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1.
Retrogressive landslides are common geological phenomena in mountainous areas and on onshore and offshore slopes. The impact of retrogressive landslides is different from that of other landslide types due to the phenomenon of retrogression. The hazards caused by retrogressive landslides may be increased because retrogressive landslides usually affect housing, facilities, and infrastructure located far from the original slopes. Additionally, substantial geomorphic evidence shows that the abundant supply of loose sediment in the source area of a debris flow is usually provided by retrogressive landslides that are triggered by the undercutting of water. Moreover, according to historic case studies, some large landslides are the evolution result of retrogressive landslides. Hence the ability to understand and predict the evolution of retrogressive landslides is crucial for the purpose of hazard mitigation. This paper discusses the phenomenon of a retrogressive landslide by using a model experiment and suggests a reasonably simplified numerical approach for the prediction of rainfall-induced retrogressive landslides. The simplified numerical approach, which combines the finite element method for seepage analysis, the shear strength reduction finite element method, and the analysis criterion for the retrogression and accumulation effect, is presented and used to predict the characteristics of a retrogressive landslide. The results show that this numerical approach is capable of reasonably predicting the characteristics of retrogressive landslides under rainfall infiltration, particularly the magnitude of each landslide, the position of the slip surface, and the development processes of the retrogressive landslide. Therefore, this approach is expected to be a practical method for the mitigation of damage caused by rainfall-induced retrogressive landslides. 相似文献
2.
Phuong Thao Thi Ngo Mahdi Panahi Khabat Khosravi Omid Ghorbanzadeh Narges Kariminejad Artemi Cerda Saro Lee 《地学前缘(英文版)》2021,12(2):505-519
The identification of landslide-prone areas is an essential step in landslide hazard assessment and mitigation of landslide-related losses.In this study,we applied two novel deep learning algorithms,the recurrent neural network(RNN)and convolutional neural network(CNN),for national-scale landslide susceptibility mapping of Iran.We prepared a dataset comprising 4069 historical landslide locations and 11 conditioning factors(altitude,slope degree,profile curvature,distance to river,aspect,plan curvature,distance to road,distance to fault,rainfall,geology and land-sue)to construct a geospatial database and divided the data into the training and the testing dataset.We then developed RNN and CNN algorithms to generate landslide susceptibility maps of Iran using the training dataset.We calculated the receiver operating characteristic(ROC)curve and used the area under the curve(AUC)for the quantitative evaluation of the landslide susceptibility maps using the testing dataset.Better performance in both the training and testing phases was provided by the RNN algorithm(AUC=0.88)than by the CNN algorithm(AUC=0.85).Finally,we calculated areas of susceptibility for each province and found that 6%and 14%of the land area of Iran is very highly and highly susceptible to future landslide events,respectively,with the highest susceptibility in Chaharmahal and Bakhtiari Province(33.8%).About 31%of cities of Iran are located in areas with high and very high landslide susceptibility.The results of the present study will be useful for the development of landslide hazard mitigation strategies. 相似文献
3.
李霞宿星张满银任皓晨周自强吴玮江董耀刚王国亚 《冰川冻土》2023,(1):67-79
Analysis and assessment of landslide susceptibility using 3S technology and mathematical statistical model is still the current hot topics. It is very important for selection of unit and factor and model to the landslide susceptibility assessment reasonably. Tianshui City is selected as the study area which is in the typical regions of Longzhong ecologically vulnerable area. Based on the weights-of-evidence approach（WOE）and two kinds of assessment units（grid-unit,GU,slope-unit,SU）and also two resolutions（30 m,10 m）,a total of four differ⁃ ent data sets（GU30,SU30,GU10,SU10）is established. Then quantitative analysis and contrast assessment di⁃ vision of the loess landslide susceptibility in the study area though selected four kinds of thirteen factors. The re⁃ sults show that stratum lithology,altitude,relief amplitude,roughness and slope are the key control factors of landslide development in the area. The geological factors and topographic factors control and determine the for⁃ mation and development of the landslides in study area. The susceptibility value of stratum lithology is the high⁃ est value. Statistical analysis of susceptibility division is carried out according to the point and area of landslide respectively. The landslide ratio shows that the division based on the slope-unit is higher than that of the grid-unit. Landslide susceptibility area in highest division based on the slope-unit and 10m high resolution is account⁃ ed for the highest. Therefore,it has higher precision in landslide susceptibility analysis and assessment that us⁃ ing the slope-unit and high resolution data. The landslide susceptibility result is consistent with the actual land⁃ slide development in the study area. The division results can also be used for the landslide prevention and control and national spatial planning in the study area. © 2023 Chinese Journal of General Practitioners. All rights reserved. 相似文献
4.
