Rozprawy doktorskie: „Risk analysis of landslides”

1

Hewitt, Dolan. "Risk analysis associated with flank failure from Putauaki, Bay of Plenty, New Zealand". The University of Waikato, 2007. http://hdl.handle.net/10289/2337.

Pełny tekst źródła

Streszczenie:

Volcanoes are dynamic evolving structures, with life cycles that are punctuated by episodes of flank instability. Putauaki (Mount Edgecumbe) is a stratovolcano located onshore in the Bay of Plenty, New Zealand. The aim of this study was to assess the stability of Putauaki and analyse the risk associated with volcanic collapse. To achieve this objective, a multidisciplinary approach was used, incorporating geomorphological and geological mapping, rock mass classification, laboratory testing to identify geotechnical properties of materials representative of the volcano, stability modelling, and analysis of landslide run-out zones. Putauaki comprises two predominant features including the larger and younger Main Cone (the summit lying 820 m a.s.l., slope angles up to 36 ), and smaller and older Main Dome (the summit lying 420 m a.s.l., slope angle of 24 ). Both features show little evidence of erosion or surface water. Rock mass description defined six lithotechnical units including indurated andesite, indurated dacite, scoriaceous andesite, altered andesite (all categorised as hard rocks), and block and ash flow and Matahina Ignimbrite (both categorised as soft rocks). The uniaxial compressive strength (UCS) of indurated andesite and indurated dacite was 60 4 MPa and 44.7 0.9 MPa respectively, correlating with moderately strong rock. Discontinuities of the indurated units were widely spaced, showed medium persistence and wide aperture, and were slightly weathered. Infill comprised predominantly loosely packed, very strong, coarse gravel. UCS of scoriaceous andesite and altered andesite was 25 5 MPa and 15 1 MPa respectively, allowing categorisation as very weak rock. Discontinuities of scoriaceous andesite were widely spaced, showed high persistence and wide aperture, and were moderately weathered. Discontinuities of the altered andesite were moderately spaced, showed low persistence and wide aperture, and were highly weathered. Infill of scoriaceous and altered andesite was loosely packed, moist, weak to very weak medium gravel. The block and ash flow was a poorly sorted, loosely packed, sandy, gravely and cobble rich matrix supported deposit. The Matahina Ignimbrite was a very weak, discontinuity-poor deposit. Shear box testing indicated cohesion and friction angle of 0 MPa and 42.1 (block and ash flow) and 1.4 x 10-3 MPa and 41.7 (Matahina Ignimbrite) respectively. These values are similar to published values. Correlation of each lithotechnical unit to its respective rock mass description site allowed approximate boundaries of each unit to be mapped. Each unit's mass strength was combined with measured bulk densities and incorporated into two dimensional slope profiles using the stability modelling package GalenaTM. Ten slope profiles of Putauaki were constructed. Failure surfaces for each slope profile were defined using the Bishop simplified multiple analysis method. Four slope profiles showed the potential for small scale failure (less than 0.1 km2 of material). The remaining six slope profiles showed the potential for large scale failure (greater than 0.1 km2 of material). Stability of these six slope profiles was investigated further in relation to earthquake force, watertable elevation, and a disturbance factor of the rock mass (D). Conditions of failure graphs for profile 6a showed that at low D (less than 0.4), earthquake forces and watertable elevation must be unrealistically high for the region (greater than 0.33 g; greater than 15% watertable elevation) in order produce a factor of safety less than 1. The remaining five slope profiles showed potential to be unstable under realistic earthquake forces and watertable elevations. Two of these profiles were unable to achieve stability at D greater than 0.8 (profile 4) and D greater than 0.9 (profile 5). A D value of 0.6 (intermediate between 0.4 and 0.8) is argued to most realistically represent Putauaki. The fact that Putauaki has not undergone large scale failure to date supports the conclusion that the constructed models overestimate the influence of those factors which promote slope instability. Maximum and minimum landslide run-out zones were constructed for the slope profiles exhibiting the potential for large scale failure. Definition of the position and extent of maximum and minimum run-out zones assumed H/L (fall height to run-out length) ratios of 0.09 and 0.18 respectively, as well as the 'credible flow path' concept. Identified impacts of landslides sourced from Putauaki include inundation of Kawerau Township, Tarawera River, forestry operations, road networks, and power supplies. Based on these impacts, the risk posed by landslides from each slope profile was categorised as ranging from relatively low to relatively high. Landslides sourced from the south-west flanks pose a relatively low risk due to their prerequisite of unrealistically high watertable elevations and earthquake forces. Landslides sourced from the north-west flanks pose a relatively high risk as minimum run-out will inundate north-east parts of Kawerau Township. Landslides sourced from the eastern flanks pose a moderate risk due to their run-out zones avoiding Kawerau Township.

Style APA, Harvard, Vancouver, ISO itp.

2

BLAHUT, JAN. "Debris flow hazard and risk analysis at medium and local scale". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2010. http://hdl.handle.net/10281/10914.

Pełny tekst źródła

Streszczenie:

Increased population, its wealth and activities lead to increased risk from landslide hazards in the mountain areas. The presented study deal with the analysis of debris flow hazard and risk at medium (regional) and local (site-specific) scale. Study took place in part of Valtellina Valley in Italian Central Alps. The first part of the study presents information about landslide hazard, risk and debris flow processes. It also shows historical information about natural disasters in the study area of Mountain Consortium of Municipalities of Valtellina di Tirano together with the results from a geo-database built for the study area. The database covers a period from 1600 till 2008 and it represents an important source of information for civil protection purposes. In the second part of the study, the debris flow susceptibility, hazard and risk analysis is performed at medium scale for the whole studied territory. Firstly, a new debris flow database was prepared and used as an input for susceptibility modelling together with the official sources. Susceptibility modelling was performed, using a bi-variate statistical technique Weights-of-Evidence and then the best performing susceptibility map was selected. Afterwards, spatial comparison of different susceptibility models was made, using advanced statistical techniques (Kappa Statistic, Principal Component Analysis, and Distance Weighted Entropy). Even though the modelling results show similar performance when assessed by standard evaluation techniques, their spatial pattern is very different. This may have serious outcomes in choosing the model which is most correctly delimiting the susceptible areas. Consequently, the results from the susceptibility modelling were coupled with temporal occurrence of debris flows in order to acquire initiation probabilities. These were subsequently used as inputs for runout modelling to obtain hazard maps at medium scale. Finally, medium scale risk maps were prepared by overlaying hazard maps with the elements at risk. Then, three risk maps were obtained. Two of the maps quantify economic risk from debris flows and the third qualitatively delimits total risk areas. Besides limitations and uncertainties within all steps of the analysis, an economic estimation of prospective consequences was done, being very important for the local stakeholders as well for the general public. Third part of the work presents two case studies related to quantitative risk assessment at local scale. Selvetta debris flow event, which happened in July 2008, was studied in the field obtaining information about the debris flow and building damage. The event was back-calculated and used for estimating synthetic vulnerability functions for buildings. In the second case study, located in Tresenda, hypothetical debris flow hazard was modelled for three return periods. Hazard scenarios were prepared and risk was quantified in economic terms using the vulnerability curves from the first case study of Selvetta. The results and the method applied for the quantification of risk reveal as very promising. As a consequence, it may be very interesting to apply this approach in different socio-economic and environmental settings in order to test its robustness. Presented thesis proposes a debris flow hazard and risk analyses approach at medium and local scale. Besides its feedbacks arising from available data, models, changing natural and socio-economic conditions and other intrinsic limitations, the study shows a possible approach applicable within integrated debris flow risk management framework.

Style APA, Harvard, Vancouver, ISO itp.

3

Konsoer, Kory M. "LiDAR, GIS, and multivariate statistical analysis to assess landslide risk, Horseshoe Run Watershed, West Virginia". Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5729.

Pełny tekst źródła

Streszczenie:

Thesis (M.S.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains vii, 129 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 79-86).

Style APA, Harvard, Vancouver, ISO itp.

4

Erener, Arzu. "An Approach For Landslide Risk Assesment By Using Geographic Information Systems (gis) And Remote Sensing (rs)". Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12611314/index.pdf.

Pełny tekst źródła

Streszczenie:

This study aims to develop a Geographic Information Systems (GIS) and Remote Sensing (RS) Based systematic quantitative landslide risk assessment methodology for regional and local scales. Each component of risk, i.e., hazard assessment, vulnerability, and consequence analysis, is quantitatively assessed for both scales. The developed landslide risk assessment methodology is tested at Kumluca watershed, which covers an area of 330 km2, in Bartin province of the Western Black Sea Region, Turkey. GIS and RS techniques are used to create landslide factor maps, to obtain susceptibility maps, hazard maps, elements at risk and risk maps, and additionally to compare the obtained maps. In this study, the effect of mapping unit and mapping method upon susceptibility mapping method, and as a result the effect upon risk map, is evaluated. Susceptibility maps are obtained by using two different mapping units, namely slope unit-based and grid-based mapping units. When analyzing the effect of susceptibility mapping method, this study attempts to extend Logistic Regression (LR) and Artificial Neural Network (ANN) by implementing Geographically-Weighted Logistic Regression (GWR) and spatial regression (SR) techniques for landslide susceptibility assessment. In addition to spatial probability of occurrence of damaging events, landslide hazard calculation requires the determination of the temporal probability. Precipitation triggers the majority of landslides in the study region. The critical rainfall thresholds were estimated by using daily and antecedent rainfalls and landslide occurrence dates based on three different approaches: Time Series, Gumble Distribution and Intensity Duration Curves. Different procedures are adopted to obtain the element at risk values and vulnerability values for local and regional scale analyses. For regional scale analysis, the elements at risk were obtained from existing digital cadastral databases and vulnerabilities are obtained by adopting some generalization approaches. On the other hand, on local scale the elements at risk are obtained by high resolution remote sensing images by the developed algorithms in an automatic way. It is found that risk maps are more similar for slope unit-based mapping unit than grid&ndash
based mapping unit.

Style APA, Harvard, Vancouver, ISO itp.

5

Paul, Simon. "Urban Growth and Environmental Risks - A GIS-Based Analysis of Landslide Susceptibility in Bukavu (Democratic Republic of the Congo)". Thesis, Umeå universitet, Institutionen för geografi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-161193.

Pełny tekst źródła

Streszczenie:

The city of Bukavu, located at the eastern border of the Democratic Republic of Congo in the province of South Kivu, is a large and densely populated urban agglomeration that has experienced rapid growth during recent years. At the same time, Bukavu has been repeatedly struck by environmental hazards, especially by devastating landslides. The steepness of slopes in the city’s hilly and mountainous terrain is one of the most important factors contributing to landslide susceptibility, but the anthropogenic impact resulting from uncoordinated urban sprawl and land cover change additionally plays a crucial role in exacerbating the vulnerability of neighbourhoods. This thesis utilizes GIS software to provide cartographic material for landslide risk assessment in Bukavu and the city’s surroundings. It examines risk exposure related to slope inclination of densely built-up areas, the spatial development of the city and urban growth tendencies, and complements these aspects with information about land cover and the terrain.

Style APA, Harvard, Vancouver, ISO itp.

6

Ziegler, Guilherme La Flor. "AVALIAÇÃO DO RISCO A ESCORREGAMENTOS DEVIDO A OCUPAÇÃO URBANA NA VILA BELA VISTA EM SANTA MARIA-RS". Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/7819.

