Loading...

Table of Content

    15 April 1982, Volume 49 Issue 2 Previous Issue    Next Issue
    THE VALLEY TRENDS AND NEOTECTONIC STRESS FIELD OF SOUTHEAST CHINA
    Ai Nan-shan, Liang Guo-zhao, Scheidegger. A. E.
    1982, 49 (2):  111-122.  doi: 10.11821/xb198202001
    Abstract ( 472 )   PDF (667KB) ( 512 )   Save
    The directions of river valley trends in the coastal region of Southeast China and its vicinity were investigated.The distribution of river valleys, like other geomorphological features, is nothing but the result of the antagonistic action of endogenic and exogenic effects. Valleys caused by erosion alone should be randomly oriented. Evidence from statistical ana-lyses of valley directions shows that the latter are not random. This non-randomness of valley directions results from the endogenic effects, the origin of which lies in the global tectonics or plate-tectonics.The determination of the preferred valley orientations in an area has to be carried out by a statistical procedure. For this purpose, a program developed earlier to fit one or more distributions of the type of exp (k cos2θ ) to the direction-data was employed. The best-fitting "mean" directions were determined by computer using a function-minimization procedure. Prom these directions the principal stress directions have been calculated. The latter vary clockwise from N 111°E (in the East) to N 131°E (in the Middle) and to N 175°E (in the "West), they agree with those calculated from fault plane solutions of earthquakes, showing that the valleys of the area can indeed be interpreted as shear phenomena of the neotectonic stress field. This field is a con-sequence of the collision of the Eurasian with the Indian, the Philippine and the Pacific Plates.
    Related Articles | Metrics
    AN ANALYSES ON THE PALAEOGEOGRAPHIC ELEMENTS OF KARST DEVELOPMENT IN THE WUMIN BASIN, GUANGXI
    Lin Jun-shu, Zhang Yao-guang, Wang Yan-ru, Zhao Zhong-ru
    1982, 49 (2):  123-135.  doi: 10.11821/xb198202002
    Abstract ( 704 )   PDF (1740KB) ( 449 )   Save
    By analysing the distribution of caves and terraces, the lithology of sediments, the ancient vertebrate fossils and sporo-pollens in the Wumin Basin, the conclusions may be drawn as follows:1. During the tertiary, the Wumin B.isin was under erosion-denudation condition. The present peak-top planation surface of 230-300 m above the sea level represents an old peneplain. In the Quaternary, the basin with its current Karst features was gradually developed.2. In the Quaternary, the paleoclimate experienced several great fluctuations with humid-hot conditions alternating with dry-cool climates. For instance, the accumulation of Gigantopitheeus fauna fossils in the Ganxu Cave in the early Middle Pleistocene, as well as Elephas maximus fossils and Liqidamber-Polypodiaceae-Ptcris-Cyatheaeeae monsoon forest sporo-pollens complex in the late period of Late Pleistocene, all reflect a humid-hot environment.3. The rhythemic variations of the paleoclimate eventually lead to an unbalance of corrosion intensity. In addition, the base-level fluctuation which were resulted from the neotectonic movements and the global paleoclimatic variations resulted in an obvious differntiation of Karst development intensity both temporal and spatial. The stratified caves in different level bear evidence to such a process.4. As the latitude in the Wumin Basin being rather low, the duration of humid-hot periods has been longer and, when entering into the dry-cool periods, the ampli-tude of temperature lowering has been less conspicuous. These are very favorable for corrosion action. For example, the corrosion-denudation intensity in the Elephas-peat accumulated period (about 30000-40000BP. as dated by C14 and corresponding to a sub-interglacial stage of W黵m glaciation) was more than double that of present to-day.Consequently, the "peak-forest" (Fenglin) landscape in the Wumin Basin is a typical tropical karst topography, which has undergone repeated humid-hot environ-ments since the Quaternary. To a certain extent, it represents the case nearby the tropic of cancer in South China.From this, it may be seen that the palaeogeographic conditions are a basic evi-dence to study the development of the karst geomorphology and exogenic process, as well as to divide the basic karst geomorphologic types.
