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1.
飓风等自然灾害的发生会对沿海地区造成巨大的社会、经济损失,因此有必要合理评估这些区域的建筑在飓风作用下的灾害。已有研究指出,全球气候变暖会影响未来飓风的强度和发生频率。本文考虑飓风发生(随机)过程的非平稳性,提出了沿海地区飓风灾害评估的新方法。用非齐次泊松过程来描述飓风的发生,并用时变的统计参数(均值、标准差)来反映飓风强度的变化。在此基础上,给出了累积飓风灾害的均值、方差的显式公式。选取美国佛罗里达州迈阿密县进行案例分析,研究了飓风过程非平稳性对累积灾害的影响。  相似文献   

2.
Growing coastal populations, rising sea levels, and likely increases in the frequency of major storm events will intensify coastal vulnerability in coming decades. Decisions regarding how and when to fortify estuarine shorelines against coastal hazards, such as erosion, flooding, and attendant property damages, rest largely in the hands of waterfront-property owners. Traditionally, hard engineered structures (e.g. bulkheads, revetments, seawalls) have been used to protect coastal properties, based on the assumption that these structures are durable and effective at preventing erosion. This study evaluates the validity of these assumptions by merging results from 689 surveys of waterfront-property owners in NC with empirical shoreline damage data collected along estuarine shorelines after Hurricanes Irene (2011) and Arthur (2014). The data show: 1) homeowners perceive bulkheads to be the most durable and effective at preventing erosion, but also the most costly; 2) compared to residents with revetments and natural shorelines, property owners with bulkheads reported double the price to repair hurricane damage to their property and four times the cost for annual shoreline maintenance; 3) 93% of evident post-hurricane shoreline damage was attributable to bulkheads or bulkhead hybrids and a higher proportion of surveyed homeowners with bulkheads reported having property damage from hurricanes; and, 4) shoreline hardening increased by 3.5% from 2011 to 2016 along 39 km of the Outer Banks. These results suggest that bulkheads are not meeting waterfront property-owner expectations despite continued use, and that nature-based coastal protection schemes may be able to more effectively align with homeowner needs.  相似文献   

3.
The climatological characteristics of landfalling Gulf of Mexico hurricanes are presented, focusing on the basic parameters needed for accurately determining the structure and intensity of hurricanes for ocean response models. These include the maximum sustained wind, radius of maximum winds, the Holland-B parameter, the peripheral or far-field pressure, the surface roughness and coefficient of drag, and the central pressure for historical hurricanes in the Gulf.Despite evidence of a slight increase in the annual number of named storms over the past 50 years, presently there is no statistically significant trend in tropical storms, hurricanes, or major hurricanes in the Gulf of Mexico. In addition, the long-term variability of tropical cyclones in the Gulf reflects the observed variability in the Atlantic basin as a whole. Analyses of hurricane winds from multiple sources suggest the presence of a bias toward overestimating the strength of winds in the HURDAT dataset from 7% to 15%. Results presented comparing HURDAT with other sources also show an overestimation of intensity at landfall, with an estimated bias of ~10%.Finally, a review of recent studies has shown that hurricane frequencies and intensities appear to vary on a much more localized scale than previously believed. This exacerbates the sampling problem for accurate characterization of hurricane parameters for design and operational applications.  相似文献   

4.
Hurricane generated waves as observed by satellite   总被引:1,自引:0,他引:1  
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5.
This study set out to test the hypothesis that hurricanes and tropical storms limit the recruitment and subsequent survival of massive non-branching corals on the barrier reef off the coast of Belize in the Gulf of Honduras. Overall, the surface areas of 523 individual coral specimens were measured, and recruitment dates were then modelled. There was no significant difference in coral cover or coral biodiversity between any of the sites studied (p > 0.1). There were significant differences in non-branching coral recruitment in years when hurricanes impacted the area (p < 0.05) compared with years when no hurricanes impacted the area. There were significantly more non-branching massive corals recruited in non-hurricane years (mean 7.7) than in hurricane years (mean 3.8; p = 0.011). When years with tropical storms are added to the years with hurricanes, there was significantly lower coral recruitment (mean 4.7) relative to non-storm or hurricane years (mean 7.4; p = 0.019). These results show that hurricanes and severe storms limited the recruitment and survival of massive non-branching corals of the Mesoamerican barrier reef and on patch reefs near the Belize coast in the Caribbean, and suggests that marine park managers may need to assist coral recruitment in years where there are hurricanes or severe storms.  相似文献   

