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1.
Despite the recognition of the need for mitigation approaches to landslide risk in developing countries, the delivery of ‘on-the-ground’
measures is rarely undertaken. With respect to other ‘natural’ hazards, it is widely reported that mitigation can pay. However,
the lack of such an evidence base in relation to landslides in developing countries hinders advocacy amongst decision makers
for expenditure on ex-ante measures. This research addresses these limitations directly by developing and applying an integrated
risk assessment and cost–benefit analysis of physical landslide mitigation measures implemented in an unplanned community
in the Eastern Caribbean. In order to quantify the level of landslide risk reduction achieved, landslide hazard and vulnerability
were modelled (before and after the intervention), and project costs, direct and indirect benefits were monetised. It is shown
that the probability of landslide occurrence has been substantially reduced by implementing surface-water drainage measures
and that the benefits of the project outweigh the costs by a ratio of 2.7–1. This paper adds to the evidence base that ‘mitigation
pays’ with respect to landslide risk in the most vulnerable communities—thus strengthening the argument for ex-ante measures.
This integrated project evaluation methodology should be suitable for adoption as part of the community-based landslide mitigation
project cycle, and it is hoped that this resource, and the results of this study, will stimulate further such programmes. 相似文献
2.
Soil properties of major landslides that occurred recently on the mid-altitude slopes of Mount Elgon, eastern Uganda were
analysed. A mudflow, located at the Kitati protected forest site, and two deep debris flows on the Nametsi and Buwabwala deforested
steep slopes (36°–58°) were surveyed. In order to test the hypothesis that ‘soils at the landslide sites are particularly
‘problem soils’ and thus prone to landslides’, the following analyses were undertaken: particle size distribution, Atterberg
limits, shear strength and factor of safety (F s). Soils at the Kitati and Buwabwala sites exhibited expansive potential, owing to clay contents well above 20%. A clay content
exceeding 32% was identified at the Nametsi debris flow site implying an extremely high expansive potential of the soil. High
liquid limits (LLs) at Kitati (59%) and Buwabwala (53%) meant that the soils qualified as vertisols susceptible to landslides.
High plasticity indices (PIs) (averaging 33%) also confirmed the vertic nature of soils at the Nametsi debris flow site. Whereas
the value of F
s
< 1 for the Kitati site signifies an inherently unstable slope, Nametsi and Buwabwala are supposedly stable slopes ( F
s
> 1). Despite this finding, the stable sites could be described as only conditionally stable because of the interplay of
various physical, pedological and anthropogenic factors. The results point to the fact that soils at the landslide sites are
inherently ‘problem soils’ where slope failure can occur even without human intervention. Therefore, the hypothesis that soils
at three landslide sites are inherently ‘problem soils’ and prone to landslides, is accepted. 相似文献
3.
The climatic condition of Western Ghats has influenced the process of weathering and landslides in this mountainous tract
along the southwest coast of India. During the monsoon period, landslides are a common in the Western Ghats, and its intensity
depends upon the thickness of the loose unconsolidated soil formed by the process of weathering. Debris landslides with a
combination of saprock, saprolite and soil, indicate the role of weathering in landslide occurrences. This paper reports on
how the weathering in the windward slope of Western Ghats influences the occurrence of landslides and the factors which accelerate
the weathering process. Rock and soil samples were collected from the weathering profile of hornblende gniess and granite
gneiss. The chemical analysis and the calculated Chemical Index of Alteration (CIA) indicate the significant weathering and
its possible influence on landslide occurrences in the study area. Mainly, the CIA value of lateritic soil and forest loam
indicated the extent of high chemical weathering in this region. Rainfall is the dominant parameter influencing the chemical
weathering process. In addition, deforestation, land use practices and soil erosion are some of the other important factors
accelerating the weathering process and landslide occurrences in the region. The locations of the previous landslides superimposed
on geology and soil show that most of the landslide occurrences are associated with the highly weathered zone, particularly
lateritic soil and the ‘severe’ (rock outcrop) erodability zone. 相似文献
4.
