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    15 December 1992, Volume 11 Issue 4 Previous Issue    Next Issue
    CHINESE CRITICAL ENVIRONMENTAL SITUATION AND AREA
    Yang Qinye, Zhang Yili, Li Goudong
    1992, 11 (4):  1-10.  doi: 10.11821/yj1992040001
    Abstract ( 821 )   PDF (819KB) ( 29863 )   Save
    Anthropogenic environmental degradation is greatly disadvantageous to people's surviving and sufficient,rational utilization of natural conditions and natural resources.This paper explains how to compile "the Chinese map of critical eco-environmental situation and areas (1:10000000)" on the basis of the method applied and provided by the Russian geographers and revised according to the Chinese characteristics.About 100 different sizes of the most critical areas are reflected on the map,and they concentrate in the trausitional belt between semiarid and subhumid districts and the populous industrial areas,the former is Chinese backward economic region where eco-environment is compained with poverty and the latter is environment-affected regions by industry.As for provincial distribution,the eco-environmental situation of Zhejiang,Fujia,Anhui,Xizang (Tibet) and Xinjiang Provinces (or autonomous regions) is inless critical level,and that of Jilin,Liaoning,He-bei,Shanxi,Ningxia,Sichuan and Jiangsu is in the most critical level,and it also approaches to the international research on this subject.It points out that this research provides a probable method to have an integrated research combining natural and human sciences.In such aspects to recognize the human impact and delineate the scope of eco-environmental problems and the critical degrees through the landuse situation and population density,there is something needed to be improved because thfs kind of landuse classification according to the human impact (including technology factors) is not completely suitable for Chinese situation.
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    A RURAL FUNCTIONAL CLASSIFICATION OF THE HUANG-HUAI-HAI REGION AND THEIR AREAL DEVELOPMENT MODES
    Yao Jianqu, Guo Huancheng
    1992, 11 (4):  11-19.  doi: 10.11821/yj1992040002
    Abstract ( 617 )   PDF (659KB) ( 540 )   Save
    The study of rural functional classification,which mainly deals with comprehensive rural-space division in terms of utilization of rural resources,areal division of labour,regional change of function,harmony of agricultural structure and composition of industrial sectors,forms a major reseach field of rural geography both inside and outside China.Taking 364 counties (or cities) of the Huang-Huai-Hai Region as the areal study units,the thesis analyses the variation of rural function in the region,identification of functional features as well as extraction of functional indices.On the basis of the analysis,the thesis then makes a classification of the rural functional types and approches the spatial distribution law of rural functional types,the industrial features and relevant development ways for the different functional types.
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    ANALYTIC SOLUTION OF STABLE CHANNEL GEOMETRY
    Sun Zhilin
    1992, 11 (4):  20-27.  doi: 10.11821/yj1992040003
    Abstract ( 607 )   PDF (487KB) ( 598 )   Save
    This paper has obtained the exact analytic solutions for the cross-section curve,area and wet perimeter from the differential equation of stable channel geometry based on the fundamental assumption that particles on the channel boundary are in the threshold movement.The morphologic equations therefore are first strictly derived from simultaneous equations,including continuity equation and flow resistance formula.Comparison of the theoretical morphologic equations with measured data shows a good agreement.According to the integral mean-value theorem,moreover,another form of solution for the cross-section curve is found,which is very simple for the hydraulic computation of the stable channel.
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    ON THE FORMATION AND EVOLUTION OF THE JIYANG LAKE-BASIN DURING EARLY TERTIARY
    Zhang Baoming, Ren Senhou, Xiao Zongfeng
    1992, 11 (4):  28-37.  doi: 10.11821/yj1992040004
    Abstract ( 461 )   PDF (815KB) ( 494 )   Save
    Tectonism and climatic condition are the most principal factors controlling the formation and evolution of the lake-basin.It is because of their combined action that a great variety of lakes and their sedimentary constructions in ancient and modern,Chinese and foreign are brought about.In this paper,the varieties of paleogeographies at different stages during early Tertiary in the Jiyang lake-basin are reconstructed,mainly based on paleotectonics,paleotopography,the lower Tertiary deposits,paleontology,paleoecology and the results of minor elements and isotope analysis,also with the aids of sporo-pollen data from other researches.In the early Tertiary,NW-SE trending regional tensile stress field and a series of mantle bulges such as Bohai Gulf mantle bulge with triple junction consisting of lower Laohe,Huanghua and Jiyang was formed in Eastern China,because the Pacific plate was subducted northwestwards and the Eastern Asian continental plate margin crept oceanwards.For this reason,the research district became the southern branch of the Bohai Gulf continental rift basin,in which the evolution had mainly gone through four stages including spreading and faulting-down from initial(Kongdian Epoch of early Eocene) to intense(from Shahejie-4 Epoch of middle Eocene to Shahejie-2 Epoch of early Oligocene).
