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1.
《Comptes Rendus Geoscience》2008,340(9-10):644-650
The knowledge of past catastrophic events can improve flood risk mitigation policy, with a better awareness against risk. As such historical information is usually available in Europe for the past five centuries, historians are able to understand how past society dealt with flood risk, and hydrologists can include information on past floods into an adapted probabilistic framework. In France, Flood Risk Mitigation Maps are based either on the largest historical known flood event or on the 100-year flood event if it is greater. Two actions can be suggested in terms of promoting the use of historical information for flood risk management: (1) the development of a regional flood data base, with both historical and current data, in order to get a good feedback on recent events and to improve the flood risk education and awareness; (2) the commitment to keep a persistent/perennial management of a reference network of hydrometeorological observations for climate change studies. 相似文献
2.
渭干河-库车河绿洲是南疆地区主要棉花生产基地之一, 随着气候变化和棉花种植面积的日益扩大, 雹灾对棉花生产的危害日趋严重. 利用该地区4个气象站44 a逐一地面降雹过程资料和33 a灾情信息, 对冰雹时空变化特征、活动规律、强度、受灾面积和影响因素等进行研究. 结果表明: 降雹空间分布为北部靠山地带多于南部平原地带, 受灾面积的空间分布则相反; 降雹以周期短、强季节性特征为主, 各县中等以上降雹天气占80%以上, 降雹趋于高发和强发的态势. 降雹频次与气温和降水呈较好的相关性, 冰雹多发年气温偏低、降水偏多, 冰雹少发年气温偏高、降水偏少. 位于南部靠近沙漠的沙雅县受灾最为严重, 雹灾与降雹强度、地域、季节和作物面积及类型等有关, 该地区棉花受灾机率大. 相似文献
3.
The effect of undersampling on estimating the size of extreme natural hazards from historical data is examined. Tests using synthetic catalogs indicate that the tail of an empirical size distribution sampled from a pure Pareto probability distribution can range from having one-to-several unusually large events to appearing depleted, relative to the parent distribution. Both of these effects are artifacts caused by limited catalog length. It is more difficult to diagnose the artificially depleted empirical distributions, since one expects that a pure Pareto distribution is physically limited in some way. Using maximum-likelihood methods and the method of moments, we estimate the power-law exponent and the corner size parameter of tapered Pareto distributions for several natural hazard examples: tsunamis, floods, and earthquakes. Each of these examples has varying catalog lengths and measurement thresholds, relative to the largest event sizes. In many cases where there are only several orders of magnitude between the measurement threshold and the largest events, joint two-parameter estimation techniques are necessary to account for estimation dependence between the power-law scaling exponent and the corner size parameter. Results indicate that whereas the corner size parameter of a tapered Pareto distribution can be estimated, its upper confidence bound cannot be determined and the estimate itself is often unstable with time. Correspondingly, one cannot statistically reject a pure Pareto null hypothesis using natural hazard catalog data. Although physical limits to the hazard source size and attenuation mechanisms from source to site constrain the maximum hazard size, historical data alone often cannot reliably determine the corner size parameter. Probabilistic assessments incorporating theoretical constraints on source size and propagation effects are preferred over deterministic assessments of extreme natural hazards based on historical data. 相似文献
4.
1961-2014年新疆冰雹灾害时空分布特征 总被引：2，自引：0，他引：2
通过整理、 普查得到1961-2014年新疆以县为单位的雹灾频次、 受灾面积、 经济损失的样本序列, 在此基础上定义了表征雹灾程度的无量纲数损失指数. 结果表明: 新疆雹灾频次集中出现在阿克苏地区、 博州、 石河子地区, 5-8月为多发期, 6月最多. 雹灾的年际变化呈现出2～5 a的短周期和7～8 a的长周期, 20世纪60、 70年代为新疆雹灾的少发期, 1980-1994年、 2001-2014年为雹灾的两个集中高发期. 按照地区累计灾损指数将新疆雹灾划分为5个等级, 阿克苏地区属严重雹灾区, 喀什地区、 塔城地区、 伊犁州属重雹灾区, 石河子地区、 博州、 昌吉州、 巴州、 克拉玛依市属中雹灾区, 阿勒泰地区、 克州、 和田地区、 哈密地区属轻雹灾区, 吐鲁番地区和乌鲁木齐市属微雹灾区. 相似文献
5.