This paper examines the possible storm surge damage from a major hurricane to hit the Houston Metropolitan Statistical Area
(MSA.) Using storm surge analysis on a unique data set compiled from the Texas Workforce Commission (QCEW), the paper estimates
the expected industry-level damage for each county in the Houston MSA. The advantages of using GIS to analyze the expected
storm surge damage estimation is that it provides an accurate estimation of the number of affected employees and probable
wages losses, by industry and county, based on QCEW data. The results indicate that the ‘Basic Chemical Manufacturing’ and
‘Oil and Gas Extraction’ industries incur the highest employee and payroll losses while the ‘Restaurants and Eateries’ has
the largest establishment damage if a major hurricane were to hit the Houston MSA. 相似文献
5.
Landslide inventories are essential because they provide the basis for predictive landslide hazard and susceptibility assessments and because they allow for the manipulation and storage of temporal and spatial data. The National Landslide Database has been developed by the British Geological Survey (BGS). It is the most extensive source of information on landslides in Great Britain with over 15,000 records of landslide events each documented as fully as possible. This information is invaluable for planners and developers as it helps them investigate, avoid or mitigate areas of unstable ground in accordance with Government planning policy guidelines. Therefore, it is vital that the continual verification, collection and updating of landslide information is carried out as part of the Survey’s ‘National Capability’ work. This paper describes the evolution from a static database to one that is continually updated forming part of a suite of national digital hazard products. The history of the National Landslide Database and associated Geographical Information System (GIS) is discussed, together with its application and future development. 相似文献
6.
This paper addresses the temporal variation of rainfall-triggered landslide hazard within the broader context of natural risk
evolution. Analysis of a sequence of aerial photos covering a period of 60 years allowed the establishment of a record of
landsliding for a site in the Wellington region, New Zealand. The data show one very dominant peak in the magnitude of landslide
occurrence in the late 1970s, followed by a continuous decrease. Landslide hazard can be expressed by the frequency and magnitude
of the landslide events, with the total surface area affected used as a surrogate for magnitude. However, the distinct decline
of landslide magnitude through time from the 1980s onwards indicates that landslide hazard may change with time. This possibility
is further explored by correlating potential landslide triggering storms with the magnitude of the landslide event, using
the ‘Antecedent Soil Water Status’ model in combination with daily rainfall. The relation between magnitudes of rainfall and
magnitudes of landslide events is found to be weak, suggesting that a given ‘Critical Water Content’ (antecedent soil water
status and rainfall on the day) does not produce similar magnitudes of landsliding. Furthermore, the study shows that reactivation
of previous landslides before the peak landslide occurrence of the late 1970s is low, while the situation is reversed after
this peak and reactivation in the subsequent years plays a larger role. It is concluded that the pattern of landsliding cannot
be explained by the pattern of rainfall and other factors are controlling the variation of landslide hazard in time. A possible
explanation is a change of the geomorphological system with time, instigated by a massive period of landsliding (the late
1970s peak). Subsequent sediment exhaustion of source areas resulting from this period appears to alter the system’s subsequent
reaction to an external trigger such as rainfall. The study demonstrates that landslide hazard analysis in general should
not rely on the integral of the frequency–magnitude relationship only, but should include potential non-linear changes of
system settings to increase the understanding of future system behaviour, and therefore hazard and risk.
相似文献
7.
This paper evaluates the impact of recent shifts in the geopolitical outlook of the United States—specifically the ‘Global
War on Terror’ and its domestic ramifications—on the prior project of reconfiguring the US state to an after-Fordist ‘workfare’
paradigm. In particular, the paper attempts to situate recent developments in the reconfiguration of the American welfare
state within the context of debates over the ‘exceptional’ nature of US politics post-9/11. The extent to which this has had
a bearing on work practices, welfare provision and workfarism is investigated, citing examples from the post-9/11 era. On
the basis of such examples it has been suggested that the project of reconfiguring the US welfare state and labour relations
does overlap and intersect with the emergency practices that the US state has instituted domestically as part of the War on
Terror. However, the reconfiguration of the US welfare state towards a neoliberal or workfarist paradigm is, we argue, largely
part of the ‘normal’ (as opposed to exceptional) fabric of US politics. The project of reconfiguring the US welfare state
is ongoing and largely autonomous (although not entirely removed) from the use of exceptional practices in relation to the
US security state. Investigation of this relationship, we assert, provides a potentially fruitful ‘new direction’ for both
critical geopolitics and political economic geography, and grounds for interaction between the two. 相似文献
8.