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    SEA LEVEL FLUCTUATION AND DEPOSIT ENVIRONMENT OF THE HOLOCENE PEAT IN DALIAN REGION
    Liu Guohai, Gao Shanming, Li Yuanfang, Yan Fuhua
    1992, 11 (4):  38-46.  doi: 10.11821/yj1992040005
    Abstract ( 650 )   PDF (2740KB) ( 686 )   Save
    Dalian Region belongs to a wet and semi-wet monsoon climate of warm-temperate zone with an annual average temperature between 8 and 10 centigrade,and an annual precipitation of 550-1000 mm.There is a landscape of the conifer and broadleaf forest.The natural forest with pine and oak,ect.is only found in the lower mountainous and hilly areas.Coastal zone has been developed earlier and most of them have become farmlands I.Deposit Environment of PeatThe alongshore peat was mostly deposited in the nutritional cacustrine-swamp environment under the warm-temperate wetted climate from middle-late stage of middle Holocene to early stage of the late Holocene.It belongs to herb-xylophyta type mainly with herbaceous plant and generally the depositiny rate is about 0.7-1.1 mm/a.
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    ANALYSIS OF SENSIBILITY ON ECONOMIC DAMAGE IN THE FLOODED AREA OF LOWER HUANGHE RIVER OF BANK-BREACHING
    Chen Liding, Lu Zhongchen
    1992, 11 (4):  47-56.  doi: 10.11821/yj1992040006
    Abstract ( 515 )   PDF (653KB) ( 504 )   Save
    Through analysing the relationships,between bank-breaching and economy,the authors proposed a method to calculate the sensitivi ty coefficient,and have calculated the sensitivity coefficient of economic damage of flood to each county in the flooded area of lower Huaughe River with the method,further to classify the thirty-two counties into five classes on sensitivity coefficient,which provide a basis for future combatting a flood and going to the rescue in hurry,or changing the channel artificially,also to give a method for future study on economic damage of flood.
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    THE QUATERNARY COARSE SAND-GRAVELS DEPOSITS IN YECHENG, XINJIANG AND THE CORRELATIONS WITH THE UPRISING OF KUNLUN MOUNTAINS
    Zhu Liping
    1992, 11 (4):  57-67.  doi: 10.11821/yj1992040007
    Abstract ( 500 )   PDF (2923KB) ( 480 )   Save
    A series of Quaternary sands and gravels are well distributed on the northern foot of West Kunlun Mountains in Yecheng area oi' Xinjiang.Based upou their appearance and composition of landforms,these deposits in different ages occur in zonation.The Xiyu Conglomerate (Q1) of early pleistocene,conformably contacted with the red sandstone and siltstone of pliocene at the front of the mountains,is drawn and intensively deformed with the upheaval of the Kunlun Mountains.Wusu Group (Q2),a group of grayish sand-gravels unconformably covered on the pliocene and lower pleistocene strata,extended toward the front of the mountains to form the high pluvial platfrom.The lower pluvial platforms are constructed of upper pleistocene strata which spread outside the high pluvial platforms and in the valleys outside the mountains.They have been weathered to form thesurface of conglomerate-Gobi.In addition,aeolian sandy loess spread fromthe periphery of Taglamagan Desert to the high mountains below the elevation of 4,200m asl.
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    STUDY ON CHEMICAL GEOGRAPHY OF SCHISTOSOMIASIS IN THE YANGTZE VALLEY
    Wang Mingyuan, Zhang Shen
    1992, 11 (4):  68-74.  doi: 10.11821/yj1992040008
    Abstract ( 457 )   PDF (511KB) ( 385 )   Save
    Schistosomiasis in the Yangtze Valley is mainly distributed in the middle-lower reaches of the Yangtze River,the Chengtu Plains and others.The results of this research show that chemicogeographical environment is the essential ecological factor in epidemic of schistosomiasis.The content of trace element Sr,Ba,Rb,Sc,Cs,F,Th,Pb,Zn,Cd,Sb,Se,La,Ce,Yb,Tb,Lu of water bodies (the water through a filter film,the water without being filtered and sediments) in endemic area is higher than those of nonendemic area.However content of V,Fe,Ni,Mo,As,Hg of water bodies in endemic area is lower than those of nonendemic area.The average continuous multipler index of 31 trace elements of water bodies in endemic area exceeds 1.The molal ratio of Ca to Mg of sediments in endemic area is approximately equal to those (0.8) suitable for the existence of miracidia.
