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1.
In August 2009, Typhoon Morakot caused massive flooding and devastating mudslides in the southern Taiwan triggered by extremely heavy rainfall (2777 mm in 4 days) which occurred during its passage. It was one of the deadliest typhoons that have ever attacked Taiwan in recent years. In this study, numerical simulations are performed for the storm surge and ocean surface waves, together with dynamic meteorological fields such as wind, pressure and precipitation induced by Typhoon Morakot, using an atmosphere–waves–ocean integrated modelling system. The wave-induced dissipation stress from breaking waves, whitecapping and depth-induced wave breaking, is parameterized and included in the wave–current interaction process, in addition to its influence on the storm surge level in shallow water along the coast of Taiwan. The simulated wind and pressure field captures the characteristics of the observed meteorological field. The spatial distribution of the accumulated rainfall within 4 days, from 00:00 UTC 6 August to 00:00 UTC 10 August 2009, shows similar patterns as the observed values. The 4-day accumulated rainfall of 2777 mm at the A-Li Shan mountain weather station for the same period depicted a high correlation with the observed value of 2780 mm/4 days. The effects of wave-induced dissipation stress in the wave–current interaction resulted in increased surge heights on the relatively shallow western coast of Taiwan, where the bottom slope of the bathymetry ranges from mild to moderate. The results also show that wave-breaking has to be considered for accurate storm surge prediction along the east coast of Taiwan over the narrow bank of surf zone with a high horizontal resolution of the model domain.  相似文献   

2.
Summary In August 2002, many parts of central Europe were affected by heavy precipitation and flooding caused by a cut-off cyclone. This study shows that this cyclone developed as a result of the propagation of a Rossby wave packet. The wave-packet propagation along the relatively weak subtropical jet was accompanied by wave-breaking and re-emission in the subtropics. In particular, there was an interaction between the Rossby wave packet and a precipitation band along the east coast of North America associated with tropical storm Cristobal. This interaction had a significant influence upon the formation of the European cut-off low. Results from numerical simulations from two different initial conditions are investigated to study this interaction. Downstream influences from tropical storm Cristobal upon the development of this cyclone and associated flooding precipitation are confirmed by sensitivity analysis using ensemble forecasts. It is concluded from analysis and simulations that poor forecast skills of tropical storm Cristobal affected the predictability of the European cut-off low.  相似文献   

3.
渤海西岸致灾风暴潮的统计预报模型   总被引:2,自引:0,他引:2  
王月宾 《气象》2007,33(9):40-46
渤海西岸是风暴潮灾害多发区,1990年代以后发生几率和灾害损失明显增加。利用气象科学和海洋水文科学相结合的方法,依据黄骅港潮汐资料,对发生在渤海西岸的风暴潮进行统计分析。结果表明,台风和强冷空气配合气旋是造成渤海西岸风暴潮的主要天气系统,偏东大风增水和天文潮叠加是造成风暴潮的直接因素;风暴潮和天文潮汐都有半日潮现象。在此基础上,建立了渤海西岸风暴潮预报模型,通过台风或冷空气配合气旋影响时增水值的计算,结合天文潮汐资料,做出最高潮位预报。应用该预报方法对渤海西岸发生的7次风暴潮进行回报,预报值与实测值基本相当,是基层台站较实用的预报方法。  相似文献   

4.
The incidence of major storm surges in the last decade have dramatically emphasized the immense destructive capabilities of extreme water level events, particularly when driven by severe tropical cyclones. Given this risk, it is vitally important that the exceedance probabilities of extreme water levels are accurately evaluated to inform risk-based flood and erosion management, engineering and for future land-use planning and to ensure the risk of catastrophic structural failures due to under-design or expensive wastes due to over-design are minimised. Australia has a long history of coastal flooding from tropical cyclones. Using a novel integration of two modeling techniques, this paper provides the first estimates of present day extreme water level exceedance probabilities around the whole coastline of Australia, and the first estimates that combine the influence of astronomical tides, storm surges generated by both extra-tropical and tropical cyclones, and seasonal and inter-annual variations in mean sea level. Initially, an analysis of tide gauge records has been used to assess the characteristics of tropical cyclone-induced surges around Australia. However, given the dearth (temporal and spatial) of information around much of the coastline, and therefore the inability of these gauge records to adequately describe the regional climatology, an observationally based stochastic tropical cyclone model has been developed to synthetically extend the tropical cyclone record to 10,000 years. Wind and pressure fields derived for these synthetically generated events have then been used to drive a hydrodynamic model of the Australian continental shelf region with annual maximum water levels extracted to estimate exceedance probabilities around the coastline. To validate this methodology, selected historic storm surge events have been simulated and resultant storm surges compared with gauge records. Tropical cyclone induced exceedance probabilities have been combined with estimates derived from a 61-year water level hindcast described in a companion paper to give a single estimate of present day extreme water level probabilities around the whole coastline of Australia. Results of this work are freely available to coastal engineers, managers and researchers via a web-based tool (www.sealevelrise.info). The described methodology could be applied to other regions of the world, like the US east coast, that are subject to both extra-tropical and tropical cyclones.  相似文献   