Pełny tekst źródła

Streszczenie:

The study of geological and geotechnical characteristics of the slopes and indication of eviction those considered high risk geotechnically, can prevent tragedies caused by landslides materials. This dissertation was the main objective of evaluate the landslide risk due to urban occupation on the slope of strand west hill Cechela located in the Bela Vista village of the municipality of Santa Maria-RS. The methodology applied in this work consisted in review of the literature, field investigations, laboratory tests for characterization and determination of the resistance parameters of the soil layers, survey report of the intervention area, registration of housing under conditions of high risk to landslides, stability analysis of the slope of strand west hill Cechela and comparison of risk observed with that presented in the Municipal Plan of Reducing Risks of Santa Maria (PMRRSM). The results of inspection report are: the hillside with slopes greater than 30% is located in area not suited to urban occupation; there are deposits of small thickness colluviums situated directly on the substrate sandstone bedrock of the formation Botucatu; the most significant processes of instability on the slope are the landslides planar shallow colluvial soils. The register of homes indicates that if not done containment works two houses should be removed. The results of direct shear tests indicated that the increase of humidity and saturation degree cancels the cohesive intercept and significantly reduces the angle of internal friction of colluvium and sandstone. However, under natural conditions no saturation occurs due to the local geological conditions. The stability analysis with the use of software obtained safety factors (FS) of 1.40 and 2.57 for profiles of 07 and 17 HOUSES, showing that the slopes of the hill are stable. The landslide risk observed in the study area is less than that indicated in the PMRRSM. This work shows that must be constructed surface drainage devices and/or containment of the soil near the House 07 and 17 sites and suggests that today's families are kept in the slope of strand west hill Cechela. It is noteworthy that the village community Bela Vista should be instructed with relevant information to the identification of risks and the municipal plan risks should be reviewed.
O estudo das características geológicas e geotécnicas de encostas e indicação de desocupação daquelas consideradas geotecnicamente de alto risco, podem evitar tragédias causadas por deslizamentos de materiais. Esta dissertação de mestrado teve o objetivo principal de avaliar o risco a escorregamentos na encosta da vertente oeste do morro Cechela devido à ocupação urbana localizada na vila Bela Vista do município de Santa Maria-RS. A metodologia aplicada neste trabalho consistiu no levantamento bibliográfico, investigações de campo, ensaios laboratoriais para a caracterização e determinação dos parâmetros de resistência das camadas dos solos, laudo de vistoria da área de intervenção, cadastro das moradias em condições de risco elevado a escorregamentos, análise de estabilidade da encosta da vertente oeste do morro Cechela e comparação do risco observado com aquele apresentado no Plano Municipal de Redução de Riscos de Santa Maria (PMRRSM). Os resultados do laudo de vistoria são: a encosta com declividades superiores a 30% está localizada em área não adequada à ocupação urbana; existem depósitos de colúvios de pequena espessura situados diretamente sobre substrato rochoso arenítico da formação Botucatu; os processos de instabilização mais significativos na encosta são os escorregamentos planares de solos coluvionares rasos. O cadastro das moradias indica que se não forem executadas obras de contenção duas casas deverão ser removidas. Os resultados dos ensaios de cisalhamento direto indicaram que o aumento da umidade e grau de saturação anula o intercepto coesivo e reduz significativamente o ângulo de atrito interno do colúvio e do arenito. No entanto, nas condições naturais não ocorre a saturação devido a condições geológicas do local. As análises de estabilidade com o uso de software obtiveram fatores de segurança (FS) de 1,40 e de 2,57 para os perfis das CASAS 07 e 17, evidenciando que os taludes da encosta são estáveis. O risco a escorregamentos observado na área em estudo é menor do que aquele indicado no PMRRSM. Este trabalho evidencia que devem ser construídos dispositivos de drenagem superficial e/ou de contenção do solo junto aos locais da CASA 07 e 17 e sugere que as atuais famílias sejam mantidas na encosta da vertente oeste do morro Cechela. Destaca-se que a comunidade da vila Bela Vista deve ser instruída com informações relevantes para a identificação de riscos e que o plano municipal de riscos deve ser revisto.

Style APA, Harvard, Vancouver, ISO itp.

7

Salvador, Mateus da Mota. "Identificação e avaliação de eventos extremos na bacia hidrográfica do Rio Piranga". Universidade Federal de Viçosa, 2014. http://locus.ufv.br/handle/123456789/3823.

Pełny tekst źródła

Streszczenie:

Made available in DSpace on 2015-03-26T13:28:31Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2342421 bytes, checksum: 3404a977b901b66674c56658086227e5 (MD5) Previous issue date: 2014-02-20
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Floods and landslides are among the natural disasters most frequent that cause more economic and social losses in the world. In Brazil, a critical place is the Piranga River Watershed (PRW), located in Minas Gerais State and which comprises the Doce River headwaters. The setting is mainly due to the occurrence of extreme rainfall events associated with lack of planning and management of soil and inadequate occupation. Given the above, it is important to look after tools that help in interpreting information regarding the environment dynamics and also, tools that can identify, understand and predict the impact of changes caused to the environment. Therefore, this study was developed in two parts, involving the occurrence of extreme events in the PRW. In the first was presented a methodology for landslidesusceptible areas identification with the support of field experiments and strategic decision analysis based on multi-criteria evaluation. In the second part, the objective was to calibrate and validate a hydrological model in order to assess the effect land cover changes on the watershed hydrology opposite major floods. It can be concluded that the proposed methodology allowed the identification of landslide-susceptible areas in good agreement with the conditions observed in the field. The hydrological model was able to represent with good precision the watershed hydrological behavior and the scenarios simulation indicated an increase trend of floods occurrence due to changes in land cover. It is expected that this study enables the improvement of landslides and floods understanding and also, that it contributes as a tool for risk management in the PRW.
Enchentes e deslizamentos de terra estão entre os desastres naturais mais frequentes e que causam mais prejuízos econômicos e sociais no mundo. No Brasil, uma região crítica é a Bacia Hidrográfica do Rio Piranga (BHRP), localizada no Estado de Minas Gerais e que abriga a nascente do Rio Doce. O cenário deve-se principalmente à ocorrência de eventos de precipitação extremos associados à falta de planejamento e manejo no uso do solo e à ocupação acelerada e inadequada. Diante do exposto, é importante a busca por ferramentas que ajudem na interpretação de informações referentes à dinâmica dos recursos ambientais e que possam identificar, compreender e predizer o impacto de alterações provocadas ao meio ambiente. Nesse sentido, desenvolveu-se este trabalho na forma de dois estudos envolvendo a ocorrência de eventos extremos na BHRP. No primeiro, apresenta-se metodologia para a identificação de zonas de suscetibilidade a deslizamentos de terra com apoio de experimentos de campo e análise estratégica de decisão por avaliação multicritérios. Já no segundo estudo, o objetivo foi calibrar e validar modelo hidrológico para avaliar o efeito das mudanças de cobertura do solo no comportamento hidrológico da bacia frente a grandes cheias. Conclui-se que a metodologia apresentada permitiu a identificação de áreas suscetíveis à ocorrência de deslizamentos de terra com boa concordância em relação às condições observadas em campo. O modelo hidrológico foi capaz de representar com boa concordância o comportamento hidrológico da bacia e a simulação de cenários indicou um aumento na tendência de ocorrência de enchentes devido às mudanças na cobertura do solo. Espera-se que os resultados deste estudo permitam aprimorar a compreensão sobre os deslizamentos e enchentes e que possam contribuir como ferramenta para gestão de riscos na BHRP.

Style APA, Harvard, Vancouver, ISO itp.

8

Oven, Katie Jane. "Landscape, livelihoods and risk : community vulnerability to landslides in Nepal". Thesis, Durham University, 2009. http://etheses.dur.ac.uk/183/.

Pełny tekst źródła

Streszczenie:

The occurrence of fatal landslides in Nepal is increasing with time, faster than the effects of monsoonal variations. Possible explanations for the trends observed include: land-use change, population growth, and the development of transport infrastructure. However, to date, there is little evidence to support these postulated causes and very little research into the nature of landslide vulnerability in the Nepalese context. This research takes an interdisciplinary approach to examine, and where necessary, challenge a series of assumptions made regarding landslide vulnerability in Nepal with a view to developing a better understanding of social vulnerability and its underlying causes. Firstly, a bottom up livelihoods based approach is adopted to examine the following research questions: (1) Who is vulnerable to landslide hazard?; (2) Why do people occupy landslide prone areas?; and (3) How do ‘at risk’ rural communities perceive and respond to landslide hazard and risk? In so doing, this thesis approaches the question of landslide vulnerability from the perspective of the vulnerable people themselves. Secondly, the research explores how scientists and policy experts view landslide risk management in Nepal and how policy is subsequently informed and shaped. The findings highlight the impact of infrastructure projects in rural Nepal. Within the Upper Bhote Koshi Valley clear transitions in settlement patterns and rural livelihoods (and thus the occupation of landslide prone areas) have been seen over time. For the majority of households, their decision to occupy these areas is driven by the economic and social benefits associated with the road. Landslide risk therefore emerges not just from societal marginalisation but also from situations of relative prosperity. The findings suggest that occupants of landslide prone areas have a good understanding of landslide hazard and its associated risk. However, these risks are contextualised in relation to other social concerns. The significance of the findings for landslide policy and practice are addressed along with different actors’ views of landslide risk management in Nepal.

Style APA, Harvard, Vancouver, ISO itp.

9

Chan, Hoi-ting Janet. "Site-specific quantitative risk assessment in the slope safety system in Hong Kong". Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B43895633.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

10

El-Ramly, Hassan Mahmoud Fawzy. "Probabilistic analyses of landslide hazards and risks, bridging theory and practice". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ60290.pdf.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

11

Neal, David Miller. "A comparative analysis of emergent group behavior in disaster : a look at the United States and Sweden /". The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487263399026004.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

12

Ho, Yung-chi, i 何勇智. "Analysis of surface strains and velocities at the Pos Selim landslide". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/192992.

Pełny tekst źródła

Streszczenie:

The objectives of the study were 1) to carry out sensitivity analysis to determine the effects of different mesh geometries on the calculated surface strain field of the Pos Selim landslide; 2) to examine the strain field 2003-5 using the best mesh; 3) to examine the velocity profiles 2005-10 as compared to 2003-5; and 4) to draw conclusions about landslide mechanics. The original data used by Wong 2010 was adopted for fulfilling objectives 1 and 2. The corrected vector data by Lam 2012 was adopted for fulfilling objective 3. The main analysis method was done by the calculation by the Excel and was presented in graph by either Excel or Surfer 6.0. Contours are constructed by hand rather than computer for greater reliability. The strain fields for different meshes are broadly similar. The velocity data 2003 – 2010 has been interpreted in relation to the suggestion of Puzrin & Schmid 2011 that any compression zone at the toe will be reflected in a bi-modal velocity profile. The velocity profiles are not bi-modal, suggesting no compression zone exists at the toe. This supports the field evidence, which suggests that failure had already occurred in 2003, in the sense that a rupture surface had fully formed from head to toe. A Fault-Articulation Hypothesis has been tested using the rupture surface profiles suggested by Wu 2009. This hypothesis is “the landslide exploits existing faults and makes new ones where needed to assist articulation”. Evidence supporting the Fault-Articulation Hypothesis was found. It was found that Faults B and C were exploited for turning between different segments at South and Central Sections, where new faults T1, T2 and T3 were formed for turning in Head Graben. At North Section Fault B appears to have been exploited for turning between the Main Body and Head Graben but neither a geological nor a new fault appears to exist between the Main Body and the Toe Buttress. The velocity profiles 2003 – 5 and 2005 – 10 were compared. It is evident that the landslide decelerated significantly during this period.
published_or_final_version
Applied Geosciences
Master
Master of Science

Style APA, Harvard, Vancouver, ISO itp.

13

Turel, Mesut. "Soft computing based spatial analysis of earthquake triggered coherent landslides". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45909.

Pełny tekst źródła

Streszczenie:

Earthquake triggered landslides cause loss of life, destroy structures, roads, powerlines, and pipelines and therefore they have a direct impact on the social and economic life of the hazard region. The damage and fatalities directly related to strong ground shaking and fault rupture are sometimes exceeded by the damage and fatalities caused by earthquake triggered landslides. Even though future earthquakes can hardly be predicted, the identification of areas that are highly susceptible to landslide hazards is possible. For geographical information systems (GIS) based deterministic slope stability and earthquake-induced landslide analysis, the grid-cell approach has been commonly used in conjunction with the relatively simple infinite slope model. The infinite slope model together with Newmark's displacement analysis has been widely used to create seismic landslide susceptibility maps. The infinite slope model gives reliable results in the case of surficial landslides with depth-length ratios smaller than 0.1. On the other hand, the infinite slope model cannot satisfactorily analyze deep-seated coherent landslides. In reality, coherent landslides are common and these types of landslides are a major cause of property damage and fatalities. In the case of coherent landslides, two- or three-dimensional models are required to accurately analyze both static and dynamic performance of slopes. These models are rarely used in GIS-based landslide hazard zonation because they are numerically expensive compared to one dimensional infinite slope models. Building metamodels based on data obtained from computer experiments and using computationally inexpensive predictions based on these metamodels has been widely used in several engineering applications. With these soft computing methods, design variables are carefully chosen using a design of experiments (DOE) methodology to cover a predetermined range of values and computer experiments are performed at these chosen points. The design variables and the responses from the computer simulations are then combined to construct functional relationships (metamodels) between the inputs and the outputs. In this study, Support Vector Machines (SVM) and Artificial Neural Networks (ANN) are used to predict the static and seismic responses of slopes. In order to integrate the soft computing methods with GIS for coherent landslide hazard analysis, an automatic slope profile delineation method from Digital Elevation Models is developed. The integrated framework is evaluated using a case study of the 1989 Loma Prieta, CA earthquake (Mw = 6.9). A seismic landslide hazard analysis is also performed for the same region for a future scenario earthquake (Mw = 7.03) on the San Andreas Fault.

