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  • 1996 Volume 16 Issue 2
    Published: 20 March 1996
      
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  • ORGANIC GEOCHEMISTRY MARKERS OF CLIMATIC EVOLUTION IN LOESS REGION OF CHINA
    Jia Rongfen, Zhao Lin, Liu Youmei, Wen Qinzhong
    1996, 16(2): 97-105. https://doi.org/10.13249/j.cnki.sgs.1996.02.97
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    The samples collected from Weinan loess section (L2-So) have been analysed by TOC(total organic carbon) and Rock-Eval.The curve of TOC with depth has been set up and compared well with other climatic markers.The main periods of TOC variation of the last 0.14 Ma are 67.08 Ka and 18.29 Ka,which is near with the period of the variation of sunshine,showing that the TOC variation may be controlled by the variation of 65°N sunshine.The distribution of pyrolysis hydrocarbon and its parameters have been researched in detail in the section.It shows that there are two kinds of hydrocarbon associated with climatic change.One is called biological reduce hydrocarbon (pHC2-1) which is in the range of Tmax 350℃ ~500℃,and associated with atmospheric water.The other is called carbonate inclusion hydrocarbon (pHC2-2) which is in the range of Tmax 500~600℃ and formed by evaporation and associated with dry climate.The formula calculating humidity has been deduced: Qg=pHC2-1/(pHC2-1+pHC2-2).The range of humidity of the section is 47%~77% and the reducing order is S1-3>S1-2>O>S1-1>L1-4>L1-1>L1-3>L1-5.And the trend of the humidity is still increasing today.
  • A STUDY ON THE MECHANISM OF RECESSION AND STRUCTURE TRANSFORMATION OF NORTHEAST OLD INDUSTRIAL BASE
    Li Chenggu
    1996, 16(2): 106-114. https://doi.org/10.13249/j.cnki.sgs.1996.02.106
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    On the basis of analying the features of“Northeast phenomenon”and the historical development process of western old industrial bases,using the industrial structure theory and economic growth theory,this paper discusses the restrictive factors in old industrial bases recession and studies the mechanism of recession of old industrial buses.According to the successful experience of western old industrial bases transforming,the paper point-ed out the aim,way and measure of northeast old industrial base transforming in China.The main conclusions drawn from the study are as follows:1. The main feature of recession of old industrial bases is low increase,low speed and bad benefit.2. The regional superiority is the objective foundation of industrial base formation and development.3. The main reason of lod industrial base recession is the industrial structure aged.4. The adjustment industrial structure is the dey way of northeast old industrial base transforming.5. The aims of northeast old industrial base transforming inelude adjusting the relationship between raw industry and manufacture industry,light in-dustry and heavy industry,adjusting industrial technical structure and product structure.6. The way of northeast old industrial base transforming consists of making new industrial development pattern,adjusting industrial allocation,improving regional investment environment,speeding up the developlment of southern coast zone,developing greatly town industry,laying down a series of measures that promote the reform of northeast old industrial base.
  • THE COMPOSITION AND ORIGIN OF SALT LAKE BRINES IN XINJIANG
    Zheng Xiyu, Liu Jianhua
    1996, 16(2): 115-123. https://doi.org/10.13249/j.cnki.sgs.1996.02.115
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    According to field survey and laboratory study,the authors discuss the general situations of salt lakes in Xinjiang,the major and minor compositions of salt lake brines,the hydrochemical types of these salt lakes,and also the matter sources of the brine composition and their enrichment characters.
  • THE FRACTAL DIMENSION OF RIVER NETWORKS AND ITS INTERPRETATION
    He Longhua, Zhao Hong
    1996, 16(2): 124-128. https://doi.org/10.13249/j.cnki.sgs.1996.02.124
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    This paper describes the fractal characteristics of river network,the computation methods and the interpretation of the fractal dimension of the river networks.Based on the calculation of fractal dimension in fourteen large basins and sixty-seven subbasins in China the following points are pointed out in this paper;(1) The river networks are fractals.Their geometric structrures has some self-simialrity.(2) The fractal dimension of river networks can be computed by box counting method.Suitable box size should be selected before reliable result can be got.(3) The real river system is too complicated to be described by just one fractal dimension.Multi-fractals is more suitable for depicting large river systems.Because the large river basins have many subbasins.And in every subbasin,the environment is quite different and there can be calculated a dimension.(4) The fractal dimension of river network reflects the degree of the river evolution.Using the fractal dimension,we can divide the evolution stages of the cycle of erosion through which the river systems are on.The larger the fractal dimension,the later the stage.The threshold for separating the three evolution stages are:D=1.6 and D=1.89.These two values remain further improvement.
