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    20 March 1984, Volume 4 Issue 2 Previous Issue    Next Issue
    PROPER DEVELOPMENT AND CAREFULL PROTECTION OF LAND RESOURCES IN THE LOESS PLATEAU
    Zhu Xianmo
    1984, 4 (2):  97-105.  doi: 10.13249/j.cnki.sgs.1984.02.97
    Abstract ( )   PDF (607KB) ( )   Save
    Loess plateau is the birth place of Chinese agriculture,in which abundent and varied land resources are distributed.The soil stratum is rather thick and fertile, which provides an eucellent condition for growing plants and developing agriculture. In this area,irrational uses of the land and plunder managment have been Carried out for over thousands of years;the whole land has been almost cut into fragments,and the soil erosion is very serious;therefore the people’s daily life is very poor now.At the same time,the whole ecological environment becomes worse and worse,and the storm flow always brings flood catastrophe to endanger the people’s life and property in the low basin. The more extensive cultivation,the lower productivity;conversely,the lower productivity,the more extensive cultivation;the higher embankment hides the greater danger;conversely,the greater danger seeks the higher embankment. These two vicious cycles have been vigorously curried on in the Hunghe region basin.Therefore,it is an extremely urgent task to work out a long term plan for the conscientious protection,renovation and rational development and use the land resources as a whole. The only counter measure to deal with the special conditions of the loess plateau and the necessity of river dredge and development is that we have to enrich soil fertility,promote soil infiltration and strengthen soil anti-denudebility by means of rapid revegetation as an core and in addition with some necessary mechanical protection measures in order to put the total precipitation infiltrating into the ground as a strategic aim.And at the same time,all the agricultural productions are required to adjust their practices to concretely obey this strategic aim.
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    ANALYSIS OF CIRCULATION FACTORS TO EFFECT ON PERSISTENT LOW TEMPERATURE IN SUMMER IN THE NORTHEAST CHINA
    Zhang Shaoqing
    1984, 4 (2):  107-114.  doi: 10.13249/j.cnki.sgs.1984.02.107
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    In this paper,the author analysed the monthly pressure change of sea sur-face in India-Pakistan area (70—90°E°,10°—30°N)and computed the correla-tion coefficients between South-Asia high of 100 mb and four factors of four areas-the low pressure of India-Pakistan sea surface,the high pressure of the west Pacific,the temperature of the Pacific sea surface,the snow cover of the Qinhai-Xizhang plateau,and then following conclusions were reached: 1.The extensively per sistent low temperature easily occurs in summer in the Northeast China when the India-Pakistan monsoon is weaker and converserly, when the monsoon becomes strength,no extensively persistent low temperature occurs. 2.The monthly pressure anomaly exists stability in the sea surface of the India-Pakistan area The correlation coefficients of anomalies between summer and winter,spring are respectively 0.726 and 0.879,which are more than confi-dence level α= 0.001. 3.There are periodically climatic oscillation with regular pressure ano-maly,about 14—15 years,in India-Pakistan region. 4.In summer (Jun.-Sept.)there is a negavitive correlation between the low pressure of India-Pakistan area and the high pressure of the South Asia, the coeff,is-0.6399 which closes to the confindence level α=0.001 and the correlaton coeffient between India-Pakistan low and the area index of west Pacific high at 500 mb layer is equal to-0.4447,which is more than confidence level α= 0.05. 5.In summer the mean percentage of rain fall anomaly of five statiions on the Xizhang plateau,Lasa,Changtu,Rikeze,Bange,Lin zhi,correlated with the South-Asia high of 100 mb and the sea surface pressure of the Indi-a-Pakistan area.Their correlation coefficients are respectively 0.346 and-0.396, Which close to the Gonfidence level α= 0.1.
