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    Earth Surface Processes
  • Earth Surface Processes
    ON THE INTEGRITY CONCEPTION OF THE 19TH CENTURY’S GEOGRAPHY IN GERMANY
    Lee Shutan, Lu Cheng
    1983, 2(3): 1-7. https://doi.org/10.11821/yj1983030001
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    The middle of the nineteenth century is the great turning point in the development of geography, marking the end of the classic and the beginning of the scientific geography. All these happened in Germany. The geography in this period synthesized all kind of concepts from the great discoveries, the rich facts of geographical knowledge, the great advances of natural science and philosophy. Geography at that time was based on the conception of integrity. The division of geography into the physical and the human was a phenomenon of later development. The establishment of the 19th century's unifying cencept in Germany had a profound influence upon the modern and contemporary geography.This paper aims at analysing the development of philosophy and matural science of that time in the relation with integrity conception.The geographical idea is synthetically influenced by philosophy ideas of kant, Hegel and Feuerbach, Marx and Engels etc., while the development of natural sciences provided the basis for establishing conception of unity for the contents of geography reguired in the connection of phenomena. Later, the authors discuss the conception of unity from the angle of the geography itself. The pioneers of the scientific geography were Humboldt and Ritter, followed by Richthofen and Ratzel. They played an active role in the development of scientific contents of geography both in theory and practice.The authors emphasize that both the regional and unifying conceptions are still the core of modern geography in spite of the tendency of branching off in the field of geography itself.
  • Earth Surface Processes
    EXPANSION AND CONTRACTION OF THE BAIYANGDIAN LAKE SINCE 10,000 YEARS AGO
    Wang Huichang
    1983, 2(3): 8-18. https://doi.org/10.11821/yj1983030002
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    The Baiyangdian Lake is situated in a depression between the alluvial fans of yongding River and Hutuo River at the eastern foot of the Taihang Mountains. It has long been known as "a bright pearl of the Central Hebei Plain". However, the bright pearl is recently in danger of being annihilated. For this reason it is very important studying its evolutional law since 10,000 years ago and forecasting its developmental trend in the future. According to a large amount of field observations, drill records and historical-archaeological materils, a lithofacies-paleogeographic sectional map of Baiyangdian Area in the Holocene was drawn. It shows that the Holocene Series may be divided into three phases. In the Lower Holocene Series there were mainly alluvial sediments, but limnetic deposits occupied an important place in the Middle Holocene Series and the greyish black oozy layer which represented the limnetic environment possessed greater thickness and wider extent. In the upper Holocene Series the alluvium predominated again and covered over the limnetic deposits of the Middle Holocene Series.Futhermore the auther indicated that the ancient Baiyangolian Lake had undergone three stages of evolution during the last 10,000 years. In the Early Holocene the previous lake which had been died out in the dry and cold weather at the end of the Late Pleistocene rejuvenated once again around the present lake. Owing to the Atlantic Climate Optimum and the transgression in the eastern part of the Hebei Plain, the extent of the ancient lake expanded to the maximum in the Middle Holocene. However, in the Late Holocene the vast ancient Baiyangdidn lake was disintegrated, contracted step by step and died out in greater part, and only the present Baiyangdian Lake survived.The main factors controlling the expansion and contraction of the lake are climatic changes and sea level fluctuations. In addition, both the deposition of the rivers and man's irrational use of natural resources have accelerated the processes of disintegration and contraction of the lake in the Late Holocene.