Dalia Bach Kirschbaum Robert Adler Yang Hong Stephanie Hill Arthur Lerner-Lam 《Natural Hazards》2010,52(3):561-575
A systematic inventory of landslide events over the globe is valuable for estimating human and economic losses, quantifying
the relationship between landslide occurrences and climate variations and for evaluating emerging global landslide prediction
efforts based on remote sensing data. This study compiles a landslide catalog for rainfall-triggered events for several years,
drawing upon news reports, scholarly articles, and other hazard databases to provide a landslide catalog at the global scale.
While this database may only represent a subset of rainfall-triggered landslides globally, due to lack of reports, it presents
a lower boundary on the number of events globally and provides initial insight into the spatiotemporal statistical trends
in landslide distribution and impact. This article develops a methodology for landslide event compilation that can be used
in evaluating global landslide forecasting initiatives and assessing patterns in landslide distribution and frequency worldwide. 相似文献
6.
7.
An integrated flood risk assessment model for property insurance industry in Taiwan 总被引：13，自引：11，他引：2
Hsu Wen-Ko Huang Pei-Chiung Chang Ching-Cheng Chen Cheng-Wu Hung Dung-Moung Chiang Wei-Ling 《Natural Hazards》2011,58(3):1295-1309
Taiwan is located in an area affected by Northwest Pacific typhoons, which are also one of the most important sources of rainfall
to the island. Unfortunately, the abundant rainfall brought by typhoons frequently produces hazards. In recent years, typhoons
and floods have caused serious damage, especially Typhoon Morakot in 2009. In this study, a probabilistic model is developed
based on historical events which can be used to assess flood risk in Taiwan. There are 4 separate modules in this model, including
a rainfall event module, a hydraulic module, a vulnerability module, and a financial loss module. Local data obtained from
the Taiwan government are used to construct this model. Historical rainfall data for typhoon and flood events that have occurred
since 1960, obtained from the Central Weather Bureau, are used for computing the maximum daily rainfall for each basin. In
addition, the latest flood maps from the Water Resources Agency are collected to assess the probable inundation depth. A case
study using the local data is carried out. Assessment is made to predict possible economic loss from different financial perspectives
such as the total loss, insured loss, and loss exceeding probabilities. The assessment results can be used as a reference
for making effective flood risk management strategies in Taiwan. 相似文献
8.
Floods in Greece, a statistical and spatial approach 总被引：4，自引：3，他引：1
Flooding is one of the most important types of disasters in southern Europe recording many victims and extended damages over the last century. The increased pressure for urban expansion together with the high population density has increased flood risk considerably in the region. Greece is not an exception in this regime, having a very rich flooding record since the ancient times. In this work, an extensive catalogue of flooding phenomena during the last 130?years in Greece has been compiled based on numerous sources. Based on this record the temporal and spatial distribution of flood events and victims was examined. In total, 545 events were identified, causing 686 human casualties and inflicting extensive damage across the country. Results showed seasonality patterns with more events clustering in November. They also showed that urban environments tend to present a higher flood recurrence rates than mountainous and rural areas. An increasing trend in reported flood event numbers during the last decades was discovered, even though the number of human casualties remains relatively stable during the same period. Moreover, spatial patterns were identified highlighting areas and administrational entities with higher flood recurrence rates across the country. 相似文献
9.
The authors show that historical property damage losses from US hurricanes contain climate signals. The methodology is based
on a statistical model that combines a specification for the number of loss events with a specification for the amount of
loss per event. Separate models are developed for annual and extreme losses. A Markov chain Monte Carlo procedure is used
to generate posterior samples from the models. Results indicate the chance of at least one loss event increases when the springtime
north–south surface pressure gradient over the North Atlantic is weaker than normal, the Atlantic ocean is warmer than normal,
El Ni?o is absent, and sunspots are few. However, given at least one loss event, the magnitude of the loss per annum is related
only to ocean temperature. The 50-year return level for a loss event is largest under a scenario featuring a warm Atlantic
Ocean, a weak North Atlantic surface pressure gradient, El Ni?o, and few sunspots. The work provides a framework for anticipating
hurricane losses on seasonal and multi-year time scales. 相似文献
10.
The 1356 Basel earthquake was the strongest event to have shaken NW Europe in the last thousand years. The peculiar location of this historical event makes it possible to relate it to normal faulting along the edges of the Rhine Graben, as well as to reverse faulting along the Jura frontal thrust or to fault reactivation within the Hercynian basement. Alternate hypotheses are discussed and their implications compared taking into account available structural data and results of the morphotectonic study performed in the epicentral area. This study combines field observations with the analysis of SPOT satellite imagery, aerial photographs, and detailed topography. It is concluded that the Basel earthquake most probably reactivated a basement fault (reverse or wrench fault) beneath the shallow-depth aseismic detachment that underlies the Jura Mountains. 相似文献
11.