6.
A hydrodynamics-based surge scale for hurricanes   总被引:2,自引:0,他引:2  
Record hurricane surges over the last several years have demonstrated the need for an improved surge hazard warning scale for hurricanes. Here, a simple hydrodynamics-based surge scale for hurricane surge hazard is presented. This surge scale incorporates readily available meteorological information along with regional-scale bathymetry into a single measure of expected surge levels at the coast. We further outline an approach for estimating expected flood inundation and damages based on the alongshore extent of high surges during hurricanes. Comparisons between this new surge scale and historical hurricane observations show a measurable improvement over existing surge indices, including the Saffir-Simpson scale. It is anticipated that the proposed surge scale will improve public awareness of surge hazard and assist governments in communicating critical decisions regarding evacuation and emergency response.  相似文献   

7.
Many avenues of research are currently being tried for understanding and predicting hurricane intensity forecasts. We have listed several such research avenues being pursued by the research community. This article addresses the use of high-resolution aircraft reconnaissance datasets used for daily data assimilation over three years of hurricane histories that cover rapid intensification cases. We show a number of dynamical and thermodynamical parameters, derived from these datasets, which seem to hold promise for future use in short range statistical forecasts on rapid intensification. These include the vertical differential of heating in the complete potential vorticity equation, the conversion of divergent kinetic energy to rotational kinetic energy, the transformation of shear vorticity to curvature vorticity, and the advection of the earth's and the relative angular momentum into the inner core of hurricanes. We find a rapid growth in the time history of each of these parameters as the rapid intensification occurs. These are demonstrated for a number of recent hurricanes.  相似文献   

8.
Trends in the Atlantic tropical cyclones and the cyclones that had tracks through North Carolina were analyzed for more than 100 years. From about 1970, there appears to be an increase in the mean number of storms developing. The number of storms affecting North Carolina each decade has been increasing since the 1960s. In the 1980s, 1990s, and into the 2000s, there was an increase in the number of landfalling storms in North Carolina. Although August and September are the most active months of the Atlantic hurricane season, the hurricane season for North Carolina peaks in September. Wind distribution and frictional convergence associated with landfalling hurricanes in North Carolina are discussed. Convection and precipitation patterns of landfalling hurricanes are presented. Two examples of the effect of spatial surface moisture distribution on intensification of tropical cyclones over land after landfall are discussed.  相似文献   

9.
《Ocean & Coastal Management》2003,46(11-12):1069-1083
Emergency managers should balance the benefits and costs of voluntary and mandatory evacuation orders when issuing orders prior to a hurricane. The only estimate of hurricane evacuation costs is the often-quoted “one million dollars per mile” of evacuated coastline. The purpose of this paper is to pursue better measures of the opportunity costs of hurricane evacuations that depend on storm intensity, behavior, and population. We model the hurricane evacuation decision of households using revealed and stated preference methods with data from a survey of North Carolina residents who experienced 1998s Hurricane Bonnie. We use the evacuation predictions and estimates of household evacuation costs to estimate the aggregate opportunity costs of hurricane evacuations. We find that hurricane evacuation costs for ocean counties in North Carolina range from about $1 million to $50 million depending on storm intensity and emergency management policy. These costs are much less than “one million dollars per mile” of evacuated coastline.  相似文献   

10.
Potential impact of sea level rise on coastal surges in southeast Louisiana   总被引:1,自引:0,他引:1  
Potential impacts of 0.5 and 1.0 m of relative sea level rise (RSLR) on hurricane surge and waves in southeast Louisiana are investigated using the numerical storm surge model ADCIRC and the nearshore spectral wave model STWAVE. The models were applied for six hypothetic hurricanes that produce approximately 100 yr water levels in southeastern Louisiana. In areas of maximum surge, the impact of RSLR on surge was generally linear (equal to the RSLR). In wetland or wetland-fronted areas of moderate peak surges (2-3 m), the surge levels were increased by as much as 1-3 m (in addition to the RSLR). The surge increase is as much as double and triple the RSLR over broad areas and as much as five times the RSLR in isolated areas. Waves increase significantly in shallow areas due to the combined increases in water depth due to RSLR and surge increases. Maximum increases in wave height for the modeled storms were 1-1.5 m. Surge propagation over broad, shallow, wetland areas is highly sensitive to RSLR. Wave heights also generally increased for all RSLR cases. These increases were significant (0.5-1.5 m for 1 m RSLR), but less dramatic than the surge increases.  相似文献   

11.
Knowledge of coral recruitment patterns helps us understand how reefs react following major disturbances and provides us with an early warning system for predicting future reef health problems. We have reconstructed and interpreted historical and modern-day recruitment patterns, using a combination of growth modelling and in situ recruitment experiments, in order to understand how hurricanes, storms and bleaching events have influenced coral recruitment on the Caribbean coastline of Tobago. Whilst Tobago does not lie within the main hurricane belt results indicate that regional hurricane events negatively impact coral recruitment patterns in the Southern Caribbean. In years following hurricanes, tropical storms and bleaching events, coral recruitment was reduced when compared to normal years (p = 0.016). Following Hurricane Ivan in 2004 and the 2005–2006 bleaching event, coral recruitment was markedly limited with only 2% (n = 6) of colonies estimated to have recruited during 2006 and 2007. Our experimental results indicate that despite multiple large-scale disturbances corals are still recruiting on Tobago’s marginal reef systems, albeit in low numbers.  相似文献   

12.
The 2005 hurricane season in the Gulf of Mexico was the worst in the history of offshore production, with Hurricanes Katrina and Rita destroying 110 oil and gas structures and eight mobile offshore drilling units. Infrastructure destroyed by accident or natural catastrophe are decommissioned according to the same federal regulations that guide normal decommissioning operations, but depending on the nature of the destruction and the market conditions in the months following the event, special conditions and delays may occur. Historically, offshore infrastructure destroyed by hurricanes or other unusual circumstances have been considered for inclusion in the Louisiana Artificial Reef Program (LARP) under the Special Artificial Reef Site (SARS) category. The purpose of this paper is to review the impact of the 2005 hurricane season on the LARP and the current status of the SARS program. We examine the criteria employed in project evaluation and approval as well as aggregate program statistics. The characteristics and risks associated with decommissioning destroyed infrastructure are also described. At the end of 2006, 10 projects representing 35 platforms destroyed in the 2005 hurricane season have been approved as SARS in the Gulf of Mexico, effectively doubling the number of sites and structures classified as SARS.  相似文献   

13.
A contrasting study of the large-scale circulation features responsible for months or seasons with many hurricanes and those with few hurricanes has revealed that the frequency of hurricane formation over the North Atlantic Ocean is enhanced by the following conditions:There exists a well-developed subtropical high-pressure belt displaced to the north; a deep Icelandic low; a stronger-than-normal polar vortex with a deep polar trough dipping far southward along the eastern part of the United States; a dominant high-pressure ridge over western Canada and the United States; and a jet stream displaced northward over these regions. At 200 hPa, an anomalous anticyclonic circulation prevails over the subtropical North Atlantic. A stronger-than-normal upper easterly flow prevails. Positive sea surface temperature anomalies prevailing on a seasonal or long-term basis tend to be favorable for the formation of hurricanes.  相似文献   

14.
Hurricane flooding is a leading natural threat to coastal communities. Recent evidence of sea level rise coupled with potential future global warming indicate that sea level rise will accelerate and hurricanes may intensify over the coming decades. In regions fronted by barrier islands, the protective capacity of these islands may diminish as they are degraded by rising sea level. Here we present a hydrodynamic and geospatial analysis of the relative role of barrier island degradation on potential future hurricane flooding. For the City of Corpus Christi, Texas, USA, hurricane flooding is projected to rise between 20% and 70% by the 2030s, resulting in an increase in property damages and impacted population. These findings indicate that adaptive management strategies should be developed and adopted for mitigating loss of natural barrier islands when these islands act as protective features for populated bayside communities. Finally, this study illustrates a method for applying models to forecast future storm protection benefits of barrier island restoration projects.  相似文献   

15.
Inertial oscillations as deep ocean response to hurricanes   总被引:1,自引:0,他引:1  
We discuss the deep ocean response to passing hurricanes (aka typhoons), which are considered as generators of near-inertial, internal waves. The analysis of data collected in the northwestern parts of the Pacific and Atlantic oceans in the hurricane season permit us to assess the deep ocean response to such a strong atmospheric forcing. A large number of moorings (more than 100) in the northwestern Pacific have allowed us to characterize the spatial features of the oceanic response to typhoons and the variable downward velocity of near-inertial wave propagation. The velocity of their downward propagation varies in the range 1–10 m/hour. It is higher in the regions of low stratification and high anticyclonic vorticity. The inertial oscillations generated by a hurricane last for 10–12 days. The mean anticyclonic vorticity in the region increases the effective frequency of inertial oscillations by 0.001–0.004 cyc/hour.  相似文献   

16.
Gloria was a fast-moving, intense hurricane that grazed the North Carolina coastline in September, 1985. The resulting storm surge was measured remotely using a telephone-linked wave data system as well as a local tide gage. The surge was hindcast using the model of Jelesnianski (1967) which was developed for shore-parallel storm tracks. The agreement with measurement was quite satisfactory. The data suggest extremely rapid rise times for the peak surge of hurricanes moving at high speed along the coast.  相似文献   

17.
An extensive database of one-dimensional spectra observed during the passage of hurricanes is examined. Spectra recorded within eight times the radius to maximum winds of the centers of hurricanes are unimodal and remarkably similar to previously recorded fetch limited spectra. Parametric spectral forms such as JONSWAP and that of Donelan et al. approximate the data well. In addition, the functional dependence of the spectral parameters α and γ on the inverse wave age is consistent with that observed under fetch limited conditions. It is concluded that the similarity of the hurricane wave spectra to those observed for simpler fetch limited spectra is largely due to the effects of nonlinear interactions. The shape stabilizing effects of the nonlinear interactions reshape spectra consisting of a mix of swell and wind-sea to conform with typical one-dimensional fetch limited wind-sea forms.  相似文献   

18.
A version of the WAVEWATCH III wave model featuring a continuously moving spatial grid is presented. The new model option/version is intended for research into wind waves generated by tropical cyclones in deep water away from the coast. The main advantage of such an approach is that the cyclones can be modeled with spatial grids that cover much smaller areas than conventional fixed grids, making model runs with high spatial resolution more economically feasible. The model modifications necessary are fairly trivial. Most complications occur due to the Garden Sprinkler effect (GSE) and methods used to mitigate it. The basic testing of the model is performed using idealized wind fields consisting of a Rankine vortex. The model is also applied to hurricane Lili in the Gulf of Mexico in October 2002. The latter application shows that the moving grid approach provides a natural way to deal with hurricane wind fields that have a high-resolution in space, but a low resolution in time. Although the new model version is originally intended for tropical cyclones, it is suitable for high-resolution modeling of waves due to any moving weather pattern.  相似文献   

19.
This article reviews several microwave instruments employed in research and analysis of tropical cyclones (TCs), typhoons, and hurricanes. The instruments discussed include scatterometers, microwave radiometers, synthetic aperture radars (SARs), and rain radar from space. Examples of the particular contribution by one or more of these instruments in analysis of several storms illustrate the comprehensive new views provided by the SeaWinds scatterometers, the detailed high-resolution wind field provided by RADARSAT-1 SAR, particularly inside and in the vicinity of hurricane “eyes,” and the presence of secondary flows in the region between rainbands in TCs. The high spatial resolution of precipitation data from the Tropical Rainfall Measuring Mission's rain radar, combined with scatterometer or SAR data, give a significant improvement in the details that can be seen from space, at the surface, and in the precipitating areas of TCs. The microwave instruments provide a penetrating view below the upper level cirrus clouds. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

20.
Data are presented indicating the complexity and highly variable response of beaches to cold front passages along the northern Gulf of Mexico, in addition to the impacts of tropical cyclones and winter storms. Within the past decade, an increase in the frequency of tropical storms and hurricanes impacting the northern Gulf has dramatically altered the long-term equilibrium of a large portion of this coast. A time series of net sediment flux for subaerial and nearshore environments has been established for a section of this coast in Florida, and to a lesser extent, Mississippi. The data incorporate the morphological signature of six tropical storms/hurricanes and more than 200 frontal passages.

Data indicate that (1) barrier islands can conserve mass during catastrophic hurricanes (e.g., Hurricane Opal, a strong category 4 hurricane near landfall); (2) less severe hurricanes and tropical storms can promote rapid dune aggradation and can contribute sediment to the entire barrier system; (3) cold fronts play a critical role in the poststorm adjustment of the barrier by deflating the subaerial portion of the overwash terrace and eroding its marginal lobe along the bayside beach through locally generated, high frequency, steep waves; and (4) barrier systems along the northern Gulf do not necessarily enter an immediate poststorm recovery phase, although nested in sediment-rich nearshore environments. While high wave energy conditions associated with cold fronts play an integral role in the evolution and maintenance of barriers along the northern Gulf, these events are more effective in reworking sediment after the occurrence of extreme events such as hurricanes. This relationship is even more apparent during the clustering of tropical cyclones.

It is anticipated that these findings will have important implications for the longer term evolution of barrier systems in midlatitude, microtidal settings where the clustering of storms is apparent, and winter storms are significant in intensity and frequency along the coast.  相似文献   


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