Style APA, Harvard, Vancouver, ISO itp.

14

Rodriguez, Pineda Carlos Eduardo. "Hazard assessment of earthquake-induced landslides on natural slopes". Boston Spa, U.K. : British Library Document Supply Centre, 2001. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.247774.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

15

Tatard, Lucile. "Statistical analysis of triggered landslides: implications for earthquake and weathering controls". Thesis, University of Canterbury. Geological Sciences, 2010. http://hdl.handle.net/10092/4011.

Pełny tekst źródła

Streszczenie:

We first aim to review the external perturbations which can lead to landslide failure. We review the perturbations and associated processes in five sections: i) increase of slope angle, ii) increase of load applied on the slope, iii) rise of groundwater level and pore pressure, iv) frost weathering processes and v) earthquake loading. Second, we analyse the New Zealand landslide catalogue, integrating all landslides recorded in New Zealand between 1996 and 2004. We analyse the New Zealand landslide series in time and rate and find a strong correlation in landslide occurrences. The time correlation found between landslide occurrences for events occurring more than 10 days apart is not found to be driven by the earthquake-landslide nor the landslide-landslide interactions. We suggest the climate-landslide interactions drive, non-linearly and beyond the empirically reported daily correlation, most of New Zealand landslide dynamics. Third, we compare the landslide dynamics in time, space and rate of New Zealand, Yosemite cliffs (California, USA), Grenoble cliffs (Is`ere, French Alps), Val d’Arly cliffs (Haute-Savoie, French Alps), Australia and Wollongong (New South Wales, Australia). Landslides are resolved as correlated to each other in time for all catalogues. The New Zealand, Yosemite, Australia and Wollongong landslide daily rates are well fitted by a power law for rates between 1 and 1000 events per day, suggesting that the same mechanism(s) are driving both the large landslide daily crises and the single events. The joint analysis of the six catalogues permits to derive parameters that allow to sort the relative landslide dynamics in each of the six areas. From the most re-active landslide area (New Zealand) to the less re-active area (Grenoble), the global trend of the different parameters are: i) decreasing departure from randomness; ii) decreasing maximum daily rates and area over which the trigger operates; iii) decreasing landslide triggering for landslides occurring one day apart; iv) decreasing global interaction to earthquake, rainfall and temperature. Fourth, we compare earthquake aftershock space distributions with landslide space distributions triggered by the Chi-Chi MW7.6 earthquake (Taiwan), by the MW7.6 Kashmir earthquake (Pakistan), by the MW7.2 Fiordland earthquake (New Zealand), by the MW6.6 Northridge earthquake (California) and by the MW5.6 Rotoehu earthquake (New Zealand). We resolve the seismic aftershock and landslide normalised number of events to display roughly similar patterns with distances, when comparing the landslide distributions to their aftershock distribution counterparts. When comparing the five landslide - aftershock distribution pairs for a given mainshock, we do not resolve a clear common pattern. Then we compare landslide and aftershock distance distributions to ground motion observations (Peak Ground Acceleration, Peak Ground Velocity and Peak Ground Displacement) and we find no linear scaling of the number of landslides or aftershocks with none of the ground motion variables. We suggest that landslides and aftershocks are driven by the same mechanisms and shed light on the Peak Ground Displacement and associated static stress changes on landslide triggering.

Style APA, Harvard, Vancouver, ISO itp.

16

Pecoraro, Gaetano. "Monitoring strategies and warning models for weather-induced landslides". Doctoral thesis, Universita degli studi di Salerno, 2019. http://elea.unisa.it:8080/xmlui/handle/10556/4284.

Pełny tekst źródła

Streszczenie:

2017 - 2018
Weather induced landslides cause a large number of casualties as well as severe economic losses worldwide every year. Such a diffuse risk cannot be mitigated only by means of structural works, typically characterized by significant economic and environment al impacts. Therefore, landslide early warning systems (LEWS) are being increasingly applied as non structural mitigation measures aiming at reducing the loss of life probability and other adverse consequences from landslide events by prompting people to a ct appropriately and in sufficient time to reduce the possibility of harm or loss. The systems can be distinguished, as a function of the scale of design and operation, in two different categories. Territorial systems (Te LEWS), deal with multiple landslid es over wide areas at regional scale, i.e. typically a basin, a municipality or a region; local systems (Lo LEWS) address single landslides at slope scale. In a preliminary phase of this study, a detailed review of Lo LEWS operational worldwide is provide d. The information has been retrieved from peer reviewed articles published in scientific journals and proceedings of technical conferences, books, reports, and institutional web pages. The main characteristics of these systems have been summarized and des cribed according to a scheme based on a clear distinction between three modules: landslide model, warning model and warning system. The monitoring strategies implemented therein have been presented and discussed, focusing on the monitored parameters and th e monitoring instruments for each type of landslide. Subsequently, warning models developed within Te LEWS for weather induced landslides have been analyzed , pointing out that: their outputs are strongly dependent from the accurateness and reliability of t he information on landslide occurrences; and only meteorological variables are considered in most of occurrences; and only meteorological variables are considered in most of the cases, thus leading to an unavoidable uncertainty in the empirically the cases, thus leading to an unavoidable uncertainty in the empirically defined thresholds. defined thresholds. To overcome these issues, original procedures for To overcome these issues, original procedures for defining wardefining warning models are herein proposed and tested on case studies ning models are herein proposed and tested on case studies in Campania and Emiliain Campania and Emilia--Romagna regions (Italy) and in Norway. In Italy, Romagna regions (Italy) and in Norway. In Italy, a probabilistic approach has been developed to determine landslide a probabilistic approach has been developed to determine landslide conditional probabilities related to rainfall of specific conditional probabilities related to rainfall of specific intensity and intensity and duration. The adopted Bayesian methodology allows to consider the duration. The adopted Bayesian methodology allows to consider the uncertainty of the data and to provide a quantitative assessment of the uncertainty of the data and to provide a quantitative assessment of the reliability of the results. Data on landslide occurrences have been derived reliability of the results. Data on landslide occurrences have been derived from a new landslide inventofrom a new landslide inventory, named “FraneItalia”, wherein data are ry, named “FraneItalia”, wherein data are retrieved from online journalistic news; the correlations between retrieved from online journalistic news; the correlations between landslides and rainfall have been assessed by analylandslides and rainfall have been assessed by analyzzing satelliteing satellite--rainfall rainfall records within weather alert zones. On the other hand, the methodology records within weather alert zones. On the other hand, the methodology prproposed for Norway aims at integrating the hydrooposed for Norway aims at integrating the hydro--meteorological meteorological variables employed within the regional model used by the national early variables employed within the regional model used by the national early warning system (i.e. combinations of relative water supply and relative soil warning system (i.e. combinations of relative water supply and relative soil water saturation degree) with monitoring datwater saturation degree) with monitoring data collected at local scale, a collected at local scale, specifically pore water pressure observations acquired by the Norwegian specifically pore water pressure observations acquired by the Norwegian Geotechnical Institute for a variety of projects. The analyses are carried Geotechnical Institute for a variety of projects. The analyses are carried out on a number of hydrological basins (test areas) defined at national out on a number of hydrological basins (test areas) defined at national scale andscale and selected considering the occurrence of landslides in loose soils selected considering the occurrence of landslides in loose soils from 2013 to 2017 and the availability of a significant number of pore from 2013 to 2017 and the availability of a significant number of pore water pressure measurements. For each basin, the alerts issued by the water pressure measurements. For each basin, the alerts issued by the regional model are assessed by means of a 2regional model are assessed by means of a 2--step step analysis employing analysis employing indicators derived from simple moving averages of the pore water indicators derived from simple moving averages of the pore water pressure measurements. pressure measurements. The warning models developed herein were successfully applied to The warning models developed herein were successfully applied to selected case studies. Therefore, the proposed methodologies can be selected case studies. Therefore, the proposed methodologies can be considered valuconsidered valuable frameworks considering aspects that are crucial for able frameworks considering aspects that are crucial for improving the efficiency of the models, such as: the potential of nonimproving the efficiency of the models, such as: the potential of non--conventional landslide inventories and remote sensing monitoring conventional landslide inventories and remote sensing monitoring instruments to complement the traditional sources of data, the uinstruments to complement the traditional sources of data, the use of se of probabilistic techniques for defining more objective rainfall thresholds, probabilistic techniques for defining more objective rainfall thresholds, and the additional contribution of the information derived from the local and the additional contribution of the information derived from the local observations of pore water pressures.observations of pore water pressures. [edited by Author]
XXXI ciclo

Style APA, Harvard, Vancouver, ISO itp.

17

Faber, Ethan J. "Development of a landslide risk rating system for small-scale landslides affecting settlements in Guatemala City". Thesis, Colorado School of Mines, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10014960.

Pełny tekst źródła

Streszczenie:

Many settlements in the Guatemala City Metropolitan Area (GCMA) face significant possibilities of fatalities due to their location in steep ravines that are subjected to periodic large-scale landslides. Since the housing in the at-risk areas is relatively low-cost, it is typically cost-prohibitive to mitigate the risk to an acceptable level. Thus, permanent relocation is the only truly viable option to ensure the long-term safety of everyone. However, there are several economic and social obstacles impeding successful implementation of a relocation program. Still, there are many other landslide risk reduction techniques (such as retaining walls, community drainage systems, and alert systems) implemented by government organizations and non-profit groups. These techniques are helpful in landslide risk reduction (LRR), but residents are only partially involved in the entire process. Therefore, increasing residents’ education and ability to better understand their level of landslide risk will help with LRR. Residents can integrate and collaborate with the government organizations and non-profits implementing mitigation techniques and of even greater benefits, the education and ability for residents to understand their landslide risk can provide additional avenues for LRR not otherwise achievable. The purpose of this research is to develop a landslide-risk-rating-system (LRRS) that can be used by trained residents to better understand their risk (similar to other landslide or rockfall hazard-rating systems commonly used by department of transportation organizations). The focus of this LRRS is only on small-scale landslides (typically the size of a house or less) because evaluating the risk of large-scale landslides is too complicated to be done by trained non-technical experts. The LRRS asks questions related to landslide risk that can be used to calculate a landslide risk score to indicate the relative level of risk. The LRRS was created by reviewing published literature documenting other landslide rating systems and incorporating similar factors correlated with landslide risk. Then, forty sites were visited in the GCMA to inventory the factors at houses that are vulnerable to landslides in order to evaluate which factors were most useful for predicting the relative risk. The predicted risk scores were compared to ranked risk scores estimated by the author to ensure the results were valid. Statistical analysis identified which of these factors best-predicted landslide risk. These factors include slope angle, slope height, strength of slope material or material type, aperture of cracks, spatial impact, largest probable landslide volume, largest probable percentage of the living area that could be impacted from a landslide, and total person-hours a living area is occupied per day. Future work should focus on the transformation of the tool into a more user-friendly format for use by residents, the implementation process, and monitoring plan.

Style APA, Harvard, Vancouver, ISO itp.

18

Miles, Scott B. "Participatory assessment of a comprehensive areal model of earthquake-induced landslides /". Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/5609.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

19

McKay, Sara E. "Geotechnical analysis of horizontal drains as a landslide mitigation method in western Washington /". abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1437660.

Pełny tekst źródła

Streszczenie:

Thesis (M.S.)--University of Nevada, Reno, 2006.
"August, 2006." Includes bibliographical references (leaves 93-97). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.

Style APA, Harvard, Vancouver, ISO itp.

20

Chan, Hoi-ting Janet, i 陳凱婷. "Site-specific quantitative risk assessment in the slope safety system in Hong Kong". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B43895633.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

21

Bray, Malcolm John. "Beach budget analysis and shingle transport dynamics in West Dorset". Thesis, London School of Economics and Political Science (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337297.