Discovery of possible mega-thrust earthquake along the Seram Trough from records of 1629 tsunami in eastern Indonesian region 总被引：1，自引：1，他引：0
Arthur Wichmann’s “Earthquakes of the Indian Archipelago” documents several large earthquakes and tsunami throughout the Banda Arc region that can be interpreted as mega-thrust events. However, the source regions of these events are not known. One of the largest and well-documented events in the catalog is the great earthquake and tsunami affecting the Banda Islands on August 1, 1629. It caused severe damage from a 15-m tsunami that arrived at the Banda Islands about a half hour after violent shaking stopped. The earthquake was also recorded 230 km away in Ambon, but no tsunami is mentioned. This event was followed by at least 9 years of uncommonly frequent seismic activity in the region that tapered off with time, which can be interpreted as aftershocks. The combination of these observations indicates that the earthquake was most likely a mega-thrust event. We use an inverse modeling approach to numerically reconstruct the tsunami, which constrains the likely location and magnitude of the 1629 earthquake. Only, linear numerical models are applied due to the low resolution of bathymetry in the Banda Islands and Ambon. Therefore, we apply various wave amplification factors (1.5–4) derived from simulations of recent, well-constrained tsunami to bracket the upper and lower limits of earthquake moment magnitudes for the event. The closest major earthquake sources to the Banda Islands are the Tanimbar and Seram Troughs of the Banda subduction/collision zone. Other source regions are too far away for such a short arrival time of the tsunami after shaking. Moment magnitudes predicted by the models in order to produce a 15-m tsunami are Mw of 9.8–9.2 on the Tanimbar Trough and Mw 8.8–8.2 on the Seram Trough. The arrival times of these waves are 58 min for Tanimbar Trough and 30 min for Seram Trough. The model also predicts 5-m run-up for Ambon from a Tanimbar Trough source, which is inconsistent with the historical records. Ambon is mostly shielded from a wave generated by a Seram Trough source. We conclude that the most likely source of the 1629 mega-thrust earthquake is the Seram Trough. Only one earthquake >Mw 8.0 is recorded instrumentally from the eastern Indonesia region although high rates of strain (50–80 mm/a) are measured across the Seram section of the Banda subduction zone. Enough strain has already accumulated since the last major historical event to produce an earthquake of similar size to the 1629 event. Due to the rapid population growth in coastal areas in this region, it is imperative that the most vulnerable coastal areas prepare accordingly. 相似文献
12.
A New Zealand palaeotsunami database has been developed. The philosophy has been to include as much tsunami-related data as possible. Most of the events recorded are true palaeotsunamis that occurred prior to the historical record or have no written observations. Some are hybrids that are in some manner poorly recorded historical events. Data include physical evidence from geological, archaeological and geomorphological sources and cultural information from anthropological research and prehistorical Māori oral recordings. Each line of data represents a summary of one piece of evidence containing key details listed under a series of headings. The estimated veracity of each line item is based upon the sum of the information contained in the linked reference(s). The palaeotsunami database contains approximately 300 line items and describes between 35 and 40 palaeotsunamis. This wealth of data helps to improve our understanding of tsunami sources, event its magnitude and frequency. 相似文献
13.
Risk assessment of Tunguska-type airbursts 总被引：1，自引：1，他引：0
The Tunguska airburst, which devastated a taiga forest over an area greater than 2,000 km2 in a remote region of Central Siberia in 1908, is a classic example of extraterrestrial encounter discussed in the asteroid/comet
impact hazard and risk assessment literature (e.g. Longo 2007; Carusi et al. 2007). Although it is generally agreed that the cosmic body caused damage by bursting in the air rather than through direct impact
on the Earth’s surface, the Tunguska event is often referred to as an impact event. To the best of our knowledge, no detailed
studies have been performed to quantify the risk of a similar-sized event over a populated region. We propose here a straightforward
probabilistic risk model for Tunguska-type events over the continental United States and use established risk metrics to determine
the property (buildings and contents) and human losses. We find an annual average property loss of ~USD 200,000/year, a rate
of ~0.3 fatalities/year and ~1.0 injuries/year ranging from a factor 3 below and to a factor 3 above the indicated values
when a reasonable rate uncertainty for Tunguska-type events is taken into account. We then illustrate the case of an extreme
event over the New York metropolitan area. While we estimate that this “nightmare” scenario would lead to ~USD 1.5 trillion
of property loss, ~3.9 millions of fatalities and ~4.7 millions of injuries, such event is almost impossible (occurrence once
every ~30 million years) and should only be considered as an illustrative example. 相似文献
14.