    Related Articles | Metrics
    GEOGRAPHICAL DISTRIBUTION OF SELENIUM CONTENT IN HUMAN HAIR IN KESHAN-DISEASE AND NON-DISEASEZONES IN CHINA
    Environment and Endemic Disease Section, Institute of Geography, Chinese Academy of Sciences
    1982, 49 (2):  136-143.  doi: 10.11821/xb198202003
    Abstract ( 439 )   PDF (500KB) ( 339 )   Save
    Keshan disease in China is distributed in a transitional area between the humid region in the south-eastern part and the semiarid and arid regions in the north-western part. It forms a wide belt running from the North-East to the South-West, known as disease zone. Both sides beyond the zone are disease-free. They are respectively called the south-eastern non-disease and the north- western non-disease zones. The districts of Keshan disease distributed uncontinuously as patches.The disease zone presents a low selenium environment where the soil-plant-animal-man system is in a circulation of low selenium. The inhabitants there are mainly fed on local agricultural and supplementary foods. The constitution of their diet is quite simple and poor, lacking entirely of sea products. The fact causing Keshan disease in some particular districts is the biological effect of low selenium environment. The con-tent of selenium in human hair presenting at random on 2129 samples of persons at 181 points in 17 provinces, cities and autonomous regions indicates that it increases re-gularly from the disease zone to the disease-free ones.According to the difference in physical environment and the geographical location of disease districts, the disease zone might be divided into three major regions: the North-Eastern region, the North-Western region and the South-Western (including Tibet) region. The mean value of selenium content in human hair in the North-Bastern region is 0.069±0.027 ppm, in the North-Western and the South-Western regions 0.093±0.032 ppm and 0.087±0.032 ppm respectively. The differences are not remarkable (p>0.05). The total mean value is 0.085±0.032ppm. Yet. in these three regions mentioned above, the mean values of selenium content in human hair for the disease-free districts adjacent to the disease districts are 0.146±0.032 ppm, 0.209±0.108 ppm and 0.17±0.057 ppm respectively. The total mean value is 0.187ii:0.086 ppm. The differences between disease and disease-free districts within the disease zone are exceptionally remarkable (p < 0.001).Tibet is an unique physico-geographical region. The disease districts are distri-buted in the semiarid temperate montane shrub and alpine steppe belts in south Tibet where the selenium content in human hair is 0.067±0.036 ppm. The semi-humid cold-temperate alpine shrub-steppe belt in North Tibet is disease-freeregion. And the semi-humid warm-temperate montane coniferous forest belt in East Tibet is the district of Kaschin-Beck’s-disease, where the selenium content in human hair is 0.256±0.045 ppm or 0.076±0.039 ppm, the same as that in other districts.The results mentioned above show that there is no remarkable change of selenium content in human hair for any disease districts that are distributed in different regions and inhabited by different nationalities. Obviously, the low selenium environment se-rves as a physico-geographical index.The south-eastern non-disease zone differs greatly from the disease zone in physi-cal environment. The selenium content in human hair in the subtropical yellow-brownish and yellow-cinnamon soils zone (IVA1) is basically correspondent with that in the red and yellow earths zone (IVA2), being 0.383±0.130 ppm and 0.333± 0.079 ppm respec-tively. The selenium content in human hair in the lateritic red earth zone (IVAs) is identical with that in latosol zone (in its western part VA1) and the mean value is 0.493±0.062 ppm, and 0.491±0.085 ppm. For the north-western non-disease zone, the content of selenium is close to that in the south-eastern non-disease zone. Within them the mean value in the temperate piedmont desert-steppe with sierozen zone (in its eastern part, HD2) is 0.462±0.122 ppm. It is consistent with that in IVA3 and VA, zones within the south-eastern non-disease zone. They are 0.391±0.135 and 0.366?.109 ppm in warmtemperate grey-brownish desert soil zone (HD3) and brown desert soil zone (HID1). In forest-steppe and meadow-steppe zone (VHC1) on Tibetan plateau it is 0.240 ±0.045 ppm.The frequency distribution cur
    Related Articles | Metrics
    THE CAUSE OF THE SALINIZATION OF THE BOSITENG LAKE AND THE WAYS OF ITS CONTROL
    Xinjiang Comprehensive Expedition Team of Wasteland Resources
    1982, 49 (2):  144-154.  doi: 10.11821/xb198202004
