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1.
Abu Muhammad Shajaat Ali 《Natural Hazards》2007,40(1):89-111
This paper examines the nature and causes of September 2004 hazardous flood that affected the dry and drought prone southwestern
region of Bangladesh. It also examines human perception of this new hazard and their methods of adjustments to its negative
impacts. Field research for this study includes personal interviews of 453 victim families living in four thanas (lowest administrative
units) in Jessore and Satkhira districts of southwestern Bangladesh. Findings of the study suggest that all victim respondents
viewed this flood event as a natural hazard, which has caused severe damage to standing crops, fish ponds, permanent trees
and homesteads, and deteriorated human health and sanitation conditions. Its long-term impacts on fish farming, soil quality
degradation, as well as changing land use/land coverage are also noteworthy but yet to be adequately explored. Both perceived
and scientific causes of this flood event include high rainfall for a week before the flood, unusual movement of low pressure
system into the affected area, cloudy weather and low evaporation, siltation of the regional riverbeds, and rolling back of
the Ganges River water through the Ichamati and Bhagirati rivers. These factors also caused hazardous flooding at the same
time in the Ichamati and Bhagirati Rivers and their floodplains in the West Bengal province of India. To release the overflow
of flood water inside India, the Indian border patrol breached the Ichamati river embankment in several places along Satkhira
and Jessore international border which had aggravated the flood situation in the study area. 相似文献
2.
3.
Salvatore Alparone Daniele Andronico Tiziana Sgroi Ferruccio Ferrari Luigi Lodato Danilo Reitano 《Natural Hazards》2007,43(3):333-350
Volcanic eruptions may create a wide range of risks in inhabited areas and, as a consequence, major economic damage to the
surrounding territory. An example of volcanic hazard was given between 1998 and 2001 by Mt. Etna volcano, in Italy, with its
frequent paroxysmal explosive activity that caused more than a hundred fire-fountain episodes. In the period January–June
2000, in particular, 64 lava fountains took place at the Southeast Crater. During the most intense explosive phase of each
episode, a sustained column often formed, reaching up to 6 km above the eruptive vent. Then, the column started to expand
laterally causing more or less copious tephra fallout on the slopes of Etna; ash and lapilli, therefore, constituted a serious
danger for vehicular and air traffic. A software and hardware warning system was developed to mitigate the volcanic hazard
indicating the areas affected by potential ash and lapilli fallout. The alert system was mainly based on the good correspondence
between the pattern of volcanic tremor amplitude and the evolution of explosive activity. When a fixed tremor threshold was
exceeded, a semiautomatic process started to send faxes to Civil Defence and Municipalities directly affected by tephra fallout,
together with information on wind directions from the Meteorological Office. The application of this methodology, during the
last 14 eruptive episodes in 2000 and the 14 events occurred in 2001, demonstrated the good correspondence between the forecasts
on the areas affected by tephra fallout and the effective tephra distribution on land. Despite the integrity of the performance
provided by the alert system, small discrepancies occurred in the technical procedure of alerting, for which possible solutions
have been discussed. The improvement of this type of system, could become basic for the Etnean region and be proposed for
similar volcanic areas throughout the world. 相似文献
4.