Pełny tekst źródła

Streszczenie:

Comprehensive sediment budgets are compiled for a series of pocket shingle beaches in West Dorset backed by massive soft cliffs that degrade in a rapid and complex manner. Studies involve the identification and quantification of sediment (primarily shingle) inputs, transfers, storage and outputs within terrestrial and marine subsystem components. Results are unified within budget and flow models and applied to tackle questions of coastal evolution and management. Research involved mapping and sampling of the ground forming materials in terms of their beach forming potential. Cliff landsliding and recession are analysed using comparisons of historical maps, aerial photos and documentary evidence. A method of quantifying the release, throughput and supply to the beaches of various sediment grades from the eroding cliffs is presented. The volumes and types of sediment at the beach and in the inshore zone are investigated by various profile, intertidal, and offshore surveys. Detailed sampling and sediment analysis of the beaches is undertaken to elucidate beach drift and for attrition assessments through comparisons with cliff inputs. Shingle tracing experiments using aluminium tracers are conducted to study transport and sorting at two contrasting sites over a full spectrum of wave energy conditions. Validated littoral drift volumes and original wave power relationships are developed. Information is compiled to produce budget models for the main beaches. Complex long established links are demonstrated between eroding cliff sources and the shingle beaches that they supply. Chesil Beach is identified as the ultimate shingle sink suggesting that it is not entirely a product of the Holocene transgression as often envisioned, but a component of a Lyme Bay process system and open periodically to inputs of shingle from the west. Adverse impacts arising from various human interventions are highlighted using the models.

Style APA, Harvard, Vancouver, ISO itp.

22

Trandafir, Aurelian Catalin. "Dynamic displacement analysis of earthquake-induced catastrophic landslides in saturated cohesionless soils". 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/147830.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

23

Касіянчук, Д. В. "Оцінка екологічних ризиків для природної та техногенної складової екзогенних процесів Карпатського регіону". Thesis, Івано-Франківський національний технічний університет нафти і газу, 2016. http://elar.nung.edu.ua/handle/123456789/45.

Pełny tekst źródła

Streszczenie:

Дисертацію присвячено екологічній проблемі - оцінці еколого-геологічних ризиків розвитку екзогенних геологічних процесів шляхом розподілу на природні та техногенні процесоініціюючі фактори. Встановлено, що прогнозування екзогенних геологічних процесів слід здійснювати з урахуванням роздільного впливу факторів, які сприяють їх розвиткові та активізації. Визначено оптимальний для даної території комплекс природних та техногенних факторів. Величиною, що на кількісному ймовірнісному рівні враховує вплив просторових і часових чинників є інтегральний просторовий показник небезпеки проявів екзогенних геологічних процесів. Виконаний аналіз просторової імовірності небезпеки від проявів екзогенних геологічних процесів для території Івано-Франківської області з побудовою відповідних карт для природної та техногенної складових. На основі сформованих моделей ризиків проведена їх оцінка для окремих територій Карпатського регіону, що надає передумови для створення як просторового так і часового прогнозу.
The thesis highlights the current scientific and applied problems of risk of exogenous geological processes that define the level of environmental safety of territory. The problem of public safety and numerous objects in the areas of dangerous exogenous geological processes is one of the major social and environmental problems of nowadays because of damages caused by these processes. The main kinds of EPG that cause the most negative effects are landslides, mudflows and karst. Theoretical and experimental researches made by the author, allow to summarize their main results. The development and widespread of exogenous geological processes and their impact on environmental safety in Ukraine and the Carpathian region in particular demonstrates the need for a detailed study of these processes in their relationship with the initiating factors. Having conducted the theoretical investigations allow to substantiate the analysis of algorithm groups of factors, based on the definition of the distribution factor characteristics of their unification, informative evaluation factors, the calculation of integrated indicators. In the analysis of natural and man-made component factors of development and activation of landslides, mudflows and karst, as technological conditioned advisable to consider the following: geological (distance to lots violation geological environment (water intakes and quarries), the rate of infestation and localities within an area, geomorphological (distance to the source of vibration, level of vibration, change the angle of inclination, stability factor, distance to roads, railways, distance to the village), hydrogeological (factor of disturbance, the level of ground waters) and landscape (changes in forest cover, distance to the border forest). The spatial analysis is based on communication between groups using factors weighing indicator informativeness factors and integral index. To improve existing methods for prediction of time use the new temporal factor characteristics as moon phase and global temperature. The final result of research is environmental geological risk assessment based on comprehensive integrated spatial indexes revitalization and development of exogenous geological processes, which are quantitative probabilistic take into account the level of total performance factors. The spatial analysis is done by mapping the spatial distribution of the integral index. Evaluation of ecological and geological risks manifestations of hazardous of exogenous geological processes will ensure the safe construction and operation of commercial engineering structures, plan measures to prevent emergency situations effectively protect the population from natural disasters, which in turn will lead to stability ekoheosystem and environmental security of the region and state as a whole.

Style APA, Harvard, Vancouver, ISO itp.

24

Balal, Onur. "Probabilistic Seismic Hazard Assessment For Earthquake Induced Landslides". Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615453/index.pdf.

Pełny tekst źródła

Streszczenie:

Earthquake-induced slope instability is one of the major sources of earthquake hazards in near fault regions. Simplified tools, such as Newmark&rsquo
s Sliding Block (NSB) Analysis are widely used to represent the stability of a slope under earthquake shaking. The outcome of this analogy is the slope displacement where larger displacement values indicate higher seismic slope instability risk. Recent studies in the literature propose empirical models between the slope displacement and single or multiple ground motion intensity measures such as peak ground acceleration or Arias intensity. These correlations are based on the analysis of large datasets from global ground motion recording database (PEER NGA-W1 Database). Ground motions from earthquakes occurred in Turkey are poorly represented in NGA-W1 database since corrected and processed data from Turkey was not available until recently. The objective of this study is to evaluate the compatibility of available NSB displacement prediction models for the Probabilistic Seismic Hazard Assessment (PSHA) applications in Turkey using a comprehensive dataset of ground motions recorded during earthquakes occurred in Turkey. Then the application of selected NSB displacement prediction model in a vector-valued PSHA framework is demonstrated with the explanations of seismic source characterization, ground motion prediction models and ground motion intensity measure correlation coefficients. The results of the study is presented in terms of hazard curves and a comparison is made with a case history in Asarsuyu Region where seismically induced landslides (Bakacak Landslides) had taken place during 1999 Dü
zce Earthquake.

Style APA, Harvard, Vancouver, ISO itp.

25

Tambe-Ebot, Mathias Ashu Tako. "Proposing a Theoretical GIS Model for Landslides Analysis : The Case of Mount Cameroon". Thesis, Linköpings universitet, Institutionen för datavetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-65899.

Pełny tekst źródła

Streszczenie:

This study presents a theoretical GIS model to investigate the relative impacts of geomorphic and environmental factors that govern the occurrence of landslides on the slopes of Mount Cameroon and its surrounding areas. The study area is located along the Cameroon Volcanic Line (CVL), a major structural feature that originates from the south Atlantic and continues into the continental landmass. The quite frequent seismic activity, geologic character, humid tropical climate and high human pressure on hill slopes are the major factors behind the occurrence of landslides in Mount Cameroon. This paper, therefore, underscores the necessity of in-depth follow-up studies concerned with landslides prevention and management based on the relevance of sufficient reliable field methods in landform geomorphology and interpretation. As much is yet to be done to acquire data for structural and surface geology, hydrology, geomorphic processes and physiography of Mount Cameroon, it is difficult at this point in time to considerably apply suitable methods using GIS that would enable identifying and delineating the landslide-prone areas. In addition, the application of environmental surface monitoring instruments will not be meaningful without a clear presentation of which areas are a cause for concern (given that the employment of any slope stability monitoring and rehabilitation efforts will be only possible after appropriate problem-area identification has been done). Consequently, based on the writer’s previous work in the Mount Cameroon area and available related literature, a methodology using GIS is proposed, which provides the capability to demonstrate how the impact of individual or collective geomorphologic site-specific factors on landslides occurrence could be justified. Considering that digital data may not be readily available, a procedure for the creation of data and analysis of themes is proposed and illustrated. The factors analysis approach in landslides analysis may be cheaper and easier to employ in Mount Cameroon and similar problem regions in developing countries (given that there may be problems of limited financial resources and available expertise in GIS technology and applications). The study underscores and recommends the necessity for a later practical implementation with the availability of adequate resources.

Style APA, Harvard, Vancouver, ISO itp.

26

Yfantis, Georgios. "Kinematics of soft soil landslides based on the analysis of microseismic monitoring data". Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25953.

Pełny tekst źródła

Streszczenie:

Landslide failures are a worldwide problem claiming human lives and causing catastrophic damages to infrastructure, with their impact able to reach that of war conflicts. For these reasons this thesis is going to investigate on the use of microseismic monitoring to study the kinematic behaviour of landslides and help towards the design of an optimised early or real time warning system. All findings are based in field experiments, using 1D and 3D short period seismometers, designed to understand the capabilities and limitations of microseismic monitoring in order to enhance the first and minimize the last. The first goal of this thesis is to understand accuracy of microseismic monitoring in locating weak seismic events. The effect of the seismic velocity model is studied against common seismological assumptions, while different aperture sizes of microseismic arrays are put into test for achieving optimum location results. Next, in order to allow the study of the expected landslide seismicity during a future landslide failure, a novel methodology, an up-scaled shear box, is designed to induce landslide like seismic signals. The proposed methodology can recreate soil slip events allowing control over different geotechnical conditions, such as stress levels, thus reproducing different landslide failure scenarios. The up-scaled shear box methodology is then used to test a novel engineered seismic source: glass shard piles placed inside the landslide's mass, triggered from the landslide's displacements. The material characteristics of glass shards don't change in time, e.g. due to saturation, and have a stable seismic signature during displacement. For these reasons glass shard piles can act as the common seismic source, overcoming the time consuming process of identifying landslide complex failure mechanisms. Finally, failure is induced to two landslide vertical faces under controlled conditions. Both landslides have identical characteristics, e.g. size and geology, with the only difference that in one of them a glass shard pile was incorporated. Visual observations, displacement and loading observations of the landslide faces, timed with a GPS clock, allowing for their detection on the seismic recordings and the characterisation of failure events. The collected data are found to correlate well with the experiments conducted with the up-scaled shear box methodology, allowing for their validation.

Style APA, Harvard, Vancouver, ISO itp.

27

Flores, Raul. "Framework for probabilistic analysis of recurrent landslides a case study of El Berrinche /". Connect to this title online, 2008. http://etd.lib.clemson.edu/documents/1233080741/.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

28

Ciurleo, Mariantonietta. "A methodological approach for the analysis of shallow landslides in non-collapsible soils". Doctoral thesis, Universita degli studi di Salerno, 2013. http://hdl.handle.net/10556/1318.

Pełny tekst źródła

Streszczenie:

2011 - 2012
Shallow landslides in non-collapsible, fine-grained soils are natural phenomena which, due to their simultaneous occurrence over large areas, often cause agricultural production loss, with enormous economic damage. Although the scientific community has offered in depth analyses of landslides in collapsible soils, shallow landslides in non-collapsible soils, have been paid very little attention in spite of their consequences. The few works available in scientific literature are based on monodisciplinary approaches which provide useful specific information on these phenomena; yet, at the same time, they also oversimplify the problem, often neglecting some relevant issues. Such issues can be best highlighted and addressed following a multisisciplinary and multiscalar (deductive or inductive) approach, as some authors have evidenced in very different geological and environmental contexts affected by medium- to deep -seated landslides. Within such a context, rich in approaches but lacking in references to shallow landslides in non-collapsible soils, the present thesis seeks to offer a methodological contribution for creating a homogeneous reference framework for the phenomena examined. At the same time, this work seeks to answer specific questions concerning the ways in which these phenomena are triggered. The proposed methodology has been tested and validated over an area in southern Italy, in which shallow landslides are very frequent. The predisposing factors and the triggering causes have been analysed going from small scale, through geological models, to large scale by means of geotechnical analyses performed at slope and large scale. On the one hand, this approach allowed to identify the predisposing factors of the morphological evolution of the reliefs in the main tectonic structures, drainage lines and in the main lithology; on the other hand it allowed the characterization of large scale and detailed scale landslides by identifying their triggering mechanisms, and by investigating specific aspects such as the hydraulic and mechanic properties of the soil and the pore water pressure regime in situ. In particular, three main triggering mechanisms have been identified and analysed at large scale which differ in terms of morphometric characteristics, volumes involved, and which do not show a casual slope distribution. Subsequently, a (saturated and unsaturated) modelling of groundwater regime for these mechanisms has been performed which provided the input data for stability analysis carried out through physically based and limit-equilibrium methods. The overall validity of the results obtained highlights the efficacy of the methodology applied and recommends its use in geo-environmental contexts which differ from the one in which this methodology has been tested and validated. For this purpose, at the end of the present thesis, a series of general considerations have been discussed by making use of preliminary applications to internationally well-known case studies available in scientific literature. [edited by author]
XI n.s.

