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  • 1982 Volume 37 Issue 1
    Published: 15 January 1982
      

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  • Chunfen Lee
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    In recent geography there have been changes in content, approach and techniques, As to content the variety of subjeetmatter is increasing on the one hand and reducing on the other. Whatever the changes might be in this regard, traditions are the foundation of development. Improvements are made on what has already been achieved. The traditional themes of spatial arrangement of phenomena, Man-environment relationship and regional studies are much the same. As those today, an important change is the shift of aspect. Themes of spatial arrangement are being directed from mere description to locational analysis, i.e., how things are located in relation to other things; to formation and modification of distributional patterns. Those of Man-environment relationship is shiftng from emphasis on the influence of environment on man to that on the impact of man on environment. Those of regional studies are transferring from the study of individual homogeneous regions to that of functional regions, interregional relationship and spatial organization of regions.One of the great improvements is the increasing emphasis on the importance of the way the geographer approaches his subjectmatter. In this respect, three different approaches are distinguished, namely, spatial analysis, ecological analysis and regional complex analysis. They are closely related. The way of structuring geography in terms of these three approaches merits recommendation, for they approach problems on the related variables as well as their links. It is to be noted that such approaches stress the unity of geography rather than diversity, thus breaking through the long-standing two-fold dualism of geography, i.e., the separation of systematic from regional geography and that of physical from economic geography, although specialization in one branch of geography may be necessary for a geographer to make progress. It is especially the artificial split between physical and economic geography that has in a large degree hindered the progress of geography as a whole. Moreover, such approaches as these are favorable for inter-disciplinary communication, which would promote the development of geography on practical as well as on academic sides.With regard to techniques some geographers hold that the most obvious recent changes have been in method and techniques which enable geographers to do researchmore accurately and more quickly. Nevertheless, the quantitative techniques are new only in the sense that they have been used extensively only in recent years. Also, there is a sympton of trend that some being used are completely unsuited to the purpose of geography, while the older but still useful techniques are discarded.To sum up, recent developments of geography have been made on the basis of traditional accomplishments, as a result of social needs, progress of related sciences and demand of development of the discipline itself. Themes of recent geography are little different from the traditional ones but have been injected new ideas and lights, shifted emphasis of aspects and innovated methods and techniques. It is also commendable that encouraging improvements are witnessed in the combination of theory with practice.
  • Su Shiyu, Li Juzhang, Su Yingping, Yin Zesheng, Shen Yuchang
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    Geomorphology is one of the most basic elements in geographic environments. Geomorphologic mapping is significant in representing landforms in space distribution. It helps to understand the various features of geomorphologic conditions.The task of compiling 1:1,000,000 national geomorphologic map is to enhance the study of land resources and agricultural regionalization. This paper discusses several problems in designing such a map.1. Geomorphologic classification and legend system. The legend system mainly includes five levels:a. With base colours for representing the cartographic unit of geomorphologie form of originb. Form symbols of earth surface texturec. Symbols of rock compositiond. Symbols and annotation of chronologye. Symbols of base map2. Some principles for representation of geomorphologic map.The purpose of geomorphologie map is to represent earth surface form. Therefore, images of geomorphologic features in cartographic area should be first of all considered. Then secondly, the original state system; and thirdly, the representation of geomorphologic map.3. Compiling techniques.Apart from conventional method, we considered that the analysis of remote sensing imagries and computer-aid-cartography should be applied, for it can improving mapping quality and enhance the efficiency of mapping greatly.
  • Li Juzhang
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    The quantitative index of terrace is in which where S1 - area of horizontal projection of the terrace surface S2 - area of horizontal projection of the terrace slope J1 - average gradient of the terrace surfaces J2 - average gradient of the terrace slope.