    Abstract ( 552 )   PDF (671KB) ( 617 )   Save
    The Bositeng Lake is the biggest fresh water lake in the inland region of China. The area of the lake is 980 square kilometres, its water volume-7.73 cubic kilometres, its average water depth-7.7 metres, and the average altitude of the lake level-1047.59 metres. The Kaidy River is the main source of its water supply.Under the influence of human activities, the mineralization of the lake water has been constantly increasing. In the year 1958 its mineralization was less than 0.4 g/1, while in 1975 it rose to 1.5 g/1, and in 1980 to 1.8 g/l. The average annual increase was 0.06 g/l, which is quite amazing. The hydrochemical types of the lake water also had been changed from HCO3-Na and HCO3-Xa-Mg in 1958 to S04-CI-Na-Mg and SO4-Cl-HCO3-Na-Mg in 1975. By 1980, it changed further to Cl-SO4-Na-Mg and Cl-SO4-HCO3-Na-Mg type.The cause of the increase in mineralization of the lake water, on one hand, is due to the considerable flow of mineralized farm drainage water into the lake. According to investigation data, the amount of the drainage reaches 0.265 cubic kilometres per year, and salt carried into the lake amounts 637 thousand tons. On the other hand, because the Kaidy River has partly changed its course, large amounts of its water flow direct into the Konche River, without travelling through the Bositeng Lake. As a result, the entering fresh water has decreased from 2.3 cubic kilometres in 1958 to 1.26 cubic kilometres at present, and therefore, the lake water circulation has been hindered. The salt carried into the lake is more than that out of the lake, hence giving rise to the salt accumulation and increase in water mineralization.In order to prevent the lake water from the increase in mineralization, it is neces-sary to control and reduce the quantity of salt delivering into the lake by farm drai-nage water, to accelerate the lake water circulation by recovering the quantity of fresh water flowing into the lake to the previous level, and to conduct a regular moni-toring of water quality.
    Related Articles | Metrics
    A SPECIAL FORM OF URBANIZATION OF RURAL POPULATIONIN CHINA──A COMMENT ON THE POPULATION OFBOTH WORKERS AND PEASANTS
    Yao Shi-mou, Wu Chu-cai
    1982, 49 (2):  155-163.  doi: 10.11821/xb198202005
    Abstract ( 542 )   PDF (649KB) ( 971 )   Save
    A city is a product resulting from a deep-going change in the development of social economy and social division of labour. Along with the evcrrising of production level in industry and agriculture, a tremendous change in the urban population structure has taken place, in which more and more rural population is flowing into the city, thus giving an added impetus to their ever-growing development and creating a problemknown commonly as the so-called "urbanization of population’’. Generally speaking, this is an inevitable tendency in the development of social productivity as well as a sign of social progress.At present, China’s rural area is overweighed with population, low in agricultural productivity, under-developed in commodity economy and is rather far from being urbanized. Up to 1979, the population proportion in cities and towns in our country was recorded as 13.3%, a percentage that is not only much lower than that of the world (about 40%), but also than that of those countries in the third world, such as India, nevertheless, in the course of the accomplishment of four modernizations, the transforma-tion of agricultural production system, the rapid growing in agriculture, industry and trade and the application of agricultural mechanization, quite a number of strategical problems, such as how to transform those surplus labourers who are free from their farmlands and which road to take towards rural urbanization, lie ahead of us and dese-rve to be seriously dealt with. We hold that in addition to turning the rural population directly into the urban population, another way should be sought out in order to meet the requirements of our national conditions and the level of our productive development. Over the past years, there has existed in the rural population structure a new kind of population by the name of "both workers and peasants". This is a new emerging force with full vitality and promising prospects, which is not only a principal approach to the solution of superfluous labourers in the countryside, but also a special or transi-tional form of urbanizing our rural population.The so-called "worker-peasant population", or "quasi-urban population" named for those who are engaged in non-agricultural