和20mm以内。研究结果表明,RTK技术在一定条件下完全可用于滑坡灾害的动态实时变形监测。 相似文献
20.
Regional landslide susceptibility zoning with considering the aggregation of landslide points and the weights of factors 总被引：4，自引：0，他引：4
In this paper, we propose a methodology for landslide susceptibility assessment at a regional scale in Yunnan, southwestern province of China. A landslide inventory map including 3,242 landslide points was prepared for the study area. Five factors recognized as correlated to landslide (namely, lithology, relative relief, tectonic fault density, rainfall, and road density) were analyzed and mapped in geographic information system. An index expressing the correlation between each factor and landslides [called class landslide susceptibility index (CLSI)] was proposed in the study. While analyzing landslide distribution in a large area, point aggregation might be expected. To quantify the uncertainty caused by aggregation, class landslide aggregation index was proposed. To account for the importance of each of the factors in the landslide susceptibility assessment, some weights were calculated by means of analytic hierarchy process. We propose a weighted class landslide susceptibility model (WCLSM), obtained by the combination of CLSI values of each factor with the correspondent weight. WCLSM performance in the study area was evaluated comparing the results obtained by first modeling all landslides and then by performing a time partition. The model was run including only landslides that occurred before 2009 and then validated with respect to landslides that occurred after 2009. The prediction–rate curve shows that the WCLSM model provides a good prediction for the study area. Of the study area, 21.4 % shows very high and high susceptibility and includes the 87.7 % of the number of landslides that occurred after 2009. 相似文献