5.
径流-风暴潮相互作用可增大河口区风暴潮增水,增加风暴潮灾害风险。基于SCHISM模式建立了珠江河口风暴潮数值模型,以台风“山竹”为例,采用实测资料对模型计算结果进行验证,最高潮位相对误差在9%以内。设计了台风“山竹”实测径流与5年一遇洪水的对比试验,讨论了径流变化对河口风暴潮增水的影响,结果表明:河口口门站位风暴潮增水随径流量的增大而增大。径流增加对泗盛围、南沙等站位的风暴潮影响较大,在风暴潮增水达到最大值时影响最为显著。以径流动力作用为主的区域,当上游径流量增大时,对风暴潮增水起到负影响作用:如磨刀门水道,随着径流的增加,沿河道上溯的风暴潮增水逐渐减小,由灯笼山站3.22 m减小至马口站1.12 m。以潮汐动力作用为主的区域,当上游径流量增大时,对风暴潮增水起到正影响作用:如珠江干流,随着径流的增加,沿河道上溯的风暴潮增水逐渐增大,大虎站的最大增水值为3.44 m,中大站为4.24 m,从口门至后航道区域增大了0.8 m。   相似文献   

6.
长江下游东段高水位是该区域汛期常见的水害之一。针对长江游东段近13年高水位日,利用同期常规的水文资料和天气图等资料,以天气学原理为基础,运用风暴潮原理和农历潮汐等相关理论,分析高水位成因,探寻引发高水位的主要因子。结果表明:(1)东段高水位发生在农历潮汐高潮期,直接受其高潮位影响;(2)引发高水位的天气系统是台风和西风槽;(3)西风槽引发长江上中游洪水东泄通过东段;台风行近大陆架其强制孤立波使海面急剧上升,台风暴潮倒灌入侵东段;(4)高水位与本地降水关系不密切。  相似文献   

7.
The Strait of Georgia is a large, semi-enclosed body of water between Vancouver Island and the mainland of British Columbia connected to the Pacific Ocean via Juan de Fuca Strait at the south and Johnstone Strait at the north. During the winter months, coastal communities along the Strait of Georgia are at risk of flooding caused by storm surges, a natural hazard that can occur when a strong storm coincides with high tide. This investigation produces storm surge hindcasts using a three-dimensional numerical ocean model for the Strait of Georgia and the surrounding bodies of water (Juan de Fuca Strait, Puget Sound, and Johnstone Strait) collectively known as the Salish Sea. The numerical model employs the Nucleus for European Modelling of the Ocean architecture in a regional configuration. The model is evaluated through comparisons of tidal elevation harmonics and storm surge with observations. Important forcing factors contributing to storm surges are assessed. It is shown that surges entering the domain from the Pacific Ocean make the most significant contribution to surge amplitude within the Strait of Georgia. Comparisons between simulations and high-resolution and low-resolution atmospheric forcing further emphasize that remote forcing is the dominant factor in surge amplitudes in this region. In addition, local wind patterns caused a slight increase in surge amplitude on the mainland side of the Strait of Georgia compared with Vancouver Island coastal areas during a major wind storm on 15 December 2006. Generally, surge amplitudes are found to be greater within the Strait of Georgia than in Juan de Fuca Strait.  相似文献   

