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1.
ZHU Xiaohua 《中国海洋工程》2000,14(4):533-540
According to the fractal theory,the spatial fractal character of coastline is preliminarily dis-cussed on the basis of GIS in this paper.Two aspects are considered:one is the length demarcation ofcoastline with different scales,and the other is the confirmation of existence of the fractal character on dif-ferent boundaries of tidal flats.Finally,some significant conclusions are drawn:(1)The coastline ofJiangsu Province has the fractal character and its dimension is 1.0696.(2)It conforms to the exponentialcorrelation between different lengths(L)of coastline and scales(k).It conforms to the formula lgL(k)=-1.029lgk+2.9544 in the continental coastline of Jiangsu province.(3)Different boundaries of a tidal flathave fractal characters,and different fractal dimensions indicate different comparative intensities of ero-sion and deposition on the tidal flat.(4)The reciprocity between land and sea may affect the value offractal dimension of a coastline,just as the lithology,substantial constituent and geological s 相似文献
2.
Ｅｆｆｅｃｔｓｏｆａｄｖｅｃｔｉｏｎ,ｔｕｒｂｕｌｅｎｃｅａｎｄｒａｄｉａｔｉｏｎｏｎｆｏｒｍａｔｉｏｎｏｆｓｅａｆｏｇ──ＡｔｈｅｏｒｅｔｉｃａｌａｎａｌｙｓｉｓＫｅｙｗｏｒｄｓＲｅｌａｔｉｖｅｈｕｍｉｄｉｔｙｅｑｕａｔｉｏｎ,ａｄｖｅｃｔｉｏｎ,... 相似文献
3.
The Indian Ocean tsunami of December 26, 2004, not only affected the Bay of Bengal coast of India but also part of the Arabian Sea coast of India. In particular, the tsunami caused loss of life and heavy damage on some parts of the Kerala coast in southwest India. The tsunami traveled west, south of Sri Lanka, and some of the tsunami energy was diffracted around Sri Lanka and the southern tip of India and moved northward into the Arabian Sea. However, tsunami, being a long gravity wave with a wave length of a few hundred kilometers, has to take a wide turn. In that process, it missed the very southern part of the Kerala coast and did not achieve large amplitudes there. However, further north, the tsunami achieved amplitudes of upto 5 m and caused loss of life and significant damage. Here we identify the physical oceanographic processes that were responsible for selective amplification of the tsunami in certain locations. 相似文献
4.
REN Mei''e 《海洋学报(英文版)》2015,34(2):1-8
The Yellow River cut through Sanmenxia Gorge and discharged into the sea via the North China Plain in 150 ka BP; since then, around 86 000 × 108 t sediment has been transported passing Sanmenxia Gorge. Based on land use and land cover changes in Loess Plateau and other available evidence, an estimate of the Yellow River sediment budget is presented here: about 72% of the sedimentary material was trapped in the North China Plain and the remainder(i.e., 26%) escaped to the sea. At the present stage, 0.2×108 t/a suspended sediment of the Yellow River enter the northern Yellow Sea. The transport pattern is determined mainly by the shelf current system. Annually 0.2×108–0.3×108 t of suspended particles are carried to the East China Sea; the materials are derived mainly from coastal and subaqueous delta erosion associated with the abandoned Yellow River on the Jiangsu coast. Since 1972, the lower Yellow River started to have a situation of continuous no-flow. During 1996–2000, the annual water flow and sediment discharge are only 19%, as compared with normal years(i.e., average for 1950–1979). In response to global warming and increase of water diversion from the Yellow River for industrial and urban use, the sediment flux of the Yellow River to the sea will most likely remain small in the next two to three decades. 相似文献
5.
Chao Cao Zijian Mao Feng Cai Hongshuai Qi Jianhui Liu Gang Lei Shaohua Zhao Gen Liu 《海洋学报(英文版)》2023,(7):64-78
As one of the main areas of tropical storm action in the northwestern Pacific Ocean, South China experiences several typhoons each year, and coastal erosion is a problem, making the area a natural testing ground for studying the dynamic geomorphological processes and storm response of promontory-straight coasts. This study is based on three years of topographic data and remote sensing imagery of Gulei Beach and uses topographic profile morphology, single width erosion-accretion and mean change, ... 相似文献
6.
Recently, some results have been acquired with the Monte- Carlo statistical experiments in the design of ocean en gineering. The results show that Monte-Carlo statistical experiments can be widely used in estimating the parameters of wave statistical distributions, checking the probability model of the long- term wave extreme value distribution under a typhoon condition and calculating the failure probability of the ocean platforms. 相似文献
7.