Style APA, Harvard, Vancouver, ISO itp.

29

Souza, Lucas Barbosa e. "Percepção dos riscos de escorregamentos na Vila Mello Reis, Juiz de Fora (MG) : contribuição ao planejamento e à gestão urbanos /". Rio Claro : [s.n.], 2006. http://hdl.handle.net/11449/100077.

Pełny tekst źródła

Streszczenie:

Resumo: Em meio tropical, os escorregamentos figuram entre os fenômenos que mais geram acidentes em áreas de risco, causando uma série de perdas econômicas e humanas a cada ano. Várias cidades brasileiras congregam a ameaça dos escorregamentos e a vulnerabilidade de parte significativa de sua população, mas, apesar disso, os trabalhos preventivos são iniciativas raras ou até mesmo inexistentes. Nos casos em que essa atividade é desenvolvida, geralmente pode-se verificar a negligência sobre certos aspectos fundamentais do risco, dentre eles a percepção e a conduta dos moradores envolvidos. Neste trabalho, os riscos de escorregamentos na Vila Mello Reis, em Juiz de Fora (MG), foram pesquisados por intermédio da abordagem perceptiva. Mais especificamente, foram investigadas as seguintes variáveis: percepção dos elementos condicionantes e deflagradores dos escorregamentos, da causalidade dos acidentes e da responsabilidade sobre os riscos; avaliação e escolha do local de moradia; limiares de segurança; ajustamentos à situação de risco; e tomada de decisão e participação na escala do bairro. Logo, a partir dos resultados obtidos, procurou-se construir um conjunto de propostas visando subsidiar o trabalho de planejamento e de gestão urbanos no cenário da pesquisa, sobretudo no que diz respeito à prevenção de acidentes envolvendo escorregamentos.
Abstract: In a tropical environment, the landslide appear among the phenomena that generate more accidents in risk areas, causing a series of economic and human losses each year. Several Brazilian cities gather the landslides threatment and the vulnerability of a significative part of their population, but nonethless, the preventive works are rare initiative or either nonexistants. In cases when this activity is carried out generally it can be verified the neglicency about some fundamental aspects of risk among them the perception and the behave of some community people engaged in it. In this work, the landslides risks in Mello Reis village, in Juiz de Fora city (MG), were researched through the perceivity approach. It were investigated specifically the following variables: perception of the conditioning elements and landslides startes, the accidents causes and the risks responsability; evaluation and the dweling site choicing; security threshold; adjustment to the risk situation; decision making and participation at the neighbourhood area. So, through the reached outcomes, it was tried to construct a set of propositions aiming to subsidize the planning and urban management on the research setting, above all concerning to accidents prevention due to landslides.
Orientador: João Afonso Zavattini
Coorientador: Lívia de Oliveira
Banca: Sandra Elisa Contri Pitton
Banca: Lucy Marion Calderini Philadelpho Machado
Banca: José Bueno Conti
Banca: Daniel Joseph Hogan
Doutor

Style APA, Harvard, Vancouver, ISO itp.

30

Wood, Joanne Laura. "Landslide inventories in the European Alps and their applicability and use in climate change studies". Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/25757.

Pełny tekst źródła

Streszczenie:

Landslides present a geomorphological hazard in alpine regions, threatening life, infrastructure and property. Presented in this thesis is the development of a new Regional Landslide Inventory (RI) for the European Alps. The new inventory is used to investigate links between landslide size and frequency in the European Alps and weather and climatic controls. Temperatures in the European Alps have risen by 2 C since the end of the Little Ice Age (LIA); a trend which is set to continue. Previous research has shown that past landslide clusters are centred around periods of signi ficant climate change, thus understanding how this translates to the current warming trend is important both for communities living in the European Alps and for the insurance industry. The RI compiled here, provides a substantial temporal and spatial picture of landsliding in the Alps; with particular focus on the Swiss and French Alps. The temporal distribution and estimates of completeness were tested through the use of segmented models, scaling relationships and area-frequency distributions; the post-1970 portion of the database is considered most complete, although underestimating the frequency of medium-sized landslides. Analysis of the RI in the context of synoptic weather types demonstrates that high precipitation over the European Alps is consistent with higher landslide frequencies. Whilst analysis with climate data show that annual landslide frequencies are correlated with changes in precipitation and temperature across the European Alps; accounting for up to 35% of the seasonal variation in landslide frequency.

Style APA, Harvard, Vancouver, ISO itp.

31

Hürlimann, Marcel. "Geotechnical analysis of large volcanic landslides: The La Orotava events on Tenerife,Canary Islands". Doctoral thesis, Universitat Politècnica de Catalunya, 1999. http://hdl.handle.net/10803/6217.

Pełny tekst źródła

Streszczenie:

Los grandes deslizamientos volcánicos son uno de los procesos geológicos más devastadores y pueden representar un importante peligro para la población de las zonas volcánicas. Este tipo de deslizamientos puede sobrepasar volúmenes de decenas o incluso centenares de kilómetros cúbicos. En Tenerife, siete grandes deslizamientos han afectado durante los últimos ~6 millones de años la morfología subaérea y submarina de la isla.
En este estudio se ha realizado un extenso análisis de los eventos que han formado el valle de "La Orotava" en la parte Norte de Tenerife. El estudio incluye una investigación de campo, ensayos de laboratorio y análisis de estabilidad. En el laboratorio, las propiedades mecánicas de un suelo residual han sido investigadas mediante cortes directos y ensayos triaxiales. Durante el análisis de estabilidad, los resultados de los ensayos de laboratorio han sido incorporados a diferentes tipos de modelos de estabilidad. Finalmente, las condiciones mecánicas de los modelos dos y tres dimensionales han sido estudiados mediante el método de equilibrio límite y métodos de elementos finitos.
Los resultados de los análisis revelan que la estabilidad de las laderas volcánicas puede ser reducida debido a diversos factores, como geológicos, morfológicos, climáticos y volcánicos. Los suelos residuales - bastante comunes en Tenerife - pueden haber actuado como superficie de rotura a causa de su débil comportamiento mecánico. Por otra parte, los estrechos y profundos barrancos han definido los límites laterales de los deslizamientos. Además de ello, los acantilados, el clima húmedo y especialmente la constante intrusión de diques, han llevado la ladera a condiciones de estabilidad críticas. Finalmente, una aceleración sísmica causada por un seísmo fuerte y cercano provocó muy probablemente el deslizamiento catastrófico.
En Tenerife, se ha observado una relación temporal entre los colapsos de caldera y los grandes deslizamientos, lo que permite suponer que los fuertes terremotos asociados a los colapsos de caldera hayan provocado los deslizamientos.
Large volcanic landslides are one of the most hazardous of geological processes. They have occurred about once every 25 years during the last 500 years, and are a serious risk for the population due to their great volume and mobility. In spite of their destructive potential there are few comprehensive studies analysing large landslides on volcano flanks, and the mechanisms of such mass movements are not yet resolved. Within the last few years, several hypotheses concerning the potential causes of volcanic landslides have been proposed including processes such as dike intrusion, volcanic spreading, hydrothermal alteration, seismic shocks and caldera collapse events.
Tenerife exhibits three large subaerial valleys originated by giant flank failures with ages ranging from Upper Pliocene to Middle Pleistocene. The northern submarine flank of the island is characterised by a voluminous apron of landslide debris. The La Orotava valley has been selected for analysis due to the amount of available data concerning its structure and evolution, and has been used as a test site to validate new assumptions that could be applied to other volcanic areas.
The site investigation has revealed that the present morphology of the La Orotava valley was formed by two different failures: one in the western sector and the other in the eastern sector. The mechanical stability of the preslide volcano flank was strongly reduced by geologic, morphologic, climatic and volcanological factors which play a fundamental role in the initiation of the landslides. Widespread residual soils (paleosols) might have acted as potential slip surfaces, while deep erosive canyons probably evolved into the lateral limits of the failures. A high coastal cliff and a humid climate have also contributed to the critical stability conditions. The location of the landslide amphitheatre is perpendicular to the active Dorsal rift zone and adjacent to the Las Cañadas caldera, both important influences on the stability of the volcano slopes. On Tenerife, the relationship between large volcanic landslides and vertical caldera collapses is supported by a temporal coincidence of at least two failures with caldera collapse events.
The mechanical behaviour of a residual soil sampled in the La Orotava valley has been analysed. Red coloured residual soils are generally located at the top of phonolitic pyroclastic deposits and are proposed as potential slip surfaces due to their very weak behaviour and their flat, homogeneous characteristics. They represent the only planar surface within the succession making up the volcano slopes. Their weak mechanical behaviour is characterised by volumetric collapse during shearing, a substantial reduction of shear strength for high normal stresses, and a significant increase of pore water pressure during undrained loading. The last feature is fundamental to the stability of volcano flanks since it strongly reduces the soil strength. Earthquakes, common processes in active volcanic areas, and saturated conditions can generate high excess pore pressures indicating the importance of regional climate and seismicity.
The stability analysis has considered three different mechanisms: 1) ground acceleration due to seismicity - including both tectonic earthquakes and volcano-tectonic seismic shocks produced by caldera collapse; 2) horizontal stress due to dike intrusion, and; 3) vertical shear stress due to caldera collapse. The results indicate that ground acceleration principally decreases the mechanical stability of volcano flanks, enabling failure. Horizontal stresses due to dike intrusion can also influence slope stability, but preferably act as a preparing factor destabilising the slope, and not as a final triggering mechanism. The 3D numerical simulations show the significant effect of deeply incised canyons creating high shear stress at their base.
Applying the results to the La Orotava events, the following scenario is assumed: First, deep narrow canyons, weak residual soils, humid climate, coastal cliff and persistent dike intrusion have significantly reduced the mechanical stability of the volcano slope and determined the limits of the failing mass. Then, seismicity generated by the caldera collapse episode at the end of the Guajara cycle at ~0.56 Ma triggered the catastrophic landslides.
The results of the mobility analysis show the important influence of water on the runout distances of landslides. Subaqueous drag forces reduce the velocity, while hydroplaning effects strongly increase the runout distance. For Tenerife, the model indicates that a sliding mass can advance great distances, tens of kilometres away from the island, at water depths exceeding 3000 m, as can be observed in the bathymetric data.

Style APA, Harvard, Vancouver, ISO itp.

32

Nicodemo, Gianfranco. "Vulnerability analysis of buildings in areas affected by slow-moving landslides and subsidence phenomena". Doctoral thesis, Universita degli studi di Salerno, 2017. http://hdl.handle.net/10556/2623.

Pełny tekst źródła

Streszczenie:

2015 - 2016
Slow-moving landslides and subsidence phenomena yearly induce huge damages both direct (on structures and/or infrastructures with them interacting) and indirect (corresponding to the associated economic losses). For this reason, studies aimed at analyzing and predicting the aforementioned damages are of great interest for Scientific Community and Authorities in charge of identifying the most suitable strategies for the land-use planning and management of urban areas affected by slowmoving landslides and subsidence phenomena. However, carrying out the activities related to the pursuit of those goals is not straightforward since it usually requires high costs due to the great amount of data to be collected for setting up reliable forecasting models as well as the development of proper procedures that take into account i) the identification and quantification of the exposed elements; ii) the definition and estimation of an intensity parameter; iii) the prediction of the damage severity level (generally associated with the attainment of a certain limit state). In this PhD Thesis some original procedures are proposed. In particular, on the basis of empirical and numerical methods, fragility and vulnerability curves are generated in order to predict the damage to buildings in subsidence- and slow-moving landslide-affected areas. The proposed empirical procedures, based on the joint use of DInSAR data (provided from the processing of images acquired by Synthetic Aperture Radar via Differential Interferometric techniques) and information on damages suffered by buildings (recorded and classified during in situ surveys), were tested on case studies in The Netherlands, affected by subsidence phenomena, and in Calabria Region (southern Italy) for slow-moving landslide-affected areas. The procedure based on the adoption of a numerical method was applied on a structural model representative of a single building. With reference to subsidence phenomena, the analyses were carried out for a densely urbanized municipality following a multi-scale approach. In particular, at medium scale, the subsiding areas that are most prone to ground surface settlements along with their spatial distribution and rates, were preliminarily detected. The above ground surface settlements (here considered as subsidence intensity parameter) combined with the results of an extensive damage survey on masonry buildings, allowed first retrieving, at large-scale (on building aggregates) and at detailed scale (on single buildings), the relationships between cause (settlements/differential settlements) and effect (damage severity level); then, empirical fragility curves were generated for structurally independent single buildings. These latter were validated via their comparison with fragility curves generated, with reference to two others densely urbanized municipalities, for buildings with similar structural typology (masonry) and foundation type (shallow or deep). Finally, fragility and vulnerability curves for masonry buildings were generated by using the entire database of damages. As for slow-moving landslides, the analyses were carried out at large scale. In particular, the joint use of DInSAR and damage surveys data allowed analyzing the consequences induced on the buildings (either of masonry or reinforced concrete) with shallow foundations by retrieving the causeeffect relationships and generating empirical fragility and vulnerability curves. Finally, the numerical analyses carried out on a structural model representative of a single masonry building, allowed to go in-depth in the different aspects contributing to the onset and development of building damages as well as to quantify the uncertainties inherent to the addressed issue. The obtained results highlight the huge potential of the fragility and vulnerability curves generated according to the proposed procedures that, once further calibrated/validated and jointly used with a continuous monitoring of the intensity parameter via conventional (e.g., inclinometers, GPS, topographic leveling) and/or innovative (e.g., SAR images processed via DInSAR techniques) systems, can be valuably used as tools for the analysis and prediction of the damage to buildings for land-use planning and urban management purposes in subsidence- and slow-moving landslide-affected areas. [edited by author]
Le frane a cinematica lenta e i fenomeni di subsidenza causano annualmente ingenti danni sia diretti (su strutture e/o infrastrutture con essi interagenti) che indiretti (quali si configurano le associate perdite di natura economica). Per tale ragione, gli studi volti ad analizzare e a prevedere i predetti danni sono di indubbio interesse per le Comunità e gli Enti impegnati nella individuazione delle più idonee strategie di pianificazione e di gestione delle aree urbanizzate affette dai suddetti fenomeni. Tuttavia, lo svolgimento delle attività connesse al perseguimento dei predetti obiettivi è tutt’altro che agevole in quanto richiede costi elevati, dovuti alla grande quantità di dati da acquisire per la generazione di modelli previsionali affidabili, nonché lo sviluppo di procedure che contemplino i) l’identificazione e la quantificazione degli elementi esposti, ii) la definizione e la stima di un parametro di intensità e iii) la previsione del livello di severità del danno (generalmente associato al raggiungimento di uno stato limite). La presente Tesi di Dottorato propone alcune procedure originali che, sulla base di metodi empirici e numerici, conducono alla generazione di curve di fragilità e vulnerabilità quali strumenti di previsione del danno a edifici in aree affette da frane a cinematica lenta e fenomeni di subsidenza. Le procedure empiriche proposte, basate sull’integrazione congiunta di dati DInSAR (ovvero derivanti dalla elaborazione di immagini acquisite da radar ad apertura sintetica montati su piattaforme satellitari mediante tecniche interferometriche differenziali) e sul danno subito da edifici (a sua volta classificato sulla base degli esiti di rilievi in sito dei quadri fessurativi esibiti dalle facciate), sono state testate con riferimento a casi di studio dei Paesi Bassi, affetti da fenomeni di subsidenza, e della Regione Calabria (Italia meridionale), interessati da frane a cinematica lenta. La procedura basata sull’impiego di metodi numerici è stata, invece, applicata su un modello strutturale rappresentativo di un edificio singolo. Con riferimento ai fenomeni di subsidenza, le attività svolte con un approccio multi-scalare hanno consentito preliminarmente di rilevare (a media scala) le aree che risultano essere maggiormente predisposte a cedimenti dovuti a fenomeni di subsidenza. La conoscenza della distribuzione spaziale e della entità di tali cedimenti è stata, poi, combinata con i risultati di un esteso rilievo del danno agli edifici in muratura di un’area comunale in modo da i) risalire – sia a grande scala (su aggregati di edifici) che a scala di dettaglio (singoli edifici) – alle relazioni funzionali che si stabiliscono tra causa (cedimenti assoluti/differenziali) ed effetti (livello di severità del danno) e ii) generare per singoli edifici strutturalmente indipendenti curve di fragilità su base empirica. Le curve di fragilità così calibrate sono state, poi, validate operandone un confronto con curve di fragilità generate, con la medesima procedura, per altre due aree comunali caratterizzate dalla presenza di edifici con la stessa tipologia strutturale e fondale (superficiale o profonda). Si è, infine, provveduto alla generazione di curve di fragilità e di vulnerabilità di edifici in muratura utilizzando l’intero campione di dati a disposizione. Per quanto riguarda le frane a cinematica lenta, le analisi sono state svolte esclusivamente a grande scala, dove l’uso congiunto dei dati DInSAR e del rilievo del danno a edifici in cemento armato e in muratura con fondazioni superficiali ha consentito, ancora una volta, di risalire alle relazioni causa-effetto e di generare curve di fragilità e di vulnerabilità su base empirica. Infine, l’analisi numerica effettuata su un modello strutturale rappresentativo di un singolo edificio in muratura con fondazioni superficiali ha consentito di approfondire il ruolo esercitato da alcuni fattori nella generazione e nello sviluppo del danno nonché di quantificare le incertezze che intervengono nel problema esaminato. I risultati ottenuti evidenziano l’enorme potenzialità delle curve di fragilità e vulnerabilità ottenute che, laddove ulteriormente calibrate e validate, possono essere impiegate congiuntamente con tecniche di monitoraggio in continuo dei parametri d’intensità – sia di tipo convenzionale (quali, ad esempio, inclinometri, GPS, livellazione topografica) che innovative (come quelle derivanti dall’elaborazione di immagini satellitari mediante tecniche DInSAR) – per la messa a punto di modelli previsionali utili alla pianificazione territoriale e alla gestione di aree urbane affette da frane a cinematica lenta e fenomeni di subsidenza. [a cura dell'autore]
XV n.s.

Style APA, Harvard, Vancouver, ISO itp.

33

Arena, Livia. "Analysis of DInSAR data in urban areas affected by subsidence or slow-moving landslides". Doctoral thesis, Universita degli studi di Salerno, 2014. http://hdl.handle.net/10556/1770.

Pełny tekst źródła

Streszczenie:

2012 - 2013
Subsidence and slow-moving landslides systematically cause social, economic and environmental impacts all over the world. For this reason studies aimed at both the characterization of subsidence and slow-moving landslides and the analysis of the consequences on the exposed elements interacting with them are of great interest for the scientific and the technical community. These studies, to be useful in land use planning and management, need a huge number of displacement measurements within and on the boundary of the affected areas. Recently the scientific community has shownan increasing interest in the potential of using satellite observation techniques and, in particular, interferometric methods of Synthetic Aperture Radar (DInSAR)image processing. The literature review on DInSAR applications highlights the possibility of further researches pursuing the exploitation of DInSAR potentiality in studies at different scales and the development of procedures for the proper use of interferometric data and their validation with reference to well documented case studies. To this end, this PhD Thesis is aimed at developing original procedures for the analysis of the interferometric measurements specifically devotedto pursue two main objectives: the characterization of the phenomena of interest and the prediction of consequences to buildings interacting with them. The conceived procedures were tested, in sample areas of the Campania region (southern Italy)following a multi-scale approach. With reference to subsidence phenomena, the studies at small-scale involved the entire region and were mainly aimedatdetecting subsiding macro-areas; within these latter, more detailed studies at medium scale were carried out and the most affected municipalities were individuated. At large scale,focusing on one of these municipalities, studies dealing with the analysis of parameters whose variation leadsto the generation of the damage were carried out. Finally, at the scale of the single building the interferometric data were interpretedaccording todamageability criteria adopted in engineering practice. As forslow-moving landslides, the joint use of interferometric measurements and damage surveysallowed the updating of landslide inventory maps at medium scale and the analysis of the consequencesthrough the generation of fragility and vulnerability curves within a test area including 21 municipalities of BeneventoProvince. At large-scale studies were performed on a landslide-affected area within the municipality of Ascea(Salerno Province) in order to follow the evolution - in space and time - of the analyzed phenomenon as well as to deepen its kinematic behavior, in turn useful for zoning purposes. The obtained results highlight that the conceived procedures can valuably integrate the current practice for land use planning and as well as for the selection of the most suitablemanagement strategy.
XII n.s.

Style APA, Harvard, Vancouver, ISO itp.

34

Leung, Tsui-shan. "A functional analysis of GIS for slope management in Hong Kong /". Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22032447.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

35

Bergvall, Jacob, i Louise Svensson. "Risk analysis review". Thesis, Linköpings universitet, Institutionen för datavetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119379.

Pełny tekst źródła

Streszczenie:

The risk analysis process is the foundation of creating secure systems. An accurate and well defined risk analysis will therefore be a big help for any company, indicating what resources are needed and where they should be put to use. It can be difficult to know which risk analysis methodology to use given a set of parameters such as available resources, time, money etc. In this review we will introduce several different risk analysis methodologies and classify them using our risk analysis classification system. Our classification points out some of the pros and cons for each method, making it easier to choose the one best suited for a specific scenario. We will also connect the presented methods with real-world usage of said methods. To do this we have conducted interviews with IT-security experts at several major companies and we will present previous documented usage of risk analysis methods. Larger companies tend to develop their own methods for risk analysis, and smaller companies that do not have enough time or resources to develop their own methods are more likely to use already existing methods. With that said we believe that anyone that works with risk analysis could have use of our review.

Style APA, Harvard, Vancouver, ISO itp.

36

Payne, Brad. "Project risk analysis". Thesis, Nottingham Trent University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263943.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

37

Liwång, Hans, Jonas W. Ringsberg i Martin Norsell. "Quantitative risk analysis : Ship security analysis for effective risk control options". Försvarshögskolan, Militärtekniska avdelningen (MTA), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-3800.

Pełny tekst źródła

Streszczenie:

This study reviews ship security assessment. The objectives are to explore the possibilities for quantifying and performing a more thorough ship security risk analysis than that described in the International Ship and Port Facility Security code and to evaluate to what extent this more detailed analysis increases ship security and facilitate the effective selection of risk control options. The study focuses on Somali-based maritime piracy, using piracy on the Indian Ocean as a case study. Data are collected using questionnaires and interviews with civilian and military security experts who possess firsthand experience of piracy off the coast of Somalia. The data are collected specifically for this study and describe and quantify the threat’s capability, intent and likelihood of exploiting a ship’s vulnerability. Based on the collected description of the threat, the study analyzes and describes: probability of detection by pirates, probability of successful approach, and probability of successful boarding. The performed work shows good agreement between calculated probabilities and frequencies in the cited incident reports. Also, the developed scenarios describe the most important influences on the analyzed areas. The research therefore shows that the proposed risk-based approach, which uses structurally collected and documented information on the threat, can increase ship security by assisting in selecting risk control options. The approach also allows for a better understanding of the causal relationship between threat and risk than that provided in today’s security analysis by ship owners, for example. This understanding is crucial to choosing effective and robust risk control options.

Style APA, Harvard, Vancouver, ISO itp.

38

Ravindran, Sinnappoo. "Analysis and prediction of rainfall-induced shallow landslides along the road corridors in northern New South Wales, Australia". Thesis, Griffith University, 2021. http://hdl.handle.net/10072/402732.

