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  • 1997 Volume 17 Issue 2
    Published: 20 March 1997
      

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  • Chen Shupeng, Zeng Shan
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    Chinese had noticed regional differences in ancient times and thus arouse the concept of regional sustainable development which was successfully applied to delta cultivation and civilization. Over the long term of regional development and regional exchange, much experience therefore was accumulated based on coastal zones, toward both inner land and open ocean. Regionalization, a basic job preceding sustainable development of a region, has also been carried out in China since ancient times. More important, patterns of regionalization were retained, and serve as references even today. Reflections on China’s historical enlightenment can assist us in locating the breakthroughs in regional development in the 21st century: facing the oceans with the seaport cities as nucleuses.
  • Wang Yeqiao
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    Improving land cover classification and mapping accuracy has long been an important objective for remote sensing and spatial data investigators. It is generally recognized that improvements to classification can be made by coupling the information contained in multispectral, multitemporal, and multisource spatial data with human analyst’s expertise and methodology. A direct application of conventional statistically based classification approaches, however, may not be appropriate because of the differences in measurement scales and violation of distribution assumptions for multisource spatial data. Therefore, a distribution free and scale free classification scheme is desirable. Artificial Neural Network (ANN) technology is one of the optimal choices for this type of application. In this paper, two ANN models of backpropagation (BP) and modular ANN (MANN)were discussed and applied in land cover classification. Conceptually, ANN models have the potential to operate similarly to the way in which human image interpreters do. ANN features corresponding to the synapses, neurons, and axons of the brain are input weights, processing elements, and output paths. The BP model consists of three layers. The input layer represents the input data patterns, the output layer represents the classification scheme, and the hidden layer is responsible for information transformation and calculation. MANN model consists of several subnets or individual backpropagation networks (referred to as “local experts”). Each subnet is responsible for interpreting a subset of the input data. In multisource spatial data cases, while the unique spectral information from each season can be employed by individual subnets, spectral mixings among different land cover categories in single date remote sensing data can be filtered. MANN model provide the mechanism to improve the classification performance of simple BP model. Multisource spatial data combinations on (1) multispectral, multitemporal Landsat TM data, (2) multispectral, multitemporal Landsat TM and transportation data, and (3) Multispectral, multitemporal Landsat TM and illumination model data, were classified by the two ANN models, respectively. It concluded that both BP and MANN models performed well in high dimensional multisource spatial data classification. With modular and competition mechanism, the MANN model performed better than the BP model.
  • Chen Wen, Yu Xiaogan
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    Since the critical strategy of developing the Changjiang(Yangtze) River Basin has been put forward from the beginning of the 1990s, economic development in this area has proceeded quite rapidly and industrial corridor has begun to take shape. Under the rational and complete utilization of the regional advantages, the region is expected to be the largest river industrial corridor in the world. However, this area is also facing such significant problems that there is not enough strong economic power, but there is enlarged regional disparity, low degree of industrial structure, weak regional integration and insufficient guarantee of energy, transportation and environment. Thus it is imperative to perform the development strategy to combine focal exploitation with integral development so as to harmonize the regional economy and bring integral advantages into full play. Moreover, It is also critical to adjust the industrial structure, quicken the open pace and set up the guarantee projects of energy, transportation and environment in order to assure the proper fast and sustainable growth.
  • Liu Hong, Zhao Shuzhi
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    Although the economy of various provinces integrates to a great extent, Northeast China develops quite slowly in recent years, which is the so called “Phenomenon of Northeast China”. However, with favorable conditions and great potential for further development, Northeast China’s economy will surely be revived through accelerating reform and opening up to the outside world, increasing investment in science and technology, improving infrastructure facilities and shifting the economic growth pattern.
  • Shan Weidong, Bao Haosheng, Zhang Fengxuan
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    Any spatial diffusion process is a time and dependent process. A spatial diffusion has its regularities of time and space. Since T. Hagerstrand originated the time-space analysis, the theories on spatial diffusion have been developed. But, the nonhomogeneous dynamic spatial diffusion has not been solved satisfactorily. This paper gives a second order differential equation on the nonhomogeneous dynamic spatial diffusion based on a stochastic movement. The model of the random movement is set up for three neighour grids. On the basis of principles of the random movement, a probability equation can be obtained. With expanding the equation by Tayler series and taking its limit, a general partial differential equation on the spatial diffusion with time dependent can be deduced. But it is too complicated and difficult to find general solution and is only approximately analysed by the numberical method. Deriving from the studies on the spatial diffusion by Hagerstrand, a general dynamic spatical diffusion equation in the nonhomogeneous space can be resulted. Hagerstrand proved that the accumulating amounts of spatial diffusion accord with a Logistic Curve. As a diffusion has proceeded for a long time, we can find the saturated amount of diffusion from the partial differential equation. A simplified general equation on the dynamic spatial diffusion in nonhomogeneous space can be resulted from taking the saturated amount into a Logistic Curve. Finally, we give an example applying the equation for the appraisal of land basis price in Fuyang. The computing conclusions show: as the distance to diffusion center increases or the multiple quality decreases, the difference between saturated land price and instantaneous amount increases. In about two months, most of plots of the city can reach their saturated land price.
  • He Yan, Deng Wei, Zhou Deming
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    The Tumen River region plays an important role in the economic expoitation belt along the border. The wise use of water resource is the main factor which defines the regional sustained development. Based on analysis of the regional water resource system and the current situation of water resource exploitation and utilization, the paper discusses the development potentiality of the regional water resource, the influence of water resource on the regional exploitation and countermeasures in detail. The results indicate that although there is a large amount of water in this region, the water resource which can be exploited is limited. The paper also predicts that the demand of water quantity in 2010 will surpass the capacity of the regional water resource exploitation. Meanwhile, the water environment is being polluted and the water resource potentiality declines apparently in the region.
  • Wang Xiaoju, Gong Zitong
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    Soil quality is one of the most important factors for sustaining the global biosphere and the basis for sustainable agriculture development. A method for evaluating soil quality changes in time and space at small regional level was developed and used to evaluate the changes of soil quality in Qian Yan Zhou Experimental Station (QYZES) located in subtropical zone in China after 11-year reclamation. The characteristics of soil quality changes in crop land, citrus orchards, pasture, sparse grass land, artificial forests, natural forests, bare land and other land use patterns were analyzed and discussed. Supported with the software of ARC/INFO and FOXBASE, the Qian-Yan-Zhou Soil Quality Information System (QYZSQIS) was developed. By introducing a concept of relative soil quality index (RSQI), soil quality and its changes were evaluated at the small regional level of QYZES from 1983 to 1994. The study proved that the development of QYZSQIS combining with database of soil changes in various periods was an effective method for evaluating changes of soil quality in time and space at small regional levels, which may be suitable to regional levels, RSQI could serve as uniform criteria making quality levels of regional soils comparative, and ΔRSQI, the changed value of RSQI, was a good standard for the evaluation of soil quality changes. After 11-year reclamation, soils with both very low quality and very high quality were decreased in area, and soil with medium quality obviously increased. As to the land use patterns, soil quality in paddy fields, vegetable fields, and citrus orchards was dominantly improved, however, in fuel woods, sparse grass land, and bare land was mainly degraded. Herb plays an important role in conservation and improvement of soil quality in subtropicalzone in China. The study also shows that soils with higher fertility were degraded more easily. It has the same significance both for improving low quality soils and conserving higher quality soils.
  • Jiang Tong, Xu Pengzhu, Cao Wenping
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    Located in the headwater upstream of the Taihu Lake Basin, which is a dersely populated and economically developed area in China, the West Tiaoxi River catchment is a frequent flood hitted area due to its nature and characteristics of climate. A local scale integrated hydrological model has been developed for the studies of flood mechanisms and dynamics in this area. The model consists of several modules of sub models including the Xin’anjiang model and the hydraulic model of unsteady flow in open channels etc.. Testing results of the model show that it is reliable for planning the water resources engineering and for assessing flood risk.
