Table of Content

    24 March 2002, Volume 21 Issue 2 Previous Issue    Next Issue
    Original Articles
    A Study on the Spatial Process for the Evolution of Urban Agglomerations and Optimal Land Use
    XUE Dong qian, WANG Chuan sheng
    2002, 21 (2):  95-102.  doi: 10.11820/dlkxjz.2002.02.001
    Abstract ( )   PDF (102KB) ( )   Save
    The evolution of urban agglomerations includes many contents, such as population, industry, type of cities, function of cities and so on. The most comprehensive and direct expression that urban agglomerations evolve is spatial process. Urban agglomerations can be divided into three layers, namely, primacy urban belt, growth belt of urban group, and hinterland belt of urban agglomerations. The evolution of the structure follows the laws of urban growth and regional economic development. The spatial dispersion of urbanization is the beginning of spatial spreading about urban agglomerations. The spreading of urban agglomerations has four phrases, namely, the expanding phrase of multi-central cities, the directional sprawl phrase of urban space, the centripetal and centrifugal phrase between cities, and the complex expanding phrase in urban agglomerations. Concentration of industries and evolvement of industrial structures are immediacy powers of spatial expansion of urban agglomeration. There has a close connection between urban development and land exploiture. Economic development brings about land exploiture, suburbanization and the growth of urban agglomerations promote land exploiture, and construction of developing region brings land exploiture. At the same time, urban spatial growth promotes land increment. This paper analyzes the spatial process for the evolution of urban agglomerations, studies its dynamic mechanism, and describes its basic features and regulars from the structure of urban agglomerations, space of urban agglomerations and land-use of cities. At last, the paper reveals the connections between the evolution of urban agglomerations and the changes of land use as well as its development trends. That are growth axis and expanding diversity (including type, speed and direction).
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    Relationship of Upslope Contribution Area and Soil Water Content in TOPMODEL
    DENG Hui ping, LI Xiu bin
    2002, 21 (2):  103-110.  doi: 10.11820/dlkxjz.2002.02.002
    Abstract ( )   PDF (791KB) ( )   Save
    Topography-based hydrological models (TOPMODEL) make use of topographic information and the spatial distribution of topographic index (ln a /tan β ) to represent the soil water storage deficit below saturation and spatial variability of contributing area. In this paper, the physical basis of the index and its relationships with soil water storage are introduced. The effects of spatial change of drainage area ( a ) and local slope β on the spatial change of the index are analyzed. The changes of effective upslope drainage area with soil water condition are discussed. Finally, by using a 100 m×100 m DEM and single flow direction algorithm, the index distribution functions are calculated for Sumo basin on upper reaches of the Yangzi river under different channel initiation threshold. An assumption of TOPMODEL is that there is a saturated zone in equilibrium with a steady recharge rate over an upslope contributing area a . This makes TOPMODEL appropriate only for humid areas. To break this assumption, the authors argue that two concepts, i.e., effective contributing area and maximum contributing area, should be distinguished. The effective contributing area indicates the area ( a , the maximum contributing area) with soil water content over field capacity according to the theory underlying the model. The authors also propose a method to calculate Channel Initiation Threshold (CIT) in order to derive a reasonable distribution of topographic index in a watershed. The CIT is usually not easy to define because of the variation of slope length with terrain type. The authors suggest that the CIT should be defined according to a GIS analysis of statistical distribution of slope length in the study watershed.
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    Main Characteristics, Progress and Prospect of International Wetland Science Research
    YANG Yong xing
    2002, 21 (2):  111-120.  doi: 10.11820/dlkxjz.2002.02.003
    Abstract ( )   PDF (631KB) ( )   Save
    This paper concludes the main characteristics of international wetland science research. It shows that the wetland science has a long history, slow progress of development in the past and rapid progress in modern time. It has become a key subject and research field in the science research in the world. Its content and field of the research have been enlarged. It has been strengthened in both synthesis and split research. The uneven development of international wetland science exists in the world, and developed countries occupy advanced places in the wetland science research of the world; but the gap of research level between developed and developing countries is gradually reduced. It makes a detail introduction to the hot point, forward position field, progress, prospect and development trend of international wetland research in the 21st century. The main hot points and forward position fields of wetland research in the world are as follows; conservation and management of wetland, formation, development and succession of wetland, paleoenvironment reconstruction, ecological process and dynamics of wetland, greenhouse gases, greenhouse effect and global change, biodiversity, health and assessment of wetland and constructed wetland, restoration and reconstruction of degradation wetland, wise utilization of wetland, peatland and peat, wetland ecological engineering and application of new techniques and instrument.
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    Food Demand, Ensure and Countermeasures for China in the Next 30 Years
    WU Shao hong, Li Rong sheng
    2002, 21 (2):  121-129.  doi: 10.11820/dlkxjz.2002.02.004
    Abstract ( )   PDF (514KB) ( )   Save
    In the new century, foods support capability is a hot point of the world, especially by the year 2030 when population of China will reach peak value of 1 6 billion. The whole world focuses on Chinese food self sufficiency and world food market chaos. The population will enter a phase of zero increasing or decreasing after reaching the peak value. Estimated by the national situation analysis group of Chinese Academy of Sciences, in the year 2030, GNP of per capita of China will reach 12 600 USD, which is equal to medium developed countries. According to Chinese meal custom, rational foods consumption of per capita is 460 kg when GNP of per capita of China reaches 12 600 USD in year 2030. In the coming 30 years, China has to provide foods for another 300×106 people. Total foods demand will be 736 000×10 3t, which is 241 823×10 3t more than the food production of 1997, 494 177×10 3t. Rate of population increasing will be 6 5‰ annually while food demand increasing will be 12 1% annually. Without environmental damage and no impact on comparison advantage, potential of farmland production is 660 000×10 3 in year 2030, which is 90% of the total foods demand. Based on food demand per capita respectively 420 kg and 460 kg, and totally 57 96 and 73 60×10 6t, farmland (seeding area) is estimated 114 453×10 3hm 2 and 113 883×10 3hm 2. Unit food production is estimated 4 725 kg and 5 595 kg/hm 2 . Then the total food production will reach 540 8×10 6t and 637 2×10 6t. Therefore, after dynamic changes of the farmland, food supply capacity will be 93% and 87% of the requirements. Food substitution capability of non farmland resources may be as much as 90×10 6t. Countermeasures for foods ensure include guaranteeing foods supply and development. Four aspects should be recognized: policy support to protect farmland, scientific and technological progress and input, conceive of food production system, ensuring system and high efficient hydraulic projects. Establishment of policy to protect farmland will keep dynamic balance of farmland, protect farmland of East China, protect paddy field and topsoil of farmland, and improve farmland quality. Progress and input of sciences and technologies include general decision making techniques, biological techniques and industrialization, agricultural information techniques, increasing productivity of unit farmland, fodder techniques, environmental protection and agricultural disaster reduction techniques. Setting up multi purpose food production and guarantee systems is allocation of multi purpose food production system, allocation of food production bases of China, food ensuring system of China. Implementing high efficiency water conservancy projects for agriculture is saving on water and increasing the efficiency in using water. It is important to establish three systems for water saving, that is, water management system, price system and high efficient technical system. With the analysis of higher food requirement, lower farmland production and non farmland substitution, it is showed that food demand in 2030 will be 736 000 ×10 3t, of which about 90% comes from farmland and 10% comes from non farmland substitution, and food demand and supply of China for the next 30 years is basically in balance. Using the international food resources in little amount to adjust Chinese market will not cause chaos of the international food market.
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    A Discussion on Some Problems of Eco-environment Construction and Rural Economic Development in the Loess Hilly-gully Region
    XU Yong, Roy C.Sidle, JING Ke
    2002, 21 (2):  130-138.  doi: 10.11820/dlkxjz.2002.02.005
    Abstract ( )   PDF (345KB) ( )   Save
    The rural economic development is closely related with the eco environment in the Loess hilly gully region. Based on the eco environment functional status of the region in the national territorial management of China, its rural economic development has to presuppose the controlling of soil and water loss and the rebuilding of eco environment. After analyzing the relations between the building of eco environment and the developing of rural economy, this paper firstly generalized the precondition, basic principle and direction of rural economic development in the Loess hilly gully region. Secondly, the important contents and spatial types of rural economic pattern suitable to eco environment in the region were put forward. Thirdly, the development stages and industrial development sequences of that pattern were discussed. Lastly, authors set forth the methods examining the pattern feasibility from eco environment effect, economic benefit and sustainable development, and the results from applying the methods to the region showed that the pattern is practicable.
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    Land-unit Based Flow Network Model in Small Catchment with GIS Support
    LIU Gao huan, LIU Jun wei, ZHU Hui yi
    2002, 21 (2):  139-145.  doi: 10.11820/dlkxjz.2002.02.006
    Abstract ( )   PDF (773KB) ( )   Save
    Land unit is the basic unit in soil erosion management and ecological environment construction. To understand the roles of water and sand movement among the land units is significant in spatial management of small basins. The land unit is defined as a piece of land with homogeneous geographic characteristics. Within a land unit, the elevation, slope, aspect, soil type or soil texture, landuse or landcover are same or similar. It is now becoming much important in land planning and land management. This paper described the characters and functions of land unit. Based on geographic information system, the methods for land unit dividing, parameters organization, and attribute extraction were expatiated. To meet with the needs of soil erosion model, land productive model and socio economic model, which are main models developed for soil and water conservation measures, a mathematical model for calculating flow network among land units in small catchment was developed. The data set used in the model was grid format elevation data and land unit data layer. The model result was a relation table which shows flow structure of water and sand movement among land units. The flow network relation table then was connected with the erosion model to give out the flow sequence of erosion process.
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    A Review and Prospect on Regional Policy Research
    LIU Yu, LIU Yi
    2002, 21 (2):  153-162.  doi: 10.11820/dlkxjz.2002.02.007
    Abstract ( )   PDF (942KB) ( )   Save
    Regional policies refer to a series of policies, which can optimize the spatial collocation of resources and control the spread of regional discrepancies. With the development of human society, material and non material element flow among different regions, and regional economy takes on different characters; accordingly, regional discrepancies are enlarging. So it is important for central government to harmonize regional relationships by using regional policy. Of course, regional policy has brought great benefits on many countries and regions. But at the same time, there are a lot of problems in this field. For example, people have no clear ideas on regional policy, theoretic studies are not closely combined with practice works, the effects of regional policy often departs from its original objects, and so on. Especially, China’s regional policy is weak on theoretic research, and the practice status is anxious. Detailedly, the cost of reional policy is rather high, there are so many accidental factors in the process of implementing regional policy, the contradictions among different interest main bodies appear continuously, and it is very hard to harmonize the relationships between regional policy and other special policies. In order to clear up the complicated thinking of regional policy and find out the impediment factors, which influence successful implement of regional policy, on the base of general review of regional policy, the paper gives a basic judgement of China’s regional policy--it has not built up a canonical operating and managing system under market economy mechanism. This paper also puts forward several new research tasks of regional policy. What is the essential reason that results in the effect of regional policy departing from its original objects? What is the essential reason that causes China’s regional policy taking on such situation? What are the new ideas of regional policy research? The authors simply set forth their views on these questions, and hope to arose other scholars’ interest and discussion on this topic.
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    The Research Progress of Areal Interpolation
    PAN Zhi qiang, LIU Gao huan
    2002, 21 (2):  156-152.  doi: 10.11820/dlkxjz.2002.02.008
    Abstract ( )   PDF (578KB) ( )   Save
    In a broad sense, spatial interpolation includes point interpolation and areal interpolation. In this article these two types of interpolation methods were reviewed and the areal interpolation which was not very popular to major people was especially introduced according to whether the interpolation methods use ancillary data or not. In the areal interpolation methods without using ancillary data, the algorithm and its characteristic of the following methods were introduced: point-based areal interpolation, areal-weighted interpolation, areal-weighted interpolation using control zones and pycnophylactic method. In the areal interpolation methods using ancillary data, the EM algorithm and the method using remote sensing data as ancillary data were introduced. And the special case of areal interpolation - statistics variables spatialization-was also introduced. In the end, these two types of interpolation methods were compared and the main research trend of areal interpolation was foreseen.
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    Gray Incidence Analysis between Cultivated Area and Grain Yield and its Affecting Factors of Henan Province
    LI Mao
    2002, 21 (2):  163-172.  doi: 10.11820/dlkxjz.2002.02.009
    Abstract ( )   PDF (898KB) ( )   Save
    Cultivated area, population, and grain yield in Henan Province during the past 50 years are discussed in this paper based on statistical and survey data. It is found that (a) the general trend of net cultivated area loss started in 1955 which got continued; (b) the population in Henan Province will increase to 1×10 8 in 2005 and 1 06×10 8 in 2010; (c) total grain yield and grain yield per capital have increased in a fluctuant way since 1960; (d) grain yield per capital, effective irrigated area, and crop pattern have more effects on total grain yield based on gray incidence analysis and correlation analysis approach; and (e) multiple cropping index (MCI) of cultivated area in Henan Province is higher than national average standard, and the higher MCI, the more grain yield base on Regression analysis.
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    An Evaluation of the Regional Sustainable Development System——A Case of Henan Province
    ZHENG Hai xia, QIN Yao chen
    2002, 21 (2):  173-179.  doi: 10.11820/dlkxjz.2002.02.010
    Abstract ( )   PDF (282KB) ( )   Save
    Sustainable development has become a necessary choice of human development. The regional sustainable development system is the main body of sustainable development practice, and the evaluation of the sustainable development system is the basis of sustainable development practice. Currently, the evaluation is mostly concentrated on temporal dimension, but the evaluation of spatial dimension, especially that of spatio temporal dimension and multipurpose of a region, is very few. At the same time, most of the evaluations of the regional sustainable development system is single object, and the comprehensive evaluations is scarce. From spatio temporal dimension and these points of level, coordinative, equitable and comprehensive characteristics of sustainable development,this article comprehensively gives methods of the evaluations of the regional sustainable development system, and takes Henan province as example to discover the law of temporal evolvement and spatial difference on the sustainable development system of Henan province.
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    A Primary Study on the Theories and Process of Water Resources Carrying Capacity
    ZHU Yi zhong, XIA Jun, TAN Ge
    2002, 21 (2):  180-188.  doi: 10.11820/dlkxjz.2002.02.011
    Abstract ( )   PDF (114KB) ( )   Save
    As a principle index to measure water resources security, water resources carrying capacity relates with the problem of water resources security closely and becomes an emphases of water resources study which has important effection on the recognization and construction of water resources security system. Based on the definition of water resources carring capacity, this paper brings forward the theories about the study of water resources carrying capacity, concerning with the sustainable development, water resources-socialeconomy-environment coupling system and water cycle in duality mode. After a overall review of the contents and evaluation index system, the paper summarizes the evalauation methods of water resources carrying capacity study, including the imitate model with system dynamics theory, the decision model of multiple-purpose planning etc.. Finally, the paper points out that the further study of water resources carrying capacity should strengthen integration study of different subject, apply the new technology of GIS and RS actively and pay more attention to the study of region diversity.
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    The Application of Aviation Remote Sensing to Agricultural Land Grade
    ZHANG Zheng feng
    2002, 21 (2):  189-194.  doi: 10.11820/dlkxjz.2002.02.012
    Abstract ( )   PDF (388KB) ( )   Save
    The agricultural land grade and evaluation is a necessary means to evaluate the quality of agricultural land, is the foundation to protect agricultural land, and is an urgent task for land management. Agricultural land grade and evaluation need a simple, effective method so as to save investment and manpower. The use of aviation remote sensing is suitable for this. Based on analyzing the present research situation of abroad and domestic agricultural land grade and using the experimental experience of other areas, this article discussed the application of aviation remote sensing to the plotting of grade unit and acquirement of grade factors. The grade of natural factors can be gotten from the aviation photo through establishing the relationship between the factors and the image characteristic on aviation photos. The information of economy-location factors can be gotten from the aviation photos through selecting the quantitative factors relating to the economic result of land.
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