LI Yanrong Adnan AYDIN XIANG Xiqiong JU Nengpan ZHAO Jianjun Ahmet OZBEK 《《地质学报》英文版》2012,86(4):1022-1030
5.
AhmedA.Melegy T.Paces 《中国地球化学学报》2004,23(2):155-162
Heavy metals in different environmental compartments can be hazardous to ecosystems. Budgets of Cd, Pb and Zn in small ecosystems of the Shubra E1-Kheima area in Egypt are presented. The budgets are not in steady state because they change with time. So the concentrations of the metals are a function of time. The critical loads of heavy metals to soils can be calculated from an inventory of inputs and outputs of the trace components in the catchment area.Critical time is an important parameter for critical load evaluation because it can indicate which of the heavy metals may be the most acute threat to the soils. Egyptian soil in the Shubra ElKheima area seems to be in danger of heavy metal pollution by Zn, Cd and Pb. The calculated critical loads and their exceedances are approximate indicators of the hazards in the soil system.The critical time is a warning signal to initiate an environmental evaluation of possible pollution hazards. 相似文献
6.
Bhoj Raj Pantha Ryuichi Yatabe Netra Prakash Bhandary 《《幕》》2008,31(4):384-391
Roadside slope failure is a common problem in the Himalayan region as road construction activities disturb natural slopes. Therefore, landslide susceptibility zonation is necessary for roadside slope disaster management and planning development activities. In this study, we consider a 53-kin section of a major highway in Nepal where road services are suspended for several days in the monsoon season every year. A number of methods have been used for landslide susceptibility zonation. We employed a bivariate statistical approach for this study. Relevant thematic layer maps represent- ing various factors （e.g., slope, aspect, land use, lithology, drainage density, proximity to stream and proximity to road） that are related to landslide activity, have been prepared using Geographic Information System （GIS） techniques. A total of 277 landslides （covering a total of 29.90 km2） of various dimensions have been identified in the area. A landslide susceptibility map was prepared by overlaying a landslide inventory map with various parameter maps segmented into various relevant classes. The landslide susceptibility index was seg- mented into five zones, viz. very low, low, moderate, high and very high susceptibility. Landslide susceptibility zonation maps are useful tools for the efficient planning and management of roadside slope repair and maintenance tasks in the Himalayan region. 相似文献
7.
Through a systematic study on trace elements and REE geochemistry of mudstone deposited in the basin and lower slope environments during Upper Proterozoic to Triassic in the Southwest Yangtze Mssif,three geochemical abnormal horizons of which the geochemical characteristics are quite different from those of other horizons have been established for the first time.They are the Lower Cambrian,the Upper Devonian and the Upper Permian,As compared with the crustal evolution in this area.these three geochemical abnormal horizons are corresponding to the pulling-apart periods of geotectonic cycles.which illustrates that uncommon depositional sources puring into the basin from the earth‘s interior may be one of the most important causes to originate the geochemical anomalies in these lhrizons.Thus it can be realized that the geochemistry of post-Archean sedimentary rocks has a great deal to do with the crustal evolution and it can be used as a tracer to analyze the crustal evolution.The elements in this area are mainly concentrated in these geochemical abnormal horizons,and the degree of enrichment and deficiency of trace elements in other horizons is very limited.A series of research on mineralization indicates that the main strata-bound ore deposits discovered in the Southwest Yangtze Massif occur in the Cambrian,Devonian and Permian-Trassic strata.The results of isotope tracer resarch have also proved that most of the metallogenic elements in these ore deposits came from the host strata.which illustrates that the geochemical abnormal horizons may have made great contributions to these ore-forming processes.Thus it can be concluded that it is only the particular horizons corresponding to the particular periode of earth‘s evolution that can they be the significant source beds because only in these uncommon horizons there can be highly enriched metallogeinc elements.which may be one of the most important reasons for explaining the time-bound nature of mineralization. 相似文献
8.
