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1.
Stanley A. Changnon 《Natural Hazards》2011,59(2):1175-1187
High winds are one of the nation’s leading damage-producing storm conditions. They do not include winds from tornadoes, winter
storms, nor hurricanes, but are strong winds generated by deep low pressure centers, by thunderstorms, or by air flow over
mountain ranges. The annual average property and crop losses in the United States from windstorms are $379 million and windstorms
during 1959–1997 caused an average of 11 deaths each year. Windstorms range in size from a few hundred to hundreds of thousands
square kilometers, being largest in the western United States where 40% of all storms exceed 135,000 km2. In the eastern United States, windstorms occur at a given location, on average, 1.4 times a year, whereas in the western
US point averages are 1.9. Midwestern states average between 15 and 20 wind storms annually; states in the east average between
10 and 25 storms per year; and West Coast states average 27–30 storms annually. Storms causing insured property losses >$379 million and windstorms
during 1959–1997 caused an average of 11 deaths each year. Windstorms range in size from a few hundred to hundreds of thousands
square kilometers, being largest in the western United States where 40% of all storms exceed 135,000 km2. In the eastern United States, windstorms occur at a given location, on average, 1.4 times a year, whereas in the western
US point averages are 1.9. Midwestern states average between 15 and 20 wind storms annually; states in the east average between
10 and 25 storms per year; and West Coast states average 27–30 storms annually. Storms causing insured property losses >1
million, labeled catastrophes, during 1952–2006 totaled 176, an annual average of 3.2. Catastrophic windstorm losses were
highest in the West and Northwest climate regions, the only form of severe weather in the United States with maximum losses
on the West Coast. Most western storms occurred in the winter, a result of Pacific lows, and California has had 31 windstorm
catastrophes, more than any other state. The national temporal distribution of catastrophic windstorms during 1952–2006 has
a flat trend, but their losses display a distinct upward trend with time, peaking during 1996–2006. 相似文献
2.
The disastrous effects of numerous winter storms on the marine environment in the North Sea and the Baltic Sea during the
last decade show that wind waves generated by strong winds actually represent natural hazards and require high quality wave
forecast systems as warning tools to avoid losses due to the impact of rough seas. Hence, the operational wave forecast system
running at the German Weather Service including a regional wave model for the North Sea and the Baltic Sea is checked extensively
whether it provides reasonable wave forecasts, especially for periods of extraordinary high sea states during winter storms.
For two selected extreme storm events that induced serious damage in the area of interest, comprehensive comparisons between
wave measurements and wave model forecast data are accomplished. Spectral data as well as integrated parameters are considered,
and the final outcome of the corresponding comparisons and statistical analysis is encouraging. Over and above the capability
to provide good short-term forecast results, the regional wave model is able to predict extreme events as severe winter storms
connected with extraordinary high waves already about 2 days in advance. Therefore, it represents an appropriate warning tool
for offshore activities and coastal environment. 相似文献
3.
The paper presents comprehensive statistical analyses of winds and water levels in Mobile Bay, Alabama, based on long-term meteorological and tidal observations at several locations. A procedure has been developed to select the most probable parent distribution function from a list of candidate distributions. The theoretical functions that fit the data best enable us to predict the extreme values of winds and water levels at different return periods. We have demonstrated the importance of dividing the winds into hurricane and nonhurricane seasons and separating astronomical tides from weather-driven water level changes. The statistical analysis suggests that the wind speed averaged over 8 min at Dauphin Island, Alabama, at the 100-year return period would be 48.9 m/s, which is equivalent to a sustained 1-min wind of 205 km/h, a very strong category 3 hurricane on the Saffir-Simpson scale. The probability distribution models predict that the 100-year maximum water level would be 3.23 m above the mean lower low water (MLLW) level at the bay entrance and 3.41 m above the MLLW level near the head of the bay, respectively. Extremely low water levels important to navigation are also found. Application of the predicted extreme winds and surges is illustrated through the development of a storm wave atlas in the estuary. It is expected that the methodology and results presented in this paper will benefit the management and preservation of the ecosystems and habitats in Mobile Bay. 相似文献
4.