Volcanic hazards to airports 总被引：3，自引：1，他引：2
Marianne Guffanti Gari C. Mayberry Thomas J. Casadevall Richard Wunderman 《Natural Hazards》2009,51(2):287-302
Volcanic activity has caused significant hazards to numerous airports worldwide, with local to far-ranging effects on travelers and commerce. Analysis of a new compilation of incidents of airports impacted by volcanic activity from 1944 through 2006 reveals that, at a minimum, 101 airports in 28 countries were affected on 171 occasions by eruptions at 46 volcanoes. Since 1980, five airports per year on average have been affected by volcanic activity, which indicates that volcanic hazards to airports are not rare on a worldwide basis. The main hazard to airports is ashfall, with accumulations of only a few millimeters sufficient to force temporary closures of some airports. A substantial portion of incidents has been caused by ash in airspace in the vicinity of airports, without accumulation of ash on the ground. On a few occasions, airports have been impacted by hazards other than ash (pyroclastic flow, lava flow, gas emission, and phreatic explosion). Several airports have been affected repeatedly by volcanic hazards. Four airports have been affected the most often and likely will continue to be among the most vulnerable owing to continued nearby volcanic activity: Fontanarossa International Airport in Catania, Italy; Ted Stevens Anchorage International Airport in Alaska, USA; Mariscal Sucre International Airport in Quito, Ecuador; and Tokua Airport in Kokopo, Papua New Guinea. The USA has the most airports affected by volcanic activity (17) on the most occasions (33) and hosts the second highest number of volcanoes that have caused the disruptions (5, after Indonesia with 7). One-fifth of the affected airports are within 30 km of the source volcanoes, approximately half are located within 150 km of the source volcanoes, and about three-quarters are within 300 km; nearly one-fifth are located more than 500 km away from the source volcanoes. The volcanoes that have caused the most impacts are Soufriere Hills on the island of Montserrat in the British West Indies, Tungurahua in Ecuador, Mt. Etna in Italy, Rabaul caldera in Papua New Guinea, Mt. Spurr and Mt. St. Helens in the USA, Ruapehu in New Zealand, Mt. Pinatubo in the Philippines, and Anatahan in the Commonwealth of the Northern Mariana Islands (part of the USA). Ten countries—USA, Indonesia, Ecuador, Papua New Guinea, Italy, New Zealand, Philippines, Mexico, Japan, and United Kingdom—have the highest volcanic hazard and/or vulnerability measures for airports. The adverse impacts of volcanic eruptions on airports can be mitigated by preparedness and forewarning. Methods that have been used to forewarn airports of volcanic activity include real-time detection of explosive volcanic activity, forecasts of ash dispersion and deposition, and detection of approaching ash clouds using ground-based Doppler radar. Given the demonstrated vulnerability of airports to disruption from volcanic activity, at-risk airports should develop operational plans for ashfall events, and volcano-monitoring agencies should provide timely forewarning of imminent volcanic-ash hazards directly to airport operators. 相似文献
5.
José Fernando Aceves Quesada Ana Lillian Martin Del Pozzo Jorge López Blanco 《Natural Hazards》2007,41(1):159-180
Nevado de Toluca Volcano (NTV), located in central Mexico, is a large stratovolcano, with an explosive history. The area is
one of the most important developing centers (>2 millions) in Mexico and in the last 30 yrs large population growth and expansion
have increased the potential risk in case of a reactivation of the volcano. As part of a study to assess volcanic risk, this
paper presents the results of the volcanic hazard analysis for the NTV. A total of 150 stratigraphic sections were made in
the field and three new ages were obtained. Eruptions from NTV produced a complex sequence of pyroclastic deposits that have
affected the area at least 18 times during the last 100,000 yrs. Eight vulcanian, four plinian and one-ultraplinian eruptions
as well as the destruction of at least three domes occurred in the last 42,000 yr BP as well as two sector collapses in the
last 100,000 yrs. Isopach and isopleth maps for the main ulraplinian eruption were also made. The original cone height (5,080 m.a.s.l)
was reconstructed through geomorphologic methods. The maximum distance calculated with the energy line for the block and ash
flows was 41 km, 35 km for pumice flows and 45 km for debris avalanches. The dominant wind direction at altitudes of 20–30 km
is to the east-northeast from November to March, west-northwest in April and west from May to October. Five hazards maps (block
and ash flows, pumice flows, ash fall, debris avalanches, and lahars) were made for the NTV. The pyroclastic flows and lahars
represent very high to medium hazard for Toluca, Villa Guerrero, Coatepec, Tianguistengo, Metepec, Tenango, Lerma and Zinacantepec.
