1979-2018年间山东半岛沿海台风浪危险性分布的数值模拟研究

台风浪灾害在山东半岛沿海时常发生,对人类生命财产和基础设施构成很大威胁,因此,对山东半岛海域台风浪的危险性分析具有重要的现实意义。本研究使用ADCIRC+SWAN耦合数值模式采用Holland模型风场与NCEP再分析风场组合的风场驱动,对1979—2018年36次台风过境期间的海浪过程进行了模拟。以台风过境时最大有效波高及历时频数作为危险性评价指标,给出了山东半岛近岸台风浪强度等级分布、历时频数分布以及危险性指数分布。研究结果显示,山东半岛北部为台风浪低危险区,台风浪强度等级低且历时短;南部二级强度（有效波高范围为1.3—2.5m）以上台风浪发生较为频繁,危险性高于北部;东部台风浪强度可以达到四级（有效波高4m以上）,危险性最高。     

SWAN和甘肃省气象风险预警产品在岷县一次强对流过程中的应用

介绍了临近预报系统(SWAN)和甘肃省中小河流洪水和山洪地质灾害气象风险预警平台的产品特征及其在2012年5月10日甘肃岷县强对流天气过程中的应用。SWAN系统表明,在强回波影响岷县期间,监测到最大反射率因子达到50 dBZ以上,其对应的高度为9 km;风暴体内垂直积分含水量和回波顶高的极值分别达到15 kg/m2和18 km,表明风暴在影响岷县期间发展旺盛;TITAN风暴产品也较为准确地预测了风暴的发展方向和趋势;定量降水预报产品QPF对本次过程的降水落区预报较为准确,但是降水量级预报偏小。总体来看,SWAN系统在本次强对流天气过程中发挥了很好的监测预警功能。甘肃省中小河流洪水和山洪地质灾害气象风险预警平台在云图、雷达、自动区域站的多资料融合监测中也发挥了重要作用,其暴雨云团加强显示、降水估测等功能都对强对流风暴有很好的监测预警作用。     

Wave prediction in a port using a fully nonlinear Boussinesq wave model

A wave forecasting system using FUNWAVE-TVD which is based on the fully nonlinear Boussinesq equations by Chen(2006) was developed to provide an accurate wave prediction in the Port of Busan, South Korea. This system is linked to the Korea Operational Oceanographic System(KOOS) developed by Park et al.(2015). The computational domain covers a region of 9.6 km×7.0 km with a grid size of 2 m in both directions, which is sufficient to resolve short waves and dominant sea states. The total number of grid points exceeds 16 millions,making the model computational expensive. To provide real-time forecasting, an interpolation method, which is based on pre-calculated results of FUNWAVE-TVD and SWAN forecasting results at the FUNWAVE-TVD offshore boundary, was used. A total of 45 cases were pre-calculated, which took 71 days on 924 computational cores of a Linux cluster system. Wind wave generation and propagation from the deep water were computed using the SWAN in KOOS. SWAN results provided a boundary condition for the FUNWAVE-TVD forecasting system. To verify the model, wave observations were conducted at three locations inside the port in a time period of more than 7 months. A model/model comparison between FUNWAVE-TVD and SWAN was also carried out. It is found that, FUNWAVE-TVD improves the forecasting results significantly compared to SWAN which underestimates wave heights in sheltered areas due to incorrect physical mechanism of wave diffraction, as well as large wave heights caused by wave reflections inside the port.     

浙江近海典型寒潮浪的数值模拟:以2015年3月和2016年1月为例

本文选用第三代海浪模式SWAN(SimulatingWAveNearshore),以CCMP(Cross-CalibratedMultiPlatform)风场作为驱动风场,数值模拟了2015年3月份和2016年1月份影响浙江省的两次典型寒潮,并将模拟结果与实测数据进行了对比,模拟误差均在20%之内,属于可以接受的范围,表明SWAN模型和CCMP风场能够满足此次寒潮浪数值模拟的需要。本文从风场的强度、最值风速、风向、持续时间等方面,对比了两次寒潮期间的寒潮风场;从寒潮浪的强度、最值波高分布、持续时间、涌浪分布区域等方面,对两次典型寒潮期间的寒潮浪时空分布的异同进行了研究。总体而言,2015年3月份寒潮的风场从强度上弱于2016年1月份寒潮, 3月份寒潮风场的主流大风是6～7级风,风向偏正北风;1月份寒潮风场的主流大风是6～8级风,风向偏西北风。2015年3月份的寒潮浪强度上弱于2016年1月份寒潮浪, 3月份寒潮浪波高变化剧烈的区域位于研究区域的东北部, 1月份寒潮浪波高变化剧烈的区域位于研究区域的中部和东部; 3月份寒潮浪的大浪主要是5级浪, 1月份寒潮浪的大浪主要是5、6级浪。当寒潮对研究区域的波浪场影响最为显著时,2015年3月份寒潮期间研究区域的北部多为涌浪,2016年1月份寒潮期间研究区域的南部多为涌浪。     

基于数值模拟的厦门湾波浪特征研究

本研究使用成熟的SWAN模型对厦门湾的波浪场进行了1a的数值模拟,通过与同期的珍珠湾波浪观测数据进行对比验证了模型的可靠性.根据模型的计算结果,分析了厦门湾年平均和夏、冬两季平均波高和波向的分布特征,厦门湾的风浪和涌浪组成,珍珠湾波浪观测海域主要的波浪能量生成和能量耗散过程.结果表明,厦门湾年平均有效波高较小,且有较明显的季节变化特征,夏季厦门湾平均有效波高较小,且湾内波向多为偏南向;冬季厦门湾平均有效波高相对较大,厦门岛北侧和东侧海域波向均为NE向.厦门湾湾内以风浪为主,涌浪较小,风浪、涌浪比较大,均在3以上;从湾外向湾内,风浪、涌浪比逐渐增加,至厦门湾南岸和泉州石井镇附近海域,风浪、涌浪比增加到5~6;在厦门湾东部和北部海域,风浪、涌浪比均在10以上.珍珠湾海域波浪最主要的能量耗散过程是由底摩擦引起的能量耗散,虽然冬季风速较大,但夏季风能输入的能量和白帽破碎耗散的能量均大于冬季;因冬季波浪相对较大,夏季底摩擦耗散的能量要小于冬季.     

WaveWatch的操作系统移植及其与SWAN嵌套接口的改进

为使WaveWatch和SWAN两种海浪预报模式能够有效地嵌套运行,将WaveWatch模式从UNIX移植到Windows系统下运行,同时对SWAN模式与WaveWatch模式的嵌套接口格点座标读取精度进行修改,使其能够应用于不规则边界的曲线网格和小间距规则网格的嵌套;作为检验个例,使用WaveWatchIII与SWAN模式多重嵌套的方法在Windows系统下对长江口海浪场进行数值模拟实验,得到了理想的模拟结果。     

东中国海浪流相互作用对水位和波高影响的数值研究

通过修改风应力和底摩擦应力的计算方式并引入波致辐射应力,以POM(Princeton Ocean Model)和SWAN(Simulating Waves Nearshore)模式为基础构建了浪流相互作用耦合模式,对1994年14号台风过程下的东中国海波流相互作用对水位和波高的影响进行了模拟研究.结果表明:浪流相互作用引起的水位变化主要出现在近岸浅水区.与岸边站点实测水位的对比显示,耦合后的结果相比非耦合结果更接近观测值,特别是在极值水位处.流的存在显著地影响有效波高的计算结果.在黄海海域,流对有效渡高的增减在极值处大于0.2 m.在台湾岛东北海域黑潮流系附近,流对有效波高的增加最大可达1.6 m.上述结果对改善近岸风暴潮和海浪预报具有指导意义.     

Multidirectional wave transformation around detached breakwaters

The performance of the new wave diffraction feature of the shallow-water spectral model SWAN, particularly its ability to predict the multidirectional wave transformation around shore-parallel emerged breakwaters is examined using laboratory and field data. Comparison between model predictions and field measurements of directional spectra was used to identify the importance of various wave transformation processes in the evolution of the directional wave field. First, the model was evaluated against laboratory measurements of diffracted multidirectional waves around a breakwater shoulder. Excellent agreement between the model predictions and measurements was found for broad frequency and directional spectra. The performance of the model worsened with decreasing frequency and directional spread. Next, the performance of the model with regard to diffraction–refraction was assessed for directional wave spectra around detached breakwaters. Seven different field cases were considered: three wind–sea spectra with broad frequency and directional distributions, each coming from a different direction; two swell–sea bimodal spectra; and two swell spectra with narrow frequency and directional distributions. The new diffraction functionality in SWAN improved the prediction of wave heights around shore-parallel breakwaters. Processes such as beach reflection and wave transmission through breakwaters seem to have a significant role on transformation of swell waves behind the breakwaters. Bottom friction and wave–current interactions were less important, while the difference in frequency and directional distribution might be associated with seiching.     

Distribution characteristics of wave energy in the Zhe-Min coastal area

A 10-year（2003–2012） hindcast was conducted to study the wave field in the Zhe-Min coastal area（Key Area OE-W2） located off Zhejiang and Fujian provinces of China. Forced by the wind field from a weather research and forecasting model（WRF）, high-resolution wave modelling using the SWAN was carried out in the study area. The simulated wave fields show a good agreement with observations. Using the simulation results, we conducted statistical analysis of wave power density in terms of spatial distr...     

Modeling of suspended sediment transport with waveinduced longshore current in Huanghe (Yellow) River Delta

A three-dimensional suspended sediment model(SED)developed by the present authors is coupled with the combinatorial model of COHERENS(Luyten et al.,1999) (the three-dimensional coupled hydrodynamical-ecological model for Regional and Shelf Seas) and SWAN(Holthuijsen et al.,2004) (the third generation wave model).SWAN is regarded as a subroutine of COHERENS and gets time-and space-varying current velocity and surface elevation from COHERENS.COHERENS gets time-and space-varying wave relevant parameters provided by SWAN.Effects of wave on current are applied in bottom shear stress,wave-induced depth-dependent radiation stress and surface drag coefficient calculation.At the same time,the damping function of suspended sediment on turbulence is introduced into COHERENS.So the sediment model SED has feed back on circulation model COHERENS.The SED obtains current as sociated parameters from COHERENS.Then a couple dhydrodynamic-sediment model COHERENS-SED being able to account for interaction between wave and current is obtained.COHERENS-SED is adopted to simulate three-dimensional suspended sediment transport in the Huanghe River delta.In terms of simulation results,there is obvious diffierence between top and bottom layer of wave-induced longshore current.The values of time series of sediment concentration gotten by COHERENS-SED have,generally,an accepted agreement extent with measurement.Significant wave heights and wave periods obtained by COHERENS-SED show that wave simulation case with current’s effect can give better agreement extent with measurement than case without current’s effect.In the meantime,suspended sediment concentration distributing rule obtained by COHERENS-SED is similar to former researches and measurement.