For the assessment of shallow landslides triggered by rainfall, the physically based model coupling the infinite slope stability
analysis with the hydrological modeling in nearly saturated soil has commonly been used due to its simplicity. However, in
that model the rainfall infiltration in unsaturated soil could not be reliably simulated because a linear diffusion-type Richards’
equation rather than the complete Richards’ equation was used. In addition, the effect of matric suction on the shear strength
of soil was not actually considered. Therefore, except the shallow landslide in saturated soil due to groundwater table rise,
the shallow landslide induced by the loss in unsaturated shear strength due to the dissipation of matric suction could not
be reliably assessed. In this study, a physically based model capable of assessing shallow landslides in variably saturated
soils is developed by adopting the complete Richards’ equation with the effect of slope angle in the rainfall infiltration
modeling and using the extended Mohr–Coulomb failure criterion to describe the unsaturated shear strength in the soil failure
modeling. The influence of rainfall intensity and duration on shallow landslide is investigated using the developed model.
The result shows that the rainfall intensity and duration seem to have similar influence on shallow landslides respectively
triggered by the increase of positive pore water pressure in saturated soil and induced by the dissipation of matric suction
in unsaturated soil. The rainfall duration threshold decreases with the increase in rainfall intensity, but remains constant
for large rainfall intensity. 相似文献
9.
Becoming the tallest building in the world in the mid-1990s, the Petronas Towers was the centre piece of an image of national
progress and development that Malaysian authorities sought to project internationally. The release of Fox Movies' Entrapment in Malaysia in May 1999 provoked political outrage and popular disappointment at the way in which the Petronas Towers in
Kuala Lumpur had been spliced alongside riverside ‘slums’ filmed in the town of Malacca some 150 km away. This paper provides
a critical reading of the spliced scene in the movie. At one level, the angry response of the Malaysian Prime Minister, Dr
Mahathir Mohamad, to the scene diagnoses a geopolitics of asymmetrical representational power. However, I show how Mahathir's
criticism of Entrapment in Malaysia was as much a defence of domestic political legitimacy (and national economic investibility) as it was ‘opposition’
or ‘resistance’ to hegemonic ‘Western’ (mis)representation. In addition, while the material and symbolic work of reimaging
Kuala Lumpur had sought to negate (neo)orientalist imaginings of ‘Asian’ cities, the controversial scene rendered visible
environmental ‘underdevelopment’ that has no place in a modern (vision of) Malaysia. Entrapment thus performed something in inducing Malaysian cities and citizens to ‘clean up’ their act, to practice ‘fully developed’
ways of seeing, being and being seen.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
The “PTVAM” tsunami vulnerability assessment model [Papathoma and Dominey-Howes: 2003, Nat. Hazards Earth Syst. Sci. 3, 733–744; Papathoma et al.: 2003, Nat. Hazards Earth Syst. Sci. 3, 377–389], like all models, requires validation. We use the results from post-tsunami surveys in the Maldives following the
December 26, 2004 Indian Ocean tsunami to ‘evaluate’ the appropriateness of the PTVAM attributes to understanding spatial
and temporal vulnerability to tsunami damage and loss. We find that some of the PTVAM attributes are significantly important
and others moderately important to understanding and assessing vulnerability. Some attributes require further investigation.
Based upon the ground-truth data, we make several modifications to the model framework and propose a revised version of the
PTVAM (PTVAM 2). 相似文献
11.
