Sea level change under IPCC-A2 scenario in Bohai,Yellow, and East China Seas

Because of the environmental and socioeconomic impacts of anthropogenic sea level rise （SLR）, it is very important to understand the processes leading to past and present SLRs towards more reliable future SLR projections. A regional ocean general circulation model （ROGCM）, with a grid refinement in the Bohai, Yellow, and East China Seas （BYECSs）, was set up to project SLR induced by the ocean dynamic change in the 21st century. The model does not consider the contributions from ice sheets and glacier melting. Data of all forcing terms required in the model came from the simulation of the Community Climate System Model version 3.0 （CCSM3） under the International Panel on Climate Change （IPCC）-A2 scenario. Simulation results show that at the end of the 21st century, the sea level in the BYECSs will rise about 0.12 to 0.20 m. The SLR in the BYECSs during the 21st century is mainly caused by the ocean mass redistribution due to the ocean dynamic change of the Pacific Ocean, which means that water in the Pacific Ocean tends to move to the continental shelves of the BYECSs, although the local steric sea level change is another factor.     

黄海和东海的环流数值模拟研究

本文从海洋三维原始动力学方程出发,考虑真实地形及(1/4)°×(1/4)°的水平网格,同时考虑黑潮和潮流,数值模拟黄海和东海的环流系统,主要结论是:1)模拟调和常数与分布于该区的81个台站的实测调和常数相比,日分潮振幅和位相的平均绝对误差分别为1.7cm和5.2°,半日分潮M_2振幅和位相的平均绝对误差分别为4.1cm和3.7°;2)模拟的黑潮路径与长期观测结果相吻合;3)黑潮进入研究区域后,一分支从台湾东北部分离出来后进入东海,影响可达29°N,这与海洋普查的调查结果以及文献中的结果一致;4)黑潮的一个分支北上形成对马暖流的一部分,且对马暖流是多源的,对马暖流通过对马海峡进入日本海,同时模拟结果显示一支由日本海进入研究区域的海流,后者需进一步调查和研究;5)黄海表层流主要沿南下方向,在近底层。中国和朝鲜的沿岸流为南下,黄海底层海盆由一顺时针方向的环流控制着,在中国成山头以外的北黄海底层,存在一较弱的逆时针环流。     

黄东海表层悬沙浓度次级锋面及其季节变化初探

选取了1998-2002年连续五年的比较完整的由SeaWiFS卫星水色遥感资料反演得到的黄东海表层悬沙浓度资料,辅以同期的归一化离水辐射率资料,对黄东海表层悬沙浓度(次级)锋面的分布特征及其季节变化进行了分析,得到以下结论:在黄东海海域主要存在8个悬沙浓度锋面,冬季各主要锋面都发展成熟,展现出良好的形态;在黄东海大致存在两种悬沙浓度锋面,一种是高悬沙浓度锋面,对应悬沙浓度等值线10～30mg/L,另一种是低悬沙浓度锋面,即次级锋面,对应悬浮泥沙浓度等值线2～6mg/L。悬沙次级锋面季节变化显著,2月向外海输运最远,8月离岸最近,5月和10月为过渡时期;冬半年,次级锋面的分布范围与锋面强度成反比;黄东海悬沙次级锋面的季节变化是水动力条件季节变化的结果和反映,其中风浪的掀沙作用和冬夏季显著不同的环流结构是主要控制因子。次级锋面的存在,在远源区现代沉积中心的形成中起关键作用。     

基于QN混合风场的东中国海风能资源分析

利用1999年8月～2009年7月近10年的QN混合风场资料,计算了东中国海的风能密度,并就其特征进行分析.结果表明:我国的渤海风能资源相对黄海和东海较贫乏,但仍处于可开发的范围,东海属于风能资源的较富集区.     