Babu Nallusamy 《Marine Georesources & Geotechnology》2013,31(5):437-446
Detrital zircon crystals from beach and were subjected to morphology and Inductively coupled plasma mass spectrometry (ICPMS) analysis to assess the efficacy of the zircon composition as a provenance indicator. The inclusions of rutile and sillimanite in the lattice of the zircon support metamorphic growth. Zircon grains from relatively dry alkalic and igneous rocks tend to be dominated by {100} and {101} forms, whereas those from aluminous to calc-alkaline rocks exhibit various combinations of forms, with a predominance of {211}, and those from water-rich granites and pegmatites tend to have {110} and {101} as their dominant forms. Prismatic faces develop from zircon mainly due to the temperature of the crystallisation, but the pyramidal faces were linked to chemical factors. Light group Rare Earth Element (LREE) is enriched relative to Heavy group Rare Earth Element (HREE) in zircon. It shows significant negative anomalies in Eu, Co, Rb, and Cs and positive anomalies in V, Zn, Sr, Y, Nb, and Ba. The negative anomaly of Eu is maybe due to the redox condition operative at the time of zircon crystallisation from magma, where most of the Eu could be in Eu2+ state. The ratio of the Zr/Hf in detrital zircon shows a range of values between 6.56 and 6.25%. This supports the idea of the role ascribed to mafic rocks for the parentage of southwest coastal placer deposits. 相似文献
8.
N. P. Kurian K. Rajith B. T. Murali Krishnan N. Nirupama T. S. Murty 《Marine Geodesy》2013,36(4):277-281
During the Indian Ocean tsunami of December 26, 2004, specific observations were made by our survey team about the arrival times of several tsunami waves, their amplitudes, maximum extent of horizontal inundation on land and initial withdrawal of the ocean. Here the observations on the horizontal inundation and initial withdrawal are presented and briefly discussed. 相似文献
9.
The evolution of the natural and pristine Mediterranean coastline Port aux Princes-Sidi Daoued(Gulf of Tunis,NE-Tunisia) is studied during the period of 1887–2010 on the basis of an ancient minute of bathymetry(1887) and aerial photographs treated by numerical photogrammetric methods. Morphological changes of the coastline shows a general retreat despite the absence of the various anthropogenic actions. Adding to the drift currents and the currents of high energy that are generated by the N-W dominant waves along steeply sub-marine funds, the erosion is mainly due to the sea level rise which increased since the beginning of the 2000 s. The Port aux PrincesSidi Daoued coastline works as a single littoral cell limited by Jbel Korbous to the SW and the fishing harbor of Sidi Daoued to the N-E. 相似文献
10.
Abstract While beginning to establish a German Civil GPS Information and Observation Service in 1990, the actual and (near) future GPS market in Germany was analyzed. In addition, the feasibility of using GPS for water authority tasks has been studied during past years. Typical capabilities in this area are real‐time positioning for hydrographic surveying (kinematic application) and precise transfer of levels to tide gauges and verification at offshore positions. The article describes the user interests, the requirements, some of the test campaigns, and the derived concepts for future applications. 相似文献
11.
A thorough understanding of the biogeochemical cycling of trace metals in the ocean is crucial because of the important role these elements play in regulating metabolism in marine biotas and thus, the climate. However, a precise and accurate analysis of trace metals in seawater is difficult because they are present at extremely low concentrations in a high salt matrix. In this study, we report an analytical method for the preconcentration and separation of six trace metals, Fe, Ni, Cu, Zn, Cd and Pb, in seawater using a seaFAST automatic solid-phase extraction device, analysis by a triple quadrupole collision/reaction technique with inductively coupled plasma mass spectrometry (ICP-MS), and quantification by the isotope dilution technique. A small volume (10 mL) of seawater sample was mixed with a multi-element isotope spike and subjected to seaFAST procedures. The preconcentrate solution was then analyzed using the optimized collision/reaction cell mode of ICP-MS, with NH3 gas for Fe and Cd with a flow rate of 0.22 mL/min and He for Ni, Cu, Zn and Pb with a flow rate of 4.0 mL/min. The procedure blanks were 130 pmol/L, 3.0 pmol/L, 6.8 pmol/L, 37 pmol/L, 0.29 pmol/L and 0.42 pmol/L, for Fe, Ni, Cu, Zn, Cd and Pb, respectively. The method was validated using five reference materials (SLRs-6, SLEW-3, CASS-6, NASS-7 and GEOTRACE-GSC), and our results were consistent with the consensus values. The method was further validated by measuring full-water-column seawater samples from the subtropical Northwest Pacific Ocean, and our results demonstrated good oceanic consistency. 相似文献
12.