Giant landslides are common along the upper Yellow River from Longyang Gorge to Liujia Gorge, and some of them even blocked and dammed the upper Yellow River. Chronology is inevitable in studying the mechanism of giant landslides. Controversy exists about the chronology of those giant landslides, and some have not yet dated. The Dehenglong landslide is the largest one among them. In this study, OSL samples were collected from lacustrine silty sediments and loess directly overlying the landslide sediments, as well as fault sediments related to the landslide. This landslide yielded an age of 89 ± 8 ka, which is identical with the fault age of 73 ± 5 ka at two sigma errors. The agreement of a topographic analysis and the absolute age of landslides imply that the formation of the Dehenglong landslide is strongly correlated with the tectonic activity. 相似文献
9.
The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the research area. The reefs have different thicknesses ranging from 0.5 m to 11.5 m and lengths varying from 1 m to 130 m. The reef-building organisms include Archaeoscyphia, Recepthaculitids, Batostoma, Cyanobacteria and Pulchrilamina. Through the research of characteristics of the reef-bearing strata of the Early Ordovician in the Yichang area, four sorts of biofacies are recognized, which are (1) shelly biofacies: containing Tritoechia-Pelmatozans community and Tritoechia-Pomatotrema community; (2) reef biofacies: including the Batostoma, Calathium-Archaeoscyphia, Pelmatozoa-Batostoma, Archeoscyphia and Calathium-Cyanobacteria communities; (3) standing-water biofacies: including the Acanthograptus-Dendrogptus and Yichangopora communities; and (4) allochthonous biofacies: containing Nanorthis-Psilocephlina taphocoense community. The analysis of sea-level changes indicates that there are four cycles of sea-level changes during the period when reef-bearing strata were formed in this area, and the development of reefs is obviously controlled by the velocity of sea-level changes and the growth of accommodation space. The authors hold that reefs were mostly formed in the high sea level periods. Because of the development of several subordinate cycles during the sea-level rising, the reefs are characterized by great quantity, wide distribution, thin thickness and small scale, which are similar to that of Juassic reefs in northern Tibet. The research on the evolution of communities shows that succession and replacement are the main forms. The former is favorable to the development of reefs and the latter indicates the disappearance of reefs. 相似文献
10.
Study on the snowdrift disaster influenced by w-beam barrier used in expressway北大核心CSCD 总被引：1，自引：0，他引：1
Snowdrift is one of the most typical snow disaster forms of road traffic in Xinjiang area. Its impact on road traffic is mainly reflected in reducing driving visibility and causing traffic interruption induced by a large amount of snow on the road surface. The snowdrift disaster along the road in Xinjiang area shows the characteristics as many points,long lines and wide spread occurring with uneven distribution in time and space. Snowdrift question involves wind field,snow distribution field,temperature field and humidity field coupling,which is a very complex scientific problem. At the same time,the prevention and control of snowdrift disasters is also a practical problem that needs to be solved urgently in the construction and operation of road traffic infrastructure in cold areas. For expressways in areas of frequent snowdrift occurring,its snowdrift disaster caused by the w-beam barrier is becoming more and more obviously. But there is still a lack of in-depth research on the w-beam barrier,which is one kind of auxiliary facilities of the highway deepening the snowdrift disaster. In view of the status mentioned above and in order to explore the causes and prevention methods to snowdrift disaster by w-beam barrier,on the background of Beijing-Urumqi Expressway（G7）engineering,the field model tests of the w-beam barrier,the cable barrier and the no barrier embankment were designed. The study also combined with numerical simulation and highway field investigation and other methods in order to verify each other. In the meantime,the influence of the w-beam barrier and cable barrier on the road snowdrift disaster of the highway is studied,and the distribution law of wind field and snow field on the embankment surface with w-beam barrier and cable barrier is obtained. The results show that the snowdrift velocity increases from the foot of the embankment on the upwind side till to the w-beam barrier installed at the shoulder of or the central divider of the road. Then it moves to the road surface through the gap in the lower part of the w-beam barrier. At this time the w-beam barrier disturbs the wind field near the ground,causing a weak wind area to appear behind the beam,resulting in a large number of snow particles deposited. Especially when the lower gap of the w-beam barrier is filled with snow,the road area behind the w-beam barrier covers the driving lane with snow,which seriously affects the road capacity. While the section without setting up a barrier or setting a cable barrier is conducive to the passage of snowdrift flow. Considering the uncertainty of future climate change,in order to better prevent the impact of snowdrift on traffic operation safety,it is proposed to replace the w-beam barrier in some areas with serious wind and snow disasters with cable barrier that meet the safety requirements of expressways. Moreover,other snowdrift protection measures such as snow fences,snow barriers and snow walls can also be adopted. The research results can provide useful reference for snow removal of the expressway and new expressway construction in the windy and snow areas of Xinjiang. © 2022 Science Press (China). 相似文献
11.