Kerala, a southern state of India, experienced a severe flooding due to multi-day extreme rain events during July and August months of 2018. This disaster was one of the worst floods to hit the state and resulted in heavy losses of lives and property. Natural Disaster Management Authority of India reported that 483 people lost their lives and more than 50 lakhs population were affected severely. This short communication focuses on examining this flood event using satellite remote sensing. It is reported that Kerala received an excess of about 56% rainfall during July and August from multi-day extreme rainfall episodes. Few regions of Kerala received the rainfall in the range of 270–300 mm on August 14 and 15. Hourly rainfall events in the excess of 25 mm have also been reported during heavy rainy days. The present study reports that multi-day heavy rainy events during July and August brought an accumulated rainfall of about 1600 mm, which resulted in extreme flooding over Kerala.
相似文献15.
新疆冰雹灾害经济损失评估及风险区划研究 总被引：5，自引：0，他引：5
基于1984-2014年新疆雹灾受灾面积、总成灾面积、农作物播种面积、新疆生产总值及以县为单位的雹灾频次等统计数据,构建雹灾经济损失指标和风险度指标,进行新疆冰雹灾害评估研究。其中雹灾经济损失指标可用于评价新疆雹灾经济损失的趋势变化,风险度指标可借助GIS空间信息处理技术形成新疆雹灾风险区划。研究表明：雹灾经济损失总体呈波动上升趋势,且受环境不稳定度的影响较大,二者保持着较好的正相关性。新疆冰雹灾害总体以中、低度风险为主,高风险次之。高风险区主要集中在喇叭形河谷地带的伊犁地区及其两侧的阿克苏、博州等地,建议通过调整农业产业结构、提升人工防雹能力等方式降低上述区域的雹灾损失。 相似文献
16.
H. Nazari M. Fattahi B. Meyer M. Sébrier M. Talebian M. Foroutan K. Le Dortz M. D. Bateman M. Ghorashi 《地学学报》2009,21(6):417-426
Although sliced by several strike slip faults, a large part of Central Iran remained aseismic during the period of time covered by the instrumental and historical seismic records. Stating the existence of earthquakes in the Holocene is therefore important for the assessment of the regional seismic hazard. A palaeoseismic study of the Deshir fault demonstrates that Central Iran hosted large earthquakes during latest Pleistocene and Holocene. The last event corresponds to 1 m‐deep fissures, which sandy infilling yielded an optically stimulated luminescence (OSL) age of 2.8 ± 1.4 ka. At least two previous events, outlined by older fissures and/or colluvial wedges, have been recorded over the last 10–30 ka. The magnitudes are difficult to assess because the actual slips per event are unknown. The size of the fissures and the significant vertical displacement associated with a colluvial wedge are nevertheless compatible with M ≈ 7 events along a primary strike‐slip surface break. 相似文献
17.
In the paper we report the state-of-the-art of seismicity study in the Baikal rift system and the general results obtained. At present, the regional earthquake catalog for fifty years of the permanent instrumental observations consists of over 185,000 events. The spatial distribution of the epicenters, which either gather along well-delineated belts or in discrete swarms is considered in detail for different areas of the rift system. At the same time, the hypocenters are poorly constrained making it difficult to identify the fault geometry. Clustered events like aftershock sequences or earthquake swarms are typical patterns in the region; moreover, aftershocks of M ⩾ 4.7 earthquakes make up a quarter of the whole catalog. The maximum magnitude of earthquakes recorded instrumentally is MLH7.6 for a strike-slip event in the NE part of the Baikal rift system and MLH6.8 for a normal fault earthquake in the central part of the rift system (Lake Baikal basin). Predominant movement type is normal faulting on NE striking faults with a left lateral strike-slip component on W–E planes. In conclusion, some shortcomings of the seismic network and data processing are pointed out. 相似文献
18.