A new debris avalanche would probably affect the south and northeast because of active faulting (E–W and NW–SE) and existing
topographic differences in height. 相似文献
6.
GIS and Volcanic Risk Management 总被引：7，自引：0，他引：7
Volcanic catastrophes constitute a majorproblem in many developing and developed countries. Inrecent years population growth and the expansion ofsettlements and basic supply lines (e.g., water, gas,etc.) have greatly increased the impact of volcanicdisasters. Correct land-use planning is fundamental inminimising both loss of life and damage to property.In this contribution Geographical Information Systems(GIS), linked with remote sensing technology andtelecommunications/warning systems, have emerged asone of the most promising tools to support thedecision-making process. Some GIS are presented fortwo volcanic areas in Italy, Mt. Etna and Vesuvius.GIS role in risk management is then discussed, keepingin mind the different volcanic scenarios of effusiveand explosive phenomena. Mt. Etna system covers alarge area (more than 1,000 km2) potentiallyaffected by effusive phenomena (lava flows) whichcause damage to both houses and properties in general.No risk to life is expected. The time-scales of lavaflows allow, at least in principle, modification ofthe lava path by the building of artificial barriers.Vesuvius shows typically an explosive behaviour. Inthe case of a medium size explosive eruption, 600,000people would potentially have to be evacuated from anarea of about 200 km2 around the Volcano, sincethey are exposed to ruinous, very fast phenomena likepyroclastic surges and flows, lahars, ash fallout,etc. Ash fallout and floods/lahars are also expectedin distal areas, between Vesuvius and Avellino,downwind of the volcano. GIS include digital elevationmodels, satellite images, volcanic hazard maps andvector data on natural and artificial features (energysupply lines, strategic buildings, roads, railways,etc.). The nature and the level of detail in the twodata bases are different, on the basis of thedifferent expected volcanic phenomena. The GIS havebeen planned: (a) for volcanic risk mitigation (hazard,value, vulnerability and risk map assessing), (b) toprovide suitable tools during an impending crisis, (c)to provide a basis for emergency plans. 相似文献
7.
Probability-weighted hazard maps for comparing different flood risk management strategies: a case study 总被引：5，自引：1，他引：4
Giuliano Di Baldassarre Attilio Castellarin Alberto Montanari Armando Brath 《Natural Hazards》2009,50(3):479-496
The study proposes an original methodology for producing probability-weighted hazard maps based on an ensemble of numerical
simulations. These maps enable one to compare different strategies for flood risk management. The methodology was applied
over a 270-km2 flood-prone area close to the left levee system of a 28-km reach of the river Reno (Northern Central Italy). This reach is
characterised by the presence of a weir that allows controlled flooding of a large flood-prone area during major events. The
proposed probability-weighted hazard maps can be used to evaluate how a structural measure such as the mentioned weir alters
the spatial variability of flood hazard in the study area. This article shows an application by constructing two different
flood hazard maps: a first one which neglects the presence of the weir using a regular levee system instead, and a second
one that reflects the actual geometry with the weir. Flood hazard maps were generated by combining the results of several
inundation scenarios, simulated by coupling 1D- and 2D-hydrodynamic models. 相似文献
8.
The production of flood hazard assessment maps is an important component of flood risk assessment. This study analyses flood hazard using flood mark data. The chosen case study is the 2013 flood event in Quang Nam, Vietnam. The impacts of this event included 17 deaths, 230 injuries, 91,739 flooded properties, 11,530 ha of submerged and damaged agricultural land, 85,080 animals killed and widespread damage to roads, canals, dykes and embankments. The flood mark data include flood depth and flood duration. Analytic hierarchy process method is used to assess the criteria and sub-criteria of the flood hazard. The weights of criteria and sub-criteria are generated based on the judgements of decision-makers using this method. This assessment is combined into a single map using weighted linear combination, integrated with GIS to produce a flood hazard map. Previous research has usually not considered flood duration in flood hazard assessment maps. This factor has a rather strong influence on the livelihood of local communities in Quang Nam, with most agricultural land within the floodplain. A more comprehensive flood hazard assessment mapping process, with the additional consideration of flood duration, can make a significant contribution to flood risk management activities in Vietnam. 相似文献
9.
