Table of Content

    15 November 1996, Volume 51 Issue 6 Previous Issue    Next Issue
    Wang Jici, Song Xianghui, Li Guangyu
    1996, 51 (6):  481-488.  doi: 10.11821/xb199606001
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    This paper examines the Beijing’s new-tech agglomeration centered on Beijing New-tech Experimental Zone which is proved to be China’s most intense concentration of innovative business activity.It analyzes the spin-off process of new-tech firms,illustrates the factors influencing the agglomeration and dispersion of the new-tech firms and detects their dispersion patterns and ongoing changes.Five agglomeration factors are:access to universities and research institutes,information availability,access to market,tax policy and ability to link public and private entites(network relationships,regulations).Among them the first and second ones are major agglomeration factors.Two dispersion factors are:high land costand house rent:and poor traffic conditions.Since the Electronic Street came out,there has been a tendency for some research and development facilities and production operations to migrate from Beijing to coastal cities in southeastern China.At present time there are branch plans of the companies all over the country except Tibet and Ningxia autonomous region.The distribution of the total revenues is highly concentrated In southeastern China.Not withstanding the many benefits that China derives from the Beijing New-Tech Experimental Zone,contentions issues remain.Because R&D expenditures are very low,the companies have to involve in a lot of commercial activities.The commercialization of Zhongguancun area is clearly seen.There is a danger that Zhongguancun area could turn into an electronic commercial area but not into a new-and high-tech innovation area.Beijing’s experience emphasizes the importance of establishing an new financial mechanism to support Chinese new-and high-tech enterprises.Creating industrial dynamism,fostering innovation and effective inter-firm linkage,upgrading industrial structure and achieving competitive advantageare the key to the economic performance of Beijing’s new-tech agglomeration.
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    Gong Shengsheng
    1996, 51 (6):  489-500.  doi: 10.11821/xb199606002
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    This paPer researches the urban spatial development on the Two-Lake Plain (in CentralChina)for the past more than 2000 years,and following conclusions are obtained:1.The urban administrative gradation has changed from 2 grade to 4 grade:2 grade during22lBC-AD220 and AD589-756;3 grade during AD220-589 and AD757-960;4 grade duringafter AD960.2.The urban development has two historical perids:the period having Jiangling as the chiefcity(before AD1279)and the period having Wuhan as the chief city(after AD1279),and In the13th century,the modern urban spatial structure took its shape basically.3.The urban distributions have 3 times spatial dynamic equilibriums:equilibrium of the distribution of the cities above county level around 200BC,that of cities of county level and above countylevel around AD900,that of all cities and towns around AD1980.4.The centres of gravity of the distributions of cities and towns moved from northwest Qianjiang county to southeast Jianli county,with a straight distance of about 75 kilometers.5.The urban spatial development has a typical circular-convergence model.The shorter thedistance is from the core of the plain,the more the cities which appeared later,almost all citiesabove county level distribute in the periphery of the plain which is the ecotone of hills and plains,showing a powerful ecotone function.6.The urban spatial structure basically accords with Walter Christaller’s central-place-theory,having a embryonic compound system of central place stucture which mainly combines the transportation priority with the commerce priority.
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    Chen Hang
    1996, 51 (6):  501-507.  doi: 10.11821/xb199606003
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    This paper mainly consists of two parts.Firstly,a theoretical analysis about the backgroundand factors for the formation of sea-port regional complexes with sPecific structural and spatial features is given,in which the competition on overlapping hinterland and the complementation of functional comparative advantage among sea ports in a region are stressed.Secondly,the general patternand rules of the development of sea-port regional complexes are addressed.Based on the empiricalstudy of China’s experience,the author puts forward an evolution pattern of sea-port rngional complex with five phases of development,that is,the birth of sea ports,the gradual development of seaprots,the initial development of sea-port regional complex,and the formation and improvement ofsea-port regional complex.
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    Huang Guangqing
    1996, 51 (6):  508-517.  doi: 10.11821/xb199606004
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    Shell mound and sand dune are wto typical patterns of Neolithic cultural sites on the Zhujiangdelta which belongs to the zone of ancient fishing culture along the coast of South China.Shellmound is heaped with a large quantity of mollusk shells and some archaeological deposits includingpottery,Stone artifacts.Three types of shell mound have been recognized in terms of the differenceof mollusk assemblage:fresh,brackish and marine,associated with riverine environment,estuarineenvironment and marine environment respectively.Sand dune (an archeological term used in SouthChina),a sand body containing archaeological deposits,is mostly characterized by beach or coastalaeolian sand,associated with coastal environment which is directly affected by the sea,particularlythe delat-front islands.Many archaeological evidences have shown that fishing played a significanteconomic role in the living of ancient inhabitants.Such an ancient fishing economy was closely related to the paleogeographic environment,particularly the water resources.Numerous data haveshown that the ancient people began to immigrate into the Zhujiang delta around 6 000aBP whenthe sea-level rose to the present position.At that time,the delta basin was mostly submerged bymarine transgression,forming a huge ancient embayment providing an abundance of fishery resources for the ancient people.A particular fishing culture was formed on the Zhujiang delta.Sealevel rise and marine transgression seems to be an imPortant factor in the origin and development ofthe Neolithic culture on the Zhujiang delta.The declination of the Neolithic culture was most likelyto be caused by low sea-level and marine regression.
