山溪性可冲性强潮河口曹娥江高水位初步研究

应用多年的实测资料 ,分析了曹娥江河口高水位成因 ,结果表明 ,曹娥江河口洪水位具有山溪性和可冲性的特点 ,人类活动对高水位有较大影响。应用统计分析法和成因分析法推求 1 %设计高水位 ,讨论了成因分析法中上、下边界条件的选取 ,其选取原则对其他潮汐河口确定设计高水位具有借鉴意义     

钱塘江河口潮波特性变化及原因剖析

为掌握钱塘江河口潮波特性的响应机制,采用小波分析法研究了该河口 6 个潮位长期观测站的年平均高、低潮位及年平均涨潮历时等时间序列的变化特征,结合该河口实施的治江缩窄工程及径流周期性变化,探讨了该河口潮波特性时空变 化的因果关系。结果表明：1953—2017 年,钱塘江河口呈现出高潮位显著抬升、涨潮历时缩短,低潮位在河口上段略有抬高、中段大幅抬升、下段变化不大的趋势;受治江缩窄工程进展、位置以及径流周期性变化等影响,各站潮波特性的变化在时间上存在差异;钱塘江河口的治江缩窄工程加剧了河口下段的潮波变形和潮波反射,增强了河口上、中段的河流特性,导致高潮位抬升、涨潮历时缩短,是造成潮波特性变化的主要原因;径流直接影响河口上、中段的潮位和潮流,此外,还通过流速变化改变河床地形而间接影响潮波特性。     

径流和风对涌潮影响的数值模拟

由于实际江道中地形和江道轮廓等复杂性,难以分析涌潮演变规律。以钱塘江河口为基础,建立了概化河口的水动力数学模型,将复杂问题简单化,通过数学模型计算分析了径流和风况对潮差、涨潮历时、涌潮高度和涌潮传播速度的影响。结果表明,不同河段存在涌潮高度最大值的相应临界流量,越往下游,临界径流量越大;涌潮高度随风向变化规律是"逆风"<"无风"<"顺风";顺风条件下,风速越大,涌潮高度越大。     

强潮河口水下地形测量潮位控制研究

钱塘江河口属于强潮河口,具有潮差大、流急、地形复杂和局地潮汐变化大等特点,对潮位控制设计与实施造成较大困难。为解决钱塘江河口水下地形测量潮位控制难题,针对强潮河口的水下地形和潮汐特征进行分析,提出了该区域潮位控制的潮位站布设方案与作业时间要求。实测数据表明,只要合理布设潮位站、选择合适的时间段作业,强潮河口水下地形测量的潮位控制可以达到规范精度要求。     

河口地貌对潮汐不对称性影响的数值模拟研究

河口地貌形态对潮汐不对称性的产生和发展有着至关重要的作用。本文根据英国Humber河口数据建立了概化模型,研究了在同一纳潮量情况下,主槽断面形态、平面形态和河口收缩率对河口潮汐不对称性的影响。结果表明,较深的主槽能使相位差峰值出现较晚且峰值更大,从而影响局部区域的涨潮流强弱,主槽越浅,最大落潮流速越小,落潮所需历时越长,河口更倾向于涨潮主导,窄潮滩倾向于涨潮主导型,宽潮滩倾向于落潮主导型;平面形态沿程收缩且长度较长的河口涨潮主导型最强,此外,河口宽度沿程缩窄会加大主槽的余流流速,减小潮滩的余流流速;随着河口平面收缩率的增强,主槽的余流流速减小,潮滩余流流速增大,潮滩更倾向于涨潮主导。本文进一步丰富了河口地形地貌变化对潮汐不对称性影响的认识,可为河口区工程建设和管理维护提供科学依据。     

潮汐河口支流建闸闸下淤积研究

潮汐河口建闸的关键问题是闸下淤积。在潮汐河口支流口门上建闸,其闸下淤积面貌主要取决于干流主槽的位置,这与在潮汐河口干流上建闸的闸下淤积问题有着本质上的差异。以钱塘江河口支流曹娥江口门建闸为例,应用河床演变分析、动床实体模型和现场冲淤试验预测了曹娥江大闸闸下淤积面貌和淤积速率,为曹娥江大闸的建设提供了科学依据。     

闽浙山溪性河口的径流特性及其对河口的冲淤影响

本文从区域自然地理环境着眼,分析了降水与径流的关系、河川的产水产沙条件、径流年际与季节变化的规律、洪峰过程及其特征,阐述了径流特征对河口的影响:丰枯水年河口段大范围的冲淤变化,洪枯季节的冲淤变化;不同河口的冲淤物质的差异。图4,表9,参考文献3。     

长江河口潮波时空特征再分析

长江河口的潮波传播受到近岸及河口浅水地形及长江径流的显著影响,表现出很强的时空变化特征。已有相关研究主要关注徐六泾以下的河口段,还缺少对河口系统的潮波特征分析。本文基于大通、南京、徐六泾和牛皮礁4站的年内连续潮位资料,分析了主要天文分潮和浅水分潮的振幅沿程变化、季节变化特征和规律,认识到洪季大径流对江阴以上的近口段潮汐衰减作用显著大于枯季,而河口段的平均潮差有一定的半年周期变化,年内秋季最大。口内高频浅水分潮振幅在河口下段最大,且洪季大于枯季,低频浅水分潮则在河口上游振幅最大,由此反应径流对潮汐改造的非线性作用。这些认识可为水道航运及相关河口研究提供基础认识。最后本文也指出关于长江河口潮汐特征尚需进一步研究的若干问题,以期下一步工作取得相应进展。     

变化环境下的钱塘江河口潮位特性及其影响因素

利用钱塘江河口沿程的闸口、七堡、仓前、盐官、澉浦和乍浦等7个潮位站的实测资料,分析了1953～2007年各站年最高潮位、年平均高潮位、年平均低潮位的不同变化特性,并对主要的影响因素进行了分析。线性拟合结果表明,自20世纪50年代以来,钱塘江河口沿程各潮位站年最高潮位抬升幅度达0.57～1.05m,其中七堡站年最高潮位抬升值最大;年最高潮位显著抬升的时间主要发生在20世纪90年代后,该时段年最高潮位抬升值占年最高潮位总抬升值的70.5%～92.6%,极值潮位出现频率显著增加。分析表明,1990年后钱塘江围垦面积仅占总围垦面积的21.6%,因此河口围垦不是造成年最高潮位抬升的唯一因素,而影响浙江的台风频次增多及围垦造成的潮波反射加剧是造成高潮位抬升的主要原因。钱塘江河口年平均高潮位的沿程变化出现趋势性的抬升现象,各站年平均高潮位抬高幅度接近,为0.43～0.49m,但不同潮位站因与围垦河段的相对位置不同,年平均高潮位抬升的历史过程存在明显差异。河口下游段的澉浦、乍浦站年平均高潮位呈现单一的抬升趋势,且与河口逐年累计围垦面积存在很好的相关关系(相关系数大于0.95);而河口上游段的闸口—盐官河段则以1970年为界,年平均高潮位明显有两次抬升过程,受围涂进程影响的机制比较复杂。钱塘江河口年平均低潮位多年来维持在一个相对稳定的水平上,但沿程年际间平均低潮位的变化却不相同。河口上游段的潮位站受径流丰枯及其引起的江道冲淤影响,年平均低潮位年代际呈现出波动的特性;澉浦以下的潮位站年平均低潮位受潮汐控制为主,年代际变化幅度甚微。钱塘江河口不同河段因受径流、潮流、治江围垦等因素的影响程度不同,其潮位特征值沿程的变化特点也不同,需要在河口工程设计、防洪减灾与河口治理等方面引起重视。     

钱塘江涌潮对地形变化的响应研究

钱塘江涌潮以汹涌磅礴闻名中外,并对沿江防灾减灾带来巨大挑战,研究涌潮规律具有重要的学术价值和现实意义。采用涌潮数学模型研究钱塘江涌潮在地形变化下潮汐和涌潮特征的变化。结果表明,地形变化对潮汐和涌潮影响显著;随着地形的降低,钱塘江沿程低潮位下降,高潮位总体呈下降趋势,潮差增大,涨潮历时增加;涌潮高度和涌潮最大流速随相对Froude数呈先增后减规律,起潮点上移,涌潮传播速度增大;当地形降低到临界值后,相对Froude数小于1,涌潮消失。研究结论解释了钱塘江丰水地形涌潮大、枯水地形涌潮小的现象。为保护涌潮资源,维持适当的江道容积是必要的。     

中国鱼类名录Ⅻ--鳚亚目、(鱼衔)亚目、喉盘鱼亚目、鰕虎鱼亚目、微体鱼亚目、刺尾鱼亚目、带鱼亚目、鲭亚目、鲳亚目、金枪鱼亚目、攀鲈亚目、刺鳅亚目

鳚亚目 4 科 33 属 95 种，鰕虎鱼亚目 5 科 98 属 259 种，刺尾鱼亚目 5 科 11 属 65 种，鲈形目 19亚目 104 科 535 属 1799 种。     

The distribution of Mn,Fe, Cu,Ni, Co,Ga, Cr,V, Ba,Sr, Sn,Zn, and Pb,in some soil-sized particulates from the lower troposphere over the world ocean

Soil-sized particulates have been collected on board ship by a mesh technique from the lower troposphere of the North, Equatorial and South Atlantic Ocean, northern and southern Indian Ocean, South and East China Sea and various coastal localities.Spectrographic analysis reveals that, on average, the particulates have concentrations of Mn, Ni, Co, Ga, Cr, V, Ba, and Sr which are of the same order of magnitude as those in average crustal material. In contrast, the average concentrations of Pb, Sn, and Zn are one order of magnitude higher than those in average crustal material.Within this “world-wide” average there are significant geographical variations in the distributions of Pb, Sn, and Zn which may be related to anthropogenic sources.On the basis of trace-element distributions lower tropospheric soil-sized marine particulates have been divided into four genetic components; local, zonal, inter-zonal, and global. The proportions of these components vary geographically, and each component may have both a natural and an anthropogenic fraction.     

Distribution, abundance, and growth of larval tautog, Tautoga onitis, in Buzzards Bay, Massachusetts, USA

Tautog, Tautoga onitis, is an abundant species of fish in estuaries of the northeastern United States. Planktonic tautog larvae are abundant in summer in these estuaries, but there is little information on rates of growth of tautog larvae feeding on natural assemblages of food in the plankton. We examined abundance and growth of larval tautog and environmental factors during weekly sampling at three sites along a nearshore‐to‐offshore transect in Buzzards Bay, Massachusetts, USA during summer 1994. This is the first study of a robust sample size (336 larvae) to estimate growth rates of field‐caught planktonic tautog larvae feeding on natural diets, using the otolith daily‐growth‐increment method. The study was over the entire summer period when tautog larvae were in the plankton. The sampling sites contrasted in several environmental variables including temperature, dissolved oxygen (DO), and chlorophyll a concentration. There was a temporal progression in the abundance of tautog larvae over the summer, in relation to location and temperature. Tautog larvae were first present nearshore, with a pronounced peak in abundance occurring at the nearshore sites during the last 2 weeks in June. Larvae were absent at this time further offshore. From late June through August, larval abundance progressively decreased nearshore, but increased offshore although never approaching the abundance levels observed at the nearshore sites. The distribution and abundance of tautog larvae appeared to be related to a nearshore‐to‐offshore seasonal warming trend and a nearshore decrease in DO. Otoliths from 336 larvae ranging from 2.3 to 7.7 mm standard length had otolith increment counts ranging from 0 to 19 increments. Growth of larval tautog was estimated at 0.23 mm·day^?1, and length of larvae prior to first increment formation was estimated at 2.8 mm indicating that first increment formation occurs 3–4 days after hatching at 2.2 mm. Despite spatial and temporal differences in environmental factors, there were no significant differences in growth rates at any of three given sites over time, or between sites. Because larval presence only occurred at a narrow range of temperature (17–23.5 °C) and DO (6.5–9.3 mg·l^?1), in situ differences in growth did not appear to be because of differences in larval distribution and abundance patterns relative to these parameters.     

Cadmium,cobalt, copper,iron, lead,nickel and zinc in Indian Ocean water

Results of trace-metal analyses of water samples obtained during a cruise with the Soviet R.V. “Akademik Kurchatov” in the Indian Ocean are presented. The determinations were performed on board with atomic absorption spectrophotometry after a two-stage dithiocarbamate—Freon extraction procedure. Trace-metal concentrations found are in the same range as those found recently for similar open-ocean areas by other workers. The values for lead and zinc are probably high due to contamination. Vertical profiles indicate biogenic processes as controlling factors for the increase of cadmium, copper and nickel concentrations with depth. Iron shows an irregular depth distribution as a result of large random variations in concentration.     

The behavior of Zn,Cd, Cu,Ni, Co,Fe, and Mn in anoxic baltic waters

In June 1981, dissolved Zn, Cd, Cu, Ni, Co, Fe, and Mn were determined from two detailed profiles in anoxic Baltic waters (with extra data for Fe and Mn from August 1979). Dramatic changes across the O₂H₂S interface occur in the abundances of Cu, Co, Fe, and Mn (by factors of ?100). The concentrations of Zn, Cd, and Ni at the redox front decrease by factors between 3 to 5.Equilibrium calculations are presented for varying concentrations of hydrogen sulfide and compared with the field data. The study strongly supports the assumption that the solubility of Zn, Cd, Cu, and Ni is greatly enhanced and controlled by the formation of bisulfide and(or) polysulfide complexes. Differences between predicted and measured concentrations of these elements are mainly evident at lower ΣH₂S concentrations.Cobalt proved to be very mobile in anoxic regions, and the results indicate that the concentrations are limited by CoS precipitation. The iron (Fe²⁺) and manganese (Mn²⁺) distribution in sulfide-containing waters is controlled by total flux from sediment-water interfaces rather than by equilibrium concentrations of their solid phases (FeS and MnCO₃). The concentrations of these metals are therefore expected to increase with prolonged stagnation periods in the basin.     