The frequency in occurrence and severity of floods has increased globally. However, many regions around the globe, especially in developing countries, lack the necessary field monitoring data to characterize flood hazard risk. This paper puts forward methodology for developing flood hazard maps that define flood hazard risk, using a remote sensing and GIS-based flood hazard index (FHI), for the Nyamwamba watershed in western Uganda. The FHI was compiled using analytical hierarchy process and considered slope, flow accumulation, drainage network density, distance from drainage channel, geology, land use/cover and rainfall intensity as the flood causative factors. These factors were derived from Landsat, SRTM and PERSIANN remote sensing data products, except for geology that requires field data. The resultant composite FHI yielded a flood hazard map pointing out that over 11 and 18% of the study area was very highly and highly susceptible to flooding, respectively, while the remaining area ranged from medium to very low risk. The resulting flood hazard map was further verified using inundation area of a historical flood event in the study area. The proposed methodology was effective in producing a flood hazard map at the watershed local scale, in a data-scarce region, useful in devising flood mitigation measures. 相似文献
10.
P. W. Webley K. Dean R. Peterson A. Steffke M. Harrild J. Groves 《Natural Hazards》2012,61(2):661-671
Over the last 40 years, there have been numerous volcanic eruptions across the North Pacific (NOPAC) region that posed a potential
threat to both local communities and transcontinental aircraft. The ability to detect these volcanic clouds using satellite
remote sensing and predict their movement by dispersion modeling is a major component of hazard mitigation. The Puff volcanic
ash transport and dispersion model, used by the Alaska Volcano Observatory, was used to illustrate the impact that these volcanic
ash clouds have made across the NOPAC and entire Polar region over the past 40 years. Nearly, 400 separate ash clouds were
analyzed that were either reported or detected to have reached above 6 km (20,000 ft) above sea level, an average of one ash
cloud every 1.25 months. Particular events showed that ash clouds can be tracked from Alaska to Greenland (Crater Peak, Mount
Spurr in 1992), from Kamchatka to Alaska (Kluvicheskoi Volcano in 1994), from Alaska to California (Mount Cleveland Volcano
in 2001) and from multiple events within 1 day (Mount Augustine Volcano in 2006). This study showed the vast number of events
that have impacted this Polar region and how tracking them is useful for hazard mitigation. 相似文献
11.
We present a 3-D Poisson model that permits identification and quantification of volcanic phenomena distributed through space and evolving in time (i.e., spatiotemporal data). Specifically, the model: (1) is volcanologically informative in solving problems of volcanic risk/hazard which depends on the location and time of future events; (2) contains model fitting computation algorithms that are efficient; and (3) is flexible enough to handle a large class of volcanic risk/hazard studies. Furthermore, we apply the model fitting techniques developed in this paper to the volcanic data from the Yucca Mountain project to demonstrate a unified volcanic hazard analysis. This study also evaluates the sensitivity of the statistical models developed by experts who have addressed the volcanic hazard/risk assessment problem near the Yucca Mountain region. 相似文献
12.
Ibidun O. Adelekan 《Natural Hazards》2011,56(1):215-231
The paper presents the result of a vulnerability assessment of urban dwellers to a major flood hazard in Abeokuta, southwestern
Nigeria in July 2007. This was achieved by means of questionnaire survey administered to 248 flood area residents. Flood vulnerability
was assessed by examining exposure, susceptibility, and coping indicators in the study area. Findings of the study show that
although about 50% of respondents had experienced floods, in Abeokuta or elsewhere in the past, majority (66%) did not anticipate
a flood event of such magnitude to occur despite its location on a flood plain and, therefore, were unprepared for such hazard.