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    CHANNEL CHANGE OF LOWER REACHES DOWN RESERVIORS UNDER VARIOUS NATURAL CONDITIONS
    Gong Guoyuan
    1984, 4 (2):  115-124.  doi: 10.13249/j.cnki.sgs.1984.02.115
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    This paper analyses channel changes of the lower reaches down reserviors and the transformations of river pattern.These rivers flow through different areas with various backgrounds and natural environments. The characteristics of channel changes under different natural conditions are.(1)The more the released discharge,the longer duration the flow and the further from the dam the erosional base level,then the longer the scour distance is;the more the discharge and the finer the material,the more intensive the scour is.(2)Three situations of channel change exist in longitudinal direction: (a)A concave or linear profile is associated with the grading of bed material and the unequality of scour over river bed (b)When bed material is composed of uniform medium or fine sand and the bed is equally scoured,the parallel lowering of the bed will occur and the longitudinal profile will inherit its original form.(c)Affeeted by the bedrock and the tributaries with heavy load, the profile will be convex.(3)Three types of transverse evolution are:(a)When both the bank and the bed are less mobile,the released discharge will primaryly cause deep scour and results in a narrowed cross-section and in decrease of width-depth ratio.(b)When the bank is less mobile than the bed,the deep scour will occur prior to the lateral erosion and the width-depth ratio might increase.(c)When both the bank and the bed are composed of uniform loose material,the deep scour and the lateral erosion will parallelly operate and less change will occur in the width-depth ratio. As far as the river pattern trasformation considered,the shorter the duration of the released flow,the more the regional storm runoff,and the worse the vegetation,then the more difficult the transformation from braided river to other river patterns.In constrast,the longer the duration of flow,the less the sediment load from the basin and the better the Vegetation,then the easier the evolution of a braided river to a single meandering river is.constrainted by the boundary conditions,these rivers may changed into a confined meandering or stable islandtype river.
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    THE ECONOMIC GEOGRAPHIC BASIS OF THE SEAPORT’S,DEVELOPMENT AND DISTRIBUTION
    Chen Hang
    1984, 4 (2):  125-131.  doi: 10.13249/j.cnki.sgs.1984.02.125
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    The basis on which a seaport depends for existence and development is its hinterland.Hinterlands may be divided into two types:the direct hinterland only belonging to a specific port,and the complex or overlapls hinterland,i.e. several hinterlands can simultaneously use a certain port.Thus the property and development of any port,as well as its character and scale are not only closely related to its own specific regional background,but also affected by other relative ports,especially the adiacent ones.In other words,all ports have their econo-mic geographic bases respectively. The categoies of the regional background of ports consist of:(1)the hi-nterland and its link with the port in traffic and transport.(2)the condition of mineral resources in the hinterland.(8)the level of development and the type of economic structure in the region directly affected by the port.(4) the scal of the city which the port relies on.(5)the natural condition of the harbour and neig hbourring region.(6)the location of the port,etc.All the factors above mentioned act to the ports in different way and varying degree Because the relative ports,especially the neighbourrings,have an overla-pping complex hinterland,the shipping goods can be tran sf ered to anyone of them.This brings naturall’y an influence each other on their development.In fact, they check each other and have respective roles to play.Finally the regional combination of the port co nstitutes’1a regional port group~I. This paper analyses and assesses the regional background of the ports,and makes an approach to the regional port combination,so as to get a clear under-standing about their action on the seaports~ fo rmation,development and distri-bution.All of these provide scientific basis from point of view of geography for rationally planning and locating seaports.
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    QUATERNARY STRATIGRAPHY IN THE ZHUJIANG DEITA
    Li Pingri, Huang Zhenguo, Zhang Zhongying, Li Konghong
    1984, 4 (2):  133-142.  doi: 10.13249/j.cnki.sgs.1984.02.133
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    This peper deals with the Quateranry stratigraphy devision in Zhujiang Delta based on the analysis of the C14dating and stratigraphic correlation,sedimen-tary facies and cycles,as well as climatic variations reflected by spore-pollen analysis.It is concluded that six formations could be distinguished in chrono-logical order,since the Middle Late Pleistocene (Q32),namely: (1)Shipai (石排)formation(Q32-1),which is marked b the yfollowing features:C14dating about37,000±1480 years B.P.—30,000±2800 years B.P.; terrestrial gravel or thick sand with buried forests formed during a period of lowersea level;spore-pollen group representing colder climate. (2)Xinan (西南)formation (Q32-2),its lithological characteristics are mainly of dark grey clay with marine or brackish fossil acconding to C14dating (28,240±2220—15,000±550 years B.P.)and spore-pollen group representing warmer climate,it Can be concluded that this formation of deltaic facies was deposited under trangressive condition,during the late stage of Würm sub-inter-glaciation. (3)Sanjiao(三角)formation(Q33-Q41),which is characterized by deep weathering clay or alluvial thick sand and gravel interbedded with buried fo-rests.This formation is clearly the product of weathering in terrestrial environ-ment,during tile period of global lower sea level of the Late würm glaciation and Early Holocene. (4)Henglan(横栏)formation(Q42-1),its C14 dating are 8050±200— 5020±150 years B.P.,greyish black muds with abundant marine fossil.In addi-tion,the result of spore-pollen analysis indicates that the climate of that time was greatly warmer than that of Q33-Q41,and an extensive transgression exerted a strong effect on the Middle Holocene sedimentation in the Zhujiang Delta. (5)Wanqingsha(万顷沙)formation(Q42-2),similar to the 3rd stratum, is mainly composed of terrestrial sediments such as shallow-weathering clay, thick sand or fine sand interbedded with fresh water diatoms or shells and abun-dant buried forests.Horizontally,the facies turns to marine muds.Their C14 datings are 4940±250—2510±110 years B.P.and the spore-pollen group reflects a colder climate at that time.Thus,this formation might have been deposited un-der local regressive condition. (6)Denglongsha (灯笼沙)formation (Q43),which is mainly composed of derk grey mud and silt clay.From the C14dating (2350±110—1260±90 years B.P.),warmer spore-pollen composition and facies,this formation seems to be a part of the sediments of deltaic environment from about 2500 years B.P. up to the present.