《地学前缘(英文版)》2015,6(6)
The governing factors that influence landslide occurrences are complicated by the different soil conditions at various sites.To resolve the problem,this study focused on spatial information technology to collect data and information on geology.GIS,remote sensing and digital elevation model(DEM) were used in combination to extract the attribute values of the surface material in the vast study area of SheiPa National Park,Taiwan.The factors influencing landslides were collected and quantification values computed.The major soil component of loam and gravel in the Shei-Pa area resulted in different landslide problems.The major factors were successfully extracted from the influencing factors.Finally,the discrete rough set(DRS) classifier was used as a tool to find the threshold of each attribute contributing to landslide occurrence,based upon the knowledge database.This rule-based knowledge database provides an effective and urgent system to manage landslides.NDVI(Normalized Difference Vegetation Index),VI(Vegetation Index),elevation,and distance from the road are the four major influencing factors for landslide occurrence.The landslide hazard potential diagrams(landslide susceptibility maps) were drawn and a rational accuracy rate of landslide was calculated.This study thus offers a systematic solution to the investigation of landslide disasters. 相似文献
12.
Landslide spatial decision support systems (LS-DSS) are computer-based systems that combine the geographic storage, search, and retrieval capabilities of geographic information systems with the decision models and optimizing algorithms used to support decision-making for landslide problems. This study proposes an optimization process of region object-oriented classification (ROC) to analyze the landslide image information. The surface information from the Wan Da reservoir area is collected and studied. We collected different spectrum with several texture information to analyze the surrounding area of the Wan Da reservoir. ROC is used to classify the landslide area. Entropy-based classification is used as a classifier in ROC to determine the landslide/nonlandslide area. The parameters of S (similarity) and A (area) are used and then the best combinations are found. An optimize algorithm is developed to access the above variables to perform the best classification outcomes. The relations of occurrence vs. non-occurrence of landslide which are linked to the attributes of land surface are studied. An improved translation model (Expert Knowledge Translation Platform) is also presented to increase the accuracy. This could be of help to manage/monitor the landslide area near the reservoir. 相似文献
13.
This study deals with landslide susceptibility mapping in the northern part of Lecco Province, Lombardy Region, Italy. In so doing, a valid landslide inventory map and thirteen predisposing factors (including elevation, slope aspect, slope degree, plan curvature, profile curvature, distance to waterway, distance to road, distance to fault, soil type, land use, lithology, stream power index, and topographic wetness index) form the spatial database within geographic information system. The used predictive models comprise a bivariate statistical approach called frequency ratio (FR) and two machine learning tools, namely multilayer perceptron neural network (MLPNN) and adaptive neuro-fuzzy inference system (ANFIS). These models first use landslide and non-landslide records for comprehending the relationship between the landslide occurrence and predisposing factors. Then, landslide susceptibility values are predicted for the whole area. The accuracy of the produced susceptibility maps is measured using area under the curve (AUC) index, according to which, the MLPNN (AUC?=?0.916) presented the most accurate map, followed by the ANFIS (AUC?=?0.889) and FR (AUC?=?0.888). Visual interpretation of the susceptibility maps, FR-based correlation analysis, as well as the importance assessment of predisposing factors, all indicated the significant contribution of the road networks to the crucial susceptibility of landslide. Lastly, an explicit predictive formula is extracted from the implemented MLPNN model for a convenient approximation of landslide susceptibility value.