Pre-warning of the flood event was generally lacking among flood area residents as only 8% of respondents indicated pre-warning,
which was based on personal observations. Response to the flood hazard was mainly reactive for both private and public agents
as flood risk reduction measures were not in place. 相似文献
13.
Application of Remote Sensing in Flood Management with Special Reference to Monsoon Asia: A Review 总被引：4，自引：1，他引：4
The conventional means to record hydrological parameters of aflood often fail to record an extreme event. Remote sensingtechnology along with geographic information system (GIS)has become the key tool for flood monitoring in recent years.Development in this field has evolved from optical to radarremote sensing, which has provided all weather capabilitycompared to the optical sensors for the purpose of flood mapping.The central focus in this field revolves around delineation of floodzones and preparation of flood hazard maps for the vulnerable areas.In this exercise flood depth is considered crucial for flood hazardmapping and a digital elevation model (DEM) is considered to bethe most effective means to estimate flood depth from remotelysensed or hydrological data. In a flat terrain accuracy of floodestimation depends primarily on the resolution of the DEM. Riverflooding in the developing countries of monsoon Asia is very acutebecause of their heavy dependence on agriculture but any floodestimation or hazard mapping attempt in this region is handicappedby poor availability of high resolution DEMs. This paper presents areview of application of remote sensing and GIS in flood managementwith particular focus on the developing countries of Asia. 相似文献
14.
Flood Hazard Assessment for a Hyper-Tidal Estuary as a Function of Tide-Surge-Morphology Interaction 总被引：1，自引：0，他引：1
Charlotte Lyddon Jennifer M. Brown Nicoletta Leonardi Andrew J. Plater 《Estuaries and Coasts》2018,41(6):1565-1586
Astronomical high tides and meteorological storm surges present a combined flood hazard to communities and infrastructure. There is a need to incorporate the impact of tide-surge interaction and the spatial and temporal variability of the combined flood hazard in flood risk assessments, especially in hyper-tidal estuaries where the consequences of tide and storm surge concurrence can be catastrophic. Delft3D-FLOW is used to assess up-estuary variability in extreme water levels for a range of historical events of different severity within the Severn Estuary, southwest England as an example. The influence of the following on flood hazard is investigated: (i) event severity, (ii) timing of the peak of a storm surge relative to tidal high water and (iii) the temporal distribution of the storm surge component (here in termed the surge skewness). Results show when modelling a local area event severity is most important control on flood hazard. Tide-surge concurrence increases flood hazard throughout the estuary. Positive surge skewness can result in a greater variability of extreme water levels and residual surge component, the effects of which are magnified up-estuary by estuarine geometry to exacerbate flood hazard. The concepts and methodology shown here can be applied to other estuaries worldwide. 相似文献
15.
流域暴雨山洪过程时空异质性强,准确评估雨洪变化特性和洪水危险性对山洪灾害防治具有重要意义。以7个降雨特征指标和6个洪水特征指标刻画流域场次雨洪特性,采用中国山洪水文模型和洪水频率指标相结合,模拟和评估口前流域洪水过程及其危险性。结果表明：场次洪水洪峰模数、洪峰时间偏度、高脉冲历时占比、涨落洪速率与降雨总量、平均雨量、最大雨强、雨峰位置系数、基尼系数等降雨特征指标显著相关,三场致灾洪水过程的降雨均呈现量级大、强度大、历时短、暴雨中心偏中下游的特点;率定期和验证期的平均径流深相对误差均在9%以内,平均洪峰流量相对误差均在11%以内,平均峰现时间误差均在1.7 h以内,平均Nash-Sutcliffe系数为0.80和0.76;各场次洪水有0.0%～93.3%的河段流量达到一般危险及以上等级,三场致灾洪水过程的危险性等级最高,分别有80.0%、35.0%和1.7%的小流域河段流量达到高危险及以上等级。研究可为山区小流域暴雨洪水危险性评估、灾害响应和复盘等提供技术支撑。 相似文献
16.