  • Zhu Zhihui
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    Various geographical and climatological factors that affect solar radiation reaching the ground are analysed. Based upon the screen method, several convenient factors representing shady and transparent degree of the sky are determined. Then, a set of empirical equations suitable for the continental region of China are established by means of the stepwise regression method to estimate the monthly or monthly average daily total, direct and diffuse solar radiation.The results of the author’s tests indicate that the accuracy of these unified equations is no less than that of regional equations. So, by using these unified equations, it is possible to overcome the inconvenience in the regional calculation. These equations embody the decreasing effect of fly ash and smoke screen on direct solar radiation as "well as their enhancing effect on diffuse solar radiation. It seems that fly ash and smoke screen do not have apparent influence on total solar radiation. Bela-tive sunshine is still the dominant factor affecting total and direct solar radiation. Two supplementary factors significantly affecting total solar radiation are elevation and water vapour. They roughly reflect the atmospheric transparency affecting total solar radiation in winter half year. The seasonal variation (especially between winter and summer) of these equations shows quantitatively the effect of the China’s monsoon climate on solar radiation.
  • Wang Yongyen, Teng Zhihong, Yue Leping
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    Owing to hardness of quartz, the surface texture of grains produced during thier formation, transportation and deposition remains for a long time. It may be used as an evidence for illustrating the origin of loess.The surface texture of quartz grains may be divided into two types梞echanical and chemical. The former was formed during the formation and transportation of grains, while the latter, mainly formed during deposition. Mechanical texture includes cleavage planes, conchoidal fractures, pits, grooves with round and smooth bottom, broken fissures, pitted surface texture, etc. They might be formed in different environmental processes, but most of them show some evident marks of aeolian transportation, such as the abrasion of blown sand on the edges and surface as wall as at the groove bottom of the quartz grains.As for the chemical texture, it might have been subjected to weathering in situ especially in the process of deposition. Chief chemical texture includes silica precipitates, chemical etching and dissolution phenomena, such as round pits, triangular pits, pits with lid, convex parts in different shapes, etc.The surface texture of silt quartz grains shows that the formation of the loess materials might have passed through different processes, but the wind action is supposed to have played an important role during transportation.On the basis of the study of surface texture of quartz grains, it may be considered that the genesis of loess in China are due to multi-factors but the chief one being aeolian.
  • Wang Huaqun, Li Penglai
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    Swamp as an unique natural complex is one of the component parts of geographical landscapes. Conventionally only the swamp distribution and the ratio of their area are shown on the general geographic maps. The types of swamps have never been distinguished scientifically.Contents of swamps representation on general geographic maps are discussed, including cartographic classification of swamps and method of expression area method expressed with symbols. According to the result of research work of our institute in recent years and our experience in compilating practice,we use the sheet of the north-eastern part of China at the scale of 1: 1,500,000 as an example. Preliminary experience are introduced, including (1) analysis and utilization of cartographic informations) (2) field observation and mapping, (3) cartographic generalization, (4) procedure of compilation. Finally, the authors point out that there are still some defects in the representation and compilating method for swamps on these sheets that need further study.
  • Wang Zhonglong, Bai Zhongyuan, Chen Yuan
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    Tian Shan is one of the regions with deep snow cover in China. Frequent occurrences of snow drift bring in havoc to communication and transportation, agricultural production and livestock raising.In montane regions, it is rather convienient to study the movement and transport of drifting snow 011 the basis of corrected formula of wind velocitj- distribution. The threshold of the movement of snow particles is related with the physical properties of the particles themselves as well as with the outside environment conditions. In snowy or non-snowy weather, not only the relation between the height of the blowing snow and different kinds of parameters is different, but the strength of drifting snow in layers of various heights is different also. This artiele gives the figures and formula for calculating the unit snow drift quantities of different snow cover density in snowy or non-snowy weather, and discusses the problems of developmental length of snow drift in montane regions.The mechanism of accumulation of drifting snow resulted from the vortex grag-caused hy a sudden change in the curvature of the terrain. As for the road, different fields of flow on different landforms near the roadbed may give rise to different pro-cessess and quantities of drifting snow. Drift accumulation in Tian Shan is mainly located at the leeward or windward, turning and flow circle section, as well as extremely high or low embankment.On the basis of field observation, modelling experiments in the wind tunnel and the effects obtained by means of large scale engineering, we have developed some measures for controlling snow accumulation. In addition, we have proposed "leading", "modifying", "preventing" and "sweeping" as controlling measures, and also discuss the mechanism of some protective measures, their types and their main applications and influencing factors and calculating formulae.
