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    1991年, 第1卷, 第3期 刊出日期:1991-09-20 上一期    下一期
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    论文
    AN ANALYSIS OF THREE ELEMENTS OF WATER BALANCE IN THE CHANGJIANG RIVER BASIN
    杨远东
    1991 (3):  197-211. 
    摘要 ( 731 )   PDF(2707KB) ( 913 )  

    The general trend of three elements (precipitation, runoff and evaporation) of the water balance of the Changjiang River Basin is discussed from the regional distribution of the mean annual values of view, i.e. isogram. The distribution of precipitation is non-uniform. The distribution of runoff mainly supplied from precipitation is more uniform than that of precipitation. The distribution of the evaporation from land is much more uniform than that of precipitation and runoff. Time distribution of these three elements shows the characteristics of comparatively distinct yearly variation and few variation between years. The relationship between precipitation and runoff, and between precipitation and evaporation in the humid region in the Changjiang River is analyzed. The slopes of their straight line correlation are nearly equal. The internal relationship between variables should be paid attention to, otherwise, a pseudo correlation may be resulted in. The paper provides the method of quantitative computation and general conclusion of probability between the regions and the whole basin. The empirical formulae based on certain inference are tested with the data of the Changjiang River.

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    POPULATION GROWTH IN BEIJING:TRENDS AND COUNTERMEASURES
    胡兆量, Francis Yee, George Chusheng Lin
    1991 (3):  212-220. 
    摘要 ( 732 )   PDF(391KB) ( 788 )  

    Beijing'population has experienced a dramatic increase eversince the founding of the People's Republic of China. Population growthin Beijing can be broadly broken down into three major components'natural increase, immigration, and the growth of floating population. Thecontinuous growth of Beijing's population is closely linked with its centralized multi-function. The comprehensive countermeasures to control Beijing's population growth are proposed, for example, decentralizing economicfunctions, including developing the suburbs, developing the metropolitan areaand creating counter-magnetic centers, reforming the administrative and economic systems.

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    THE FLORISTIC STRUCTURE OF THE XIZANG PART OF THE QINGHAI-XIZANG PLATEAU PLANT SUBKINGDOM
    李恒, 武素功
    1991 (3):  221-233. 
    摘要 ( 669 )   PDF(2511KB) ( 679 )  

    The flora of the Qinghai-Xizang Plateau belongs to the floristic subkingdom of the Holarctic plant kingdom. The Xizang part of this subkingdom can be divided into 4 plant regions. 1) the Yarlung Zangbo River valley region. There are 1,003 species of seed plants, making up 19.38% of the total species in Xizang, and 159 endemic species, 15.89% of the total seed plants. The flora originates mainly from the East Himalayas and the Hengduan Mountains. 2) The Tanggute region. There are 349 species of seed plants and 10 endemic species. The flora represents an intermediate one between the Qinghai-Xizang Plateau and the Hengduan Mountains.3) The Qiangtang region. There are 255 species of seed plants and 18 endemic species. The flora derived from the Himalayan flora and mixed with a great number of Tethysian elements. 4) the Ali region. There are 547 species of seed plants and 41 endemic species. The flora seems to be closely related to Tethysian one.

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    RELATIONSHIP BETWEEN DEVELOPMENTS OF THE HUANGHE AND YONGDING RIVERS AND THE EVOLUTION OF THE FOSSIL LAKES OF THE CENOZOIC ERA IN THE DRAINAGE AREA
    李容全, 杨明川
    1991 (3):  234-247. 
    摘要 ( 738 )   PDF(3734KB) ( 900 )  

    The Huanghe and Yongding rivers were formed before the early and middle Pliocene epoch. Then they became interior rivers because of the appearance of interior fault lake basins at the end of the Pliocene epoch. The interior flow period continued until the end of the early Pleistocene or the middle pf the Middle Pleistocene, and then they changed into the exterior rivers again till today.

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    A PREDICTION ABOUT THE EFFECT OF THE BUILDING OF SHUIKOU HYDROPOWER STATION ON THE ECOLOGICAL ENVIRONMENT OF THE MIDDLE-LOWER REACHES OF THE MINJIANG RIVER
    余泽忠
    1991 (3):  248-261. 
    摘要 ( 663 )   PDF(606KB) ( 950 )  

    The building of Shuikou Hydropower Station in the Minjiang River is the largest one in the region of east China. Its install capacity is 1.4 million kw., and its generated energy of planning is 4.95 billion kwh each year. In accordance with a comprehensive survey of the valley of the middle-lower reaches of the Minjiang River and the characteristic of hydrography and in association with the specific type of the hydrography station, we can be sure that no harm will be done to the ecological environment when a hydropower station is built at Shuikou. Not only the deposition of silt within the reservoir must not be very serious, it is also more favorable than before for the irrigation of farmland on plains in the lower reaches of the Minjiang River and inland navigation.In addition, after the completion of the power station, the ecological environment will be the same as before both at the Minjiang River estuary and beyond it.

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    A STUDY ON THRESHOLDS IN THE CHANGE OF ALLUVIAL FAN AND DELTA OF THE HUANGHE RIVER, CHINA
    曹银真
    1991 (3):  262-271. 
    摘要 ( 682 )   PDF(432KB) ( 897 )  

    In the river systems, the environmental change always undergoes a process from quantitative to qualitative change. The upper limit of the qualitative change is called threshold. When the process reaches or goes beyond the limit, the original event series will be replaced by the other event series. Investigations show that the evolution of the Huanghe River alluvial fan and delta has also under gone a process from quantitative to qualitative change. The geometric forms in each process are roughly the same. This threshold of the geometric forms not only provides us a quantitative index for plotting the periodicity of the alluvial fan and delta, but also is of importance for estimation of the trend of natural environmental change.It is shown that there are three periodic alluvial fans of the Huanghe River since the middle Holocene and four periodic delta since 1855 A.D., the thresholds of their geometric forms are from 0.93 to 0.94 and from 1.2 to 1.21 respectively.The changing trend in the past and the natural environmental condition at present indicates that the lower reaches of the Huanghe River has some possibilities to burst its banks at the Dongbatou-Gaocun to flow northward. Therefore some proper protection measures are suggested.

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    INVESTIGATION ON FUNDAMENTAL CHARACTERISTICS OF HYDROCHEMISTRY IN HEAD AREA OF THE CANGJIANG RIVER
    邓伟
    1991 (3):  272-283. 
    摘要 ( 713 )   PDF(525KB) ( 724 )  

    The results of water sample analyses and investigation in the head area of the Changjiang River reveal that the characteristics of hydrochemistry of the river vary with drainage basins. In the drainage basin of the Tuotuo River, the mineral concentration of water is generally high, ions of Cl- and Na+ are obviously dominant. The water tends to be salty, and the type of hydrochemistry is rather complex. In the drainage basin of the Dam River, the mineral concentration is mainly in a low and middle level, ions of HCO3- and Ca2+ are higher than others, and the type of hydrochemistry is relatively simple. The ground water in deep layers plays an important role in recharging surface water, and the stable recharging results in little change in chemical composition of surface water.

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    PRELIMINARY EXPLORATION OF DEVELOPMENT STRATEGY OF PUDONG IN SHANGHAI
    何兴刚
    1991 (3):  284-292. 
    摘要 ( 542 )   PDF(2479KB) ( 676 )  

    The article, in a comprehensive view, explores the strategic vantages, strategic urgency, strategic goals, strategic planning as well as strategic steps.

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