8.
Summary Austral summer 2000/01 in the southern African region was unusual in several respects. Tropical cyclone activity in the southwest Indian Ocean was substantially less than average despite large areas of this region showing anomalously warm sea surface temperatures (SST) for much of the season. Many areas of southern Africa experienced above average rainfall with local flooding in parts of Mozambique. In the tropical southeast Atlantic, a large warm SST anomaly evolved off the coast of Angola and northern Namibia in late summer suggesting a Benguela Ni?o event. During the late summer (February–April 2001), three particularly widespread and intense wet spells occurred over tropical southern Africa, one of which coincided with tropical cyclone Dera. This study considers the generation and evolution of the middle wet spell of late summer 2001 and its relationship with tropical cyclone Dera. This storm was generated in the northwestern part of the Mozambique Channel and then tracked more or less due south through the Channel and into the subtropical southwest Indian Ocean. Rainfall associated with Dera contributed to the ongoing floods over central Mozambique that arose from rains earlier in the season. Dera occurred in early March following a relatively long period of no tropical cyclone activity in the southwest Indian Ocean. A build up of favorable conditions during the preceding weeks contributed towards the storm whereas an anticyclonic anomaly east of Madagascar led to the northerly steering current and the southward track of tropical cyclone Dera out of the Mozambique Channel.  相似文献   

9.
Abstract

A powerful storm passed over the coastal waters of eastern Canada on the 21 and 22 January 2000 causing significant damage to coastal infrastructure. The storm generated a large (>1.4 m) storm surge in the southern Gulf of St. Lawrence that unfortunately coincided with a high spring tide. This resulted in record high water levels in the southern Gulf of St. Lawrence (e.g., the highest level at Charlottetown since records began in 1911) and severe flooding around Prince Edward Island and along the eastern shore of New Brunswick.

During January 2000, a recently developed storm surge forecast system was running in pre‐operational mode at Dalhousie University. The core of the forecast system is a depth‐averaged, non‐linear, barotropic ocean model driven by forecast winds and air pressures produced by the Canadian Meteorological Centre's regional atmospheric forecast model. In this study we assess the forecast skill of the surge model for the 21 January storm by comparing its 24‐hour forecasts with two independent hourly dataseis: (i) sea levels recorded by 12 tide gauges located in eastern Canada and the north‐eastern United States, and (ii) depth‐mean currents recorded by an acoustic Doppler current profiler deployed on the outer Scotian Shelf. Overall, the forecasts of coastal sea level and depth‐mean currents are reasonable and have forecast errors below about 0.1 m and 0.1 m s?1 respectively.  相似文献   

10.
广东省1991~2005年5种主要海洋灾害概况   总被引:7,自引:6,他引:1  
广东省近15年因风暴潮、海浪、赤潮、溢油、海水入侵等海洋灾害造成直接经济损失约438.9亿元人民币,死亡、失踪577人。其中风暴潮灾害最为严重,年直接经济损失超过20亿元的海洋灾害是由台风风暴潮引起的;灾情的地域差异是粤西较重,粤东次之,珠江口较轻。2001~2005年与1991~2005年相比,近5年海洋灾害的年均直接经济损失和死亡、失踪人数减少。但2006年又是海洋灾害重灾年。  相似文献   

11.
Sea-level rise is a major coastal issue in the 21st century because many of the world??s built assets are located in the coastal zone. Coastal erosion and flooding are serious threats along the coast of Ghana, particularly, the eastern coast where the Volta delta is located. Past human interventions, climate change and the resultant rise in sea-levels, increased storm intensity and torrential rainfall have been blamed for these problems. Accelerated sea-level rise and storm surge pose serious threat to coastal habitat, bio-diversity and socio-economic activities in the coastal zone of Ghana and elsewhere. There is the need for an holistic assessment of the impacts of sea-level rise on the coast zone in order to formulate appropriate adaptation policies and strategies to mitigate the possible effects. Using the eastern coast of Ghana as a case study, this paper assesses the physical impacts of accelerated sea level rise and storm surge on the coastal environment. It evaluates adaptation policies and plans that could be implemented to accommodate the present and any future impacts. Field investigation and Geographic Information System (GIS) are among the methods used for the assessment. The outcome of the assessment has provided comprehensive knowledge of the potential impacts of accelerated sea-level rise and storm surge on the eastern coast. It has facilitated identification of management units, the appraisal of alternate adaptation policies and the selection of the best policy options based upon the local conditions and environmental sustainability. Among other things, this paper reveals that the eastern coast of Ghana is highly vulnerable to accelerated sea-level rise and therefore, requires sustainable adaptation policies and plans to manage the potential impacts. It recommends that various accommodation policies, which enable areas to be occupied for longer before eventual retreat, could be adapted to accommodate vulnerable settlements in the eastern coast of Ghana.  相似文献   

12.
基于城市内涝仿真模型,根据天津沿海地区的地形、地貌特征以及排水系统等对城市内涝仿真模型进行改进,在沿海边界和河口设置时变水位,使得模型拓展到既能模拟暴雨产生的内涝,也能模拟由于风暴潮侵袭造成的淹没情景。该模型对天津沿海地区历史上典型风暴潮个例以及10年、20年、50年、100年一遇重现期风暴潮产生的积水范围和积水深度进行了模拟,并对2012年8月3日台风达维 (1210) 造成的天津沿海风暴潮进行了业务试应用。将历史风暴潮个例模拟结果以及2012年8月3日的评估结果与实际灾情进行对比,结果显示模型具有较好的模拟能力,可应用于风暴潮灾害的评估和预估业务中,为相关部门和行业提供决策参考。  相似文献   

13.
风暴潮是指由强烈的大气扰动所导致的海面异常升高现象,由热带气旋引起的风暴潮常对沿海地区造成巨大的社会经济、人类活动和生命财产危害。依靠数据驱动的强非线性映射能力的机器学习方法较传统数值模式预报在耗费研究资源和计算时间上更具优势。本文选取广东省珠江口为研究区域,基于卷积长短时记忆网络(Convolutional LSTM network,ConvLSTM)机器学习算法展开风暴潮漫滩预报研究,利用由再分析资料驱动的数值模式产品构建了历史台风漫滩数据集,用于机器学习模型训练、验证和测试。研究了两种预报方式,一种是基于海表面高度场的自回归预报,另一种是依赖预报风场和初始海表面高度场进行的预报;它们可以实现基于数据驱动的风暴潮漫滩预报,其中自回归预报模型表现更优。相较于传统动力学数值预报,基于数据驱动的ConvLSTM预报模型结构更为轻便,所需驱动数据更少,在缺少边界条件、地形、径流等信号时,在短临预报中仍能基本复现数值模式模拟的结果。  相似文献   

14.
Tens of millions of people around the world are already exposed to coastal flooding from tropical cyclones. Global warming has the potential to increase hurricane flooding, both by hurricane intensification and by sea level rise. In this paper, the impact of hurricane intensification and sea level rise are evaluated using hydrodynamic surge models and by considering the future climate projections of the Intergovernmental Panel on Climate Change. For the Corpus Christi, Texas, United States study region, mean projections indicate hurricane flood elevation (meteorologically generated storm surge plus sea level rise) will, on average, rise by 0.3 m by the 2030s and by 0.8 m by the 2080s. For catastrophic-type hurricane surge events, flood elevations are projected to rise by as much as 0.5 m and 1.8 m by the 2030s and 2080s, respectively.  相似文献   

15.
Two linear methods, including the simple linear addition and linear addition by expansion, and numerical simulations were employed to estimate storm surges and associated flooding caused by Hurricane Andrew for scenarios of sea level rise (SLR) from 0.15 m to 1.05 m with an interval of 0.15 m. The interaction between storm surge and SLR is almost linear at the open Atlantic Ocean outside Biscayne Bay, with slight reduction in peak storm surge heights as sea level rises. The nonlinear interaction between storm surges and SLR is weak in Biscayne Bay, leading to small differences in peak storm surge heights estimated by three methods. Therefore, it is appropriate to estimate elevated storm surges caused by SLR in these areas by adding the SLR magnitude to storm surge heights. However, the magnitude and extent of inundation at the mainland area by Biscayne Bay estimated by numerical simulations are, respectively, 22–24 % and 16–30 % larger on average than those generated by the linear addition by expansion and the simple linear addition methods, indicating a strong nonlinear interaction between storm surge and SLR. The population and property affected by the storm surge inundation estimated by numerical simulations differ up to 50–140 % from that estimated by two linear addition methods. Therefore, it is inappropriate to estimate the exacerbated magnitude and extent of storm surge flooding and affected population and property caused by SLR by using the linear addition methods. The strong nonlinear interaction between surge flooding and SLR at a specific location occurs at the initial stage of SLR when the water depth under an elevated sea level is less than 0.7 m, while the interaction becomes linear as the depth exceeds 0.7 m.  相似文献   

16.
运用昌邑市下营水文站和寿光市羊口水文站的资料,对莱州湾风暴潮的形成机制和影响系统进行了分析.结果发现:诱发莱州湾风暴潮的天气系统主要有热带气旋、温带气旋及冷锋.由于莱州湾特殊的地理构造和地形条件,风暴潮在爆发过程中,有3个比较明显的天气机制,即爆发前的东南大风、爆发中的东北大风及其持续时间、天文大潮.对风暴潮各阶段的增水量值进行了定量的估计.  相似文献   