相似文献14.
Causes and extent of environmental impacts of landslide hazard in the Himalayan region: a case study of Murree, Pakistan 总被引：2，自引：2，他引：0
Pakistan is located at the cross-roads of plate boundaries, experiencing multiple hazards of earthquake, flood, drought, water-logging, salinization and recurrent landslides. This paper examines the causes and environmental impacts of frequently occurring landslide hazards in the Murree area of Pakistan??s Himalayan region. These are wide ranging in nature and in terms of the damage that result. The area under research was divided into eight blocks and randomly data collected. It was observed that landslides mostly occur along the road network and disturbed slopes. Immature geology, a wide variation in climate and degradation of the natural resource-base were found to be some of the causal factors responsible for the landslide hazards. During the past three decades, rapid expansion of urban zones contributed to the changing vulnerability of the area. The analysis revealed that a large majority of the households (75%) in the area have been directly or indirectly affected by landslide hazards. Damages to already scarce agricultural land, infrastructure and other properties are each year a regular and escalating phenomenon. Landslide size, frequency and consequent costs of damage have increased considerably. 相似文献
15.
16.
基于深度学习的CZ铁路康定—理塘段滑坡易发性评价 总被引：1，自引：0，他引：1
CZ铁路康定至理塘段地处青藏高原东部边缘,区域内地形地貌多变、地质构造复杂,滑坡灾害极其发育,严重威胁着CZ铁路康定至理塘段的规划建设和未来安全运行。因此,选取高程、坡向、平面曲率、剖面曲率、地形起伏度、地表切割度、地形湿度指数、归一化植被指数、岩性、距断层距离、距河流距离、距道路距离共计12个影响因子构建滑坡空间数据库,采用深度学习的卷积神经网络(convolutional neural network,CNN)模型进行滑坡易发性评价,根据易发性指数将研究区划分为极高易发区(13.76%)、高易发区(14.00%)、中易发区(15.86%)、低易发区(18.17%)、极低易发区(38.21%)5个等级,并与人工神经网络(artificial neural network,ANN)模型进行对比。结果表明,CNN模型的评价精度AUC(0.87)大于ANN(0.84)模型,且极高易发区的频率比值高于ANN模型,CNN模型在本研究区有着更高的预测能力;极高和高易发区主要分布在水系较为发育的地区,沿着雅砻江和其他河流两侧2 km范围内呈带状分布。滑坡易发性评价结果较好地反映了研究区滑坡灾害发育的分布现状,能够为该区的CZ铁路建设和未来安全运行过程中的防灾减灾工作提供科学的依据。 相似文献
17.
Owing to fragile geo-morphology, extreme climatic conditions, and densely populated settlements and rapid development activities, West Java Province is the most landslide hazardous area in Indonesia. So, a landslide risk map for this province bears a great importance such as for land-use planning. It is however widely accepted that landslide risk analysis is often difficult because of the difficulties involved in landslide hazard assessment and estimation of consequences of future landslide events. For instance, lack of multi-temporal inventory map or records of triggering events is often a major problem in landslide hazard mapping. In this study, we propose a simple technique for converting a landslide susceptibility map into a landslide hazard map, which we have employed for landslide risk analysis in one ideally hazardous part of volcanic mountains in West Java Province. The susceptibility analysis was carried out through correlation between past landslides and eight spatial parameters related to instability, i.e. slope, aspect, relative relief, distance to river, geological units, soil type, land use and distance to road. The obtained susceptibility map was validated using cross-time technique, and was collaborated with the frequency-area statistics to respond to ‘when landslide will occur’ and ‘how large it will be’. As for the judgment of the consequences of future landslides, expert opinion was used considering available literature and characteristic of the study area. We have only considered economic loss in terms of physical damage of buildings, roads and agricultural lands for the landslide risk analysis. From this study, we understand the following: (1) the hazard map obtained from conversion of the susceptibility map gives spatial probability and the area of an expected landslide will be greater than 500m2 in the next 2 years, (2) the landslide risk map shows that 24% of the total area is in high risk; 30% in moderate risk; 45% in low risk and no risk covers only 1% of the total area, and (3) the loss will be high in agricultural lands, while it will be low in the road structures and buildings. 相似文献
18.
