Numerical Study of Storm Surge Inundation in the Southwestern Hangzhou Bay Region During Typhoon Chan-Hom in 2015

Storm surge inundation is a major concern in marine hazard risk assessment during extreme weather conditions.In this study,a high-resolution coupled model(the ADVanced CIRCulation model+the Simulating WAves Nearshore model)was used to investigate the storm surge inundation in the southwestern Hangzhou Bay region during Typhoon Chan-hom in 2015.The simulated hydrodynamic processes(sea surface wave and storm tide)were validated with measured data from wave buoys and tide gauges,indicating that the overall performance of the model was satisfactory.The storm surge inundation in the coastal area was simulated for several idealized control experiments,including different wave effects(wave-enhanced wind stress,wave-enhanced bottom stress,and wave radiation stress).Dike overflowing cases with different dike heights and dike breaking cases with different dike breach lengths were considered in the simulation.The results highlight the necessity of incorporating wave effects in the accurate simulation of storm surge inundation.Dike height significantly influences the magnitude and phase of the maximum inundation area in the dike overflowing cases,and dike breach length is an important factor impacting the magnitude of the maximum inundation area in the dike breaking cases.This study may serve as a useful reference for accurate coastal inundation simulation and risk assessment.     

山东省周边海域波浪能资源评估

采用第三代海浪模式SWAN对2001-2010年期间山东省周边海域的波浪状况进行了数值模拟。波浪能数值模拟值与台站观测值的比对结果表明模拟值可靠、实用。分析发现山东省周边海域平均波能流密度以2 000W/m以下为主,低于中国南部海域及欧美沿岸波能流密度。选取12个典型代表点,从波能流密度大小、变化特征、稳定性等角度分析了不同代表点的波浪能情况,发现山东周边波能流密度受气候变化影响近10年来呈上升趋势。综合不同区域波浪能大小及需求情况,建议选取山东半岛东部海域、蓬莱外围岛屿近渤海中部海域和渤海中部海域作为波浪能开发利用的首选区域。其中成山头东部海域波能流密度在冬季高达5 000 W/m,在该季节大部分区域可归为一类资源丰富区。基于此,建议开发利用中小规模的波浪能供电设备或供电设施。     

大型浅水湖泊太湖波浪特征及其对风场的敏感性分析

以空间均匀的实际风场为驱动,利用SWAN模式模拟了太湖波浪场,结果表明:SWAN模式能够较好的模拟太湖波浪的生成与传播,适用于大型浅水湖泊(太湖);同时分析了该风场驱动下下太湖风浪谱,波浪的绝对频率主要集中在0.45～1.0 Hz的中高频率段;风向与波向具有高度一致性.在同一风速下,太湖不同区域波浪成长稳定时间不同,湖心区稳定的谱峰频率在0.342～0.585 Hz之间,湾区及西山岛附近狭长水域稳定的谱峰频率在0.447～0.765 Hz之间;在同一区域,风速增大,波浪稳定时间减少,谱峰频率沿低频推移,在湖心区谱峰频率最小不低于0.340 Hz,湾区、西山岛附近狭长水域最小不低于0.447 Hz;风向的改变对湾区及西山岛附近狭长水域的波浪频谱形状影响较大.     

An ocean wind-wave climatology for the Southern Brazilian Shelf. Part II: Variability in space and time

Previously validated model results were used to characterize the wave climate over the Southern Brazilian Shelf (SBS). The low mean significant wave height over the western South Atlantic shelves was shown together with examples of cyclone-induced extreme wave fields and other typical wave conditions. The mean offshore spectra showed a bimodal shape with a predominance of S/SSW and ENE/E waves with distinctive interannual rising periods in wave energy density. Along-shelf wave energy gradients were seen near the coast with higher energy located off capes and coastal projections and energy minima between them. A considerable drop in wave energy suggests the 40 m depth as the mean wave base and consequently the lower limit of the SBS shoreface. The upper shoreface mean wave energy density varied abruptly along the shelf in response to differences in bottom declivities. The large and shallow shoreface was responsible for an intense refraction of the waves and hence very small angles of attack. Additionally, it was shown the sheltering effect caused by capes and coastal projections and a remarkable north/south energy asymmetry between them, caused by a windowing on the wave propagation to the shore. Altogether, it was possible to state that bottom friction plays a major role in wave differentiation along the SBS shoreface, thus suggesting that shelf morphology might indeed be more important to generate wave variability than the offshore wave variation itself.     

Improvement and application of a saturation based wave dissipation function in SWAN model

Wave dissipation characteristics in SWAN (Simulating Waves Nearshore) model are investigated through numerical experiments. It is found that neither the fully developed integral parameters of wind waves (significant wave height and peak frequency) nor the high frequency spectral tail can be well reproduced by the default wave dissipation source terms. A new spectral dissipation source term is proposed, which comprises saturation based dissipation above two times of peak frequency and improved whitecapping dissipation at lower frequency spectrum. The reciprocal wave age (u /c p ) is involved into the whitecapping model to adjust dissipation rate at different wind speed. The Phillips higher frequency saturation parameter in the saturation-based dissipation is no longer taken as a constant, but varies with wave age. Numerical validations demonstrate that both the wind wave generation process and higher frequency spectrum of wind waves can be well simulated by the new wave dissipation term.     

NUMERICAL SIMULATION OF TYPHOON WAVE UNDER THE INFLUENCE OF WINNIE （NO. 9711）

In this paper, the wind field provided by a meso-scale atmospheric model is employed. When main physical processes, including wave-current interactions, are considered, the latest version of the third generation wave model SWAN is applied to simulate the typhoon wave generated by Typhoon Winnie. The model results are compared with the TOPEX/POSEIDON and ERS-2 satellite altimeter data and analyzed in details. Then the distribution of wave fields are analyzed, with the results showing that applying SWAN to simulate large-scale domain can also fairly reproduce the observed features of waves and realistically reflect the distribution of typhoon waves.     

海浪灾害对贻贝脱落率的影响

海洋灾害造成贝类养殖损失的价值评估是海洋科学与水产科学交叉产生的新科学命题,同时也是渔业经济学与保险价值核算的难题.本文从海浪导致贻贝脱落致灾的角度展开研究,采用第三代海浪模型SWAN,以嵊泗海域作为研究区,通过P-Ⅲ曲线拟合、波高重现期分析,定量研究了台风期间贻贝脱落率与有效波高之间的相关性.研究表明,当有效波高达到...     

滨海核电可能最大台风浪的推算

采用当前国际流行的第三代波浪模式SWAN探讨了滨海核电工程可能最大台风浪的计算,并分析了可能最大台风浪与相伴随的可能最大风暴潮成长规律.分析得可能最大台风浪通常滞后可能最大风暴潮增水峰值,推算得到的可能最大台风浪高于遮浪海洋站观测到的最大波高,为滨海核电工程可能最大台风浪的推算提供参考.     

水动力时空变化对近岸风浪演化的影响——以渤海湾西南岸为例

采用SWAN模型和ADCIRC模型建立了风浪、潮汐和水流联合作用的耦合数值模式,并通过渤海湾西南岸实测资料对该模式进行了验证。利用该模式分析了近岸区水位和流场时空变化对风浪模拟结果的影响,计算结果表明水位变化对近岸区风浪模拟结果有显著影响,特别是中等大风过程高潮位时波高受水位影响的变化幅值可达0.5m以上,且水深越浅影响越大。但在岸滩平缓的近岸海域由于流速、流向的时空变化不太剧烈,流场作用和波浪辐射应力作用对波浪场的影响都基本可以忽略。在模拟近岸风浪过程时,应选用耦合模式。     

基于台风风场模型的台风浪数值模拟

以CCMP风场资料为背景风场,结合藤田风场模型、Myers风场模型、Jelesnianski风场模型、Holland风场模型,分别构建全新的海面风场.基于非结构三角网格,采用第三代近岸海浪模式SWAN对2011年第5号强热带风暴“米雷”产生的台风浪进行数值模拟.比较SWAN模式模拟的结果和浮标实测数据,发现风场模型能够有效提高台风中心附近3至5倍台风最大风速半径范围内风场和台风浪有效波高的模拟精度.对比4种风场模型对应的台风浪模拟结果,发现Holland风场模型模拟的有效波高与浮标实测值最接近.