Severe weather affecting European transport systems: the identification,classification and frequencies of events 总被引：1，自引：0，他引：1
Andrea Vajda Heikki Tuomenvirta Ilkka Juga Pertti Nurmi Pauli Jokinen Jenni Rauhala 《Natural Hazards》2014,72(1):169-188
Severe weather can have serious repercussions in the transport sector as a whole by increasing the number of accidents, injuries and other damage, as well as leading to highly increased travel times. This study, a component of the EU FP7 Project EWENT, delineates a Europe-wide climatology of adverse and extreme weather events that can be expected to affect the transport network. We first define and classify the relevant severe weather events by investigating the effects of hazardous conditions on different transportation modes and the infrastructure. Consideration is given to individual phenomena such as snowfall, heavy precipitation, heat waves, cold spells, wind gusts; a combined phenomenon, the blizzard, is also considered. The frequency of severe weather events, together with the changes in their spatial extension and intensity, is analyzed based on the E-OBS dataset (1971–2000) and the ERA-Interim reanalysis dataset (1989–2010). Northern Europe and the Alpine region are the areas most impacted by winter extremes, such as snowfall, cold spells and winter storms, the frequency of heavy snowfall. The frequency of hot days is highest in Southern Europe. Severe winds and blizzards are the most common over the Atlantic and along its shores. Although heavy rainfall may affect the whole continent on an annual basis, extreme precipitation events are relative sparse, affecting particularly the Alps and the Atlantic coastline. A European regionalization covering similar impacts on the transport network is performed. 相似文献
5.
Freezing rain (FZRA) is well documented as a major weather hazard, producing damage to structures, the environment, and humans,
and delaying various operations such as transportation. Assessing the risk of freezing rain events requires information for
various areas of the nation about the frequency, duration, and intensity of these events along with the associated weather
conditions that affect the damage caused by freezing rain. This includes temperatures (dry and wet bulb), the amount of precipitation,
and winds during freezing rain. The purpose of this work was to develop a national and regional climatology of freezing rain
events in the US for the period of 1928–2001 to addresses these conditions. 相似文献
6.
青藏高原积雪对高亚洲地区水和能量循环起着重要的反馈和调节作用,其变化影响着融雪性河流流量,对下游水资源和经济活动具有重要影响。中分辨率成像光谱仪（MODIS）具有较高的时空分辨率,被广泛应用于积雪遥感动态监测,然而光学遥感积雪受云层影响严重,且青藏高原地区水汽分布不均,局地对流活跃,积雪的赋存时间变化快,这给高原地区逐日积雪监测及其气候学制图带来挑战。在考虑青藏高原地形和积雪分布特征情况下,结合现有的云覆盖下积雪判别算法,采用8个不同方法的组合,逐步实现MODIS逐日无云积雪算法。选取2009年10月1日-2011年4月30日两个积雪季为研究期,并采用145个地面台站观测雪深数据对去云算法各步骤过程开展精度验证,结果表明：当积雪深度>3 cm时,逐日无云积雪产品总分类精度达到96.6%,积雪分类精度达83%,积雪判对概率（召回率）达到89.0%,算法可实现青藏高原地区逐日无云积雪动态监测和积雪覆盖气候学数据重建,对高亚洲地区的水、生态和灾害等全球环境变化影响研究具有重要的意义。 相似文献
7.
This study examines the effect of severe wind events on the mean and variance of housing price indices of six metropolitan
statistical areas (MSA) that are vulnerable to hurricanes and/or tornadoes. The research focuses on three areas that experienced
significant tornado activity (Fort Worth-Arlington, Nashville, and Oklahoma City) and three hurricane-prone areas (Corpus
Christi, Miami, and Wilmington, NC). An econometric time series model that captures the housing market responses to severe
windstorms is utilized. The model estimates changes in the local housing price index (HPI) as a function of several control
variables as well as dichotomous variables that correspond to the tornadoes and hurricanes. As expected, the statistical findings
indicate an immediate but short-lived decline in housing prices following a tornado or hurricane. Somewhat surprising is the
result that the impact on the housing market is remarkably consistent whether the wind event was a hurricane or a tornado.