  • Huang Xichou, Zhu Yauming, Fu Deyi, Meng Xianxi, She Zhongsheng
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    The Changbai Mountain Nature Keserve is one ot the nature reserve of the MAB Programme. The whole ecosystem appears to be vertically differentiated into zones. This study shows that in the ecological environment, not only the composition and content of chemical element have obvious areal diferentiation, but also the migration, exchange and cycling of chemical elements in each vertical zone are clearly different.In the rock soil and plant of different vertical zones of Changbai Mountain, the changes of Zn and Pb content apparently and consistently present positive abnormality, while the changes of Cr and Xi content present negative abnormality; so that this region should, be called the bio-geochemistry region with high Zn. Pb content and low Cr, Xi content.The chemical composition and content of the- rock and soil in the Alpine tundra zone is similar to those of the rock and soil in the Ermans Birch zone, both of them have higher K, Xa contents and lower Ca. Mg, Fe, Mn contents. And contrary to the contents of those chemical compositions of the rock and soil in the coniferous and broad-leaved mixed forest zone, where has lower K. Xa contents and higher Ca, Mg, Fe, Mn contents. This difference is mainly resulted from different mineral composition of base rock.The bio-concentrative characteristics of trace elements in each zone are different too. Some elements are of lower content in rock and soil, but of higher content in plants. It indicates that those elements are bioelements to plant. Of course, these bioelements assimilated from environment by plant are only in limited amount; it indicates that the element content in plant is not in a simple linear relationship to the ele-
  • Yang Yichou, Li Bingyuan, Yi Zesheng, Zhang Qingsong
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    Landform on the Xizang Plateau is generally characterized by gentle rolling plateau surface. There are also a series of continous and towering mountains standing above the plateau surface, and these lofty mountains are the centres where both the ancient and modern glaciers developed. Numerous broad valleys and basins are inlaid in the interior of plateau surface. The upstreams of the exterior drainage system and most portions of the interior drainage system are meandering in the broad valleys while lakes dotted and spread all over the basins. The plateau surface is down cut by channels of middle and lower reaches of the exterior drainage system. In addition, karstie, aeolian and volcanic landforms have been developed on the plateau surface.The landform on the Qinghai-xizang plateau is a result of underthrust with a small angle of Indian plate into Eurasion plate. Since late Cretaceous, the Indian plate has, (due to the continous expansion of Indian Ocean floor,) pushed northward, approached and finally underthrust underneath the Eurasian plate. The different mountain-making movements of Hercynia, Indo-China, Yanshan and Himalaya acted upon Indian plate with horizontal movement and caused it disintegrated internally. As a result, the disintegrated smaller and younger plates, underthrusting along rift zones in stages underneath the Eurasian plate. The Yanshan movement exerted the greatest influence and laid the foundation of landforms of the plateau, while the early Himalayan movement finally made the plateau as an independent macromorphologic entity. The premitive plateau is thus formed. The ncotectonic movements, occurred since the end of Tertiary and acted upon the plateau, in the form of vertical movement have caused intense uplift of the plateau in stages, this open up the new era for the formation of the "World Koof". The strong uplifting of the plateau, coordinated with the global climatic cold-warm fluctuation created unique water-heat regime for the plateau. The complicated and homogeneous distribution and integration of the various land-forms are originated horizontally and vertically by many times of climatic alternation of glacial and interglacial periods.