Factorial analysis of annual erosion-accretion cycles of tidal flats in the front area of the southern Changjiang river delta     

Yang Shilun  Chen Xiangfeng  Zhang Zhengti 《中国地理科学(英文版)》1997,8(1):1-11

Based on surveyed data from seven coastal sections and the collected data of wind, sea level, tide, nearshore suspended sediment concentration and river flux from adjacent stations, this paper deals with regressive correlation between monthly average flat elevation and monthly average figures of the influential factors. All sections except one which is located within the river mouth showed negative correlation between flat elevation and sea level and between flat elevation and tidal range, with correlation coefficients being −0.53 – −0.91 (−0.77 on the average) in the former condition and −0.56 – −0.97 (−0.80 on the average) under the latter. Each of the sections with available suspended sediment concentration (SSC) data shows a positive correlation between flat elevation and SSC, with correlative coefficients being 0.35 – 0.97 (0.66 on the average). Only two sections (one in the Changjiang River Estuary and the other in the Hangzhou Bay) which are similar to beaches in sediment grain-size and slope gradient showed a negative correlation between flat elevation and onshore wind frequency and between flat elevation and average wind velocity, with correlative coefficients being respectively −0.57 and −0.69 (−0.63 on the average) in the former situation and −0.61 and −0.75 (−0.68 on the average) in the latter. Other sections did not show uniform relationship between flat elevation and wind conditions. Due to local marine factors the nearshore SSC in the studied area is negatively correlated with the Changjiang River sediment flux (r=−0.78), which results in false negative correlation between flat elevation and river sediment flux. The paper also gives sediment dynamic and morphodynamic explanation for the above correlations. Sea level rise results in the spread of breaker zone from subtidal area to intertidal area and then increases the intertidal water energy. The larger the tidal range, the stronger the tide currents and the easier for the flat to be eroded. The higher the SSC of flood water, the easier for the sediment to deposit down. Because of correlations among the influential factors, it is difficult to give the prime one which dominates the erosion and accretion processes in tidal flats.  相似文献   

On the opening-up and development of shanghai’s pudong new area     

Wanzhong Yang 《中国地理科学(英文版)》1993,3(4):348-356

In the development of Pudong, a strategic idea and goal ought to be fully realized, that is: with the development of Pudong as a lead, to further open up the cities along the Changjiang (Yangtze) River, build Shanghai into an international center for economy, finance and trade, thus to spark a new economic take- off in the Changjiang River Delta and the whole Changjiang River Basin. To develop Pudong, the infrastructure construction must be developed first; and the development of primary, secondary and teriary industries must be well coordinated. At present, the stress should be laid on tertiary sectors like finance, foreign trade, comerce, real estate, far-ocean transport, post and telecommunication, information and travelling service and so on. In the secondary industry, export processing and high and new technological industries should be put first, while the original raw-material industry should be improved in processing depth. As to the primary industry, a metropolitan suburban agriculture should be established. In spatial distribution, the present extension has been eastward along the Huangpu River axis. By the end of this century, five districts: Waigaoqiao-Gaoqiao, Qingningsi-Jinqiao, Lujiazui-Huamu, Zhoujiadu-Liuli and Beicai-Zhangjiang, will be developed. Meanwhile, it must be well coordinated between developing Pudong and reforming Puxi.  相似文献   

Areal expansion of urban Shanghai     

Yan Zhongmin  Tang Jianzhong 《GeoJournal》1990,21(1-2):57-64

Conclusion Many elements contributed to the urban expansion of Shanghai, but port expansion, industrial growth, population change and construction of new housing quarters were the main. Moreover, they were interdependent and interactive. This article summarizes these influences, on urban spatial expansion in Shanghai. It will be helpful in further approaches to this issue.  相似文献   

IMPACT OF URBANIZATION ON STRUCTURE AND FUNCTION OF RIVER SYSTEM——Case Study of Shanghai, China   总被引：3，自引：1，他引：2  

YUAN Wen Philip JAMES YANG Kai 《中国地理科学(英文版)》2006,16(2):102-108

1INTRODUCTION Since the 1750s, promoted by Industry Revolution and the rapid development of science and technology, large-scale urbanization swept over the world. So far, it isestimatedthatmorethan60%oftheriversin the world have been experienced high levels of human modifica- tion (ALLAN, 1995). River systems have now become oneofthemostdeeplyhuman-affectedecosystemsinthe earth. To approach the impact ofhuman activitieson riv- ersystem as a multidiscipline topic has been a focus of res…  相似文献   

Observed residual currents off the Changjiang （Yangtze） Rivermouth in summertime of 1959 and 1982     

朱建荣戚定满  肖成猷 《中国海洋湖沼学报》2004,22(3):250-255

Data taken in two large scale ocean observations in China in summer 1959 and 1982 were used to analyze the residual current off the Changjiang (Yangtze) River mouth. The currents at surface off the mouth in July 1959 and 1982 flow northeastward and eastward due to the river discharge, the current speed was larger in 1982 than in 1959. All the bottom currents flow landward due to baroclinic effect. The surface current was controlled by the river runoff and the Taiwan Warm Current (TWC). A return current at surface off the mouth was observed in September 1959. In general, the bottom currents were controlled by the TWC in most study area in addition to the runoff near the mouth. Although driven by 3-D model with the monthly averaged forces (river discharge, wind stress, baroclinic effect, open boundary water volume flux and tidal mixing) in August, the simulated circulations were basically consistent with the observed ones with episodic time manner.  相似文献   