Hurricanes and tornadoes are vastly different in terms of the point probabilities of a hit, the scope of the affected area
and the lead time that supports last minute preparation to mitigate damage. It appears that the market response to destruction
of real property does not distinguish between the types of wind event that produced the damage to the region. Results suggest
that windstorms result in an immediate one-half to two percent reduction in total MSA housing value. This corresponds to a
range of $34 million to $580 million in lost housing value. Estimates indicate some differences in how long market values
continue to decline in the periods following the wind event; however, most of the decline occurs within four quarters after
the windstorm. These differences can be attributed to the particular time series characteristics of the specific housing markets
and their respective housing price indices. The market serves the purpose of integrating and normalizing the losses. In so
doing the market provides a metric— a method for calibrating and comparing structural damage caused by different phenomenon.
相似文献
| Yongsheng WangEmail: |
8.
Marina Aloysius Mannil Mohan S. Suresh Babu Vijayakumar S. Nair K. Parameswaran K. Krishna Moorthy 《Journal of Earth System Science》2008,117(1):353-360
MODIS (Moderate Resolution Imaging Spectroradiometer) level-3 aerosol data, NCEP (National Centers for Environmental Prediction) reanalysis winds and QuikSCAT ocean surface winds were made use of to examine the role of atmospheric circulation in governing aerosol variations over the Bay of Bengal (BoB) during the first phase of the ICARB (Integrated Campaign for Aerosols, gases and Radiation Budget) campaign (March 18–April 12, 2006). An inter-comparison between MODIS level-3 aerosol optical depth (AOD) data and ship-borne MICROTOPS measurements showed good agreement with correlation 0.92 (p < 0.0001) and a mean MODIS underestimation by 0.01. During the study period, the AOD over BoB showed high values in the northern/north western regions, which reduced towards the central and southern BoB. The wind patterns in lower atmospheric layers (> 850 hPa) indicated that direct transport of aerosols from central India was inhibited by the presence of a high pressure and a divergence over BoB in the lower altitudes. On the other hand, in the upper atmospheric levels, winds from central and northern India stretched south eastwards and converged over BoB with a negative vorticity indicative of a downdraft. These wind patterns pointed to the possibility of aerosol transport from central India to BoB by upper level winds. This mechanism was further confirmed by the significant correlations that AOD variations over BoB showed with aerosol flux convergence and flux vorticity at upper atmospheric levels (600–500 hPa). AOD in central and southern BoB away from continental influences displayed an exponential dependence on the QuikSCAT measured ocean surface wind speed. This study shows that particles transported from central and northern India by upper atmospheric circulations as well as the marine aerosols generated by ocean surface winds contributed to the AOD over the BoB during the first phase of ICARB. 相似文献
9.
Anthropogenic effects and climate change threats on the flood diversion of Erchung Floodway in Tanshui River,northern Taiwan 总被引：1，自引：0，他引：1
Hurricanes pose serious threats to people and infrastructure along the United States Gulf and Atlantic coasts. The risk of the strongest hurricane winds over the North Atlantic basin is analyzed using a statistical model from extreme value theory and a tessellation of the domain. The spatial variation in model parameters is shown, and an estimate of the limiting strength of hurricanes at locations across the basin is provided. Quantitative analysis of the variation is done using a geographically weighted regression with regional sea surface temperature as a covariate. It is found that as sea surface temperatures increase, the expected hurricane wind speed for a given return period also increases. 相似文献
10.