Pełny tekst źródła

Streszczenie:

Globally, landslides have occurred regularly and caused massive destruction with numerous loss of life. Although they may result from earthquakes, geological factors and human activities, landslides are mostly caused by heavy or prolonged rainfall. Furthermore, research indicates that rainfall-induced landslides are primarily responsible for landslides that occur on mountainous terrains. Some of the worst rainfall-induced landslides across the world which caused loss of life and destruction of property and infrastructure, occurred in Nepal in 1926, 1988 and 2009; in Thailand in 2008; in India in 2009 and in Japan in 2012. Thredbo landslide occurred in southern region of New South Wales (NSW), Australia in 1997, killed 18 people, destroyed two lodges and moved over 1000 tonnes of liquefied earth and debris over slope. The cause of this landslide was heavy rainfall, melting snow and leaking water pipeline. In northern NSW, many roads were closed for weeks and months due to rainfall-induced landslides from 2009 till 2019. Waterfall Way leading to Dorrigo Mountain from Raleigh was closed in 2009 (3 times), 2011, 2013, 2015, 2017 & 2019 and the road users have to travel more than three hours on alternative routes to reach the other side of the Dorrigo Mountain. Gwydir Highway at Gibraltar Range was closed in 2011 and 2013; Oxley Highway at Mt Seaview was closed in 2011 and 2013. Summerland Way at Mt Lindesay was closed in 2011 and 2017 and Bruxner Highway at Mallanganee Range was closed in 2011, 2013 and 2015. Road closures make inconvenience to the road users impacting access, work travel, school travel, medical travel and long-distance travel and there are economic consequences as well. There were over 100 landslides occurred along the state road corridors in northern region of NSW, Australia, since 2009 till 2019. Rainfall events triggered about 80% of landslides in northern NSW. Rainfall-induced landslides occur in this region in every two years according to historical records from 2009. Mountain passes such as Mt Seaview, Dorrigo Mountain, Gibraltar Range, Ramornie – Cangai Bluff, Mallanganee Range and Mt Lindesay are adversely affected by rainfall-induced landslides. Therefore, there are economic and social needs to address root causes of rainfall-induced landslides along the road corridors. Despite the common occurrences of rainfall-induced landslides in the Australian region of northern New South Wales (NSW), there has been no study conducted on this phenomenon for this region. This thesis conducts a comprehensive analysis of shallow landslide events that occurred along the road corridors in northern New South Wales (NSW) throughout the period of 2009 - 2019. Furthermore, this thesis employs the analysis to prognosticate future patterns of rainfall-induced shallow landslides for this region. The scope of this thesis includes analysis of rainfall-induced shallow landslides occurred in coarse-grained soils, prediction of shear strength of coarse-grained soils using soil suction and prediction of rainfall-induced shallow landslides using different approaches such as rainfall threshold, rainfall index and limit equilibrium method in northern NSW. It involves developing a relationship among rainfall characteristics, soil characteristics and slope characteristics. The study found out that when moisture content of soil is increased, there is a reduction in matric suction and thereby a decrease in shear strength. It also revealed that slopes consist of coarse-grained soils are vulnerable to rainfall-induced landslides. The slopes consist of sedimentary rocks and igneous rocks at mountain passes are vulnerable to landslides. The slopes are susceptible to rainfall-induced shallow landsides when the slope angle is greater than 25 degrees. The key benefit of this thesis is that government, road authorities and industry can use the simple tools that can predict rainfall-induced shallow landslides in northern NSW. These simple tools include rainfall threshold, rainfall index and the SLIP model that are specifically developed for northern NSW. The findings are also useful for management of road corridor and slopes in the mountain passes. This study presents the major factors that lead to shallow rainfall-induced landslides in northern NSW and proposes simple tools that can be used to predict this natural disaster. It is believed that these findings will be useful for the relevant industry including decision-makers who manage the slope assets and landslide hazard along the road corridors in northern NSW, Australia. These findings are also applicable to other parts of the world.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text

Style APA, Harvard, Vancouver, ISO itp.

39

Samtani, Nareshkumar Chandan. "Constitutive modeling and finite element analysis of slowly moving landslides using hierarchical viscoplastic material model". Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185374.

Pełny tekst źródła

Streszczenie:

The prediction of motion of slowly moving landslides, also referred to as creeping slopes, is important for the reduction of landslide hazards. Such continuous and slowly moving landslides do not represent the usual stability problems of geotechnical analysis because these slopes are neither still nor ruptured but they move. For proper modeling of the motion of landslides, it is essential to develop improved techniques that integrate appropriate modeling of geological materials involved, laboratory and field tests, and verifications using computational methods. This dissertation focusses attention on the development of such an appropriate model for the time-dependent behavior of creeping landslides. Based on field observations it is proposed that the phenomenon of creeping landslides can be considered as involving the motion of a large mass of soil over a parent (fixed) mass with pronounced shear deformations occuring in a thin layer between the moving mass and the parent mass. The thin layer is refered to as interface zone while the overlying mass is refered to as solid body. The generalized Hierarchical Single Surface (HiSS) series of plasticity models are adopted to characterize the solid body. The interface zone is modeled using the specialization of the HiSS models for conditions occuring in the thin layer. Time dependency is introduced in constitutive models by adopting Perzyna's elastoviscoplastic formulation. The parameters for the HiSS and interface models are determined from laboratory tests on soils obtained from an actual slowly moving landslide at Villarbeney in Switzerland. Triaxial tests along various stress paths and oedemeter tests are conducted for the solid body. New analytical solutions are derived for prediction of oedometer tests. A general procedure for determination of viscous parameters is developed and techniques to process raw creep test data are proposed. Novel and representative simple shear interface tests are conducted to find parameters for the interface model. Special techniques for experimental analysis have been developed. A modified interface model to simulate the observed phenomenon of only compaction under shear is proposed. The parameters for the constitutive models are verified by numerically backpredicting experimental tests. An existing finite element code has been modified to incorporate various aspects of the small strain elastoviscoplastic formulation. Field measurements in the form of inclinometer profiles at various borehole locations on Villarbeney landslide are available. These inclinometer profiles are predicted using the proposed model. A comparison of the field measurements and the results from finite element analysis shows that such a model can be successfully used for predicting the behavior of slowly moving landslides.

Style APA, Harvard, Vancouver, ISO itp.

40

Zhang, Minhao. "Managerial perception of supply chain quality risk : risk analysis and decision analysis". Thesis, University of York, 2017. http://etheses.whiterose.ac.uk/20715/.

Pełny tekst źródła

Streszczenie:

Due to increased supply chain complexity, ensuring the quality of supply materials or products from upstream suppliers has become a challenge for firms. A great deal has been written on possible solutions and strategies to deal with supply chain quality risk (SCQR) in recent years. However, the manager’s decision-making process in relation to SCQR has not been fully researched. To close this gap, the aims of this study were to scrutinise managers’ perceptions of SCQR, as well as the antecedents of and decision-making related to perceived SCQR. The relevant literature was comprehensively reviewed in order to build a foundation for the conceptualisation of perceived SCQR. This study proposed that the managerial perception of SCQR was a multi-dimensional concept with four representations. A rigorous scale development process was adopted to develop a set of reliable instruments to measure perceived SCQR. With a sample of 316 Chinese manufacturers, the validity and reliability of the measurement scales for the representations of SCQR perception were assessed. Based on the risky-decision making model, a theoretical framework of the managerial decision-making process in relation to perceived SCQR was proposed. Furthermore, the agency theory and resource dependence theory were drawn on to identify factors related to the supply chain relationship and supply chain quality barriers that might have effects on three of the representations of SCQR. Based on the resource dependence theory, it was found that buyer and supplier dependence affect the representations of SCQR differently. The empirical results indicate that the inability to test and inability to trace are significant drivers of the perception of SCQR. The representation of SCQR impact on the intention of adopting two oriented quality management practices was also examined. The result reveals that when managers face increasing SCQR, they tend to be conservative in applying the quality management practices.

Style APA, Harvard, Vancouver, ISO itp.

41

Penha, Ricardo Miguel do Brito. "Default risk : analysis of a credit risk model". Master's thesis, Instituto Superior de Economia e Gestão, 2016. http://hdl.handle.net/10400.5/12902.

Pełny tekst źródła

Streszczenie:

Mestrado em Ciências Actuariais
Uma parte considerável do negócio bancário inclui naturalmente o empréstimo de dinheiro. Inerentemente, o risco de não receber de volta o montante emprestado é assumido pela instituição bancária. Neste trabalho, o risco de incumprimento é estudado através da função de distribuição das perdas agregadas. Depois de feita a ponte entre as características de uma carteira de empréstimos de um banco e as características de uma carteira de apólices de seguros vida, os resultados da Teoria de Risco podem ser aplicados à carteira em estudo. O CreditRisk+, geralmente classificado como o modelo actuarial, é um modelo de risco de crédito que tem por base esta ponte. Para aplicação deste modelo, é necessária informação relativa às probabilidades de incumprimento de cada devedor e a exposição ao risco, que no nosso caso é igual ao montante em dívida. Na primeira parte deste trabalho é estimada a probabilidade de incumprimento através de um modelo logit, tendo em conta alguns indicadores financeiros da empresa. Seguidamente, no contexto de um modelo de risco coletivo, é aplicado o método iterativo de Panjer. Seguindo a metodologia proposta pelo modelo CreditRisk+, a carteira é seguidamente dividida em setores e, em cada setor, é introduzida volatilidade à probabilidade de incumprimento. No final, conclui-se que conseguem ser obtidos resultados semelhantes utilizando métodos de aproximação menos dispendiosos, nomeadamente com a aproximação NP. Finalmente, a taxa de juro média que o banco deveria aplicar aos empréstimos em carteira é calculada, assim como a reserva que deveria ter sido constituída.
A considerable part of the banking business includes the lending of money. Inherently, a bank incurs the risk of not receiving back the money lent. In this work, default risk is studied through the distribution function of the aggregate losses. After making the link between the characteristics of a portfolio of loans and of a life insurance policies portfolio, Risk Theory results are applied to the portfolio of loans under study. CreditRisk+, usually classified as the actuarial model, is a credit risk model which uses this link. As an input to this model, both the individual probabilities of default for each obligor and the exposure at risk are needed. The first part of this work focus on the estimation of the probability of default through a logit model, taking into account some financial indicators of the company. Then, in the context of a collective risk model, Panjer?s recursive algorithm is applied. Following the methodology of CreditRisk+, the portfolio is then divided into sectors and default volatility is introduced in each sector, reaching a different aggregate loss distribution function. At the end, we find that similar results are obtained with less time consuming approximation methods, particularly with NP approximation. Finally, the average interest rate that the bank should have charged to the loans in the portfolio is found as well as the amount of money that should have been reserved to account for losses.
info:eu-repo/semantics/publishedVersion

Style APA, Harvard, Vancouver, ISO itp.

42

Duplantis, Serin. "Landslide Inventory Mapping and Dating using LiDAR-Based Imagery and Statistical Comparison Techniques in Milo McIver State Park, Clackamas County, Oregon". PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/271.

Pełny tekst źródła

Streszczenie:

A landslide inventory was conducted for the Redland and Estacada Quadrangles of western Oregon using LiDAR DEMs. Many of these landslides were field verified. In total, 957 landslides were mapped using LiDAR whereas previously, only 228 landslides were believed to exist in the study area based on SLIDO information. In Milo McIver State Park, 41 landslides were mapped using LiDAR. SLIDO indicated only three landslides present within the park. A sequence of seven terraces of the Clackamas River is mapped in Milo McIver State Park. Landslides in the park predominantly occur between these terraces. Soils studied from representative areas within landslide complexes and terrace surfaces help to formulate a soil chronosequence for the study area. The youngest soils, Entisols, develop in less than 1,600 years, Inceptisols between 1,600-10,000 years, and the oldest soils, Alfisols, develop in at least 10,000 years. Classifications of soil profiles netted ten Alfisols (mainly on upper terraces), 49 Inceptisols, and 20 Entisols (reactivated slides in the complexes). The soils are predominantly ML soils and have Loam and Silt Loam textures. Results of spectral analysis, carried out on the LiDAR DEMs, indicate that the spectral character of landslides changes with age. However, applying statistical tools such as the Kolmogorov-Smirnov test (K-S test) and cluster analysis suggest that it is not possible to use spectral analysis to determine the relative age of failed surfaces. The K-S test showed that the spectral character among landslides varies widely. Cluster analysis resulted groupings not based on age or terrain type. The result of the cluster analysis illustrates that it may not be realistic to use a single cutoff, which separates failed terrain from unfailed, in the spectral distributions to analyze an entire region. In all, the results of the spectral analysis were not conclusive. Individual landslides, not complexes, should be used in future studies, since complexes have slides that are continually reactivating. The landslides were also too young to display very much differentiation in age based on soils and spectral analysis. Essentially, a similar study should be conducted using individual landslides with a large age range for more conclusive results.

Style APA, Harvard, Vancouver, ISO itp.

43

Burden, Justin Matthewson. "Development and implementation of a limit equilibrium procedure for the three-dimensional analysis of asymmetric landslides". Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/43891.