  • THE IMPACT OF HUMAN ACTIVITIES ON THE WETLAND ECOLOGICAL SYSTEM IN THE MIDDLE REACHES OF THE CHANGJIANG RIVER
    Cai Shuming, Zhou Xinyu
    1996, 16(2): 129-136. https://doi.org/10.13249/j.cnki.sgs.1996.02.129
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    The plain lake area in the middle reaches of the Changjiang(Yangtze) River is an important part of Chinese wetland resources.Because of its long-time exploitaton and development,it is a main base of agricultural production and developed economic zone,and is renowned as“Country of fish and rice”.But in the meantine,it also has resulted in a series of impact on the ecological environment,thus it is urgent to protect the wetland resources and environment.
  • ON RIVER TERRACES OF THE UPPER REACHES OF THE HUANGHE RIVER AND CHANGE OF THE RIVER SYSTEM
    Yang Dayuan, Wu Shengguang, Wang Yunfei
    1996, 16(2): 137-143. https://doi.org/10.13249/j.cnki.sgs.1996.02.137
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    The upper reaches of the Huanghe (Yellow) River,a length of 1350 km from Gyaring Lake to Guide county,cuts through the great slope of the northeast part of the Qinghai-Xizang (Tibet) Plateau and it runs through a few of Mesozoic-Cenozoic depositional basins,for example,Guide basin,Gonghe basin,Xinghai basin,Zoige basin,Ngoring-Gyaring basin etc.,the sections between them are a series of gorges of the Huanghe River.Based on author’s investigation,there is a terrace of 7 steps in the Huanghe River valley by Guide county,a terrace of 3 steps being formed by the ancient Huanghe River and 7 steps in Gonghe basin,6 steps by Gamao Yangqu town,5 steps by Tangnaihai town,Xinghai County,3 steps by Maqu town,Gansu Province,and one step by Ngoring-Gyaring Lake.The overall upper reaches of the Huanghe River was linked up by a series of the stream captures occurred after strongly uplifting of the Qinghai-Xizang area into a plateau.A section of the ancient Huanghe River through the place Gahaitan located on northeastern Gonghe basin towards east into Guide basin was developed during the end of Middle Pleistocene to the middle of the Late Pleistocene,and then it migrated towards southeast to the place Longyangxia Gorge about 60000 years ago.And the gorge from Maqu to Tangnaihai was linked up about 20000 years ago.
  • PRELIMINARY STUDY ON FLASH FLOODS IN TARIM RIVER BASIN
    Wang Run, Cao Qianzhao
    1996, 16(2): 144-149. https://doi.org/10.13249/j.cnki.sgs.1996.02.144
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    Flash floods are the important events of the hydrological regime of rivers in arid areas.In the Tarim River,northwestern China,flash floods are being monitored.The observed data and investigation demonstrate the difference in time,place,frequency and intensity of their occurrences.Two main flash floods are put forward,they are rainstorm flash flood (RFF) and glacier lake outburst flood (GLOF) by two cases of flash flood in the two tributaries of the Tarim river presented in this paper.It analyses and compares the causes and the development of the two kinds of flash floods.Through further discussion about influence of flash floods on the main channel of the Tarim River,conclusion can be drawn that the greatest flood in record of the main channel come from the GLOF of the upper reaches of the Kunmalik River,especially augmented by great ablation flood.Finally the advantages and disadvantages from flash floods to the environment of the catchment are demonstrated in the paper.
  • INPACTS OF ORIENTATIONS OF SLOPES AND ELEVATION ON RAINFALL IN MOUNTAINOUS REGIONS
    Wang Ling
    1996, 16(2): 150-158. https://doi.org/10.13249/j.cnki.sgs.1996.02.150
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    Impacts of orientation of slopes and elevation in some mountatious areas are complicated.In North China,mountainous region may be divided into 14 sub-regions according to the variations of different parameters of rainfall with elevation.The variation of rainfall with the local elevation shows an increasing tendency of logarthmic function while the variation of rainfall with macro-regional height shows a decreasing tendency of exponential function.On the basis of sub-regions,the variations of the distrubusions of rainfall in mountainous regions may be expressed as a linear function of geographical coordinates:Pi= a0i+a1iψ+a2iλ+a3ih where Pi is the rainfall calculated.a0i is a constant,a1i,,a2i,a3i are the partial correlation coefficients,ψ is the latitude,λ is the longitude and h is the height.The maximum rainfall height often occurs in the range of a warm and wet air current forced to rise.The wetter this current is,the lower the maximum rainfall hight is,vice versa.