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    Zhang Mingli, Zeng Zhaomei, Ji Jingjun
    1996, 51 (6):  518-526.  doi: 10.11821/xb199606005
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    Since the beginning of 20 century.global air temperature has increased at a speed of 0.53℃/100 years.Regional climate variation is an important togic in the study of global change.Thus westudied on the characters of climate variations over East Asia during the period of global warming.In this paper,the grided temperature data during 1891 1990 over East Asia(70-140°E,20 55°N)from Jones et al.had ben analysed.It was found that the temperautre variations withinthe region were quite different from global average characters.They have distinguishing regionalfeatures and seasonal variations,which are as follows.1)The regional temperature arised 0.56℃/100 years.It is close to the warming value of globalaverage temperature,0.56℃/100 years.However,the main warming appeared during winter seasons.Warming value of 0.83℃/100 years was calculated for winter season.There was no evidenceof temperature increasing in summer,and it had a linear temperature trend of-0.06℃/80 years.For winter,the highest temperature occured in the end of 1980’s,while for summer the relativelywarmer period was in 1940s’.2)There are siginificant differences between different latitude zones. Temperature increasedboth in winter and summer seasons at lower latitudes,and slightly decreased in the subtropical areas.In higher latitude areas,temperature increased in winter,and decreased in summer.3)The temperature trend during recent 80 years shows that in winter seasons,the warmingareas were located north of 35°N,and the cooling areas distributed along middle and upper reachesof Yangtze and also over the areas south of Yangtze.In summer,temperature was deceased almostin the whole region,although there were some scattered warming areas such as the areas west ofLake Balkhash,India and coastal areas in southeast China.
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    Chen Ming, Fu Baopu, Zheng Weizhong
    1996, 51 (6):  527-534.  doi: 10.11821/xb199606006
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    Many observations have confirmed that under strong atmospheric conditions, leecyclone wavesare often formed at the leesides of mountains and islands.For a long time this kind of lee cyclone isconsidered to be caused by planetary boundary layer frictional effects.Further analysis shows thatthe formation of mountaion lee cyclone has much more complicated mechanism.Traditional mountainclimate theory is limited in low-amplitued perturbation theory,it is invalid in non-linear areas.Forthis reason we set up a three-dimensional numerical model to simulate mountain-induced lee vorticesand discuss the role of surface friction,stratification and coriolis force in this kind of circulation.Model results show that under strong stratification there is reversed flow in the lee of mountain.The reversed flow Is strongest In the center line,and a depole of lee vortices if formed symmetricallyalong the center line.surface friction weakens the strength of reversed flow,but enlarged the extention of lee vortices.Non-frictional dynamic effect is the basic reason for the flow separation.In thecondition of weak stratification large-amplitude mountain waves develop and an area of low velocityappears in the leeside of mountain.No reversed flow and lee vortices form under this condition.Under strong stratification we consider both coriolis force and surface frictional effects,and model simulations show that in the leeside of mountain,the depole of lee vortices disappears,while cyclonewave develops;this kind of circulations is very similar to those observed in real atmosphere;
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    Shan Pengfei
    1996, 51 (6):  535-542.  doi: 10.11821/xb199606007
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    Locating in the west of Mt.Liupan in Ningxia,the Xiji region is the area where 9-10 degreeearthquake occurred in 1920.There is a great variety of slide hazard-induced landforms,includingbedding slide types on the bottom or in the middle of loess layer and longer-belts along loess ridge onright bank of the Hulu River.Although epicentral intensity of the earthquake was about 11 12 degree,the disastrous characters of landslides here were the most serious in comparison with all otherintensity areas.Based on the systematic description of distribution of slide hazard-induced 1andforms in the Xijiregion,the paper discusses deeply the formative mechanism of the landslide resultant forms.The result of study indicated that the origin of those was not only controlled under earthquake intensity butalso influenced by physical environment,such as natural property of loess,geologic structure,geomorphic texture,regional tectonic movement and so on.Therefore the scale and distribution of somekinds of ground deformations,e.g,landslide landforms,may be a bit of unconformity in contactwith its intensity degree within the meizoseismal area.