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    DEGRADED SLOPE ON LATERITIC RED EARTH:ITS PROPERTIES, MANAGEMENT AND DEVELOPMENT IN SOUTH CHINA——WITH AN EXAMPLE OF WUHUA COUNTY
    Xie Ming, He Jianghua, Lin Meiying, Zou Guochu
    1992, 11 (4):  75-85.  doi: 10.11821/yj1992040009
    Abstract ( 528 )   PDF (837KB) ( 558 )   Save
    According to the samples from Wuhua County,Guangdong province,degraded slope on lateritic red earth in South China has the following properties.1.Pedogenic horizons are denuded.Litter horizon(A0) has disappeared; organic horizon(A)is non-clear,replaced by the transitional horizon of (AB),even (A) horizon is fully eroded,illuvial horizon (B) is revealed on the ground.2.Soil becomes sandy.Slope on arenaceous shale sandifies slightly,soil texture is still nainly "non-stony heavy loam" (> 3 mm stony content is less than 0.5%,<0.01mm physical clay 45-60%),slope on weathered granite sandifies seriously,soil texture has generally degraded to "heavy-stony medium loam" (stony> 10%,physical clay 30-45%).3.Soil chemical characteristic deteriorates.In our view,slope on lateri-tic red earth in South China starts to degrade once the content of soil organic matter falls below 3%.Soil and water loss from inappropriate land use system including farming,on steep slope,plowing up and down hills,monouculture farming,and over felling forests is the major cause of degraded slope in mountains of South China.The degraded slope in Wuhua County has been managed and developed according to different degraded degrees.
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    DISTRIBUTION OF SEASONAL SNOWCOVER AND VARIATION OF SNOW DENSITY ON THE HEADWATERS OF URUMQI RIVER BASIN
    Yang Daqing, Wang Chunzu, Zhang yinsheng, Zhang Zhizhong
    1992, 11 (4):  86-96.  doi: 10.11821/yj1992040010
    Abstract ( 658 )   PDF (733KB) ( 750 )   Save
    Because of wind drift of snow and the different thermal conditions on various locations of the microtopergraph,the distribution of the shallow snow-cover is extremely uneven in the high alpine area of Urumqi river basin.Snow depth,duration of snowcover,melting date and the stratification of the snowpack and its mean density are variable in great extent from the bottom of the river valley to north and sorthfacing slopes.Therefore snow depth and density data from the meteorological station in mountain regions generally has a very small limited representative to the nearby area.And the spatial representative of meteorological data in mountain regions should be analysed first in mapping the mountain snow depth,calculating winter and spring water budget and modelling snowmelt runoff process.
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    THE CHARACTERISTICS OF ENVIRONMENTAL HYDROLOGY OF THE NATURE RESERVE OF MEIHUA MOUNTAIN, LONGYAN, FUJIAN
    Lin Qidong
    1992, 11 (4):  97-104.  doi: 10.11821/yj1992040011
    Abstract ( 521 )   PDF (587KB) ( 517 )   Save
    The nature reserve of Meihua mountain,is located in the boundary mountain area of Lianehen,Shanhang and Lonyan in the southwest of Fu-jian.It is the largest forest area of the southwest of Fujian,and the plant cover rate is 68.4%.It has a climate with transitional characteristics of subtropic and south-subtropic.The radical drainage is the riverhead of the Ting River,Min River and Jiulong River.The density of the draniage net is 1.21 km/km2.Runoff resources abounds in the area,with the annual average of rainfall of 1700-2000 mm.Runoff coefficient ranges from 0.6 to 0.65.The runoff is more than 1200mm with seasonal wet and low runoff varying clearly.There are about 332214.5 kW of water conservancy resources.
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    THE DEVELOPMENT OF STUDYING THE POTENTIALITY OF AGRICULTURAL PRODUCTION IN CHINA
    Guo Qifeng, Fu Shuoling
    1992, 11 (4):  105-115.  doi: 10.11821/yj1992040012
    Abstract ( 628 )   PDF (862KB) ( 857 )   Save
    The potentiality of agricultural production is the content of new and developing study in recent more than ten years.It is a fundamental duty in making a study of agricultural science,geography and other ecology.In this paper,were-clarify the concept of crop productivity,put forth that the productivity contains many levels and that each level represents different productivity and has different limiting factors,and give a defination to each level.Proceeding from the atmosphere-crop-soil systerm,we summarize the calculation method of the otentiality of agricultural production.In this paper we review the outline in the past study,sythesize systematically the success in recent study and look forward to the coming scene.
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