长江口盐水入侵对径流变异和海平面变化的响应

基于1960—2019年长序列实测径流、潮位资料,采用Mann-Kendall检验和Theil-Sen估计分析了长江口径流变异和海平面变化趋势,结合MIKE21水动力模型和蒙特卡罗方法,提出了计算盐度超标率的方法,并对长江口盐水入侵风险进行了评估。结果表明：径流对数值的年方差和平均海平面高度分别呈显著下降和上升趋势;预计到2060年和2100径流对数值的年方差分别减小30%和60%,平均海平面高度分别上升0.2 m和0.4 m;海平面上升增大了长江口盐度超标率,河口中段的盐度超标率增幅相对明显;随着径流变异性的减小,长江口沿线盐度超标率呈交错增减变化;2060年和2100年长江口平均盐度超标率将从46.9%增大到52.2%和54.9%,其中海平面变化对长江口盐水入侵的影响显著大于径流变异。     

浙江省沿海海平面上升及预测

利用浙江沿海11个验潮站实测潮位资料，采用线性和非线性方法，分析浙江沿海海平面的上升变化，并对未来50年浙江沿海的海平面上升趋势进行预测。     

ENSO对珠江三角洲洪水影响

根据珠江三角洲1951—2008年34个潮位站年极高水位资料和Nino 3.4区海洋尼诺指数资料,采用GEV分布进行洪水频率计算,分析不同重现期洪水位的变化情况,对比分析洪水位重现水平在1980年前后空间变化特征。采用滑动相关分析,探讨珠江三角洲近50年来洪水位对ENSO(El Nino/La Nisa-Southern Oscillation)响应的年际变化特征。结果表明,珠江三角洲整个区域的洪水频率分布自下游到上游逐渐增大,沿海比中上游地区更易受洪涝灾害威胁。绝大多数站点不同重现期洪水位变化趋势一致,部分站点水位变化方向不完全一致。洪水位有减小趋势的站点分布在三角洲上游地区,中下游地区则主要呈现为增长趋势。洪水位与ENSO之间年际变化关系有明显阶段性,在1980年发生明显改变,跃变前后滑动相关系数的符号或强度有明显差异。洪水位对不同季节的ENSO响应不同,不同时期ENSO对洪水位的影响不同。     

Monitoring shoreline shift under rapid sea-level change on the Caspian Sea observed over 60 years of satellite and aerial photo records

The Caspian Sea is the world’s largest inland water body and endures rapid fluctuations in sea level and shoreline changes. The present study investigates and analyzes shoreline changes in the two areas of Tajan and Sefidrud on the southern coasts of the Caspian Sea using aerial photos, affixed with TM, ETM, and OLI images from Landsat satellites, as well as images rendered by Google Earth, all within the time period from 1955 to 2018. Shoreline changes were analyzed using the waterline algorithm on high resolution aerial photos and images from the Google Earth engine. Shoreline extraction on Landsat images was conducted after comparing six different indices, of which the wetness index exhibited the least mean error (1.3 m). Calculations on shoreline changes were undertaken in 4 time periods using the DSAS extension in Arc GIS 10.3 including 1955–1977, 1977–1995, 1995–2002 and 2002–2018. Coastal accretion on the Tajan shoreline after decreases in sea level were evident in the first, third, and fourth time periods, while coastal erosion was discernible in the second time period during significant increases in sea level. The situation, however, was different for the coasts of Sefidrud. The shoreline was divided into 14 distinct parts where the shoreline change rate was inconsistent with the actual changes in sea level. The dismatch between sea level and shoreline changes in the Sefidrud region points to the existence of a different set of factors, in addition to the sea level, which significantly affect the status of the coastlines.     

Temporal variability of streamflow and plant species abundance on islets as they relate to ENSO events downstream from an inversion‐type reservoir

The goal of this study was to analyse the impacts of the sequence of 1 El Niño (2009–2010) and 2 La Niña (2007–2008 and 2010–2011) events on the interannual variability of daily streamflow during the growing season (April to September) and grass species abundance downstream from the Taureau reservoir (4,070 km²) on the Matawin River (Quebec, Canada). This reservoir has inverted the natural annual cycle of streamflow: Maximum flows occur in winter and minimum flows in springtime during snowmelt. Comparison of daily flows over the period from 2006 to 2011 using various statistical tests revealed a significant increase in flows released downstream from the reservoir during the 2 La Niña events, with a particularly large increase in the growing season (April to May) during the 1st La Niña event (2007–2008). In contrast, during the El Niño event (2009–2010), streamflow decreased significantly. As far as the abundance of plant species is concerned, the total number of obligate wetland species increased significantly after the 1st La Niña event and then decreased after the El Niño event, along with the total number of terrestrial species. The study shows that relatively intense El Niño Southern Oscillation events can have significant implications for the management of flows released downstream from reservoirs in Quebec and hence affect plant species abundance on islets.     

ENSO事件及其对贵州夏季旱涝的影响

对近47年以来出现的14次ENSO事件分析，发现1991年～1997年厄尔尼诺赤道增暖首先出现位置和增暖开始的时间，与一般认为的“上半年发生的厄尔尼诺，海温正距平具有自东向西传播的特征，而下半年发生的厄尔尼诺，海温正距平具有自西向东传播的特征”不一致；并分析赤道东太平洋海温异常增暖对应初夏西太平洋副热带高压持续偏强、位置偏南，与我省夏季降雨多、夏旱轻有较好的一致性。     

Kuroshio intrusion into the South China Sea

1. INTRODUCTION Under the role of the geostrophic β -effect, wind driven ocean circulation encounters the western boundary and forms the westward intensification current with the longitude movement along the boundary in the direction of the leaving equat…     

Contributors to tidal duration asymmetry with varied coastline configurations on western shelf of Yellow Sea

Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development. A key criterion for making this decision is the resilience to coastal flooding, which depends on the ability to predict tidal level. Tidal duration asymmetry (TDA) is a key parameter in determination of the arrival and duration of flood tides. This study selected the western inner shelf of the Yellow Sea (WYS) as the study area and investigated the responses of TDA to different shoreline configurations and relative sea level rise. The responses of TDA to shoreline reconstruction yielded spatial variability locally and remotely. In the nearshore area, the responses of TDA to the complex ocean environment mainly originated from the combined functions of reflection, bottom friction, and advection, which controlled the energy transfer from M₂ or S₂ constituents to their overtides or compound tides. The sensitivity of TDA to coastline typologies was not limited to coastal waters but could stretch over the entire inner shelf. The vulnerability of tidal responses was due to the displacement of the M₂ amphidrome of the Kelvin wave on the WYS, which in turn changed tidal energy fluxes over the regime. The relative sea level rise could intensify the feedback of TDA to seawalls and land reclamation.

     

南海北部海域海底沙波演化特征

在对沙波的成因、形态以及运移机制充分探讨的基础上,给出了预测计算海底沙波形成与运移规律的理论模式。以此为基础建立了南海北部海域海底沙波波长及沙波移动的数学模型,对较大范围内的沙波形态及其运移规律进行了计算,成果表明计算区域海底沙波在正常水流条件下迁移速率相对较小,可视为比较稳定的地貌类型,为该海域海底工程实施提供参考。     

华东地区某大坝坝基水质特征及防渗帷幕性状评价

大坝运行后水环境发生剧变,库水中水质特征变化可导致坝基地下侵蚀性的加强,侵蚀大坝及坝基帷幕等结构,使坝基帷幕防渗材料逐渐流失,以致帷幕防渗效果大大降低,从而造成坝基帷幕防渗性能的衰减。因此,需要对运行多年后的大坝防渗帷幕性状评价进行评价。以华东地区某水电站重力坝为例,对坝前、坝体、坝基等点位进行水样采集分析,研究不同点位水样的pH值、水化学成分及胶状析出物等水质特征,详细论证大坝坝基帷幕防渗性状,判定帷幕总体防渗性状完好,局部存在薄弱部位。     

华东地区某大坝坝基水质特征及防渗帷幕性状评价

大坝运行后水环境发生剧变,库水中水质特征变化可导致坝基地下侵蚀性的加强,侵蚀大坝及坝基帷幕等结构,使坝基帷幕防渗材料逐渐流失,以致帷幕防渗效果大大降低,从而造成坝基帷幕防渗性能的衰减。因此,需要对运行多年后的大坝防渗帷幕性状评价进行评价。以华东地区某水电站重力坝为例,对坝前、坝体、坝基等点位进行水样采集分析,研究不同点位水样的pH值、水化学成分及胶状析出物等水质特征,详细论证大坝坝基帷幕防渗性状,判定帷幕总体防渗性状完好,局部存在薄弱部位。     

南海海啸反问题预报模式

通过COMCOT海啸模型计算南海马尼拉海沟潜在震源区单元板块单位滑动产生的海啸波在区域内传播过程,将计算结果组成相应南海海啸波数据库.采用浮标监测数据与数据库结合通过最小二乘法构建南海海啸预报模式.以假想马尼拉海沟发生8.3级地震海啸为案例,应用预报模式对华南地区进行海啸预测,采用30 min和60 min监测数据分别反演计算,在三个近岸验证点的波高和正问题结果比较误差分别在25％和17％之内,到达时间及相位基本一致,预报的计算时间在2 min以内.     

天荒坪蓄能电站在华东网的调峰作用及效益

天平抽水蓄能电站是华东地区兴建的第一座日调节纯抽水蓄能电站，装机总容量１８０万ＫＷ，电站位于浙江省安吉县境内，太湖流域西茹溪支流大溪上，距杭州５７ｋｍ，距上海１７５ｋｍ，接近华东电网的负荷中心。电站装６台３０万ＫＷ立轴、可逆、混流式水泵水轮发电电动机组。该工程于１９９４年３月正式开工，１９９８年１０月首台机组投运，至１９９９年底共投运４台。它的建设对增强华东电网调峰、调频能力，提高电网安全经济运行     

PDO和ENSO指数与三江源地区径流变化的相关关系研究

三江源地区是长江、黄河以及澜沧江的发源地。开展该地区水资源预测研究对于该区生态环境保护以及下游水资源合理规划与调配都具有重要意义。现对三江源地区5个主要水文站1957年-2005年的月径流序列,通过统计相关分析,探讨三江源地区径流变化、融雪径流时间变化与ENSO(El Nino-Southern Oscillation)、PDO(Pacific Decadal Oscillation)等大尺度气候信号月/月组合值的关系。研究表明,三江源的香达站(r=0.3,P=0.048)、直门达站(r=0.324,P=0.023)与唐乃亥站(r=0.367,P=0.009)年径流量与水文年前一年8月、9月SOI之和值在95%置信水平上存在正相关关系。香达站(r=-0.359,P=0.017)、唐乃亥站(r=-0.313,P=0.029)以及直门达站(r=-0.314,P=0.028)的月径流与相应前8个月的Nio3.4值呈显著负相关。三江源地区的5个水文站点的月径流都与相应的前第9个月的PDO值呈负相关,且都在95%置信水平上显著。三江源地区融雪径流时间与水文年前一年8月的PDO呈负相关,其中香达站(r=-0.359,P=...     

华东电网抽水蓄能电站电能计划安排方式优化算法

针对华东电网调度管辖抽水蓄能电站容量不断增加的现状,综合考虑预计用电负荷、联络线送受电计划、电站出力特性等多种因素,为了最大限度地节能降耗、提高火电机组发电负荷率,以考虑抽水蓄能电站电能计划后的发电负荷率最大为优化目标,在实际工作中研究提出了华东电网抽水蓄能电站电能计划安排方式优化算法。实践应用中,华东电网已根据此优化算法开发了计算程序,用以为电能计划编制人员提供决策依据。经实践检验,该计算程序明显提高了华东电网抽水蓄能电站电能计划的编制质量和工作效率。