Duration is a key characteristic of floods influencing the design of protection infrastructures for prevention, deployment of rescue resources during the emergency, and repartition of damage costs in the aftermath. The latter financial aspect mainly relies on the insurance industry and allows the transfer of damage costs from the public sector to the private capital market. In this context, the cost of catastrophes affecting a large amount of insured properties is partly or totally transferred from insurance companies to reinsurance companies by contracts that define the portion of transferred costs according to the temporal extent of the flood events synthesized in the so-called hours clause. However, hours clauses imply standard flood event durations, such as 168 h (1 week), regardless of the hydrological properties characterizing different areas. In this study, we firstly perform a synoptic-scale exploratory analysis to investigate the duration and magnitude of large flood events that occurred around the world and in Europe between 1985 and 2016, and then we present a data-driven procedure devised to compute flood duration by tracking flood peaks along a river network. The exploratory analysis highlights the link of flood duration and magnitude with flood generation mechanism, thus allowing the identification of regions that are more or less prone to long-lasting events exceeding the standard hours clauses. The flood tracking procedure is applied to seven of the largest river basins in Central and Eastern Europe (Danube, Rhine, Elbe, Weser, Rhone, Loire, and Garonne). It correctly identifies major flood events and enables the definition of the probability distribution of the flood propagation time and its sampling uncertainty. Overall, we provide information and analysis tools readily applicable to improve reinsurance practices with respect to spatiotemporal extent of flooding hazard. 相似文献
19.
A probabilistic technique is developed to assess the hazard from meteotsunamis. Meteotsunamis are unusual sea-level events, generated when the speed of an atmospheric pressure or wind disturbance is comparable to the phase speed of long waves in the ocean. A general aggregation equation is proposed for the probabilistic analysis, based on previous frameworks established for both tsunamis and storm surges, incorporating different sources and source parameters of meteotsunamis. Parameterization of atmospheric disturbances and numerical modeling is performed for the computation of maximum meteotsunami wave amplitudes near the coast. A historical record of pressure disturbances is used to establish a continuous analytic distribution of each parameter as well as the overall Poisson rate of occurrence. A demonstration study is presented for the northeast U.S. in which only isolated atmospheric pressure disturbances from squall lines and derechos are considered. For this study, Automated Surface Observing System stations are used to determine the historical parameters of squall lines from 2000 to 2013. The probabilistic equations are implemented using a Monte Carlo scheme, where a synthetic catalog of squall lines is compiled by sampling the parameter distributions. For each entry in the catalog, ocean wave amplitudes are computed using a numerical hydrodynamic model. Aggregation of the results from the Monte Carlo scheme results in a meteotsunami hazard curve that plots the annualized rate of exceedance with respect to maximum event amplitude for a particular location along the coast. Results from using multiple synthetic catalogs, resampled from the parent parameter distributions, yield mean and quantile hazard curves. Further refinements and improvements for probabilistic analysis of meteotsunamis are discussed. 相似文献
20.
Branka Ivančan-Picek Kristian Horvath Nataša Strelec Mahović Marjana Gajić-Čapka 《Natural Hazards》2014,72(2):1231-1252
The aim of this study was to identify the main mesoscale features and mechanisms responsible for the generation of an extreme precipitation event as a contribution to improving the modelling of processes that produce HPEs. The event occurred during the morning hours on 22 November 2010 over the Dubrovnik coast in Croatia and the hinterland mountain range of the southern Dinaric Alps and caused severe flash floods and landslides and consequent interruption of traffic and electricity supply as well as other infrastructural damage. The analysis is geographically focused on the southern portion of the eastern Adriatic region, which is prone to relatively frequent heavy precipitation events that occur mostly in autumn. This area is one of the rainiest in Europe with expected annual amounts of precipitation greater than 5,000 mm in the mountainous hinterland. The mechanisms responsible for the formation of convection were analysed using synop measurements, satellite data and numerical experiments performed with the WRF model, which was set up at the convection-permitting resolution in the innermost domain. Satellite data were used to identify the precipitation systems and to estimate the intensity of the precipitation during the period of interest. The development of the precipitation system was connected to a strong large-scale ascent over the southern Italy and southern Adriatic due to the advection of warm air and cyclonic vorticity advection, which increases with height. The numerical simulations highlighted the essential role of a southerly low-level jet stream in the transport of warm and moist air towards the affected area. The convergence of two branches of low-level marine air favoured convection triggered over the coast and sea. Furthermore, numerical sensitivity experiments suggested that the orography of the Dinaric Alps plays an essential role in the precipitation maximum over the mountainous hinterland, but also that the orography was not the crucial factor in the heavy precipitation near Dubrovnik. This study highlights the need for a dense network of observations, especially radar measurements, to validate the simulated mechanisms and improve numerical forecasts via data assimilation. 相似文献