Considering the joint probability of occurrence of high sea levels and river discharges, as well as the interactions between these sources of flooding, is of major importance to produce realistic inundation maps in river reaches affected by the sea level. In this paper, we propose a continuous simulation method for the estimation of extreme inundation in coastal river reaches. The methodology combines the generation of synthetic long-term daily time series of river discharge and sea level, the downscaling of daily values to a time resolution of a few minutes, the computation of inundation levels with an unsteady high-resolution two-dimensional model and the use of interpolation techniques to reconstruct long-term time series of water surface from a limited number of characteristic cases. The method is especially suitable for small catchments with times of concentration of a few hours, since it considers the intradiurnal variation of river discharge and sea level. The methodology was applied to the coastal town of Betanzos (NW of Spain), located at a river confluence strongly affected by the sea level. Depending on the return period and on the control point considered, the results obtained with the proposed methodology show differences up to 50 cm when compared with the standard methodology used in this region for the elaboration of flood hazard maps in accordance with the requirements of the European Directives. These results indicate the need for adaption of the standard methodology in order to produce more realistic results and a more efficient evaluation of flood hazard mitigation measures. 相似文献
11.
On the influence of spatial heterogeneity on an internal boundary layer at a short fetch 总被引：1，自引：0，他引：1
B. S. Murthy R. Latha Cini Sukumaran A. Shivaji S. Sivaramakrishnan 《Journal of Earth System Science》2009,118(1):61-70
Surface layer meteorological data collected at a coastal site, at Vasco-Da-Gama (15°21′N, 73°51′E, 58.5m MSL) (13–18 July,
2002) with prevailing southwesterly surface winds are analyzed to study the characteristics of internal boundary layer at
a short fetch using an instrumented tower (9 m). The spectral and turbulence characteristics of wind are compared with earlier
measurements made at a comparatively homogeneous terrain and the standards available in literature. The study show the smaller
eddies in the vertical velocity spectrum attains equilibrium with the underlying surface at a short fetch itself and follows
spectral similarity. However, this is not followed by longitudinal and transverse velocity spectra under unstable as well
as stable conditions. 相似文献
12.
Coastal inundation from hurricane storm surges causes catastrophic damage to lives and property, as evidenced by recent hurricanes including Katrina and Wilma in 2005 and Ike in 2008. Changes in hurricane activity and sea level due to a warming climate, together with growing coastal population, are expected to increase the potential for loss of property and lives. Current inundation hazard maps: Base Flood Elevation maps and Maximum of Maximums are computationally expensive to create in order to fully represent the hurricane climatology, and do not account for climate change. This paper evaluates the coastal inundation hazard in Southwest Florida for present and future climates, using a high resolution storm surge modeling system, CH3D-SSMS, and an optimal storm ensemble with multivariate interpolation, while accounting for climate change. Storm surges associated with the optimal storms are simulated with CH3D-SSMS and the results are used to obtain the response to any storm via interpolation, allowing accurate representation of the hurricane climatology and efficient generation of hazard maps. Incorporating the impact of anticipated climate change on hurricane and sea level, the inundation maps for future climate scenarios are made and affected people and property estimated. The future climate scenarios produce little change to coastal inundation, due likely to the reduction in hurricane frequency, except when extreme sea level rise is included. Calculated coastal inundation due to sea level rise without using a coastal surge model is also determined and shown to significantly overestimate the inundation due to neglect of land dissipation. 相似文献
13.
Xiaojing Liu Jiquan Zhang Donglai Ma Yulong Bao Zhijun Tong Xingpeng Liu 《Natural Hazards》2013,65(3):1393-1409
The traditional studies on drought disaster risk were based on the ground point data, which were unable to realize the continuity of space and the timeliness. It is shown that the monitoring and evaluation precision on drought were reduced significantly. However, remote sensing data in adequate spatial and temporal resolution can overcome these limitations. It can better monitor the crop in large area dynamically. This study presents a methodology for dynamic risk analysis and assessment of drought disaster to maize production in the northwest of Liaoning Province based on remote sensing data and GIS from the viewpoints of climatology, geography and disaster science. The model of dynamic risk assessment of drought disaster was established based on risk formation theory of natural disaster, and the expression of risk by integrating data came from sky, ground and space. The risk indexes were divided into four classes by data mining method, and the grade maps of drought disaster risk were drawn by GIS. It is shown that the spatial and temporal risk distributions of maize at each growth stage changed over time. The model has been verified against reduction in maize yield caused by drought. It demonstrated the reasonability, feasibility and reliability of the model and the methodology. The dynamic risk assessment of regional drought disaster for maize can be used as a tool, which can timely monitor the status (the possibility and extent of drought) and trends of regional drought disaster. The results obtained in this study can provide the latest information of regional drought disaster and the decision-making basis of disaster prevention and mitigation for government management and farmers. 相似文献
14.