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    DISCUSSION ON DEMARCATION OF THE EASTERN AND WESTERN PARTS OF MID-SUBTROPICAL ZONE IN HUNAN PROVINCE
    Cheng Weimin, Xu Xueren
    1984, 4 (2):  143-150.  doi: 10.13249/j.cnki.sgs.1984.02.143
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    Mid-subtropic is a major part of the subtropical zone in China,which occupies about 17.6 percent of the country’s total area.The climate is warm and humid there,with high precipitation and high temperature appearing at the same period.Areal differentiation of topography,natural resources,vegetation and soil is obvious,particularly in the eastern and western part.So it is necessary to delineate a objectively scientific basis for natural regionalization,and for rational allocation of agriculture,forestry and animal husbandry. The differences between eastern and western parts of the mid-subtropical zone obviously lie on the various composition of natural environment and the way of land use. Much controversy has been evoked about to where the demarcation line should be drawn within Hunan province and what are the criteria based on.After careful study on the differentiation in local terrain,hydro-thermal conditions as well as field survey in Hunan province,the authers would like to assign the demarcation line betwen the west and the east of mid-subtropics in Hunan province existing on the northeast of Wu-Ling Mountain,across Yuan river to east flank of Xuefen Mountain.From north to south the demarcation line passes through several counties:Shimen,Linfeng,Taoyuan,Huangcai (Ningxiang), Dongkou,Wugang,Xinning up to the administralive boundary line between Hunan and Gungxi provinces.
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    A PREDICTION ABOUT THE EFFECT OF THE BUILDING OF SHUIKO HYDROPOWER STATION ON THE ECOLOGICAL ENVIRONMENT OF MIDDLE-LOWER REACHES OF THE MIN RIVER
    Yu Zezhong
    1984, 4 (2):  151-158.  doi: 10.13249/j.cnki.sgs.1984.02.151
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    If a comprehensive survey of river course of middle-lower reaches of the Min river and the hydrographic characteristics is made,the conclusion that the harmless effect on the ecological environment when a hydropower station is built at Shuikou Can be reached.The reasons are: 1.After the station is completed,most of the minerals and organic matters will still be washed away into the lower reaches during the flood stage since the torrent of the middle reaches will go on flowing downward in great quantities. 2.After the station is completed,the discharge of lower reaches during the low water stage will be increased by the adjustment,so that the movements of tidal current will be as regular as usual and that is more favourable than before for the irrigation and navigation. 8.After the station is completed,the ecological environment will be as same as before both at the mouth of the Min river and beyond it,so there will be no obvious effects on the migration of fishes and the fishing production. The problem of any sudden disappearance of fishes at the fishing ground owing to the shortage of baits will not at all occur. 4.A great quantity of mud and sand will be washed out from the middle reaches beyond the dam so that deposition of silt within the reservoirs must not be very serious.