Fernandes Dearlyn Wu Ying Shirodkar Prabhaker Vasant Pradhan Umesh Kumar Zhang Jing 《海洋学报(英文版)》2020,39(4):18-32
Transitional ecosystems,estuaries and the coastal seas,are distinctively affected by natural and anthropogenic factors.Organic matter(OM)originating from terrestrial sources is exported by rivers and forms a key component of the global biogeochemical cycles.Most previous studies focused on the bulk biochemical and anthropogenic aspects affecting these ecosystems.In the present study,we examined the sources and fate of OM entrained within suspended particulate matter(SPM)of the Zuari River and its estuary,west coast of India.Besides using amino acid(AA)enantiomers(L-and D-forms)as biomarkers,other bulk biochemical parameters viz.particulate organic carbon(POC),δ13C,particulate nitrogen(PN),δ15N and chlorophyll a were analyzed.Surprisingly no significant temporal variations were observed in the parameters analyzed;nonetheless,salinity,POC,δ13C,PN,δ15N,glutamic acid,serine,alanine,tyrosine,leucine and D-aspartic acid exhibited significant spatial variability suggesting source differentiation.The POC content displayed weak temporal variability with low values observed during the post-monsoon season attributed to inputs from mixed sources.Estuarine samples were less depleted than the riverine samples suggesting contributions from marine plankton in addition to contributions from river plankton and terrestrial C3 plants detritus.Labile OM was observed during the monsoon and post-monsoon seasons in the estuarine region.More degraded OM was noticed during the pre-monsoon season.Principal component analysis was used to ascertain the sources and factors influencing OM.Principally five factors were extracted explaining 84.52%of the total variance.The first component accounted for 27.10%of the variance suggesting the dominance of tidal influence whereas,the second component accounted for heterotrophic bacteria and their remnants associated with the particulate matter,contributing primarily to the AA pool.Based on this study we ascertained the role of the estuarine turbidity maximum(ETM)controlling the sources of POM and its implications to small tropical rivers.Thus,changes in temporal and regional settings are more likely to affect the natural biogeochemical cycles of small tropical rivers. 相似文献
13.
ThisstudywassupportedbytheStateEducationalCommittee(SEC)ofChina.INTRODUCTIONThedissolvedorganiccarbon(DOC),ordissolvedorganicmatter(DOM),isoneofthemostimPortantorganiccarbonreservoiroftheworld,whichmayaffectthecontentofCO2intheatmospherewithatime-scaleof1OOO~1OOOOyears(Hedges,1992).Theratesofproduction,degradationortransPortationofDOCareseveralmaindynamicalparametersofDOCintheeu-photiclayer.Inthispaper,wefocusonthediurnalvariationsofDOCinordertoestimatetheseparameters.METso… 相似文献
14.
Liu Shicheng 《海洋学报(英文版)》1994,13(4):579-588
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15.
Scott E. Drummond 《Marine Geodesy》2013,36(3):381-384
16.
Kyucho is a sudden and swift current which is usually accompanied by rise of water temperature. Several features of the Kyucho in the Bungo Channel, Japan, are presented through field observations. The Kyucho in the Bungo Channel is an intrusion of warm water from the Pacific Ocean into the eastern half of the Bungo Channel, being driven gravitationally and advancing along the eastern coast of the channel. The Kyucho occurs usually in summer and seldom occurs in winter. It occurs at neap tides showing the prominent spring-neap periodicity. The modulation of the vertical mixing intensity associated with the variations of tidal current, wind and surface heating etc. is supposed to be a main cause of springneap and seasonal periodicities. 相似文献
17.
The solid state phase transformation of Cu--Al--Bi alloy under high pressure was investigated by x-ray diffraction, energy dispersive spectroscopy and transmission electron microscopy. Experimental results show that the initial crystalline phase in the Cu--Al--Bi alloy annealed at 750 °C under the pressures in the range of 0--6 GPa is α-Cu solid solution (named as α-Cu phase below), and high pressure has a great influence on the crystallisation process of the Cu--Al--Bi alloy. The grain size of the α-Cu phase decreases with increasing pressure as the pressure is below about 3 GPa, and then increases (P>3 GPa). The mechanism for the effects of high pressure on the crystallisation process of the alloy has been discussed. 相似文献
18.
ZHU Jun LIU Song QIN Yukun XING Rong’e YU Huahua CHEN Xiaolin LI Pengcheng 《海洋湖沼学报（英文）》2020,(3):841-850
Phytopathogenic fungi cause heavy negative impact on the agricultural economy,but most existing fungicides are toxic and pose a threat to both human health and environments.A green and efficient fungicide is urgently needed.Chitooligosaccharides(COSs),the degradation products of natural polysaccharide chitosan,are nontoxic and biodegradable antifungal substances.In this study,a novel type of aminourea chitooligosaccharide derivatives(AUCOS)was synthesized by successively grafting a hydrazine group and an amine-carbonyl group onto a chitooligosaccharide backbone to enhance the antifungal capability of COSs.The structures of the target compounds were identified by FTIR,1H NMR,and 13C NMR,and the degree of substitution of each product was calculated from the results of the elemental analysis.The antifungal activities of the prepared chitooligosaccharide derivatives against Fusarium solani,Verticillium albo-atrum and Phytophthora capsici were tested in vitro.The AUCOSs had better inhibitory efficiencies against the three plant pathogen fungi than that of chitooligosaccharide,of which aminourea chitooligosaccharide 2(AUCOS2)was the most promising antifungal compound,whose highest inhibition rates were 60.12%,82.95%,and 85.23%against F.solani,V.albo-atrum and P.capsici,respectively.The synthesized derivatives have good application prospects in crop protection and deserve further research. 相似文献
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