  • Earth Surface Processes
    SLOPE FEATURES AND SOIL EROSION IN THE LOESS REGION
    Cao Yinzhen
    1983, 2(3): 19-29. https://doi.org/10.11821/yj1983030003
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    In this paper the relationship between slope features and soil erosion in the loess region has been studied. Investigation shows that the angles of slopes of loess ridge and hill mostly vary from 14° to 28° The upper limit of the characteristic angles corresponds to the angle of internal friction of loess and the lower limit to half of the angle. This is coincident with the results stated by Carson (1969).The slope forms in the loess region can be separated into five types, namely straight, convex, concave, concave-convex and step slopes. The erosion position is very different on the different kind of the slopes. It mostly occurs on the downslope of the straight slope, on the mid-down slope of the convex slope, on the mid-slope of the concave slope and on the straight segments between the convex and concave elements of concave-convex and step slope.Soil erosion is greatly controlled by slope angles. The statistical analysis of the data observed in the fields shows that 15°, 26° and 45° are very important to soil erosion. The sediment yields increase with slope angles, then over 15° the sediment yields rapidly rise and washing is greatly intensified. At 26° the way of erosion changes, from the running water wash to gravitational erosion. At 45° erosion is the most intense in the slope angles between 0° and 90°. This result is supported by the mathematical deduction. The study of the three slope angles is important in both theoretical research and reasonble planning for controlling the drainage basin in a comprehensive way.
  • Earth Surface Processes
    SEVERAL PROBLEMS ABOUT HISTORICAL GEOGRAPHY IN THE SOUTHERN ROAD OF ANCIENT “SHI-YU”
    Wang Beichen
    1983, 2(3): 30-43. https://doi.org/10.11821/yj1983030004
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    The region discussed in this article is within the realm of the southern fringe of the Taklamakan Desert. It is situated along the ancient Silk Road between Khotan and Ruo-chiang. This article was written on the basis of field investigations and analysis of historical materials.The theme includes three problems.(1) Whether or not a river existed along the southern fringe of the Taklamakan Desert in the historical period? It was recorded in "Shui-jingju" (A Commentary on ancient river system) that there was a river called"Nan ho" (south river) flowing from Khotan eastward along the southern fringe of the Taklamakan Desert and pouring into the "Lou-Lan Sea" (now Lop-Nor).This concerns an important problem about historical geography, that is, Whether or not the river system of this region had experienced a fundamental change.After analysing many historical materials and modern geographical works, we find that no Nan-ho existed there throughout historical poriod.(2) Did the number of Oasis between Khotan and Ruo-Chiang gradually increase or reduce throughout historical period? Since it reflects whether the struggle of man against desertification succeeded or failed it is an important problem too.After comparing several records in historical books from Han to ching dynasty, we find that the mumber of Oasis has increased gradually period by period.(3) East of Khotan several settlements and towns had been abolished, and the main road had been shifted too. What were the causes behind these phenomena? For solving the problems, the ruins of Andere, Niya and old Cherchen were selected and discussed in this article.
  • Earth Surface Processes
    THE RALIATION REGIME IN TAPAISHAN
    Fu Baopu, Pan Yuqiang, Wang Yuelian, Li Zhaoyuan
    1983, 2(3): 44-53. https://doi.org/10.11821/yj1983030005
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    Based on the observations from the 30th of July to loth of August 1979, we have analyzed the radiation regime in Tapaishan, the highest mountain (3767 meters high) in the Tsinling Mountions.The main results are as follows.1) The variations of direct solar radiation S, diffuse radiation D, total solar radiation Q and effective radiation E with elevation are shown in Fig 3, 4 and can be described by Eg. (8), (9), (10) and (11) respectively.2) The transparency of atmosphere in the south of mountain is less than that in the north of the mountain, and, therefore, the direct solar radiation is weaker and the diffuse radiation is stronger in the south than in the north of the mountain.3) On the south slope the direct, diffuse and total solar radiation are about 16%, 60% and 23% greater than those on the north slope respectively.4) In conditions of similar underlying surfaces, the albedo of slope varies with slope orientation.It is less in south slope than in north slope.5) The mean daily albedo should be calculated by the ratio of the daily amount of reflected radiation to that of total radiation, or by formula (14). The simple method to calculate mean daily albedo by arithmetic mean may lead to serious errors.
  • Earth Surface Processes
    ANALYSIS OF PENTAD RAINFALL DURING SUMMER MONSOON OVER CHINA
    Xu Mengying
    1983, 2(3): 54-62. https://doi.org/10.11821/yj1983030006
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    In this paper, by using the Pentad rainfall data from 1966-1975, May-September for 121 stations in China to analyse the seasonal change of Pentad rainfall, major results are summarized as follows.1. The location of Pentad mean rainfall 10mm isohyet from July to August agrees with the Northern limit of summer monsoon.2. In China, large rain region moving from South to North is very obri-ous only in Eastern China, but it is not obvious in Western China.3. According to Pentad rainfall distribution in China, its Pattern may be divided into five types.