activities (chiefly in industry) in the rural area, is a transitional type between urban population and rural one, resulting from far-reaching cause of social economy and objective inevitability. Firstly, as seen from our history, the close combination of agriculture with the handicraft industry and merging altogether into one is the historical foundation of farming and developing such kind of population: secondly, owing to too many people working on less farmlands, it is an inexorable product that the commune-and brigade-run enterprises will follow the road of multi-purpose management of agricuulture-industry-commerce, and "develop in depth in agriculture", and thirdly, it is a result from the implementing of economic policies in the countryside and the effect of economic lever.It is now estimated that the amount of worker-peasant people is close to 30,000,000, accounting for about 3% of the total national population and about 10% the total la-bourers in the countryside. In China, the population in small cities and towns, especially in those commune-affiliated towns, is commonly formed by that of cities and towns (i.e. non-agricultural population), rural population and that of both workers and peasants. And such worker-peasant population has become the major component part in their population structure. According to investigations in some of the counties in Jiangsu Province, the proportion of the worker-peasant people makes up generally 25-30%, or even up to 40-50%, the total urban population, becoming virtually a basic force in the commune-and brigade-run enterprises. In spite of the fact that during the time of readjustment in national economy, new problems and troubles are bound to happen in the development of such enterprises, its general orientation is correct and we should not lose our faith in or negat
    Related Articles | Metrics
    THE CLIMATE OF THE CITY OF HANGZHOU
    Wang Chuanchen, Liu Jisong
    1982, 49 (2):  164-173.  doi: 10.11821/xb198202006
    Abstract ( 790 )   PDF (608KB) ( 583 )   Save
    Hangzhou (30°E, 120°N) dominanted by monsoon climate, its annual mean tempe-rature is 16.4℃; the average January temperature is 4.4℃, while the average July temperature is 28.5℃. The annual mean precipitation is 1390.9 mm.This paper discusses the differences of climatic elements between the urban dis-tricts of Hangzhou and its suburbs, which are summerized in the following table.The urban heat island of Hangzhou occures every night throughout year. The maximum temperature in the center of the urban heat island is 5.6℃ higher than that of its surrounding countryside.
    Related Articles | Metrics
    THE SOURCE OF GRAVAL BED LOAD OF THE YANGTZEGORGES
    Lin Cheng-ken
    1982, 49 (2):  174-182.  doi: 10.11821/xb198202007
    Abstract ( 674 )   PDF (608KB) ( 368 )   Save
    Investigations and studies on the geology and geomorphology of the Upper Yangtze River indicate that the petrographic classification and composition of the gravel bed load in the river depends on the geological and geomorphological conditions of river basin. According to the regional geological and geomorphological characteristics and their effects on the lithologieal character of the gravel bed load the source of the gravel bed load can be divided into 4 supplementary regions, namely, the Middle and lower reaches of the Jinsha Valley and middle reaches of Yalong valley; the Upper reaches of the Mian Valley and the Dadu Valley; the Upper reaches of the Jialing and the Yangtze Gorges regions.After lithogical statistical analysis of nearly 125,000 grain samples collected by the author during his three geological and geomorphologial field investigation indicate that the lithologieal characters of the gravel bed load are governed by the geological and geomorphological conditions of the watershed. Hence, a mathematical model is set up to calculate the source of the bed load by using the percentages of petrographic classi-fication of the bed load in the main districts and the confluences of the valley (Eq. (2)). The result shows that 69.9% of the source of gravel bed load at Wanxian station, situated at the entry reach of the Groges, comes from the Middle and Lower reaches of the Jinsha valley and Middle reaches of Yalong Valley, 18% from the Upper reaches of the Mian Valley and the Dadu Valley, 12.1% from the Upper reaches of the Jialing Valley; and there are about 57.1% of the total gravel bed load at Yichang Sta-tion, which is located below the Gorges, comes from the Gorges Eegion itself, and 42.9% comes from the Upper Reaches above Wanxian Station.