The study analyses the numbers of days with strong winds in Krakow during the period 2000?C2007 using anemometric records and fire department data. Patterns are identified in the seasonal and annual variation of strong winds. Particular attention is devoted to extreme events. Based on measurements, the study finds that strong winds mostly occurred in winter. Fire department call-out data show that repair of damage caused by strong winds and gusts of wind was needed equally as frequently in summertime. Strong winds accompanying summer storms are often of a local nature and are not always recorded by weather stations. Wind damage was mapped using requests for fire department assistance. 相似文献
15.
A statistical procedure for estimating the risk of strong winds from hurricanes, known as the Hurricane Risk Calculator, is demonstrated and applied to several major cities in Louisiana. The procedure provides an estimate of wind risk over different length periods and can be applied to any location experiencing this hazard. Results show that an area 100 km around the city of New Orleans can expect to see hurricane winds blowing at 49 ms?1 (44.3–53.7) [90 % confidence interval (CI)] or stronger, on average, once every 20 years. In comparison, for the same time period, the capital city of Baton Rouge and the surrounding area can expect to see hurricane winds of 43 ms?1 (38.2–47.8) (90 % CI) or stronger. Hurricane track direction is also analyzed at the cities of interest. For Morgan City, Lafayette, Lake Charles, and Alexandria, tropical cyclones with winds at least 18 ms?1 travel from the southeast to northwest. New Orleans and Baton Rouge tropical cyclones have a greater tendency to turn toward the east while within 100 km of the city, historically giving them a southwesterly approach. Tropical cyclones within 350 km off the south-central Louisiana coast occur most often in September, and the most extreme of these events are becoming stronger through time as shown with quantile regression. 相似文献
16.
An extreme ice storm in January 1998 deposited up to 100 mm of ice and resulted in significant forest damage across eastern North America. Average crown loss of over 75% was recorded in large areas of eastern Ontario and southern Quebec. A primary question that arose following the storm was: can forest damage be effectively assessed using remote sensing and other available environmental data? This paper presents two contrasting studies to address this question. The first involves damage modelling at a local scale in an unmanaged forest using spectral and spatial information in high-resolution airborne imagery. Results of field data analyses are also given that show relations between damage and forest structure and composition as well as changes in forest structure that occurred in the years following the storm. The second study involves regional scale damage mapping in managed and unmanaged forests of eastern Ontario using medium resolution satellite imagery and other environmental data. In comparison of several image classification and data interpolation methods, the best damage map was produced using a neural network classifier and a mix of Landsat and environmental data. The methods and results presented in this paper form the basis for ongoing long-term temporal study of damage impacts on forest condition. 相似文献
17.
Gerard Roe 《Quaternary Research》2009,71(2):150-161
The records of wind-blown dust (i.e., loess) in China are some of the most important terrestrial records of past climate changes, stretching back over the last 10 Ma. In the paleoclimate literature, intervals of increased dust generation have been almost always interpreted as being associated with more intense or prolonged wintertime conditions. Here it is shown that, in accordance with modern observations, dust outbreaks in Asia are predominantly springtime phenomena. During spring, frequent cyclogenesis in the lee of the Mongolian Altai and the passage of strong cold fronts produce the intense windstorms that loft and entrain dust into the air. The meteorology governing such outbreaks is likely robust in past climates. Contrary to the common paleoclimate presumption, it is actually the breakdown of the Siberian High that permits the dust-producing windstorms to occur. The importance of cold fronts in generating such windstorms suggests that cooling of high-latitude climate during the Miocene, or during glacial intervals, might play a significant role in the signal recorded in the loess deposits. The unique springtime factors that generate dust storms are an example of why the common partitioning of Asian climate into a ‘winter’ and ‘summer’ monsoon is oversimplified and can be misleading. 相似文献
18.
