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  • 1996 Volume 51 Issue 4
    Published: 15 July 1996
      
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  • QUANTITATIVE ANALYSIS ON NONHOMOGENEOS SPATIAL DIFFUSION IN GEO-SYSTEM
    Shan Weidong, Bao Haosheng
    1996, 51(4): 289-295. https://doi.org/10.11821/xb199604001
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    The Geo-system is an open and complicated system. This complexity origins from the geographic environment including natural environment and economic environment. However geographic space is a nonhomogeneos space. Furthermore.the nonhomogeneity of regions exists so absolutely that innovation diffusion in geo-system is restricted by geographic environment,as there is a great deal of differences between regions which have different natural,economic and social qualities.Then, there is no doubt that the diffusion process of any innovation is in nonhomogeneos space.Spatial diffusion relates to not only distance but also nonhomogeneity of regions.A significant body of spatial diffusion theory was formed as a result of the work of T.Hagerstrand and others. Spatial diffusion research is of importance in understanding the spread of diseases, ideas,business, products and people from initial origins through time and space. But. existent diffusion models have been found to be parsimonious and inflexible in solving practical problems, because the T.Hagerstrand’s models were based on the homogeneos space and the diffusion of geographic environment was ignored. It is considered that innovation is composed of infinite and noncontinuous small diffusion medium and the third dimension is included in space due to nonhomogeneity in this paper.We transfer the movement of innovation in two-dimensional space into a great deal of random medium movement in three-dimensional space.The random movement may be described by the Kolmogorov diffusion equation. By means of the spatial diffusion equation, we can derive the centers of isotropic diffusion,anisotropic diffusion, multiple diffusion and the dynamic diffusion equation in nonhomogeneos space.
  • STUDY ON MONITORING SNOW DISASTER IN LARGE AREAS SUPPORTED BY GIS AND RS
    Shi Peijun, Chen Jin
    1996, 51(4): 296-305. https://doi.org/10.11821/xb199604002
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    Snow cover is an improtant factor influencing animal husbandry in winter in the north part of China. The relationship among grass height,snow cover area and snow depth is a key to determine the harmfulness of snow disaster.So.using NOAA/AVHRR image to get the snow cover area and using snowfall and topographic indices from DEM to measure snow depth will provide a practical way to monitor large area snow disasters. In this paper,Xilingol League in Inner Mongolia is selected as a study area,and following problems are studies:1.Clouds and snow surfaces have similar characteristics in both visible and infrared spectra.How to identify them in determining snow cover area is necessary but difficult. Multi-temporal composite technique in processing NOAA/AVHRR image is presented and testified as an effective method in this paper.2. Two topographic indices of wind sheltering fetch and relief from DEM are put forward,which are main factors influencing snow depth.Then the model of the relationship between snow cover depth and snowfall and above indices is built,and the distribution pattern of snow cover depth is revealed.3. By overlaying snow depth map and grass height map. the harmfulness of snow disaster is evaluated in the study area.
  • THEORETICAL AND PRACTICAL VIEWS OF GIS SYSTEM INTEGRATION
    Zhang Li
    1996, 51(4): 306-314. https://doi.org/10.11821/xb199604003
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    With the development of GIS applications.GIS system integration has been the most active field in system software development.However, specialized process models have been developed,which are independent of GIS technology, and they are as complicated as GISs. Moreover.the data model of GIS still lacks spatial-temporal component needed for environmental simulation. Although it is very clear that integration is the key to GIS applications.the obstacles in integration still exist.This paper deals with some theoretical problems in system integration: concepts, problems, architecture. and methods and steps for integration.The author also introduces the contents of system integration and the considerations for engineering projects by combining the achievements obtained from two key projects (Study on Flood Damage Monitoring and Assessment Techniques and Integrated Information System for Major Disasters Monitoring and Assessment), and puts forward a new method, namely, dynamic linking, for GIS integration. Compared with the peer-to-peer or embedded architecture, dynamic linking is more flexible, more open, and more efficient in operation, However, Import/Export capability, the core of peer-to-peer architecture,is still one of the most important component of an open and dynamic integrated system because of the greatest differences between the data structures of process models and GISs.It is better for us to use open concept and object model to improve the Import/Export as an embedded function of GISs.
  • A STUDY ON THE SPACIAL BEHAVIOR OF TOURISTS IN MOUNTAIN RESORTS:GIVING CONSIDERATION TO COMPARBON OF THE TRAVELLING SPACIAL BEHAVIOR BETWEEN TOURISTS IN HUANGSHAN MOUNTAIN AND IN YELLOWSTONE PARK
    Lu Lin
    1996, 51(4): 315-321. https://doi.org/10.11821/xb199604004
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    Study on the spacial bhavlor of tourists is one of the important research fields of tourism geography.On the basis of much on-the-spot investigation,the author,taking Huangshan,Jiuhua and Quyun Mountain which all are national mountain resorts for examples,expounds two questions:(1)making use of spacial use curves of resorts to analyse movable space of tourists in the three mountains,we discover the value of mountain resorts affects the movable space of tourists.Generally,the higher the value, the wider the movable space and the more complicated the movable spacial configuration.As time passed, the movable space changed. As for Huangshan Mountain,the change of movable space of tourists is beneficial to the tourism devdlopment.(2) Through the contrast of travelling spacial behavior between tourists in Huangshan Mountain and ones in Yellowtone Park,we discover,with the lift of the social and economic Positions of tourists and the increase of distances from the residence of tourists to the resorts,the travelling spacial behavior of the tourists tends to complicate.
  • NUMERICAL SIMULATION OF THREE-DIMENSIONAL WIND-DRIVEN CURRENT IN TAIHU LAKE
    Pang Yong, Pn Peimin
    1996, 51(4): 322-328. https://doi.org/10.11821/xb199604005
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    A mathematical model of three-dimensional wind-driven current is developed with the consideration of local wind system in Taihu lake. The simulated results on the current circulation are more consistent with the observed data, especially on current speed, in comparison with the simulation with respect to two-dimensional models. In addition, it shows that the topography of the lake basin influences on lake circulation, and the existance of the Xishan Island strongly enhances the current speed in the area between Xishan and Dongshan Islands. The convergence field in Taihu lake induced by different wind directions which influence directly on the distribution of the alga in Taihu lake is computed and analysed. Considering the two bays in the north area of Taihu lake, the convergence field can be divided into three patterns: (1) convergence patterns under S and SW winds: (2) divergence patterns under N and NE winds; and (3) convergence and divergence patterns under W, NW, E and SE winds.In terms of the simulated results. the concentration of blue-green alga in Taihu lake can be known roughly.In conclusion, three-dimensional model is better than two-dimensinal model in simulating wind driven current in large shallow lakes such as Taihu lake. The long corridor between Xishan and Dongshan Islands in Taihu lake is very important to the formation of the lake circulation. The three patterns of convergence fields which result in the different distributions of the concentration of the alga are classified in the paper according to the different wind directions.
  • THE IMPACTS OF CLIMATE ON THE SOCIETY OF CHINA DURING HISTORICAL TIMES
    Wang Zheng, Zhang Piyuan, Zhou Qingbo
    1996, 51(4): 329-339. https://doi.org/10.11821/xb199604006
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    It was explored that the drying trend of eastern China were divided by abrupt changes (280’s,880’s and 1230-1260’s).The changes of population during the last 2000 years were delineated and the percentage of people living in the northern part was calculated (table 1).It shows that during the early time,the population in the northern part got the higher percentage than that living inthe southern part.Then the percentage dropped rapidly at the 13th century, and had not recovereduntil now.Table 2 gives the percentage of population of provinces showing the population constractbetween the west and the east.It shows that before the 13th century the Shanxi/Shaanxi (westernpart) were almost the same with the Jiangsu/Zhejiang (eastern part),but afterward the easternpart got higher percentage than the western part.Cultivated land and tax were adopted here toshow changes of economy.Table 3 shows the percentage cultivated land and tax of the northernpart.Same conclusion are given as that shown in Tables 2 and 3.It hints that after the 13th century,a new geographical structure was set up.The relationship between the changes of demography (and culture) with the climate are tried toinvestigated in this paper.It has been discovered that the central government often lost their rulingover this country during the cold epoch.
  • SYSTEM OF NORTHERN JIANGSU LOWLANDS ANDITS COMPLEX RESPONSES TO THE SEA LEVEL RISE
    Chen Xiaoling, Wang Lachun, Zhu Dakui
    1996, 51(4): 340-349. https://doi.org/10.11821/xb199604007
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    The system of northern Jiangsu lowlands has its particular states and structures due to the seariver interaction.It is a low-lying plain with a mean elevation of about 3 metres above sea level.Its slope gradient is about 0.2‰-2‰ and the mean gradient of channels’ water stage is 0.004‰. By making the digital elevation model and analyzing the Quaternary sedimentary facies,the system ofnorthern Jiangsu lowlands is divided into three parts: the ancient lagoon low-lying plain of Lixiahearea, the marine plain along coastal area and the Changjiang river delta plain.The sea level rise willhave severe effects on the system, which will be more frequently endangered by flood and water logging.Through analyzing the states and structures of the northern Jiangsu lowlands system.this paper studies its complex responses to the sea level rise, and gives the measures adapted to the sea levelrise.
  • ON EARTH SYSTEM SCIENCEAND SUSTAINABLE DEVELOPMENT STRATEGY (Ⅰ)
    Huang Bingwei
    1996, 51(4): 350-354. https://doi.org/10.11821/xb199604008
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    The framework of the young earth system science as the basis of strategies for sustainable development is discussed in conjunction with a brief account of its rise and development from studies onthe climatic system. There is the need for collaboration across the natural and social sciences. Integrated assessment of global and regional environmental changes is indispensable. When what can bedone to moderate or mitigate the impacts of these changes is under consideration.With regard tosustainable development, the time span is generally kept within one or two handred years.and theearth system involved consists of land, oceans and atmosphere together with the exchange of matterand energy across their interfaces.While land is the centre of socio-economic development and thescene of most complicated natural conditions,it lags behind in earth system research. Geographersare urged to make up the deficits.