The subsurface Nagaur Basin in northwest Haryana and southwest Punjab hosts evaporite sequence, conformably overlain by Nagaur
red beds and grey beds. A polymictic conglomerate intervenes the Nagaur sequence and the overlying Tertiary sequence. The
focus is on the new finds of (i) distinctive ‘grey beds’ overlying ubiquitous red beds, (ii) ‘Malout conglomerate and grit’
horizon (Palaeocene-Miocene) marking an unconformity over the Nagaur Group (early Cambrian) and (iii) ‘entrapped gas and dried-up
leaves/carbonaceous flakes’ in the conglomerate unit and succeeding Tertiary rocks. Palaeoenvironmental significance has been
discussed. The Nagaur ‘red beds’ has been likened to ‘continental red beds’ of Schreiber (1978) and ‘reworked red beds’ of
Krynine (1949). The ‘grey beds’ are channel fillings, fresh material having been derived from fresh cuttings by streams/rivers
following structural grains in the Aravalli landscape where the interfluves provided weathered (oxidised) materials for the
red beds. Association of continental red beds and grey beds is known in the Newark Series (Triassic) of the Eastern United
States and the Keweenawan ‘late Precambrian’ of the Lake Superior region. 相似文献
12.
The World Landslide Forum is a triennial mainstream conference aimed at gathering scientists, stakeholders, policy makers
and industry members dealing with the management of landslide risk. The First World Landslide Forum, organised by the International
Consortium of Landslides, UNESCO, WMO, FAO, UNISDR, UNU, UNEP, IBRD, UNDP, ICSU, WFEO, KU and the Japan Landslide Society,
was held in 2008 at the United Nations University, Tokyo. The First World Landslide Forum adopted the 2008 Tokyo Declaration
‘Strengthening the International Programme on Landslides with UNISDR’. The numerous recent disasters due to landslides show
that there is an urgent need to translate science into practical applications to assist communities, governments and disaster-relief
organisations avert and mitigate future landslide disasters. For this reason, the explicit theme of the Second World Landslide
Forum, being organised for Rome, Italy, for 3–9 October 2011, is to connect landslide scientists with landslide stakeholders
in a special landslide forum to align future innovations in landslide science and technology with the future needs of humanity
and the environment. 相似文献
13.
Landslides constitute one of the most important natural hazards in Italy as they are widespread and result in considerable damage and fatalities every year. The Italian Landslide Inventory (IFFI) Project was launched in 1999 with the aim of identifying and mapping landslides over the entire Italian territory. The inventory currently holds over 480,000 landslides and has been available by means of Web services since 2005. The aim of this study is to define quality indices for evaluation of the homogeneity and completeness of the IFFI database. In order to estimate the completeness of the landslide attribute information, a heuristic approach has been used to assign weighting values to significant parameters selected from the landslide data sheet. The completeness and homogeneity of the landslide mapping has been evaluated by means of three different methods: an area-frequency distribution analysis; the proximity of the landslides surveyed to urban areas; variation of the landslide index within the same lithology. The quality indices have allowed identification of areas with a high level of completeness and critical areas in which the data collected have been underestimated or are not very accurate. The quality assessment of collected and stored data is essential in order to use the IFFI database for definition and implementation of landslide susceptibility models and for land use planning and management. 相似文献
14.
By integrating hydrological modeling with the infinite slope stability analysis, a rainfall-triggered shallow landslide model was developed by Iverson (Water Resour Res 36:1897-1910, 2000). In Iverson’s model, the infiltration capacity is assumed to be equivalent to the saturated hydraulic conductivity for finding pressure heads analytically. However, for general infiltration process, the infiltration capacity should vary with time during the period of rain, and the infiltration rate is significantly related to the variable infiltration capacity. To avoid the unrealistically high pressure heads, Iverson employed the beta-line correction by specifying that the simulated pressure heads cannot exceed those given by the beta line. In this study, the suitability of constant infiltration capacity together with the beta-line correction for hydrological modeling and landslide modeling of hillslope subjected to a rainfall is examined. By amending the boundary condition at ground surface of hillslope in Iverson’s model, the modified Iverson’s model with considering general infiltration process is developed to conduct this examination. The results show that the unrealistically high pressure heads from Iverson’s model occur due to the overestimation of infiltration rate induced from the assumption that the infiltration capacity is identical to the saturated hydraulic conductivity. Considering with the general infiltration process, the modified Iverson’s model gives acceptable results. In addition, even though the beta-line correction is applied, the Iverson’s model still produces greater simulated pressure heads and overestimates soil failure potential as compared with the modified Iverson’s model. Therefore, for assessing rainfall-triggered shallow landslide, the use of constant infiltration capacity together with the beta-line correction needs to be replaced by the consideration of general infiltration process. 相似文献
15.