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    Yin Guokang, Chen Qinluan
    1996, 51 (6):  543-552.  doi: 10.11821/xb199606008
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    Located in the southeast Zhejiang Province along the seacoast,the lower reach FeiyunjiangRiver has a strong-tide affected river mouth with serious hazards in flood.waterlogging and stormtide.The level of both correction and development is lower in the area.By analysing its channelproperties,this paper predicts the renewal bed-forming processes of the lower reach caused by building key water control project at Shanxi and diversion works at Tanjiao at the upper and middlereaches of Feiyunjiang River as well as makes a comprehensive appraisal for feasibilities of the rivercutoff,the navigable channel regulation and the harbour construction at the strong-tide affectedreacher.1.River cut-off project can bring obvious socio-economic benefits,but it will exert a certain influence on the channel properties such as:①The limits of both tide currents and tide head will goupstream some 10 km.Consequently a transient aggradation in the river channel may occur and theriver bed will be filled up.So the flood control benefit coming from river cut-off will reduce.②After the cut-off,the channel length will be shorteded by 12.1km,with the channel storage decreaseand the gradient increase the flood peak discharge will increase and get down to the reach earlier.③Owing the expansion of the cut-off leading channel,there will be 1809×104m3 sediments in volumeinputting the channel,most of which will fill in the oxbow lake and other may deposit in the channelbelow the leading channel.This may exert an unfavourable influence on the navigable channel andharbour basin at some local reaches.2.Inside and outside the Feiyunjiang River mouth there are two places in which deepwaterberthes of 104 tonnage can be built:①Ruian new harbour area.②The water area southwest of Beilong island,and.38 km away from Ruian city.3.Building the key water control project at Shanxi and deversion works at Tanjiao.due to theregulated flow and the large amount drawn water out of the channel,will exert the following important influences on the downstream channel:①The channel runoff will reduce its transportability.②As both the tidel water and sediments discharge of the flood tide increase,aggradation in the streamchannel will be able to occur so that the average width,depth and sectional area will respectively decrease by 2.5%,3,0% and 4.0%.③The physical feature of the river channel as a whole willgradually be stable.④As the alterration range of the tidal current limit will obviously be shortened,with a more concentrated deposition in the limited range,a depositional body will occur.⑤The central bar and the riffle at the river reaches between new barbour area and the old one near Rulan citywill extend because of deposition and the movement of river-mouth bar into the mouth.⑥As thetidal current limit goes upstream,the salt-water encroachment will bring an unfavourable influenceto both the soil salinization and the fresh water supply in the flood plain region.
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    Li Xiubin
    1996, 51 (6):  553-558.  doi: 10.11821/xb199606009
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    Land use and land cover change has aroused increasing attention of scientists worldwide since1990.Recognizing the importance of this change to other global environmental change and sustainable development issues,the International Geosphere-Biosphere ProgrammeIGBP)and the HumanDimensions of Global Environmental Change ProgrammeHDP)initiated a joint core projectLand Use and Land Cover Change(LUCC)and published a Science/Research Plan for the project.To promote the national LUCC projects,the paper presents a general review on the basic concepts,background,and Progress on the metnodologies of international LUCC researches.Land use/land cover is not a new research domain but is given new meanings and research contents in the context of global environmental change.Based on the definition of land cover given bythe IGBP/HDP and other international institutions,the author proposes a new translated term ofland cover in Chinese that matches the definition closely.This will avoid misunderstanding of thedomestic LUCC projects at early stages.Land cover changes refer to conversion and modification of vegetation,changes on biodiversity,soil quality,runoff,erosion,sedimentation and land productivity.International researches onLUCC involve:1)influence of LUCC on systematic global enviromental changes like biogeochemicalcircles and climatic variation,and cumulative global environmental changes like eforestation,biodiversity reduction and land degradation;2)response of LUCC to global environmental changes;3)LUCC and sustainable development including the sustainability of different land uses.The fundamental scientific issue of LUCC research is the dynamics of land use and coverchanges,which is extremely significant to the prediction of the global environmental change in thenext 50 to 100 years.The modedling of causes-use-cover system is challenge because of its inherentcomplexity.An integrated approach to the modeling is necessary that combines:1)large-scale onsite case study approach to land use dynamics;2)direct observation and measurement of land coverchange by using remote sensing images;and 3)regional and global modeling of economic processesrelated to LUCC.
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    Sun Hanqun, Fu Baopu
    1996, 51 (6):  559-566.  doi: 10.11821/xb199606010
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    In this paper authors discussed the methods of computing the extraterrestrial solar radiation onthe slope.Then,the authors studied the combined relations of the sunrise and sunset hour angleswhich is composed of the sunrise and sunset hour angles on horizental surface and non-horizentalsurface on the slope and their variational Laws.Based.on these,the authors established the ellipticalintegral model with the expressions of elliptical integral,which is used to compute the extraterrestrial solar radiation on the slope with any orientation and gradient during any period.The resultesof the model test show that it is correct thoroughly.The elliptical integral model is severe in theory.It can be used to find and prove many natures of the extraterrestrial solar radiation on the slope.
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