  • Earth Surface Processes
    THE STUDY OF SOFTWARE OF SURFACE SYMBOL IN THE MODERN THEMATIC MAPPING SYSTEM
    Fu Susing, Cao Guifa
    1983, 2(3): 63-72. https://doi.org/10.11821/yj1983030007
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    The design of software of surface symbol has promoted the development of thematic auto-cartography. The software is possessed of the character of serial structure in using these programs. It is composed of subprogram of surface symbol, of computing sign coordinate and of plotting out independent sign. By using the software we can design different signs of quite a lot of different thematic maps, and can automatically plot them out.The realizing process of surface symbol subprogram includes transformation of coordinate of polygon, interpolation computing of terminal point, arrangement of coordinate terminal point and recovery of system of initial coordinate, etc.To achieve the process of subprogram of computing sign seat coordinates, it is necessary to define the orientation of the drawing pen in going forward, to compute how many signs in a row and to define coordinate of every sign under the left side, etc.The besal designing mind of subprogram of independent sign is that it has arranged a data district that will store digital information of initial address of sign of every kind. Increment of coordinate is computed in the program,and coordinate value of drawing pen in advance is computed in the program too. The purpose is to plot out sign of different figures. By using different data it is possible to plot out sign which can reflect quality diversity of geographical regions or feature of numerical value.In a word, the study of software provides certain technical and scientific methods for thematic auto-cartography of agricultural map and population map, etc.
  • Earth Surface Processes
    GLOBAL ICE-SNOW COVER AND CLIMATIC CHANGES
    Wang Shaowu
    1983, 2(3): 73-86. https://doi.org/10.11821/yj1983030008
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    This paper reviewed the investigations on the ice and snow covers in the Northern and the Southern Hemisphere and compared the cover areas obtained by different authors. It shows that the areas calculated from more accurate satellite data set are generally in accord with other series constructed on the basis of naked observations (Table 1).The trend in the long-period variations of sea ice cover was studied in relation to the warming trend for the period from 1920S to 1940S, and to the cooling trend during 1960S in the Northern Hemisphere (Fig.2 and Fig.3).The variations of ice cover areas in the Northern and the Southern Hemisphere show great discrepancy. It is noted that recently the arctic sea-ice area has somewhat increased while the antarctic ice is in consistent decreaseIt indicated that large interannual fluctuations were observed in the snow cover area variations in the Northern Hemisphere, especially over Eurasia, the range between the maximum (1978) and the minimum (1970)accounts for about 20% of the normal.It has long been recognized that after a heavy sea-ice year the general atmospheric circulation and climate act in considerablly different way from that after a light sea-ice year. This relationship was proved recently by synoptical studies and numerical experiments. It must stress that the climatic conditions at high northern latitudes in autumn has a significant influence on the winter sea-ice cover, which is illustrated in Fig.6.
  • Earth Surface Processes
    A PRELIMINARY ASSESSMENT OF THE WATER RESOURCES DIVERTED NORTHWARD FROM THE YANGTZE DRAINAGE BASIN
    Ge Weiya, Lwo Shouqi, Tang Peiwen
    1983, 2(3): 87-95. https://doi.org/10.11821/yj1983030009
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    The paper gives an evaluation of the quality and quantity of the water diverted northward from the yangtze Basin. It not only answers the question on the possibility of water supply from the Yangtze Basin, but also studies the practical problem of the diversion. This paper analyzes the magnitude and the quality of the water resources of the Yangtze River and estimates the water Volume provided by the Yangtze Basin in the end of the 20th century. Through evaluation and analysis., much more water can be diverted from the Yangtze in the end of the 20th century, but the optimum scheme of diversion is on the middle stretch, while the diversion on the lower stretch will make the water quality worse before the completion of the Three-Gorge project when the discharge of Datong station is smaller than 13000M3/S.