This article explores whether past exposure to debris flow disasters with a human dimension (e.g. caused in part by deforestation)
results in adaptive hazard mitigation and improved environmental and resource management practices in affected areas. When
guiding hazard mitigation practice, the ‘adaptive hazard mitigation’ approach views mitigation as a multi-dimensional experiment,
with the associated need for post-experiment monitoring, evaluation, learning and adjustment, and attention paid to multiple
scales (Bogardi 2004). This article explores how the concept of ‘adaptive hazard mitigation’ has emerged, linking this ‘adaptive management’ used
increasingly in resource and environmental management. Two case studies of disasters linked to human-induced environmental
change are examined, and the mitigation responses of local communities, NGOs and Government agencies are documented. Data
sources include secondary data (journal articles, web-based disaster reports and grey literature) on each disaster, key informant
interviews ( n = 8) and direct observation over the 2005–2006 period of post-disaster mitigation actions implemented after each disaster.
The research indicates that in both case studies, a limited range of hazard mitigation actions was employed, including both
structural and non-structural approaches. However, the research also found that causal factors involving human-induced environmental
change (e.g. deforestation) were not addressed, and overall, the hazard mitigation strategies adopted lacked monitoring, learning
and adjustment. In both case studies, responses to disaster were judged to be examples of ‘trial and error’ adaptation, rather
than either ‘passive’ or ‘active’ adaptation.
相似文献
16.
This paper presents landslide susceptibility analysis around the Cameron Highlands area, Malaysia using a geographic information
system (GIS) and remote sensing techniques. Landslide locations were identified in the study area from interpretation of aerial
photographs and field surveys. Topographical, geological data and satellite images were collected, processed, and constructed
into a spatial database using GIS and image processing. Ten landslide occurrence factors were selected as: topographic slope,
topographic aspect, topographic curvature and distance from drainage, lithology and distance from lineament, soil type, rainfall,
land cover from SPOT 5 satellite images, and the vegetation index value from SPOT 5 satellite image. These factors were analyzed
using an advanced artificial neural network model to generate the landslide susceptibility map. Each factor’s weight was determined
by the back-propagation training method. Then, the landslide susceptibility indices were calculated using the trained back-propagation
weights, and finally, the landslide susceptibility map was generated using GIS tools. The results of the neural network model
suggest that the effect of topographic slope has the highest weight value (0.205) which has more than two times among the
other factors, followed by the distance from drainage (0.141) and then lithology (0.117). Landslide locations were used to
validate the results of the landslide susceptibility map, and the verification results showed 83% accuracy. The validation
results showed sufficient agreement between the computed susceptibility map and the existing data on landslide areas. 相似文献
17.