  • DISCUSSION ON STUDIES OF EARTH SYSTEM SCIENCE ANDSUSTAINABLE DEVELOPMENT STRATEGY IN CHINA
    Xu Xiuyuan, Ge Quansheng, Zhang Piyuan
    1996, 51(4): 355-359. https://doi.org/10.11821/xb199604009
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    A sysposium on studies of earth system science and sustainable development was held in Beijing between March 9-10,1996. It is initiated by Professor Huang Bingwei, for he suggested setting up the territorial system science as the theoretical base for the sustainable development in China.Prof. Huang Bingwei shares the vast experience which he has gained by his studies, and he identifies lesson about earth system science and sustainable development.Numerous participants came from various universities, institutions and science foundations.
  • THE DEVELOPMENT AND TREND OF MODERN HISTORICAL GEOGRAPHY IN THE WEST
    Que Weimin
    1996, 51(4): 360-368. https://doi.org/10.11821/xb199604010
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    Modern historical geography has originated gradually from historical science since the end oflast century,and developed as a solitary branch of branch of modern geography up to 1930’s.On the development of modern historical geography in the west from 1920’s to 1990’s,there are four periods:(1) of discussing the discipline defimtion from 1920’s to 1950’s,which reflects the formal setting upof modern historical geography;(2)of inquiring the methodology from 1960’s to 1970’s,whichpromotes the concrete study on the historical geography;(3) of new philosophical minds from theends of 1970’s to 1980’s,which propels the synthetical research of historical geography as a whole;and (4)of the tendency of plural study since 1990,which marks the new reached peak of modernhistorical geography.Scanning the growing course of modern historical geography in the west,there are three impetuses:discovering the new data,choosing the best approach,and renewing thethoughts on the development of historical geography, neverthe less,the sum of concrete researchesis the origin for the permanent development of modern historical geography in the west.
  • ON THE STUDY OF CHINESE BUDDHISTICAL GEOGRAPHY
    Zhang Weiran
    1996, 51(4): 369-373. https://doi.org/10.11821/xb199604011
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    Religion, which mainly means Buddhism in China,should be one of the dominant indications ofChinese cultural regionazation. The study on Chinese Buddhistical geography began in the late1920s. Up to date, the related study included two types:one was the studies in Buddhistcal history,and another was the specialized studies. The former was just a supplementary method in historystudies, so its achievements can only be found oddly in history books. It was the later type that dealtwith the problems of geography. The achievements were in two aspects: one was to discuss the import route at a level of international communication, and the other was to research the geographicaldistribution of eminent monks and temples.The author assumes that:1) It is essentially to pay attention to historical changes. And thisshould be a distinguishing feature of Chinese cultural geography.2) Buddhism is composed of several layers. For the study of Buddhistical Geography,it could be devided into three layers:faithfullayer for popular people: religious layer for Buddhists: and academic layer for eminent monks. Thestudy should be based on the knowing of the layered-structure of Buddhism and the analyzing of thefactors of each layers,and then we can come to an all-round conclusion. 3) The study methodsshould be innovated.
  • URBAN SELF-ORGANIZATION UNDER THE BALANCE BETWEEN SUPPLY AND DEMAND
    Shuai JiangPing
    1996, 51(4): 374-383. https://doi.org/10.11821/xb199604012
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    City is an unequilibrium system in continuous evolution with the characteristics of self-organiza-tion.This article builds up an urban self-organization model under the balance between supply anddemand.This model is theoretically based on feedback in system,spatial interaction among regionsand stochastic fluctuation.According to Christellar’s market system and the Chinese real conditions,five important coefficients(γ(k),ρ(k),φ(k),m,b) are calculated.In modelling the evolutionprocess,the author builds up an 8×8 urban market system,and the initial condition for each market is the same.The modelling result shows that an evenly-distributed spatial structure will not appear although the initial spstial structure and population distribution are even.Further analysis points out that:(1)The main urban centers appear in the central region of acity,and city tends to form more than one centers with the same scale and the same function, whichis different from Christellar’s model.The centers do not allocate in the geometric center of the city.This kind of spatial structure supports to form multiple-center market system in a city.(2)Theevolution process of a city can be divided into three stages.In the first stage,the city changes at alow speed since the feedback is not strong.In the second stage,the strong feedback stimulates thecity to evolute fast.In the last stage,the agglomerating process and spread process become balanced,the evolution of city reaches a dynamic equilibrium.(3) In the self-organization model,thelowest land price locates in the break-point of two main centers.But in Christellar’s model,it willlocate in the closest maket of the center.The author thinks that the Central Place theory and its modification only explains a part of thedynamics in the formation and evolution of urban spatial structure.The self-organization model includes three main processes and dynamics,it can explain more characteristics of urban spatial struc-ture.Uneven distribution of urban spatial structure is the main form in reality because of spatial interaction.