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    THE MULTITEMPORAL ANALYSIS OF REMOTE SENSING IMAGES FOR LAND STUDY
    Zou Shanghui
    1984, 4 (2):  159-166.  doi: 10.13249/j.cnki.sgs.1984.02.159
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    The multitemporal analysis of remote sensing images is to compare and discriminate the differetiation in temporal images of various time and environment by means of spetific technique for revealing the process and tendency of environment revolution.This paper takes Xishui county of Hubei province as an example to expound its application on land studies. The technical methods of multitemporal analysis generally Can fall into the following Categories:1.Optic composition of two or multi-seasonal images.2. Ratio method.The normalized density ratio of MSS5 and MSS7 can better express season change of vegetation.3.Amplifying method of computer-optics.In the study,the visual interpretation still had been adopted as a principal method, supplementing with the optic composition.The results,distinguging and mapping various land types as well as expounding the dynamic changes in future in the test area have been reached.
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    FEATURES AND GENESES OF THE DIAMICTON IN THE LUSHAN REGION
    Zhang Linyuan, Mu Yunzhi
    1984, 4 (2):  167-176.  doi: 10.13249/j.cnki.sgs.1984.02.167
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    The glacial problem of the Quaternary in the eastern part of China,especially in the mountains at low latitudes and low altitudes,has been debated among domestic and foreign researchers.The points in debate are those of glaciation and non-glaciation.This paper deals with the problem in the light of some features of the diamietons of the region. The allitic weathering of the diamicton is very obvious in the region. However,a key question for determining the sedimentary environment and its genesis is of period over which warm,humid weathering prevailed.Those who advocate glaciation of the Lushan have already pointed out that under the condi-tion of warm,humid weathering the deposition of diamictons often occurred. Based on analysis of data,however,the following is proposed:the composition of diamicton of Dagu period on the piedmont came from the weathered crust constructed by vermicular red soil,in the mountains.that is to say,lt had gone through strong warm and humid weathering before deposition.This proves that the warm,humid weathring prevailed in the region in the early period. Based on its generation and development process,the original diamictons of different ages and colours in the region can be divided into three types: modern slope sediments laid down by creep,slope sediments which came from earlier diamicton and crept slowly along the slopes cut by stream,and debris-mud flow sediments. Based on a series of charateristics of the diamictons,it is considerable that the diamicions in the Lushan are not of glacial origin,however,they can not be explained by any single non-glacial process.Diamictons of different ages and geomorphological expression have been produced by various mechanisms. The Dagu diamicton(corresponding to Mindel glaciation)which was said to be typical morainedebris is really a sediments of piedmont fan.Its main features can be explained by the mechanism of debris-mud flow accumulation.
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    A CLASSIFICATION OF SAND WAVE IN ALLUVIAL STREAM
    Zhan Xiaoyong
    1984, 4 (2):  177-182.  doi: 10.13249/j.cnki.sgs.1984.02.177
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    Based on the survey in the field and the analysis of field data,this paper has introduced the concepts of sand wave and its transportation,and discussed the classification principle and then suggested a clssification system of sand wave in alluvial stream. According to the classification,the sand wave in alluvial stream is divided into two grades.The first grade includes two kinds of sand wave and the second includes six.This paper gives respectively definition to each kind of sand wave,descripting its geometrical shape,formation,transportation and so forth,and emphasis to the differentiation,in the first and the second grade of sand wave.
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    AN APPROACH TO SOME PROBLEMS OF MILITARY GEOGRAPHY
    Feng Peiyue, Shen Weilie
    1984, 4 (2):  183-187.  doi: 10.13249/j.cnki.sgs.1984.02.183
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    AN APPROACH TO RATIONAL DEVELOPMENT AND ADMINISTRATION OF THE SANJIANG PLAIN FROM CLIMATIC RESOURCE CHARACTERISTICS
    Liu Xingtu
    1984, 4 (2):  188-194.  doi: 10.13249/j.cnki.sgs.1984.02.188
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    Based on the climatic law of the Sanjiang Plain,the following suggestions on the rational development and administration of the region were pointed out. They are (1)to fertilize the existing farmland to increase yield of unit area as the agricultural direction in the future because of rich light energy resource and great production potenfial;(2)to carry out the lpolicy [regulating rivers and watercourses bringing waterlogging and draught under control and [combining draingge with storage in view of the ratio of precipitation and possible evapora-tion and unsteady precipitation;(3)to distribute rationally crops and variety to prevent low temperature hazard according to the thermal condition;(4)to take the measures to make the change of the ecological environment in good circulation because recently soil erosion becomes serious.
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