THE STATISTICAL DISTRIBUTION OF THE SPATIAL MAXIMA OF A WAVY SEA SURFACE   总被引：2，自引：0，他引：2  

孙孚  丁平兴  管长龙 《中国海洋湖沼学报》1994,12(1):1-12

A statistical distribution of the maxima of a random function in two space variables is suggested to fit with stereo observations of the sea surface. The presented distribution is a complicated mix of Gaussian, Rayleighian and Maxwellian distributions and determined by three parameters of the directional spectrum, According to the changes of the three parameters it may approach the above three distributions respectively in special cases so that it has more probability of fitting stereo data better In addition, the fact that these parameters can be directly estimated from observed data is briefly in the paper.  相似文献   

崇明岛的变迁   总被引：4，自引：0，他引：4  

褚绍唐 《地理研究》1987,6(3):9-16

本文讨论了崇明岛何时设镇、崇明县址的迁移及崇明岛的变迁等三个问题,澄清了历代县志记载混乱而产生的一些问题。  相似文献   

ON THE VERTICAL STRUCTURE OF TIDAL CURRENTS IN SHALLOWWATER NEAR THE CHANGJIANG RIVER ESTUARY     

李身铎 《中国海洋湖沼学报》1987,5(1):22-33

This research on the vertical structure of tidal current in shallow water near the Changjiang River estuary is based on a great deal of observation data of current obtained recently, and a simple mathematic model. The essential features of the structure are: (1) the maximum velocity decreases with depth, the shallower the water, the lower the velocity; (2) the orientation of maximum velocity continuously deviates from the surface to the bottom to the left at the western side of the mouth bar and to the right at the eastern side; (3) the time of maximum velocity leads steadily with depth; (4) in general, tidal currents rotate clockwise, the nearer the sea-bed, the narrower the ellipse of the tidal current; (5) the ratio W1/W2 varies non-linearly with depth, and is smaller in the middle layer than at the surface and bottom. Bottom friction is the main cause of the vertical structure.  相似文献   

配饵中不同大豆浓缩蛋白含量对中华绒螯蟹消化酶活力的影响   总被引：3，自引：0，他引：3  

李二超陈立侨  蔡永久顾顺樟  洪美玲张璐 刘超 《广东海洋大学学报》2006,26(4):14-21

研究了大豆浓缩蛋白作为饵料蛋白源对中华绒螯蟹幼蟹消化酶活力的影响．初步探讨了中华绒螯蟹对饵料蛋白源的内在适应机理。根据中华绒螫蟹的营养需求．用大豆浓缩蛋白替代鱼粉作为蛋白源配制成6种近似等蛋白等能的饵料，其中大豆浓缩蛋白在饵料中的含量分别为0、11％、22％、33％、44％和56％（分别替代鱼蛋白质量的0、18．64％、37．93％、56．90％、77．19％和100%），对照饵料全部以鱼粉作为蛋白源。用上述6种饵料喂养中华绒螫蟹50d后．测定蟹肝胰腺各种消化酶活力。结果表明：随着饵料中大豆浓缩蛋白含量的升高，胃蛋白酶和胰蛋白酶活力均芏降低之势。当大豆浓缩蛋白含量达到44％时，与全鱼粉对照组相比．胃蛋白酶和胰蛋白酶活力显著性降低（P〈0．05）；同时，淀粉酶稍呈升高之势，而纤维素酶则稍呈降低的趋势；A／T、比例呈显著上升的趋势。半大豆浓缩蛋白含量达44％时，与对照组有显著性差异，说明河蟹对植物蛋白有很强的适应性。  相似文献   

Human impact on the historical change of CO<Subscript>2</Subscript>degassing flux in River Changjiang   总被引：2，自引：0，他引：2  

FuShun Wang  Yuchun Wang  Jing Zhang  Hai Xu  Xiuguo Wei 《Geochemical transactions》2007,8(1):7

The impact of water quality changes in River Changjiang (formally known as the Yangtze River) on dissolved CO₂ and silicate concentrations and seasonal carbon flux in the past several decades (1960s–2000) was evaluated, based on monitoring data from hydrographic gauge. It was found that dissolved CO₂ and silicate in Changjiang decreased dramatically during this decades, as opposed to a marked increase in nutrient (e.g. NO₃ ^-) concentrations. Our analyses revealed that dissolved CO₂ in Changjiang was over-saturated with the atmosphere CO₂, and its concentration had showed a declining trend since the 1960s, despite that fluvial DIC flux had maintained stable. Analysis results also suggested that the decrease in dissolved CO₂ concentration was attributed to changes on the riverine trophic level and river damming activities in the Changjiang drainage basin. Due to the economic innovation (e.g. agriculture and industry development) across the Changjiang watershed, fertilizers application and river regulations have significantly altered the original state of the river. Its ecosystem and hydrological condition have been evolving toward the "lacustrine/reservoir" autotrophic type prevailing with plankton. Accordingly, average CO₂ diffusing flux to the atmosphere from the river had been reduced by three-fourth from the 1960s to 1990s, with the flux value being down to 14.2 mol.m^-2.yr^-1 in the 1990s. For a rough estimate, approximately 15.3 Mt of carbon was degassed annually into the atmosphere from the entire Changjiang drainage basin in the 1990s.  相似文献