Pełny tekst źródła

Streszczenie:

Two-dimensional limit equilibrium types of analysis have been used in engineering practice for decades and are the most commonly adopted analysis technique for assessing the stability of slopes. These methods compute a factor of safety based on a comparison of available to required shear strength along a prescribed failure surface. Forces and static equilibrium conditions are only considered in the plane of movement. However, in reality, all slope failures occur in three-dimensions. Every sliding mass has a finite length and shear forces acting at the lateral extents of the mass contribute to the resistance to movement. Errors introduced by neglecting the three-dimensional character of a slide cannot be overlooked in all cases. Examples include deep narrow excavations, convex/concave slope geometries, slopes that fail by narrow localized failure and structurally controlled failures in rock. Consideration of threedimensional effects may be of particular importance where computed two-dimensional factors of safety are marginal or when back-analyzing slope failures where derived shear strengths should reflect the influence of end effects. This thesis details the development, implementation and evaluation of a general limit equilibrium method of columns procedure suitable for analyzing the three-dimensional stability of asymmetric landslides. The proposed method, termed the three-dimensional asymmetric Spencer method, uses internal force functions to satisfy the equilibrium conditions. Unlike many of its predecessors, the algorithm satisfies force and moment equilibrium in both horizontal directions. The direction of sliding is not assumed, but rather determined explicitly in the analysis. The solution scheme is implemented in the computer program J3D. A moment balancing procedure is developed and used to investigate the effect of enforcing moment equilibrium about a vertical axis of rotation on the analysis results. Analyses completed using J3D are compared with solutions derived using existing limit equilibrium methods and three-dimensional distinct element models for several asymmetric slide examples, including the Kettleman Hills Landfill case history. Preliminary results indicate that the three-dimensional asymmetric Spencer method is well suited for the analysis of general slope stability cases, including asymmetric problems. Application of the proposed moment balancing algorithm may only be suitable for problems involving specialized slope and slip surface geometries.

Style APA, Harvard, Vancouver, ISO itp.

44

Booth, Adam, i Adam Booth. "The Role of Deep-Seated Landslides in Landscape Evolution: Quantitative Modeling and High-Resolution Topographic Analysis". Thesis, University of Oregon, 2012. http://hdl.handle.net/1794/12534.

Pełny tekst źródła

Streszczenie:

In many mountainous settings, landslides are the primary geomorphic agent that sets fundamental landscape characteristics, such as topographic relief and catchment-averaged erosion rate. The coupled system of landslides and other geomorphic processes responds to changes in climatic or tectonic forcing, but few studies have addressed these responses quantitatively, especially in terrain prone to deep-seated landslides (those thicker than the upper layer of soil). This study quantifies the topographic expressions and mechanics of deep-seated landslides using a combination of high-resolution topographic data and mathematical modeling. I first demonstrate that deep-seated landslides distinguish themselves from surrounding terrain by generating meter spatial scale surface roughness associated with gradients in strain rate of the deforming material. These methods are capable of mapping landslides with more than 80% accuracy in three study sites throughout the Pacific Northwest, United States. At longer, kilometer scale spatial wavelengths analysis of slope and drainage area data shows that landslides lengthen hillslopes and reduce ridge top elevations to leave their signature on the topography. I then develop and implement a mathematical landscape evolution model including a novel treatment of deep-seated landslide flux to simulate landslides at these longer spatial scales. The model generates topographic profiles for two different bedrock types in agreement with those observed in a study area in the Eel River catchment, California, United States. The sediment fluxes required to produce these profiles are in agreement with independently estimated modern rates. Two-dimensional simulations constrain two essential geomorphic conditions at which landslides occur. First, there must be pre-existing pockets of deep weathering, which allow landslides to erode large volumes of material at rates that episodically exceed the long term average erosion rate. Second, the characteristic time scale for landslide processes must be shorter than the time scales associated with both soil creep and river incision. As the landslide time scale shortens, landslides systematically reduce hillslope relief and increase valley spacing to reduce the mean topographic gradient. This dissertation therefore improves the objectivity of analyzing landslide-prone terrain and provides a framework for rigorously interpreting landscape response to changing climatic and tectonic forcing. This dissertation includes both previously published and co-authored material.

Style APA, Harvard, Vancouver, ISO itp.

45

Andereck, Zachary Dean. "Mapping Vulnerability of Infrastructure to Destruction by Slope Failures on the Island of Dominica, WI: A Case Study of Grand Fond, Petite Soufriere, and Mourne Jaune". Oxford, Ohio : Miami University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1173454439.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

46

劉岫雲. "Model Development for Spatial Risk Analysis with Application to Lishan Landslides". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/65800000450416797127.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

47

Hazzard, Jennifer. "Risk analysis of landslides affecting major transportation corridors in southwestern British Columbia". Thesis, 1998. http://hdl.handle.net/2429/8933.

Pełny tekst źródła

Streszczenie:

Slope failures on transportation routes can kill or injure motorists, derail trains, damage vehicles, roads and railways, delay traffic, and incur expense to transportation authorities. In southwestern British Columbia, Highways 1 and 99, the British Columbia Railway, the Canadian National Railway, and the Canadian Pacific Railway all traverse mountainous terrain, and as a result are susceptible to a variety of slope hazards. By quantitatively estimating risk at various areas along a transportation route, high-risk areas can be identified, risks can be compared with values accepted by society, remedial programs can be more effectively designed, and their success can be monitored. A database of 3287 slope failure records was compiled for the five routes mentioned above. Of these, 1764 records include volume estimates. The effects of data censoring were reduced by examining spatial and temporal patterns in landslide reporting for failures of different magnitudes on various sections of each route. Magnitude-cumulative frequency relationships were plotted for both rock falls and debris flows on each route. The rock fall relationships each display a power-law distribution for events greater than 1 m³, and are very similar in form over several orders of magnitude. Geological conditions along the routes influence the slope of the magnitude-cumulative frequency slopes. Risk of death due to slope failure on several route segments was calculated using the magnitude-frequency relationships. The estimates of annual probability of death due to rock fall range from 0.008 to 0.10, and are below the upper limits of several risk acceptability criteria. Debris flow risk estimates are less reliable, due to the limited data set. The greatest contribution to risk to life is generally from intermediate rock falls in the Fraser Canyon (1 to 10 m³), and larger rock falls in Howe Sound and the Fraser Lowland (100 to 1000 m³).

Style APA, Harvard, Vancouver, ISO itp.

48

Ering, Pinom. "Methodologies for Risk Assessment of Landslides Induced by Rainfall and Earthquake". Thesis, 2019. https://etd.iisc.ac.in/handle/2005/4944.

Pełny tekst źródła

Streszczenie:

Landslide is one of the greatest natural catastrophes and poses a major threat to lives and property worldwide. As development expands into unstable hill areas under the pressure of increasing population and urbanisation, the risk of landslide has been growing all over the world during the last decades. The present work aims at risk analysis of landslides in an effort to reduce the socio-economic impact of landslides and to mitigate the landslide risk effectively. The risk analysis of landslides is neither simple nor straightforward as the effects of different triggering factors have to be analyzed individually and managed separately. In this view, landslide risk analysis requires a detailed understanding of the physical process of landslides and the development of different methodologies to relate landslide occurrences with the characteristics of triggering factors. Rainfall and earthquakes are considered as the most common triggering factors for landslides. Due to the contrast in the characteristics of rainfall and earthquake loads, and their subsequent effects on the landslide movements, the evaluation of landslide risk by a single methodology becomes difficult, if not impossible. The present study introduces methods for risk analysis of landslides due to rainfall as well as earthquake events. These methods recognize the conditions that caused the slope to become unstable and the processes that triggered the landslide movement. Often landslides occur due to the combination of rainfall and earthquake events as the probability of concurrent rainfall and earthquake event in any area is not rare. Consequently, it is essential to evaluate the landslide risk by considering the unfortunate combination of independent events such as rainfalls and earthquakes, and the effects of their mutual interactions on landslide movements. Therefore, for regions prone to both earthquake and heavy rainfall events, risk analysis should take into consideration multiple processes rather than one single event to avoid underestimation of the threats caused by their potential interaction. Understanding the interaction of these events can form the basis and provide a rational approach for multi-hazard risk assessment. The methodologies developed in the present work aims to provide systematic and rigorous processes to formalize slope engineering practice and enhance slope management. Uncertainty is implicit in almost every field of engineering. In geotechnical engineering, the uncertainty is mainly attributed to inherent or spatial variability of soil parameters, limited number of samples, testing and measurement errors, and the modelling techniques which relate the laboratory or in-situ properties with response characteristics in terms of stability and deformation behaviour of soil. Unless all the sources of uncertainty are clearly brought out and included in the risk analysis appropriately, it is not possible to explicitly assess the risk associated with landslides. To this end, probabilistic methods which have the potential to include the spatial and temporal variability of different components should be incorporated in the risk analysis of landslides. The need for sophisticated probabilistic methods for landslide risk analysis arises from the complex response of slopes to external loads and the uncertainties in material properties. Random field theory is employed to model the inherent spatial variability prevalent in naturally occurring soils. While the spatial variation of earthquake ground motions is modelled using the random process concepts. The probabilistic methods have the ability to identify mechanisms responsible for the occurrence of landslides while incorporating uncertainties in the analysis. The present study also addresses the challenging issue of numerical simulation of large deformation problems in geomechanics. Material Point Method (MPM), which is a mesh-based particle method, is employed to simulate large deformations occurring in landslides. MPM simulates large displacement with Lagrangian material points moving through a fixed Eulerian mesh. MPM has been employed in the thesis to study the behaviour of saturated slopes under seismic excitation. Documentation of the past landslide events provides the opportunity to advance the research and practice of landslide risk analysis and also in the development of techniques for slope remediation. In general, the timely collection of data from landslide sites is a challenging problem but very important for landslide risk analysis. The present study introduces a systematic framework which aims at timely and systematic collection of data from landslide affected areas. It also updates the information on strength parameters and other conditions existing in the slope after the landslide event based on an inverse analysis. Overall, it is expected that the work reported in the thesis will furnish useful guidelines for 1) risk analysis of landslides due to rainfall, earthquake and the coalescence of rainfall and earthquake events 2) modelling the various sources of uncertainty in landslide problems 3) modelling large deformations which occur during landslide events, particularly landslides of flow types 4) collection of timely and systematic data of landslide events.

Style APA, Harvard, Vancouver, ISO itp.

49

TSAI, CHING-YA, i 蔡靜雅. "Apply Statistical Analyses with GIS to Assess Risk of Rainfall-induced Landslides". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/st6bv5.

Pełny tekst źródła

Streszczenie:

碩士
長榮大學
土地管理與開發學系碩士班
107
Taiwan has the largest area on the slopeland, and the recent extreme weather events caused by climate anomalies have increased the number of storms that hit Taiwan every year, and it is prone to large-scale landslides and debris flows. According to the report, the settlements in the remote mountainous areas of South Taiwan account for about 24% of the total Taiwan. In recent years, large-scale sediment disasters caused by typhoon rainfall have mostly concentrated in the remote mountainous areas of southern Taiwan, which poses a great threat to the environmental security of mountain settlements. Therefore, it is necessary to conduct risk analysis and discussion on remote mountainous areas in southern Taiwan. This study takes Sandimen Township and Wutai Township of Pingtung County as the research scope, and selects the Formosat II and SPOT-5 satellite images before and after four typhoon rainfalls in 2009 and 2013. Using the random trees classifier of ArcGIS platform and the texture analysis of ERDAS IMAGINE, the interpretation of the image is used to capture the surface changes and disaster information, and then analyze the slope disturbance. The product of the effective cumulative rainfall and the maximum three-hour rolling rainfall intensity was selected as the index of rainfall triggering (IRT). Index of slope environmental strength potential (ISESP) was established by using the Logistic regression model for the selected natural environmental factors and the slope disturbance degree. The relationship between IRT and ISESP was explored, and then analyze the hazard caused by rainfall induced landslides was analyzed. This study uses local surveys, questionnaire interviews, and government publicly available materials to establish the impact factors of disaster risk such as space impact, temporal impact, and disaster tolerance. According to the vulnerability factor, the vulnerability analysis of the disaster risk is estimated by factor analysis. Finally, the rainfall-induced landslide risk assessment model is established, and the disaster risk zoning of the settlement is carried out. The results of the image interpretation show that the Kappa index of the consistency coefficient averages about 0.71, which is the accuracy of the medium-high. By comparing the differences in satellite imagery before and after the rain event, the landslide area caused by Typhoon Morakot was the largest, followed by 0517 rainfall, Typhoon Kongrey and Typhoon Soulik. Based on the logistic regression analysis of the slope environmental strength potential, the overall accuracy rate is about 80%. When ISESP is fixed, the larger the IRT, the greater the damage caused by rainfall-induced landslide; vice versa. In addition, the research results of landslide risk distribution matched with historical sloping disaster points. Most of the disaster points are above the medium to medium-high risk, representing the risk map of this study is reasonable. The results of the settlement risk assessment show that the risk of disasters in the study area increases with the increase of rainfall. Among them, the Dashe and Dawu tribes are the clusters of high risk.

Style APA, Harvard, Vancouver, ISO itp.

50

Teng-ChiehHsu i 許登傑. "Study on Risk Analysis of Large Scale Landslide". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7x5m53.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Rozprawy doktorskie na temat „Risk analysis of landslides”

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych