Statistical Modeling and Trend Detection of Extreme Sea Level Records in the Pearl River Estuary     

Weiwen WANG  Wen ZHOU 《大气科学进展》2017,34(3):383-396

Sea level rise has become an important issue in global climate change studies. This study investigates trends in sea level records, particularly extreme records, in the Pearl River Estuary, using measurements from two tide gauge stations in Macau and Hong Kong. Extremes in the original sea level records(daily higher high water heights) and in tidal residuals with and without the 18.6-year nodal modulation are investigated separately. Thresholds for defining extreme sea levels are calibrated based on extreme value theory. Extreme events are then modeled by peaks-over-threshold models. The model applied to extremes in original sea level records does not include modeling of their durations, while a geometric distribution is added to model the duration of extremes in tidal residuals. Realistic modeling results are recommended in all stationary models. Parametric trends of extreme sea level records are then introduced to nonstationary models through a generalized linear model framework. The result shows that, in recent decades, since the 1960 s, no significant trends can be found in any type of extreme at any station, which may be related to a reduction in the influence of tropical cyclones in the region. For the longer-term record since the 1920 s at Macau, a regime shift of tidal amplitudes around the 1970 s may partially explain the diverse trend of extremes in original sea level records and tidal residuals.  相似文献   

山西早二叠世微古植物群基本特征   总被引：2，自引：0，他引：2  

高联达 《华北地质矿产杂志》1997,12(2):103-113

山西早二叠世德古植物－孢子花粉非常丰富，共发现６０余属１５０余种。根据孢子花粉在地质演化和分布规律，自下而上可划分三个孢子带，（１）Ｓｉｎｕｔａｔｉｓｐｏｒｉｔｏｅｓ ｓｉｎｅｎｓｉｓ－Ｇｕｌｉｓｐｏｒｉｔｅｓｃｏｃｈｌｅａｒｉｓ（ＳＣ）；（２）Ｒａｄｉｔｚｏｎａｔｅｓ ｓｏｌａｒｉｓ－Ｐｏｔｏｎｉｅｉｓｐｏｒｉｔｅｓ ｂｈａｒａｄｗａｊｉｉ（ＳＢ）；（３）Ｐａｔｅｌｌｉｓｐｏｒｉｔｅｓ ｍｅｉｓ  相似文献   

吉林省南部太古宙花岗质岩石及其成因探讨   总被引：2，自引：1，他引：2  

毕守业  张殿发 《吉林地质》1991,10(3):12-23,T001

吉林省南部早太古宙高级区和晚太古宙花岗岩—绿岩带中的英云闪长岩、奥长花岗岩、花岗闪长岩等广泛发育,各岩体分布明显受太古宙边缘穹隆及中央卵形隆起控制。在岩石化学特征上明显反映出英云闪长岩—奥长花岗岩和钙碱性两个演化趋势。经稀土模拟计算,英云闪长岩和奥长花岗岩可能由石英榴辉岩经10—40部分熔融形成。  相似文献   

冰后期海面上升对长江中下游影响的探讨   总被引：8，自引：1，他引：8  

方金琪 《地理学报》1991,46(4):427-435

本文通过地质、地貌和古水文调查资料的分析,并结合计算机数值模拟研究讨论了冰后期海面上升对长江中下游河床泥沙加积、水位变化,沿岸湖泊发育及荆江河曲形成的影响。  相似文献   

海平面上升的海岸形态响应研究方法与进展   总被引：12，自引：2，他引：12  

李恒鹏  杨桂山 《地球科学进展》2000,15(5):598-603

海岸带是人口最稠密的地带,全世界几乎一半的人口生活在沿海地区[1](根据UNCEDDE的定义,以距海岸线150 km计)。受全球变化,尤其是21世纪海平面加速上升的影响,海岸将发生复杂的形态响应过程,包括海岸侵蚀、滩地淹没和湿地沉积平衡的调整等,从而危害人类的生存和发展,引起世界沿海各国政府和科学界的广泛关注。从海平面上升海岸响应历史记录研究、海岸均衡剖面研究和形态响应模拟研究三个方面概述了海平面上升海岸形态响应的国内外研究进展,并对各种研究方法的适用范围、优点及局限性进行了讨论。  相似文献   

Historical change and future scenarios of sea level rise in Macau and adjacent waters     

Lin Wang  Gang Huang  Wen Zhou  Wen Chen 《大气科学进展》2016,33(4):462-475

Against a background of climate change, Macau is very exposed to sea level rise(SLR) because of its low elevation,small size, and ongoing land reclamation. Therefore, we evaluate sea level changes in Macau, both historical and, especially,possible future scenarios, aiming to provide knowledge and a framework to help accommodate and protect against future SLR. Sea level in Macau is now rising at an accelerated rate: 1.35 mm yr-1over 1925–2010 and jumping to 4.2 mm yr-1over 1970–2010, which outpaces the rise in global mean sea level. In addition, vertical land movement in Macau contributes little to local sea level change. In the future, the rate of SLR in Macau will be about 20% higher than the global average, as a consequence of a greater local warming tendency and strengthened northward winds. Specifically, the sea level is projected to rise 8–12, 22–51 and 35–118 cm by 2020, 2060 and 2100, respectively, depending on the emissions scenario and climate sensitivity. Under the +8.5 W m-2Representative Concentration Pathway(RCP8.5) scenario the increase in sea level by2100 will reach 65–118 cm—double that under RCP2.6. Moreover, the SLR will accelerate under RCP6.0 and RCP8.5, while remaining at a moderate and steady rate under RCP4.5 and RCP2.6. The key source of uncertainty stems from the emissions scenario and climate sensitivity, among which the discrepancies in SLR are small during the first half of the 21 st century but begin to diverge thereafter.  相似文献   

太平洋几种海面要素的升降趋势及其对海平面上升的影响     

马继瑞  田素珍  张冬生  柴新敏 《热带海洋学报》1995,(4)

对ＣＯＡＤＳ资料中１９５０－１９９２年太平洋４°×８°方区的海水表层温度及海面气温、气压、风速序列数据，进行了时间序列分析。分析结果表明：太平洋海表气温和水温年上升率分别为０．００６３℃·ａ（－１）和０．００２６℃·ａ（－１）。两者的变化趋势在赤道太平洋都有一个年上升率高值区；而在东海以北的西北太平洋广大海区，都有一个年下降率的低值区。西太平洋海面气压呈上升趋势，东太平洋则相反。气温和水温的升降区域分布特征与风速分量增强和减弱的变化趋势有关。文章还指出，中国和日本沿岸今后几十年海平面变化趋势的预测模式，应以太平洋或全球海平面上升趋势的预测为基础，加上本海区海平面的局地变化订正。  相似文献   

Postglacial sea-level changes and development stages of fluvial-estuarine system     

Li Congxian 《海洋学报(英文版)》1993,12(4):573-584

-On the basis of the data obtained from the investigations on some rivers in China and Australia, the author discusses the spatial and temporal changes of various portions of fluvial-estuarine system during postglacial sea-level rising in present coastal and deltaic areas. The evolution of a fluvial-estuarine system can be divided into four development stages: early transgression, late transgression, stationary and regression. Early transgression brought about filling-in of the paleo-valley formed in low stand of sea level. In response to late transgression the estuaries were created, during the stationary stage the big swamp was developed. The regression led to estuaries to be filled with sediments and then became deltas. At the same locality the fluvial-estuarine system changed with time. In the transgressive period the lower reach of a river changed into an estuary, and then became nearshore area. In the regressive period the nearshore area changed into an estuary , and then became delta.  相似文献   

Application of finite volume coastal ocean model to hindcasting the wind-induced sea-level variation in Fukuoka bay     

Kazuhiro Aoki  Atsuhiko Isobe 《Journal of Oceanography》2007,63(2):333-339

The wind-induced sea-level variations at Hakata tidal station in winter are reproduced realistically using a one-way nested model. This nested model is constructed with a structured finite-difference Princeton Ocean Model (POM) for the Tsushima-Korea Straits, and an unstructured Finite Volume Coastal Ocean Model (FVCOM) for Fukuoka Bay divided into triangular-cell grids. The correlation coefficient and root-mean-square error between observed and modeled results are 0.742 and 1.88 [cm], respectively. Moreover, the results show that the nested model with FVCOM is more accurate than the model in which FVCOM is replaced with a high-resolution POM for Fukuoka Bay. This indicates that the nested model constructed with structured and unstructured models works effectively in hindcasting the wind-induced sea-level variations.  相似文献   

Accretion of a New England (U.S.A.) Salt Marsh in Response to Inlet Migration, Storms, and Sea-level Rise     

C.T. Roman  J.A. Peck  J.R. Allen  J.W. King  P.G. Appleby 《Estuarine, Coastal and Shelf Science》1997,45(6):717-727

Sediment accumulation rates were determined at several sites throughout Nauset Marsh (Massachusetts, U.S.A.), a back-barrier lagoonal system, using feldspar marker horizons to evaluate short-term rates (1 to 2 year scales) and radiometric techniques to estimate rates over longer time scales (¹³⁷Cs,²¹⁰Pb,¹⁴C). The barrier spit fronting theSpartina-dominated study site has a complex geomorphic history of inlet migration and overwash events. This study evaluates sediment accumulation rates in relation to inlet migration, storm events and sea-level rise. The marker horizon technique displayed strong temporal and spatial variability in response to storm events and proximity to the inlet. Sediment accumulation rates of up to 24 mm year⁻¹were recorded in the immediate vicinity of the inlet during a period that included several major coastal storms, while feldspar sites remote from the inlet had substantially lower rates (trace accumulation to 2·2 mm year⁻¹). During storm-free periods, accumulation rates did not exceed 6·7 mm year⁻¹, but remained quite variable among sites. Based on¹³⁷Cs (3·8 to 4·5 mm year⁻¹) and²¹⁰Pb (2·6 to 4·2 mm year⁻¹) radiometric techniques, integrating sediment accumulation over decadal time scales, the marsh appeared to be keeping pace with the relative rate of sea-level rise from 1921 to 1993 of 2·4 mm year⁻¹. At one site, the²¹⁰Pb-based sedimentation rate and rate of relative sea-level rise were nearly similar and peat rhizome analysis revealed thatDistichlis spicatarecently replaced this onceS. patenssite, suggesting that this portion of Nauset Marsh may be getting wetter, thus representing an initial response to wetland submergence. Horizon markers are useful in evaluating the role of short-term events, such as storms or inlet migration, influencing marsh sedimentation processes. However, sampling methods that integrate marsh sedimentation over decadal time scales are preferable when evaluating a systems response to sea-level rise.  相似文献