J. McPhie 《Australian Journal of Earth Sciences》2013,60(4):417-433
The Hianana Volcanics consist of bedded tuff and dacitic lava that form a locally mappable unit within the extensive, Late Permian silicic volcanic sequence of northeastern New South Wales. Principal components of the bedded tuff are crystal and volcanic lithic fragments ranging from coarse ash to lapilli, accompanied by variable amounts of fine ash matrix. Well denned plane parallel thin bedding is characteristic. Sandwave bed forms, including low‐angle cross‐beds and wavy beds, are confined to an area of 2–3 km2 coinciding with the thickest sections (70 m) of bedded tuff. A high‐aspect ratio flow of porphyritic dacitic lava overlies the bedded tuff in the same area. The setting, lithofacies, extent and geometry of the bedded tuffs of the Hianana Volcanics are comparable with modern tuff rings which are composed of the deposits from base surges generated by explosive phreatomagmatic eruptions at primary volcanic vents. Many of these have also discharged lava late in their activity. Proximal parts of the Hianana tuff ring were buried by the porphyritic lava after the phreatomagmatic eruptions had ceased. In more distal sections, the bedded tuff is less than 10 m thick and dominantly comprises fine grained, plane parallel, very thin beds and laminae; these features suggest an origin by fallout from ash clouds that accompanied the phreatomagmatic eruptions. The distal ash was covered and preserved from erosion by a layer of welded ignimbrite, the source of which is unknown. 相似文献
17.
18.
Rocco Custer Kazuyoshi Nishijima 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2018,12(1):1-13
In natural hazard risk assessment situations are encountered where information on the portfolio of exposure is only available in a spatially aggregated form, hindering a precise risk assessment. Recourse might be found in the spatial disaggregation of the portfolio of exposure to the resolution of the hazard model. Given the uncertainty inherent to any disaggregation, it is argued that the disaggregation should be performed probabilistically. In this paper, a methodology for probabilistic disaggregation of spatially aggregated values is presented. The methodology is exemplified with the disaggregation of a portfolio of buildings in two communes in Switzerland and the results are compared to sample observations. The relevance of probabilistic disaggregation uncertainty in natural hazard risk assessment is illustrated with the example of a simple flood risk assessment. 相似文献
19.
An interdisciplinary approach is necessary for flood risk assessment. Questions are often raised about which factors should
be considered important in assessing the flood risk in an area and how to quantify these factors. This article defines and
quantitatively evaluates the flood risk factors that would affect the Day River Flood Diversion Area in the context of integrated
flood management in the Red River Delta, Vietnam. Expert analysis, in conjunction with field survey and Analytical Hierarchy
Process (AHP), is applied to define and quantify parameters (indicators, subcomponents, and components) that contribute to
flood risk. Flood duration is found to be the most prominent indicator in determining flood hazard. Residential buildings,
population, and pollution are other fairly significant indicators contributing to flood vulnerability from the economic, social,
and environmental perspectives, respectively. The study results will be useful in developing comprehensive flood risk maps
for policy-makers and responsible authorities. Besides, local residents will also be able to implement suitable measures for
reducing flood risk in the study area. 相似文献
20.
This paper illustrates the development of flood hazard and risk maps in Greater Dhaka of Bangladesh using geoinformatics. Multi-temporal RADARSAT SAR and GIS data were employed to delineate flood hazard and risk areas for the 1998 historical flood. Flood-affected frequency and flood depth were estimated from multi-date SAR data and considered as hydrologic parameters for the evaluation of flood hazard. Using land-cover, gemorphic units and elevation data as thematic components, flood hazard maps were created by considering the interactive effect of flood frequency and flood water depth concurrently. Analysis revealed that a major portion of Greater Dhaka was exposed to high to very high hazard zones while a smaller portion (2.72%) was free from the potential flood hazard. Flood risk map according to administrative division showed that 75.35% of Greater Dhaka was within medium to very high risk areas of which 53.39% of areas are believed to be fully urbanized by the year 2010. 相似文献