    Related Articles | Metrics
    USE OF THE CATASTROPHE THEORY MODEL TO STUDY ONTHE PROCESS OF DESERTIFICATION──AN EXAMPLEOF SAND LAND OF NORTHEAST CHINA
    Guo Shaoli, Qi Wenhu, Li Lixian
    1982, 49 (2):  183-193.  doi: 10.11821/xb198202008
    Abstract ( 497 )   PDF (664KB) ( 452 )   Save
    The phenomena of desertification appears widely in the Northeast of our country. It causes the sharp reduction of biomass of land and the decline of productive poten-tialitives, and even the loss of applicable land resources. Therefore, the investigation of the process of desertification is not only of great theoretical value, but also of practi-cal significance to prevent the occurance of the phenomena of desertification.We try to abstract and summarize the process of desertification, and describe the phenomena of desertification by means of mathematical representation. We divide the process of desertification in a certain area into three states: the stably good farmland state, unstably critical state of desertification and stable desert state. Furthermore, we consider that there is a sudden change transected from the critical state to the desert state or from the critical state to the stable good farmland state. For this reason, we can adopt this mathematical form of cusp catastrophe model to link up these three statesof desertification, and use some new concepts and methods to describe and explain the phenomena of desertification.
    Related Articles | Metrics
    THE CHARACTERISTICS OF DROUGHT AND ITS VARIATION DURING THE GROWING PERIOD FROM 1724-1979 IN BEIJING
    Feng Li-wen
    1982, 49 (2):  194-205.  doi: 10.11821/xb198202009
    Abstract ( 513 )   PDF (604KB) ( 383 )   Save
    In this paper, the rainy and clear days observations and the instrumental records of Beijing are adopted to reconstruct the series of no rain days from 1724 to 1979. Two indices-no rain days and its duration are used to discuss the characteristics of drought and its long-term variation could be summarized as follows:1. The spring drought is one of the most serious damage to the crops of Beijing, 晈hich is characterized by frequent occurances and long duration of no rain days.2. The probability of continuous dry damage in successive seasons appears less than 10%. And this probability for three successive seasons (from spring to autumn) is only less than 3.4%.3. The non-rain days in the growing period was tending to decrease in Beijing during the last 256 years. Especially in the recent 30 years (1944-1979) this area appears to be passing through a phase of abnonnaly defficient rainfall. And from 1968 onwards the no rain days still possessed a negative deviation.4. It is shown that the no rain days possesses a fluctuation of hundred years (with cycles of about 170 and 85 years) from April to October.
    Related Articles | Metrics
    GEOGRAPHY AND MAN-EARTH RELATIONSHIP
    Yang Wuyang, Jiang Meiqiu
    1982, 49 (2):  206-215.  doi: 10.11821/xb198202010
    Abstract ( 835 )   PDF (772KB) ( 826 )   Save
    In this article, the authors discussed man-earth relationship in geography dialecti-cally and historically. The history of geographic thought is divided into four stages: ancient, classical, modern and contemporary. Having approached the buds of man and earth relationship in ancient geography, the anthers point out that the outsets era of chorography in China is far earlier than that in the "West, and the ancient geography of China contains quite a lot of man earth relationship all along. The principal masters of classical geography A. Von Humboldt, C. Hitter, F. Ratzel and P. Vidal de la Blache etc. are introduced not only on their contributions but also on their shortcom-ings. In the light of a great deal of historical facts, the specialization of modern geog-raphy and the decline of man-earth theory, a.s well as the renewal of man-earth rela-tionship in contemporary geography are discussed. The regularity of differentiation and synthesis in geography are two trends being inevitable and necessary for the development of new geography.The differences of man-earth relationship between orthodox geography and con-temporary geography are illustrated along three points: (1) the philosophical founda-tion; (2) the methods of study; (3) the items of principle.The authors insisted on that the object of geography is geographical environment which is composed of (1) natural environment; (2) economic environment and (3) social-cultural environment. All of which are each studied by physical geography, eco-nomic geography and social-cultural geography respectively.Contemporary human geography, in narrow sense, is equivalent to social-cultural geography. It consists of all the aspects of economic basis (relations of production) and superstructure. The authors do believe that human geography will be developed and flourished in China in order to serve the planning and designing of the concerned government organizations.
    Related Articles | Metrics
Share: