1998 Vol. 8, No. 4

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Articles
CONTEMPORARY CLIMATIC CHANGE OVER THE QINGHAI XIZANG PLATEAU AND ITS RESPONSE TO THE GREEN HOUSE EFFECT
Liu Xiaodong, Zhang Minfeng
1998, 8(4): 289-298.
Abstract:
The knowledge of contemporary climatic change over the Qinghai Xizang (Tibet) Plateau (QXP) has been inadequate for a long time due to lack of enough observational data. In this paper, on the basis of monthly temperature and precipitation data in 1961-1990 from 48 stations on the QXP, the temperature data are extended backward to 1901 with an empirical orthogonal function (EOF) method, microscopic characteristics of contemporary climatic change over the QXP are analyzed, and the response of the plateau climate to global warming is discussed in combination with atmospheric general circulation model (GCM) outputs. The results show that the plateau climate, as a whole, has been warming since the early part of this century, that the precipitation has generally been increasing during the recent 30 years, and that these climatic trends seem to be related to the enhanced green house effect induced by increasing CO2 concentration in the atmosphere.
PEDOGEOCHEMISTRY OF CHINA AND ITS SIGNIFICANCE IN AGRICULTURAL PRODUCTION
Gong Zitong, Huang Biao, Ouyang Tao
1998, 8(4): 299-308.
Abstract:
Pedogeochemistry of China is controlled by such factors as biology, climate, parent material, topography and anthropogenesis, and the different geochemical types are formed under the different conditions of soil formation which have different abundance levels of elements. The relationship between concentration of elements and plant growth and human health depends upon available forms of element in soils. While the factors affecting element availability are soil pH and Eh, tillage and fertilization by man besides element forms in soils. On the basis of pedogeochemical types and distribution, rational plantation and application of fertilizer to soils will be of great significance for sustainable development of agricultural production.
IMPACT OF CLIMATE ON GRAIN YIELD PER UNIT AREA IN CHINA DURING THE YEARS OF 1949-1992
Xie Yun, Liu Jidong
1998, 8(4): 309-316.
Abstract:
The grain yield per unit area in China has been increasing from 1949 to 1992 with annual fluctuations, which was caused by both policies and monsoon climate. The total grain yield is divided into trend yield, which reflects the influence of economic factors, and climate yield, which reflects the impact of climate factors. The results of grain and climate yield by EOF (empirical orthogonal function) method show that the grain yield in the eastern China is higher and more fluctuating than that in the western region. The spatial and temporal distributions of climate yield were divided into four patterns. Regional unanimity of climate yield variation is the first and main spatial pattern, and then there are the spatial patterns of north-south difference and east-west difference in some years. Generally, climate conditions are good for grain yield during the 1950s and 1980s all over the country.
A CONTRAST ANALYSIS ON THE LOAD CHARACTER OF THE CHANGJIANG RIVER AND THE HUANGHE RIVER
Wang Lachun, Zhang Jianxin, Chen Xiaoling, Chu Tongqing
1998, 8(4): 317-325.
Abstract:
According to the analysis of grain size, mineral composition and inclusion in quartz grain of the suspended and bed load sampled from the Changjiang (Yangtze) River and the Huanghe (Yellow) River, the authors reveal the differentiation of loads between the two rivers. In the Huanghe River the size of suspended load is coarser than that in the Changjiang River, while the bed load is on the contrary. Through heavy mineral analysis, the biotite content of the Huanghe River loads is much higher than that of the Changjiang River, and the monomorillonite content of the former is about two times higher than the latter. All those may be attributed to the effects of different material sources and hydraulic conditions on load. The analysis of inclusion in quartz grain definitely illustrates the environmental difference of material sources between the two rivers. In the meantime, it provides a new method in seeking source of river load.
THE APPRAISAL OF SEVEN ECONOMIC ZONES IN CHINA
Hu Zhaoliang
1998, 8(4): 326-334.
Abstract:
The seven economic zones are multiple economic zones, with the characteristic of both long range economic zone and categorical economic zone. They are the transitional regions between the categorical economic zone and the comprehensive economic zone. The phenomena of overlapping are only allowed to appear in categorical economic zones. The influence of Hongkong return back to China should be considered when doing research on economic zones. Hongkong is the center of the southeastern coasts and will become an offshore banking center of the mainland. According to the theory of economic zoning, the division of the whole country into seven economic zones demonstrates the transitional nature clearly. With the further development of the economy, the deeper maturity of the central cities and the stronger connection of the regional economy, the composite economic zones will gradually turn into more integrated comprehensive economic zones.
AN ANALYSIS ON LOCATION FACTORS AFFECTING THE SPATIAL DISTRIBUTION OF SHANGHAI LAND VALUES
Du Debin, Xu Jiangang
1998, 8(4): 335-342.
Abstract:
With a technique of GIS(Geographical Information System) and a method of multiple linear regression analysis, the spatial distribution of Shanghai land values and its relationship with some location factors are examined in this paper. The database of land values consists of 166 land parcels leased during 1993-1994. The land value map shows that the spatial distribution of Shanghai land values has some distinct spatial features. Firstly, the highest land value areas are located along Nanjing Road, Huaihai Road and the Bund. Secondly, there is no conspicuous peak land value intersection within the CBD(Central Business District). Finally, The land values of Pudong are much lower than those of Puxi. The regression model between Shanghai land values and the selected location factors shows that Nanjing Road is the first important location factor affecting the spatial distribution of the land values, the city center is the second one and Huaihai Road is the third one. The Bund, the regional shopping centers and the transportation nodes have little influence on the land values. This relationship between Shanghai land values and the location factors is determined by the distribution of commercial activities, the characteristics of the CBD and the spatial form of the city.
SUSTAINABLE DEVELOPMENT OF THE SERIOUSLY POLLUTED CITIES IN CHINA ——Taking Benxi City as an Example
Cui Fengjun, Yang Xinjun
1998, 8(4): 343-351.
Abstract:
The environmental problems in the seriously polluted cities in China have been paid attention to by policy makers and foreign and domestic scholars. However, it is very difficult to improve the environmental quality fundamentally due to its complexity, for example the formation of the seriously deteriorated environment. It is considered that the terminal harnessing is an important way,but the spread of high level terminal treatment is restricted by the limit of funds and technological level. Therefore, the way for a sustainable development of the seriously polluted cities should be multiple sided, which is to correlate the operation of environmental protection with the operation of city construction. To achieve an identity of these opposites, measures should be taken during economic development and environmental protection in every developing stage. In this paper, the authors take Benxi City as a case study.
GEOCHEMICAL FEATURES OF AQUATIC ENVIRONMENT IN CRATER AND BARRIER LAKES IN NORTHEAST OF CHINA
Yan Baixing
1998, 8(4): 352-361.
Abstract:
There are many crater and barrier lakes formed by volcanic activity in northeast of China. These lakes are very rich in fresh water resource. This paper reports systematically geochemical features of some elements in water and sediment in crater and barrier lakes, and discusses the vertical changes, seasonal variation of some elemental concentrations in the lake water and the correlation and the moving coefficient of some elements in sediment. The result shows that the concentrations of Na, Rb, Cs, K, Be, W and F in the crater lake water are higher than those in the barrier lake water, the concentrations of Pb and La are higher and the concentrations of V, Co and Ba are lower in the crater lake sediment than in the barrier lake sediment. Moreover, the concentrations of elements in the lake water and sediment are effected strongly by the lithological characters of the catchment; on the other hand, the biogeochemical effect also acts as an important role.
CULTIVATED LAND RESOURCES AND ITS DEVELOPMENT IN THE TROPIC AND SUBTROPIC MOUNTAIN AREAS OF SOUTH CHINA ——A Case Study in Deqing County
Zhu Gongwu, Liu Ruihua
1998, 8(4): 362-369.
Abstract:
Deqing County of Guangdong Province is located in the tropic and subtropic mountain areas of China. Its area of cultivated land from landuse survey is 40% larger than the statistical data. Of all cultivated land, owing to flood, waterlogging, drought and barren soil, the high yield land occupies only 30% and the mid low yield land 70%, which is far more than the percent by statistics. Because the statistic area of cultivated land is less than the actual, the per unit area yield by statistics is higher than the actual. These situations generally exist in the tropic and subtropic mountain area of South China. So the measures to protect the high yield cultivated land strictly, to improve parts of the mid low yield selectively, to adjust agricultural structure further, and to control soil erosion, are necessary to make best use of its advantages and bypass the disadvantages.
UNITED INTERNATIONAL CENTRAL CITY: A NEW SPATIAL ORGANIZATION MODEL IN TUMEN RIVER ECONOMY DEVELOPMENT ZONE
Zhang Pingyu
1998, 8(4): 370-376.
Abstract:
This paper puts forward a new conceptual idea on constructing an international central city in the Tumen River Economy Development Zone (TREDZ) on the basis of analysis of the superiorities and problems in developing city, and from the view point of present social, economic and natural conditions in this area and the background of Northeast Asia. The united international central city is the best distribution model not only in its polycentric spatial structure but also in organizing form. Its feasibility and practicability are thoroughly proved from various aspects including urban planning principles, comparison of port cities, special characteristics of cooperation in TREDZ, and natural, social, cultural factors etc.
CLIMATIC CHANGE AND HUMAN ACTIVITIES OF NORTHEASTERN SAHARA IN HOLOCENE
Zhang Hucai
1998, 8(4): 377-382.
Abstract:
Chronology establishment and dating data analyses on lacustrine deposits in northeastern Sahara show that vast fresh lakes existed over there between 9900-2400 a B.P. Especially, great continuous lakes developed and got their maximum extent during the period from 9800 a B.P. to 6450 a B.P. From 6000 a B.P. to 3600 a B.P., the evolution of the lakes experienced a new stage with a property of drastic fluctuations and a periodicity of 600 years, which was the response to the climatic environment changes. On the aspect of the relation between natural environment and the human, the warm humid period in the Holocene was not only a very important time for human development and evolution, but also was a moment for human reproduction and division. On the other hand, this warm humid period was also a distinguished time to natural environment changes, the accumulation of the strong weathered debris and fine materials formed the basements for the formation of the Sahara Desert.