17.
Storm surges and wind waves in the Taganrog Bay (the Sea of Azov) are simulated with the ADCIRC+SWAN numerical model, and the mechanisms of the Don River delta flooding are analyzed. It is demonstrated that the most intensive flooding of the Don River delta occurs in case of southwestern wind with the speed of not less than 15 m/s. A storm surge leads to the intensification of wind waves in the whole Taganrog Bay due to the general sea level rise. As a result, the significant wave height near the Don River delta increases by 0.5–0.6 m.  相似文献   

18.
Belmadani  Ali  Dalphinet  Alice  Chauvin  Fabrice  Pilon  Romain  Palany  Philippe 《Climate Dynamics》2021,56(11):3687-3708

Tropical cyclones are a major hazard for numerous countries surrounding the tropical-to-subtropical North Atlantic sub-basin including the Caribbean Sea and Gulf of Mexico. Their intense winds, which can exceed 300 km h−1, can cause serious damage, particularly along coastlines where the combined action of waves, currents and low atmospheric pressure leads to storm surge and coastal flooding. This work presents future projections of North Atlantic tropical cyclone-related wave climate. A new configuration of the ARPEGE-Climat global atmospheric model on a stretched grid reaching ~ 14 km resolution to the north-east of the eastern Caribbean is able to reproduce the distribution of tropical cyclone winds, including Category 5 hurricanes. Historical (1984–2013, 5 members) and future (2051–2080, 5 members) simulations with the IPCC RCP8.5 scenario are used to drive the MFWAM (Météo-France Wave Action Model) spectral wave model over the Atlantic basin during the hurricane season. An intermediate 50-km resolution grid is used to propagate mid-latitude swells into a higher 10-km resolution grid over the tropical cyclone main development region. Wave model performance is evaluated over the historical period with the ERA5 reanalysis and satellite altimetry data. Future projections exhibit a modest but widespread reduction in seasonal mean wave heights in response to weakening subtropical anticyclone, yet marked increases in tropical cyclone-related wind sea and extreme wave heights within a large region extending from the African coasts to the North American continent.

  相似文献   

19.
热带气旋致灾因子综合影响强度评估指标研究   总被引:3,自引:1,他引:3  
整理了1949—2008年311例热带气旋影响浙江时各气象站的风雨资料、海洋观测站风暴潮资料、灾情资料等,用典型相关分析、历史灾情反演等方法建立了反映热带气旋致灾因子(风、雨、风暴潮)综合影响强度和影响范围的评估模型与等级指标。研究结果将浙江热带气旋致灾因子综合影响强度分为5级,1级最强。根据评估模型与指标对311个热带气旋进行了等级评价,并分析了各等级影响强度出现频率的空间分布特征。研究表明,1~5级影响热带气旋都有可能给浙江省带来损失,特重灾情一般由1级影响热带气旋造成,2级影响热带气旋带来的灾情也很严重,年均1.1个热带气旋的综合强度在3级以上,有可能带来较严重灾情;全省各地受热带气旋影响的强度自东而西递减,其中1级(特强)影响区域主要在东部沿海地区。  相似文献   

20.
A comparative study has been conducted to investigate the skill of four convection parameterization schemes, namely the Anthes–Kuo (AK), the Betts–Miller (BM), the Kain–Fritsch (KF), and the Grell (GR) schemes in the numerical simulation of an extreme precipitation episode over eastern Peninsular Malaysia using the Pennsylvania State University—National Center for Atmospheric Research Center (PSU-NCAR) Fifth Generation Mesoscale Model (MM5). The event is a commonly occurring westward propagating tropical depression weather system during a boreal winter resulting from an interaction between a cold surge and the quasi-stationary Borneo vortex. The model setup and other physical parameterizations are identical in all experiments and hence any difference in the simulation performance could be associated with the cumulus parameterization scheme used. From the predicted rainfall and structure of the storm, it is clear that the BM scheme has an edge over the other schemes. The rainfall intensity and spatial distribution were reasonably well simulated compared to observations. The BM scheme was also better in resolving the horizontal and vertical structures of the storm. Most of the rainfall simulated by the BM simulation was of the convective type. The failure of other schemes (AK, GR and KF) in simulating the event may be attributed to the trigger function, closure assumption, and precipitation scheme. On the other hand, the appropriateness of the BM scheme for this episode may not be generalized for other episodes or convective environments.  相似文献   

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