Risk early warning of maize drought disaster in Northwestern Liaoning Province,China 总被引：1，自引：0，他引：1
This study presents a methodology of risk early warning of maize drought disaster in Northwestern Liaoning Province from the viewpoints of climatology, geography, disaster science, environmental science, and so on. The study area was disaggregated into small grid cells, which has higher resolution than counties. Based on the daily meteorological data and maize yield data from 1997 to 2005, the risk early warning model was built up for drought disaster. The early warning crisis signs were considered from exogenous warning signs and endogenous warning signs. The probability of drought was taken as endogenous warnings sign, which was calculated by logistic regression model. Beside precipitation, wind speed and temperature were taken into consideration when assessing the drought. The optimal partition method was used to define the threshold of each warning grade. Take the year of 2009 as an example, this risk early warning model performed well in warning drought disasters of each maize-growing stage. Results obtained from the early warning model can guide the government to take emergency action to reduce the losses. 相似文献
19.
Hurricane storm surge simulations for Tampa Bay 总被引：1，自引：0，他引：1
Using a high resolution, three-dimensional, primitive equation, finite volume coastal ocean model with flooding and drying
capabilities, supported by a merged bathymetric-topographic data set and driven by prototypical hurricane winds and atmospheric
pressure fields, we investigated the storm surge responses for the Tampa Bay, Florida, vicinity and their sensitivities to
point of landfall, direction and speed of approach, and intensity. All of these factors were found to be important. Flooding
potential by wind stress and atmospheric pressure induced surge is significant for a category 2 hurricane and catastrophic
for a category 4 hurricane. Tide, river, and wave effects are additive, making the potential for flood-induced damage even
greater. Since storm surge sets up as a slope to the sea surface, the highest surge tends to occur over the upper reaches
of the bay, Old Tampa Bay and Hillsborough Bay in particular. For point of landfall sensitivity, the worst case is when the
hurricane center is positioned north of the bay mouth such that the maximum winds associated with the eye wall are at the
bay mouth. Northerly (southerly) approaching storms yield larger (smaller) surges since the winds initially set up (set down)
water level. As a hybrid between the landfall and direction sensitivity experiments, a storm transiting up the bay axis from
southwest to northeast yields the smallest surge, debunking a misconception that this is the worst Tampa Bay flooding case.
Hurricanes with slow (fast) translation speeds yield larger (smaller) surges within Tampa Bay due to the time required to
redistribute mass. 相似文献
20.
Both finite-element and finite-difference numerical models are applied to simulate storm surges and associated currents generated
by tropical cyclones that struck the coast of Andhra Pradesh, located on the east coast of India. During a cyclone, the total
water level at any location on the coast is made up of the storm surge, surge–wind wave interaction and the tide. The advanced
circulation two-dimensional depth-integrated (ADCIRC-2DDI) model based on finite-element formulation and the two-dimensional
finite-difference model of storm surges developed at IIT Delhi, hereafter referred as IITD storm surge model, are used. These
models are driven by astronomical tides at the open ocean boundary and cyclonic asymmetric winds over the surface of the computational
domain. Comparison of model simulated sea-surface elevations with coarse and finer spatial resolutions suggests that the grid
resolution near the coast is very crucial for accurate determination of the surges in addition to the local bathymetry. The
model underpredicts surges, and the peak surge location shifts more to the right of the landfall as the spatial resolution
of the model becomes coarser. The numerical experiments also demonstrate that the ADCIRC model is robust over the IITD storm
surge model for surge computations as the coastline is better represented in the former. 相似文献