  • Zhu Yanming, Huo Wenyi, Chen Dinggui
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    Samples of peat were collected from the Da Hingan Mountains. The contents of trace elements (including Cu, Pb, Zn, Cd, Hg, Cr, Hi, Co, Mn, Sr, Ba, B) in the vertical sections were measured with modern analytical methods (AAS and ICP). The results show that the dispersion regularity of trace clement concentrations was not very clear in Gulian peat and Tuqiang peat and in different stages of the same type of peat. Compared with the same type of Russian peat, the contents of Zn, Co and B in the Da Hingan Mountains was higher, but the content of Mn was obviously lower. In the high peat, the contents of trace elements increased from bottom layer to surface layer, especially for some heavy metals having close relationship with human activities. Studies on trace elemlent geochemistry spectrums of peat in different areas help to reconstruct the history of air pollution and have great environmertal significance.
  • Shan Pengfei, Cai Changjun, Wen Jinlin
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    The desertification of the earth surface is not only a kind of natural hazard but also a serious problem of eco environment. As a case study of the Lingwu-Yanchi region (i.e. Lingwu and Yanchi counties) beside the eastern bank of the Huanghe River of Ningxia, the paper first analyzes the natural environmental action, human activities and relation between them while the desertification and sand desert occurred or developed at that area in the Quaternary. The study results indicate that the changes of desertification in geological periods are a kind of climatic geomorphic processes which are completely caused and controlled by physical climatic changes of the glacial periods, but the changes in human history belong to a kind of climate human processes which are mainly controlled by climatic conditions and partly interfered by human economic activities. After that, the problems both of the desertification hazard and social continuous development are preliminarily discussed, such as the relations between land desertification and economic development of agricultural pastoral activities under the climatic warming and drying trend in the near future, and the problem of ecological and economic benefit using the way of‘decreasing the farming for increasing the grazing’ as the countermeasures on controlling the land desertification there under pouplation pressure growing fast in modern society.
  • Song Yuxiang, Cui Lijuan, Zhang Yi
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    There are distinctive tourist resources, special geographical position, and given historical background in Xingan League. All these provide advantages to develop tourism, such as traveler and natural resources, regional superiority. Both the opening of boundary regions and the advance of economic technology of Northeast Asia bring about chances to develop tourism and to exploit tourist resources. Taking tourism as the leading industry to develop economy in Xingan League is an ideal choice of the economic development. Through comprehensive evaluation, the paper presents the design of the distribution of tourist resources and the development of distinctive tourism.
  • Fu Wei
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    This paper presents constructive principles and building approaches of grey system prediction models for soil gravity erosion in loess hills and gullies. With the models, the author made test research on soil gravity erosion in Wangjiagou watershed in Lishi County, west Shanxi Provence. And the relationships between prediction values of the models and observed values of soil gravity erosion are reflected with gray relational extents, and prediction precisions of the models are analysed. Meanwhile, to mirror the dynamic changing rules of soil gravity erosion system, the principle and approaches of the remnant distinguishing are introduced, so as to improve prediction level of the models. The models have high prediction precisions, and provide a new way of quantitative analysis for researches on soil gravity erosion in loess regions.
  • Zhang Pingyu
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    This paper creates a new conception to construct the international central city of the Tumen River Development Zone on the basis of the analysis of the superiorities and problems for developing cities from the view of present condition in the Tumen River delta area and the background of Northeast Asia. The united and polycentric international city is the best distribution model not only in the spatial structrue but also in the organizing form. Its rationalization and practicability is thoroughly proved from varous aspects including the urban planning principle; comparison of port cities; specific characteristics of this area cooperation; and natural, environmental, social, cultrual factors etc.