  • ANALYSIS OF HEAVY MINERALS OF HOLOCENE LOESS ON LOESS PLATEAU AND ITS ASPECTS OF PEDOGENESIS
    He Xiubin, Tang Keli, Lei Xiangyi
    1996, 16(2): 159-163. https://doi.org/10.13249/j.cnki.sgs.1996.02.159
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    On the Loess Plateau,three typical Holocene loess sections are investigated and sampled.Compositions of heavy minerals in all samples are distinguished under microscopy and their contents are semi-quantitively analysised.The content ratios of unstable minerals to stable minerals are considered as the index to reflex the degree of weathering and pedogenesis.The results indicate that:1) The categories of heavy minerals in all samples are complex and diverse,and the dominant heay minerals (opaque minerals,epidoteand hornnlende) are almost the same.However,some differences in contents are noted,especially in contents of unstable minerals.2) The F value is susceptible index of degree of weathering and pedogenesis.3) From the view piont of pedogenics,the Hei Lu Tu soil has given rise to different natural weathering conditions and human actions,the profile of Hei Lu Tu is a multi-profile.
  • DETERMINATION OF SORPTION COEFFICIENT OF WATER-SOLUBLE ORGANIC MATTER IN SEDIMENT
    Lin Bin, Tao Shu
    1996, 16(2): 164-169. https://doi.org/10.13249/j.cnki.sgs.1996.02.164
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    Two procedures of Multiple Solid-Water Ratio(MSWR) and Sequential Extraction (SE) for determination of sorption coefficients of water-soluble organic matter in river sediment were proposed.The operational feasibility of the procedures and the procedural errors were analyzed.It was demonstrated that the MSWR method is favored over the SE method due to its operational easiness and relatively high accuracy.The content and the sorption coefficient of water-soluble organic matter of a sediment collected from the Yichun River determined with MSWR procedure are 0.247 mg/l and 0.0045 l/g respectively.
  • MULTIOBJECTIVE-STEP DECLSION METHOD IN URBAN ECONOMIC-SOCIAL-ENVIRONMENTAL CO-ORDINATLVE GROWTH
    Wang Hongwei, Ren YongLin
    1996, 16(2): 170-175. https://doi.org/10.13249/j.cnki.sgs.1996.02.170
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    Taking the output value of each industrial department as decision variable,we build the economic-social-environmental co-ordinate growth multiobjective decision model.It can be solved using step method (STEM).This model provides a useful decision method for the policymaker.
  • A METHOD FOR EVALUATING COMMERCIAL LAND DIFFERENTIAL RENT IN CITIES BASED ON GIS
    Xu Jiangang, Tu Fan, Han Xuepei
    1996, 16(2): 176-183. https://doi.org/10.13249/j.cnki.sgs.1996.02.176
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    This paper approaches to grade commercial land differential rent in cities based on Geographical Information System(GIS).Firstly,the three quantitative indexes of evaluating factor: commercial location,traffic condition and population density,are established separately in the support of the spatial database of land,traffic and population.Then,a unified evaluating index is created by using the model of discriminating geographic environment.Finally,the spatial database of commercial land rent class was established and primitive land plan was discussed according to the map of land rent class in the example of Putuo district,Shanghai.Meanwhile,a series of methods for extracting the data are developed by using PC ARC/INFO toolkits.The result shows that the study provides not only a valid means to appraise commercial land prices for land administration,but also the reliable basic data for urban planning.
  • COMPUTER AID DRAWING OF EQUIVALENT FLOW DURATION CONTOUR
    Wang Lachun, Chen Xiaoling, Du Jinkang, Yang Xiaoxuan
    1996, 16(2): 184-190. https://doi.org/10.13249/j.cnki.sgs.1996.02.184
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    After analysing the watershed landform with the method of Geography Information System(GIS),the movement of a water particle can be conveniently traced in the process of watershed flow concentration.Its flow concentration time,which is from the starting point to the watershed outlet,is connected with the length and gradient along the flow pathway.According to the method,the flow concentration time of a water particle can be computed,which makes it possible that creates the model of equivalent flow duration contour aided by computer.The simulation method is proved effective by examing Huangshan runoff experiment basin.