Arsenic,barium, germanium,tin, dimethylsulfide and nutrient biogeochemistry in Charlotte Harbor,Florida, a phosphorus-enriched estuary

Concentrations of dissolved nutrients (NO₃, PO₄, Si), germanium species, arsenic species, tin, barium, dimethylsulfide and related parameters were measured along the salinity gradient in Charlotte Harbor. Phosphate enrichment from the phosphate industry on the Peace River promotes a productive diatom bloom near the river mouth where NO₃ and Si are completely consumed. Inorganic germanium is completely depleted in this bloom by uptake into biogenic opal. The $\text{Ge}\text{Si}$ ratio taken up by diatoms is about 0·7 × 10^?6, the same as that provided by the river flux, confirming that siliceous organisms incorporate germanium as an accidental trace replacement for silica. Monomethylgermanium and dimethylgermanium concentrations are undetectable in the Peace River, and increase linearly with increasing salinity to the seawater end of the bay, suggesting that these organogermanium species behave conservatively in estuaries, and are neither produced nor consumed during estuarine biogenic opal formation or dissolution. Inorganic arsenic displays slight removal in the bloom. Monomethylarsenic is produced both in the bloom and in mid-estuary, while dimethylarsenic is conservative in the bloom but produced in mid-estuary. The total production of methylarsenicals within the bay approximately balances the removal of inorganic arsenic, suggesting that most biological arsenic uptake in the estuary is biomethylated and released to the water column. Dimethylsulfide increases with increasing salinity in the estuary and shows evidence of removal, probably both by degassing and by microbial consumption. An input of DMS is observed in the central estuary. The behavior of total dissolvable tin shows no biological activity in the bloom or in mid-estuary, but does display a low-salinity input signal that parallels dissolved organic material, perhaps suggesting an association between tin and DOM. Barium displays dramatic input behavior at mid-salinities, probably due to slow release from clays deposited in the harbor after catastrophic phosphate slime spills into the Peace River.     

Northstar-Geology,Exploration History,and Development Status,Beaufort Sea,Alaska

Exploration for oil at Northstar has been long and costly. Northstar leases were first acquired in 1979 at a joint state and federal sale by Shell Oil, Amerada Hess, and Texas Eastern. The Northstar Unit is 6 mi offshore and about 4 mi northeast of the Point McIntyre Field. Oil was first discovered in Shell's Seal Island 1 in 1983. Five additional appraisal wells were drilled (1983-1986) from two man-made gravel islands in 40 ft of water. Early engineering estimates put the cost of development at $ 1.6 billion. In February 1995, BP Exploration (Alaska) acquired a 98 % interest in the Northstar Unit from Amerada Hess and Shell Oil. When developed by BP, Northstar will be the first oil produced from federal leases in Alaska. To date, the oil industry has invested in excess of $ 140 million in exploration and appraisal operations. An additional $ 90 million was spent on lease bonus bids. The giant Prudhoe Bay and Kuparuk Fields lie along the Barrow Arch. This arch is bounded to the north by a rift margin that deepens into the present-day offshore region. Northstar is located among a series of down-stepping faults off this northern rift margin of the Prudhoe Kuparuk high. The structure is a gently south-dipping northwest-trending faulted anticline. The crest of the structure is located near 10,850 ft subsea. The primary reservoir is the Ivishak Formation (325 ft thick) of the Sadlerochit Group. This is the same primary reservoir at Prudhoe Bay, approximately 12 mi to the south. At Northstar the Ivishak is a high-energy, coarse-grained conglomeratic facies of the Ivishak Formation. The primary lithology is a pebbly chert to quartz conglomerate with occasional sandstone. This very high net to gross reservoir appears to contain no regionally continuous permeability barriers. Cementation has reduced primary porosity to less than 15 %. Accurate porosity estimates are difficult to make due to the coarse-grained nature of the lithology and the presence of kaolinite and microporous chert. Permeability is highly variable, but averages 10 to 100 mDarcies. Oil is a very light and volatile 42 API crude with approximately 2,100 ft3 of gas per stock tank barrel of oil. This oil is very different from the heavier oils (26) found to the south in Prudhoe Bay. Estimated recoverable oil reserves range from 100 to 160 million barrels. A free-standing drilling rig is required at Northstar because the reserves are beyond extended-reach drilling techniques from shore-based facilities. The current development plan is to expand the existing Seal Island to about 5 acres. This is significantly less than Endicott's 40-acre island. The proposed drilling and produc tion island will be accessed by summer barges and winter ice roads. Oil, gas, and water will be processed at a stand-alone facility and then sent to shore via a subsurface pipeline. Northstar will have the first Arctic subsea pipeline in Alaska to transport oil to shore facilities (TAPS). Preliminary tests in Spring 1996 were very successful in demonstrating the technology to successfully bury a subsea pipeline safely in the Arctic.