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1.
跨海桥隧工程设计需要推算工程位置不同重现期设计流速,由于现场缺乏长期实测流速资料,设计流速推算存在很大困难。研究提出了采用不同重现期典型风暴潮过程推算河口海岸设计流速的数值模拟方法,对河口地区考虑洪水径流与风暴潮流的耦合。在依据澳门验潮站1925—2003年实测潮位资料分析珠江口海域风暴潮过程特征的基础上,结合潮位和潮差年极值频率分析结果构建了不同重现期典型风暴潮潮型。采用平面二维水动力数学模型模拟了不同重现期风暴潮和上游一般洪水组合条件下珠江口水域的流场,得出港珠澳大桥沿线各控制点处设计流速。 相似文献
2.
开展无资料地区洪水模拟研究具有重要意义。针对于无资料地区洪水预报的挑战性,以我国东南沿海典型山区小流域—梅溪流域为例,构建了山区水文-城区水动力耦合模型。山区水文模型经河道计算流量率定后,模拟了2016年"莫兰蒂"台风场景下的城区洪水淹没过程。结果表明,模拟最大淹没水深结果与城区17处洪水淹没痕迹吻合较好,验证了耦合模型的适用性。分析了"莫兰蒂"台风场景下重点区域的淹没水深与历时。此外,根据不同重现期的设计降雨,分析了城区淹没水深与淹没范围。同时,重现期越大,城中心区域洪水滞后时间越短。 相似文献
3.
为研究城市下垫面空间格局对社区尺度内涝过程的影响, 构建社区尺度下的8种不同城市下垫面空间格局, 并建立相应的城市内涝数值模型, 模拟6种不同重现期(2 a, 5 a, 10 a, 20 a, 50 a, 100 a)设计降雨条件下内涝过程; 基于不同下垫面和降雨情景下的内涝数值模拟结果, 分别从内涝淹没特征值、时空变化过程、水动力特性等方面开展分析。结果表明: ①城市下垫面空间格局对社区尺度内涝淹没特征值、淹没时空变化过程和内涝积水流速分布均有一定影响; ②设计降雨重现期为2 a、5 a、50 a和100 a时, 不同城市下垫面空间格局间的积水总量峰值、积水面积峰值、区域最大积水深差别显著, 重现期为10 a和20 a时, 无明显差别; ③内涝积水较大流速分布主要集中在道路交汇处, 在本研究构建的情景中, 最大流速的差值占比为31.9%;④在8种不同城市下垫面空间格局中, 环形放射型格局在应对内涝方面更具弹性。本研究可为城市下垫面空间管控和城市内涝形成机理研究提供科学参考。 相似文献
4.
通过近年来对江苏沿海有影响的台风暴潮作用前后的滩面高程观测,结合台风浪资料分析,探究了江苏中部沿海潮滩对风暴潮的响应过程。结果显示:潮滩剖面在风暴潮期间呈现"低滩侵蚀、沿岸输运、高滩稳定",明显区别于沙质海岸在台风浪作用下"高滩侵蚀、离岸输运、低滩淤积"的演变特征。应用Delft3D平面二维水沙动力数学模型,模拟了正常天气和台风浪情况下的滩面演变,从动力学角度解释了潮滩间不同区域演变特征差异的原因,论证了台风浪对地貌演变的短历时"插曲式"作用,阐明了涨潮优势流是风暴侵蚀后泥沙沿岸向输运的主控因子。 相似文献
5.
为实现对复式河道大尺度漫滩洪水的快速模拟,结合洪水在滩槽行洪特点和河道一维、二维水动力学模型研究成果,在主槽与滩地分别划分为矩形和三角形网格,以左右滩唇为分界实现两网格系统嵌套;建立主槽一维水动力学数学模型,内插大断面间网格处的水力因子,在滩地采用简化的二维水动力学模型模拟滩槽间、滩地网格间水量交换,实现主槽一维与滩地二维模型侧向耦合。利用黄河下游“96·8”大洪水实测资料,对花园口至夹河滩河段洪水演进过程验证,结果表明该方法模拟精度较高,能够利用该模型模拟复式河道大漫滩洪水过程。 相似文献
6.
为研究冲积性河流造床机理,基于能量耗散原理分析河床调整与水沙过程（变异特性）间的关系十分必要。以黄河游荡型河段为例,利用实测资料分析和平面二维水沙数值模拟方法,进行了各种洪水泥沙条件下河流冲淤规律的探讨。研究发现平滩面积、河相系数与径流泥沙特征值间存在的关联性映射出冲积性河流能量关系中的制约机制;不同洪水泥沙过程的河床冲刷强度变化具有阶段性,主槽累积刷槽效应与洪水泥沙过程有密切响应关系;高效输沙的洪水过程通过塑造最适宜的河床断面形态,能实现最佳输沙效率与主槽的最大冲刷。在不同漫滩洪水条件中,综合系数Φ最大时的洪水过程具有最大累积刷槽效应,因此对应流量可作为黄河下游漫滩洪水的调控指标。 相似文献
7.
黄河下游主槽两侧修建的生产堤通常仅能抵御中小洪水,用于保护滩区农田与村庄安全;当遭遇大洪水引发生产堤溃决时,漫滩洪水会严重威胁滩区群众的生命财产安全。当前研究溃堤洪水的传播过程与演进机理多采用数值模拟,而原型观测及模型试验成果十分有限。通过溃堤漫滩洪水的概化模型试验,模拟了生产堤溃决后主槽内的水位变化及不同程度漫滩洪水的传播过程。试验结果表明:(1)溃堤后漫滩水流以涨水波的形式向滩区迅速传播,主槽内水位具有先降低,然后维持稳定,再升高,最后趋于稳定的变化过程,且溃口上、下游水位变化速率不同;滩区水位总体表现为持续升高,最后趋于稳定的趋势。(2)漫滩洪水波的波前到达时间主要与滩区地形及距溃口的距离有关,波前首先以溃口为中心呈近似对称式椭圆形分布,而后转变为非对称分布;溃堤水流在滩区传播过程中伴有水跃发生,水跃发生的位置由距溃口较远处逐渐趋向溃口位置。(3)溃口流量与溃口内外水位差直接相关,呈先减小、然后维持稳定、再减小最后为0的变化特性。研究成果不仅可以提升对溃堤洪水在滩区演进规律的认识,丰富溃堤洪水动力学理论,还可为数学模型验证提供实测资料。 相似文献
8.
风暴潮灾害风险评估研究综述 总被引：3，自引：0，他引：3
我国是受风暴潮影响最严重的少数国家之一,风暴潮灾害致灾机理的研究在过去几十年取得了极大的进展,而风暴潮脆弱性评估和综合风险评估还不能满足风暴潮灾害风险管理的需求.系统总结了风暴潮危险性、脆弱性、综合风险评估及其应用的研究进展,重点分析了典型重现期风暴潮估计、可能最大风暴潮计算、风暴潮物理脆弱性和社会脆弱性评估以及风暴潮风险评估及其应用的研究进展及不足,并对我国风暴潮风险评估急需解决的问题以及未来的研究重点进行了展望,指出了风暴潮灾害风险评估的模型化、系统化、定量化是未来风暴潮风险评估研究的发展趋势,风暴潮灾害的未来风险评估还需考虑全球气候变化以及海平面上升等因素的影响,而风暴潮灾害承灾体脆弱性的定量评价是风暴潮综合风险评估的重点和难点. 相似文献
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10.
大荔县是关中盆地的农业大区,也是陕西经济最活跃的地区之一,而水资源不足成为经济快速发展的制约因素。本文在收集资料、水文地质调查的基础上,通过对地下水采样分析测试,采用单项指标法,对大荔县地下水水质进行综合评价,找到3处地下水质安全区域;采用整理水文勘探资料、地下水流数值模拟方法对水质安全区地下水资源量、天然资源量、地下水现状开采量以及地下水开采潜力进行定量评价;结合大荔县安全饮用水缺水现状,对农村安全供水进行区划;结果表明:地下水质安全区只有黄河漫滩南部地区具有1 687×104 m3/a的开采潜力,对解决大荔县安全饮用水供需矛盾具有重要意义。 相似文献
11.
A. D. Rao P. L. N. Murty Indu Jain R. S. Kankara S. K. Dube T. S. Murty 《Natural Hazards》2013,66(3):1431-1441
The devastation due to storm surge flooding caused by extreme wind waves generated by the cyclones is a severe apprehension along the coastal regions of India. In order to coexist with nature’s destructive forces in any vulnerable coastal areas, numerical ocean models are considered today as an essential tool to predict the sea level rise and associated inland extent of flooding that could be generated by a cyclonic storm crossing any coastal stretch. For this purpose, the advanced 2D depth-integrated (ADCIRC-2DDI) circulation model based on finite-element formulation is configured for the simulation of surges and water levels along the east coast of India. The model is integrated using wind stress forcing, representative of 1989, 1996, and 2000 cyclones, which crossed different parts of the east coast of India. Using the long-term inventory of cyclone database, synthesized tracks are deduced for vulnerable coastal districts of Tamil Nadu. Return periods are also computed for the intensity and frequency of cyclones for each coastal district. Considering the importance of Kalpakkam region, extreme water levels are computed based on a 50-year return period data, for the generation of storm surges, induced water levels, and extent of inland inundation. Based on experimental evidence, it is advocated that this region could be inundated/affected by a storm with a threshold pressure drop of 66 hpa. Also it is noticed that the horizontal extent of inland inundation ranges between 1 and 1.5 km associated with the peak surge. Another severe cyclonic storm in Tamil Nadu (November 2000 cyclone), which made landfall approximately 20 km south of Cuddalore, has been chosen to simulate surges and water levels. Two severe cyclonic storms that hit Andhra coast during 1989 and 1996, which made landfall near Kavali and Kakinada, respectively, are also considered and computed run-up heights and associated water levels. The simulations exhibit a good agreement with available observations from the different sources on storm surges and associated inundation caused by these respective storms. It is believed that this study would help the coastal authorities to develop a short- and long-term disaster management, mitigation plan, and emergency response in the event of storm surge flooding. 相似文献
12.
A nested model for the simulation of tides and storm surges in the Bohai Sea, China, has been developed based on the three-dimensional finite-volume coastal ocean model. The larger domain covers the entire Yellow Sea and Bohai Sea with a horizontal resolution of ~10 km, and the smaller domain focuses on the Bohai Sea with a fine resolution up to ~300 m. For the four representative storm surges caused by extratropical storms and typhoons, the simulated surge heights are in good agreement with observations at coastal tide gauges. A series of sensitivity experiments are carried out to assess the influence of coastline change due to land reclamation in recent decades on water levels during storm surges. Simulation results suggest that changes in coastline cause changes in the amplitude and phase of the tidal elevation, and fluctuations of surge height after the peak stage of the storm surges. Hence, for the assessment of the influence of coastline changes on the total water level during storm surges, the amplitudes and phases of both the tidal and surge heights need to be taken into account. For the three major ports in the Bohai Bay, model results suggest that land reclamation has created a coastline structure that favors increasing the maximum water level by 0.1–0.2 m. Considering that during the storm surges the total water level is close to or even exceeds the warning level for these ports, further increasing the maximum water level by 0.1–0.2 m has the potential to cause severe damages and losses in these ports.
相似文献13.
Storm Surge Hazard in Canada 总被引：3，自引：2，他引：3
Storm surges occur frequently in Canada mainlydue to extra-tropical cyclones (ETC'S) also referred to as winter storms. The hurricanes from the Gulf of Mexico can affect eastern Canada including Lakes Ontario and Erie regions, after they get modified and acquire some extra-tropical characteristics. Storm surges have occurred both on the Atlantic and Pacific coasts, in the Gulf of St.Lawrence, St.Lawrence Estuary, Bay of Fundy, Hudson Bay, James Bay, Northwest Passage, Beaufort Sea, the Great Lakes and other large lakes such as Lake Winnipeg.Squall lines which are embedded in the largerscale synoptic systems like the ETC'S could also generate storm surges (referred to as edge waves) in Lakes Huron, Erie and Ontario (edge waves are most prominent in Lake Michigan, but Canada has no territory touching this lake). The effect of climate change on storm surges in the Canadian water bodies could be two-fold. First, there may be some possible intensification of the weather systems and the associated wind fields resulting in bigger surges. Second, and probably even more relevant, is an east-west and north-south shift in the tracks of the weather systems, which could expose certain new areas to storm surge activity.A high priority for proper assessment of storm surge hazard is the production of maps showing inundation zones for storm surges that might occur in populated coastal areas. Such maps can be used to improve public awareness of tsunamis and for planning purposes (i.e., to reduce or avoid the risk). 相似文献
14.
A modeling study of coastal inundation induced by storm surge,sea-level rise,and subsidence in the Gulf of Mexico 总被引：2，自引：2，他引：0
Zhaoqing Yang Taiping Wang Ruby Leung Kathy Hibbard Tony Janetos Ian Kraucunas Jennie Rice Benjamin Preston Tom Wilbanks 《Natural Hazards》2014,71(3):1771-1794
The northern coasts of the Gulf of Mexico (GoM) are highly vulnerable to the direct threats of climate change, such as hurricane-induced storm surge, and such risks are exacerbated by land subsidence and global sea-level rise. This paper presents an application of a coastal storm surge model to study the coastal inundation process induced by tide and storm surge, and its response to the effects of land subsidence and sea-level rise in the northern Gulf coast. The unstructured-grid finite-volume coastal ocean model was used to simulate tides and hurricane-induced storm surges in the GoM. Simulated distributions of co-amplitude and co-phase lines for semi-diurnal and diurnal tides are in good agreement with previous modeling studies. The storm surges induced by four historical hurricanes (Rita, Katrina, Ivan, and Dolly) were simulated and compared to observed water levels at National Oceanic and Atmospheric Administration tide stations. Effects of coastal subsidence and future global sea-level rise on coastal inundation in the Louisiana coast were evaluated using a “change of inundation depth” parameter through sensitivity simulations that were based on a projected future subsidence scenario and 1-m global sea-level rise by the end of the century. Model results suggested that hurricane-induced storm surge height and coastal inundation could be exacerbated by future global sea-level rise and subsidence, and that responses of storm surge and coastal inundation to the effects of sea-level rise and subsidence are highly nonlinear and vary on temporal and spatial scales. 相似文献
15.
Impact of Sea-level Rise and Storm Surges on a Coastal Community 总被引：7，自引：7，他引：7
A technique to evaluate the risk of storm tides (the combination of a storm surge and tide) under present and enhanced greenhouse conditions has been applied to Cairns on the north-eastern Australian coast. The technique combines a statistical model for cyclone occurrence with a state-of-the-art storm surge inundation model and involves the random generation of a large number of storm tide simulations. The set of simulations constitutes a synthetic record of extreme sea-level events that can be analysed to produce storm tide return periods. The use of a dynamic storm surge model with overland flooding capability means that the spatial extent of flooding is also implicitly modelled. The technique has the advantage that it can readily be modified to include projected changes to cyclone behaviour due to the enhanced greenhouse effect. Sea-level heights in the current climate for return periods of 50, 100, 500 and 1000 years have been determined to be 2.0 m, 2.3 m, 3.0 m and 3.4 m respectively. In an enhanced greenhouse climate (around 2050), projected increases in cyclone intensity and mean sea-level see these heights increase to 2.4 m, 2.8 m, 3.8 m and 4.2 m respectively. The average area inundated by events with a return period greater than 100 years is found to more than double under enhanced greenhouse conditions. 相似文献
16.
针对外海海平面上升对中国沿海潮波系统和潮汐水位可能带来的影响,通过西北太平洋潮波数学模型对边界海平面上升后潮波变化进行了数值模拟。研究发现边界海平面上升后,在无潮点附近东侧迟角增加,西侧迟角减小;无潮点北侧振幅增加,南侧振幅减小;辽东湾、渤海湾顶、辽东半岛东海域、海州湾至鲁南沿海、苏北沿海、台湾海峡至浙东沿海和南海平均潮差增加,海平面上升0.90 m后潮差最大增幅达0.40 m;长江口、杭州湾至对马海峡、朝鲜西海岸和莱州湾海域潮差减小。随着海平面上升量值的增加,渤海、台湾海峡潮差变化速率相对稳定,黄海、东海和南海站位变化速率有所变动;平均高水位的变化趋势与潮差一致;潮差增加的区域,高水位抬升幅度超过边界海平面上升幅度。海平面上升引起的高水位超幅变化,增加了沿海地区对风暴潮和其他灾害防护的风险。 相似文献
17.
《China Geology》2019,2(1):26-39
Bulletins of China’s National Sea Level show that the average rising rate of sea-levels in China is 3.3 mm/a over the past 40 years, with an obviously accelerated rising trend in the last decade. The rate of relative sea-level rise of the Yangtze River Delta reached >10 mm/a after considering the land subsidence, and Bohai Bay is even greater than 25 mm/a. The impact of the sea level rise to the coastal area will be greater in the coming years, so carrying out an assessment of this rising trend is urgent. This paper, taking the coastal area of Tianjin and Hebei as examples, comprehensively evaluates the impact of sea-level rise through multitemporal remote sensing shoreline interpretation, ground survey verification, elevation measurements for both seawall and coastal lowlands. The results show that the average elevation of the measured coastal areas of Tianjin and Hebei is about +4 m, and the total area of >100 km2 is already below the present mean sea level. More than 270 km, ca. 31% of the total length of the seawall, cannot withstand a 1-in-100-year storm surge. Numerical simulations of the storm flooding on the west coast of Bohai Bay, for 1-in-50-years, 1-in-100-years, 1-in-200-years and 1-in-500-years, show that if there were no coastal dykes, the maximum flooding area would exceed 3000 km2, 4000 km2, 5300 km2 and 7200 km2, respectively. The rising sea has a direct and potential impact on the coastal lowlands of Tianjin and Hebei. Based on the latest development in international sea-level rise prediction research, this paper proposes 0.5 m, 1.0 m and 1.5 m as low, middle and high sea level rise scenarios by 2100 for the study area, and combines the land subsidence and other factors to the elevation of the existing seawall. Comprehensive evaluation results indicate that even in the case of a low scenario, the existing seawall will not be able to withstand a 1-in-100-years storm surge in 2030, and the potential flooding areas predicted by the model will become a reality in the near future. Therefore, the seawall design in the coastal areas of Tianjin and Hebei must consider the combined effects of land subsidence, sea level rise and the extreme storm surges caused by it.©2019 China Geology Editorial Office. 相似文献
18.
Bay of Bengal cyclone extreme water level estimate uncertainty 总被引：4，自引：3，他引：1
19.
Storm surges in the Bohai Sea are not only associated with tropical cyclones and extra-tropical cyclones, but also cold-air
outbreaks. Cold-air outbreaks attack China from four major tracks, with each track having its own prevailing wind over the
Bohai Sea. As the pressure field of cold-air outbreaks can be converted into the surface wind, storm surges can be investigated
by the pressure field of cold-air outbreaks entirely. This paper took the different major tracks, pressure field, and high
wind period into consideration and constructed 20 scenarios to describe the actual situation of cold-air outbreaks. Based
on the results modeled by FVCOM, the influence of various cold-air outbreaks on the maximum surge in the Bohai Sea and the
probability of the surge elevation at three typical tide gauges were investigated. Finally, a powerful decision-making tool
to estimate storm surges induced by cold-air outbreaks was provided. 相似文献