In a former industrial part of Barcelona, as in the de-industrialising neighbourhoods of many big cities, the ‘new’ economy
and the ‘cultural’ economy have started to replace the ‘old’ economy, bringing new life into a declining district but also
causing conflicts of land use, housing or the preservation of architectural heritage. The latter is an important part of regeneration
and marketing policies of city governments, whereby the ‘new’ economy not only emerges from the old but the physical space
of the old industrial quarter becomes the tool and setting in which the city can re-present itself and its success story of
transformation and regeneration. Through the increasing use of information and communication technologies, which are at the
same time driving this transformation - an industry as such as well as business-aid in various sectors, cultural industries
in particular - the city has acquired a second, virtual presence. The city exists and ‘lives’ on numerous websites. Those
by city government and city organisations often have the express purpose of marketing and presenting the city, while those
by (cultural) businesses and other organisations in the district add to the mosaic of the virtual city. As a result, the old
industrial space continues to live and be productive, its economic value having changed largely into a cultural value. This
coexistence of the real and the virtual, old and new, also meets with a conflict at certain junctures. There is the positive
representation of plans and events on the city's websites on the one hand, and the undercurrent of protest and disenchantment
among the local population who find themselves marginalised from the profits and success of development, on the other.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
The increasing availability of remotely sensed data offers a new opportunity to address landslide hazard assessment at larger
spatial scales. A prototype global satellite-based landslide hazard algorithm has been developed to identify areas that may
experience landslide activity. This system combines a calculation of static landslide susceptibility with satellite-derived
rainfall estimates and uses a threshold approach to generate a set of ‘nowcasts’ that classify potentially hazardous areas.
A recent evaluation of this algorithm framework found that while this tool represents an important first step in larger-scale
near real-time landslide hazard assessment efforts, it requires several modifications before it can be fully realized as an
operational tool. This study draws upon a prior work’s recommendations to develop a new approach for considering landslide
susceptibility and hazard at the regional scale. This case study calculates a regional susceptibility map using remotely sensed
and in situ information and a database of landslides triggered by Hurricane Mitch in 1998 over four countries in Central America.
The susceptibility map is evaluated with a regional rainfall intensity–duration triggering threshold and results are compared
with the global algorithm framework for the same event. Evaluation of this regional system suggests that this empirically
based approach provides one plausible way to approach some of the data and resolution issues identified in the global assessment.
The presented methodology is straightforward to implement, improves upon the global approach, and allows for results to be
transferable between regions. The results also highlight several remaining challenges, including the empirical nature of the
algorithm framework and adequate information for algorithm validation. Conclusions suggest that integrating additional triggering
factors such as soil moisture may help to improve algorithm performance accuracy. The regional algorithm scenario represents
an important step forward in advancing regional and global-scale landslide hazard assessment. 相似文献
19.
A loess landslide occurred in the morning of October 6, 2006, in Gaolou district of Daming town, Hua country, Shaanxi, China.
The landslide originated from a valley side slope of the loess ‘yuan’ (dissected loess plateau), below which many houses are
densely located. The displaced materials smashed several houses and killed 12 persons, after traveling down a long but gentle
valley channel. Field surveys revealed that the displaced materials were highly fluidized. Because there was no rainfall before
this event, the leakage of irrigation water from the canal on the top of the slope may be the reason for the initiation. To
investigate the possible mechanisms underlying the initiation and movement of this landslide, laboratory tests on the loess
samples from the source area were performed. Some preliminary research results are presented in this report. 相似文献
20.
Small-scale flash flood events are climate-related disasters which can put multiple aspects of the system at risk. The consequences of flash floods in densely populated cities are increasingly becoming problematic around the globe. However, they are largely ignored in disaster impact assessment studies, especially in assessing socioeconomic loss and damage, which can provide a significant insight for disaster risk reduction measures. Using a structured questionnaire survey, this study applied a statistical approach and developed a structural equation model (SEM) for assessing several socioeconomic dimensions including physical impacts, mobility disruption, lifeline facilities, health and income-related impacts. The study reveals that respondents have experienced a stronger impact on direct tangible elements such as household contents and buildings as well as direct intangible elements with β coefficients 0.703, 0.576 and 0.635, respectively, at p?<?0:001 level. The direct intangible impacts affect mobility disruption with β coefficients equal to 0.701 at p?<?0:001 level which then further cause adversity to income-generating activities with β 0.316 at significant p?<?0:001 as well. The overall model fit indices show highly acceptable scores of SRMR 0.068, RMSEA 0.055 and PClose 0.092. Thus, the SEM has successfully incorporated the socioeconomic dimensions of disaster impact and explained the impact phenomena reliably. This modeling approach will allow inclusion of various variables from different disciplines to assess hazard impact, vulnerability and resilience. 相似文献
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