基于RS与GIS的层次分析法在滑坡危险性评估中的应用——以四川宣汉天台乡滑坡为例 总被引：5，自引：1，他引：4
基于遥感(RS)和地理信息系统(GIS)技术,采用多层次分析(AHP)法,以四川宣汉天台乡为研究区,根据该区实际情况,选取线性构造、道路、土地利用、坡度、坡向5种影响滑坡灾害发生的因素作为评价因子,进行区域滑坡危险性评估。在ArcGIS的空间分析环境中运行权重叠加,把研究区划分成滑坡极易发生区、易发生区、一般发生区、可能发生区、难发生区和极难发生区。通过实地调查和与研究区的滑坡灾害实证研究结果进行比较,发现评估结果与实际状况较为吻合,研究方法能够准确地评估区域滑坡灾害危险性的程度。 相似文献
19.
Landslide risk assessment using concepts of danger pixels and fuzzy set theory in Darjeeling Himalayas 总被引：4，自引：1，他引：3
Landslide risk assessment (LRA) is a key component of landslide studies. The landslide risk can be defined as the potential
for adverse consequences or loss to human population and property due to the occurrence of landslides. The LRA can be regional
or site-specific in nature and is an important information for planning various developmental activities in the area. LRA
is considered as a function of landslide potential (LP) and resource damage potential (RDP). The LP and RDP are typically
characterized by the landslide susceptibility zonation map and the resource map (i.e., land use land cover map) of the area,
respectively. Development of approaches for LRA has always been a challenge. In the present study, two approaches for LRA,
one based on the concept of danger pixels and the other based on fuzzy set theory, have been developed and implemented to
generate LRA maps of Darjeeling Himalayas, India. The LRA map based on the first approach indicates that 1,015 pixels of habitation
and 921 pixels of road section are under risk due to landslides. The LRA map derived from fuzzy set theory based approach
shows that a part of habitat area (2,496 pixels) is under very high risk due to landslides. Also, another part of habitat
area and a portion of road network (7,204 pixels) are under high risk due to landslides. Thus, LRA map based on the concept
of danger pixels gives the pixels under different resource categories at risk due to landslides whereas the LRA map based
on the concept of fuzzy set theory further refines this result by defining the degree of severity of risk to these categories
by putting these into high and low risk zones. Hence, the landslide risk assessment study carried out using two approaches
in this paper can be considered in cohesion for assessing the risks due to landslides in a region. 相似文献
20.
Mowen Xie Tetsuro Esaki Cheng Qiu Chunxiang Wang Zengfu Wang 《Geotechnical and Geological Engineering》2009,27(3):355-364
The slope failure and landslide hazard will possess the same properties within a range including the same engineering geological
conditions. To assess the landslide risk of a mountainous area, the study of landslides previously having occurred is very
important to evaluate the landslide risk around the area in which they took place. Based on the study of the mechanism of
a previous landslide recorded in Kumamoto, Japan, this study initially proposes mechanical parameters for evaluating the landslide
hazard using a 3D slope stability method. For each slope unit in the study area, the critical slip surface, which reveals
the minimum safety factor of a slope, can be obtained. The affected streams and range of possible landslide masses are analyzed
based on the debris flow simulation. This is initially applied to simulate the past landslide event and the result shows the
landslide-deduced debris flow effectively re-displayed. Overlayered with layers of infrastructure in Geographic Information
Systems (GIS), this risk map indicates which houses and road sections remain in dangerous areas. 相似文献