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    Earth Surface Processes
  • Earth Surface Processes
    WANG Li ming, YANG Yan feng, OUYANG Hong bin
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    Huge amount of steep slope land reclamation is a key reason for soil erosion and and eco environmental degradation in China. As a fundamental countermeasure of ecological rehabilitation, the experiment of returning farmland to woodland and grassland was conducted in large areas of the upper reaches of Yangtze River and the middle and upper reaches of Yellow River in the year 2000. However, a series of problems were also resulted from the process of de farming, such as food safety, allocation of ecological emigration. An important springhead of these problems is the spatial disparity of population stress caused by spatial disparity of slope farmland distribution. The more concentrated the slope farmland is, the more complex the problem of population stress is. Four population stress index models in de farming process based on GRID is designed in this research: (1) the fundamental de farming stress model based on the ratio of slope farmland to total farmland:p i= u iv i×100%.p i stands for population stress index;u i stands for the percentage of slope farmland to the neighborhood area; v i stands for percentage of farmland to the neighborhood area. (2) the modified model concerning the disparity farmland quality. (3) the modified model concerning the spatial disparity of population distribution. (4) the modified model concerning the development of economic forest on de farmed slope farmlands. Finally, taking Fengjie County for example, simulations are conducted using these models, and available results of de farming stress indexes are obtained in different locations under various conditions.

  • Earth Surface Processes
    ZHOU Jiang ping, CUI Gong hao, ZHANG Jing xiang, XU Jian gang
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    Thanks to the cooperation among the scientists from many countries across the world, the year 2000saw human finished drawingthe map of his own genome. This very accomplishment bringsnot only an increasing momentumto the knowledge of life sciences and biological technology but also great impetus and enlightenment to other fields of sciences. Under such circumstances, Prof.Chen shupeng, an Academician of CAS, took the lead in puttingforward the concept of Geo informative Tupuand attached great importance to the related researchissues and possible practical uses ensued from it. And he argued that these would definitely be of great importance to the development of both geographic science and future of the country. Following him, scholars of geography and many other disciplines began their studies on this promising topic. Based onall these, this paper probes into the connotation of geo informative Tupu and the basic characteristics that it shares with transportation network, touches on the applications of Tupu that are actually found in the field of transportation, analyses the possibility that Tupu will give to the study and improvement of transportation network when it is used efficiently as the most important information source of transportation network and combined correctly with latest technology such as RS, GIS, GPS, ITS etc. And after all thesehave been done, the paper forecasts several major aspects that Tupu will benefit transportation network when its right conception is fully understood and scientifically used.

  • Earth Surface Processes
    WAN Hong tao, ZHOU Cheng hu, WAN Qing, WANG Cheng yi
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    The computational mesh should represent the geometry, physical properties and boundary conditions of the computational domain in the flood simulation model. Based on the cell shape the computational mesh can be classified into regular mesh and irregular mesh. The generation of regular mesh is easy and simple, and as for irregular computational mesh hydrologists usually generated it manually. Due to structure and shape similarity, the automatic TIN generation algorithm can be used to generate the computational mesh for flood simulation model. The detailed flood model construction process based on GIS is to (1) delineate the computational domain; (2) generate computational mesh; (3) generate the mesh topology; and (4) extract the model parameters. The model parameters include boundary conditions, initial conditions, hydrological and geomorphological parameters and as well as other parameters for controlling the model simulation process. GIS technology can provide some spatial analytical tools for extracting some of these parameters such as the manning coefficient(roughness parameter) and calculating the average ground datum of internal point of every mesh unit and the mesh nodes, improve the capacity for defining the spatial sub-units of the computational domain and provide a better method to discrete the computational domain with enough amount of computational mesh with suitable geometry. In the river reach from Huayuankou to Jiahetan in the Huanghe River these maps of topography, landuse, water conservation engineering, hydrological observation station were used to construct the flood simulation model, and the data structure of the computational mesh is described in detail.

  • Earth Surface Processes
    YANG Cun jian, ZHANG Zeng xiang
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    In the process of spatial analysis, the vector data are always rasterized into the raster data because of the convenience for spatial analysis. How the area accuracy loses during rasterizing needs to be answered when different grid sizes are adopted in order to choose a suitable grid size. The question is answered here by rasterizing the landuse vector data of Chongqing City with grid of different sizes. Firstly, the landuse vector data are rasterized with grid of different resolutions such as 30m,60m,100m,200m,300m,400m,500m,600m,700m,800m and 1000m. The value of each grid takes the landuse type code as the dominant area. Secondly, the area for each landuse type is calculated in grid. Thirdly, the area for each landuse type is also calculated in vector and used as the actual area. Both the number and average size of polygons for each landuse type are calculated. Fourthly, the relationship among the accuracy loss, grid sizes and the average block size of each landuse type is analyzed. Finally, models for describing the relationships are formulated. It is shown that: (1)The relationship between the accuracy loss(Y) of each landuse type except the high canopy grassland and grid sizes(X) which can be described by the linear regression models such as, Y = A + BX . Here, A and B are coefficients of the models. The correlation coefficients for each model of each landuse type are all above 0.82?The correlations of the absolute value of accuracy losses and grid sizes are positive. The accuracy losses denote that the area reduces compared to the true area when the area of the average block size of each landuse type is above 101 hectare, which is opposite when the area of the average block size of each landuse type is below 82.(2)The correlations between the accuracy loss and the area of the average block size (S) of each landuse type for each grid size can be described by the regression models such as, Y = A +B ln (S) . Here, A and B are coefficients of the models. The correlation coefficients for each model of each grid size are all above 0.72 except grid size of 30 M. The correlations are positive. (3) Generally, the relationship among the accuracy loss(Y), grid size(X) and the average block size(S) of each landuse type can be described by such model as, Y = 5.366 -0.179 X -0.978ln (S) + 0.0348 X ln (S) ?The correlation coefficient of the model is 0.93.

  • Earth Surface Processes
    ZHU Jun, YANG Shi lun, XIE Wen hui, ZHAO Qing ying
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    Based on the data, which were obtained weekly at 24 sites along a transection set up in the Eastern Shore of Nanhui from Apr 1999 to Apr. 2000, this article quantificationally examines the cross shore differences of annual vertical accretion rate, absolute and relative stabilities of sediment surface. The results are as follows: (1) The annual vertical accretion rates are distinctly different at each site along the transection with a maximum of 49.5 cm/a at the site where the submergence probability is about 30% (between the average neap high water level and the average high water level) and a minimum of 2.2cm/a at the site near the seawall. The maximum is 22 times of the minimum. The annual vertical accretion rate is comparatively low where the marsh and the bare flat meets. Totally, the annual vertical accretion rates are lower at sites on the bare flat than those at sites on the marsh. (2) The absolute stabilities of the sediment surface are different at each site along the transection. Because it indicates the same phenomenon as the annual vertical accretion rate does, the difference of absolute stability is in accordance with the difference of the annual vertical accretion rate along the trasection. (3) The relative stabilities of the sediment surface are different at each site along the transection. The relative stabilities are much stronger at sites on the marsh than those at sites on the bare flat. (4) Vegetation plays an important role in protecting the shore from erosion and stimulating accretion It also enhances the relative stability of sediment surface The difference in short term evolution of intertidal muddy flat is a compositive reflection of the submergence probability, energy of the wave and tide as well as the distribution of vegetation along the transection

  • Earth Surface Processes
    FU Hua, DING Rui xing
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    Basing on the methods of sporo pollen analysis, analysis of arenaceous quartz surface and soil micromorphology, this paper deals with the genetical properties of the albic soils in the Jiang Huai Area in the Northern Subtropical Zone of China. The spore pollen analysis shows the differences between the upper and the lower horizons in soil forming environment. The upper horizon underwent warm temperate forest steppe landscape and subtropical steppe landscape, which belonged to high chemical energetic environment. After the deposition of parent materials, the soil experienced brown soil process or deposition of other materials,then the deposition suspened for long period of time.With the accumulation of new deposits and climate change, the soil forming environment became the subtropical steppe landscape.The basic condition emerged for the formation of yellow brown soil in higher land,and the lower part became marshland with inadequate water drainage. The form of the arenaceous quartz includes its surface shape and structure, and reflects the obvious differences in soil forming environment between the upper and lower horizons. The surface of arenaceous quartz in the lower horizon, especially the illuvial horizon, generally has secondary SiO 2 sediment. As the surface decomposed, some holes formed along the weak region in the quartz sand, and this behavior stands for the high chemical energetic environment. Since the materials constantly deposited and water concentrated, no high chemical energetic environment appeared in the upper horizon. The diffuse and stress stick membranes are found in the thin section of the soil micromorphology.These membranes are the sigh of the secondary clayization.The fabric and light directioal clay membranes formed in the alluvial horizon for the accumulation of clay. Overall,when the Xiashu loess and other loess materials deposited, the climate was the warm temperate forest steppe zone, it then became the northern subtropical forest steppe zone.Finally,the new materials accumated over the loess derived soils.On the bases of the superipositing parent materials,the lower horizon is now at the secondary clayization stage and after the new materials superimposed,the alluvial horizons will have illuviation of clays.

  • Earth Surface Processes
    CHENG Wei ming, ZHOU Cheng hu, TANG Qi cheng, ZHANG Bai ping, YAN Yong hui
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    The Foothill Belt in the northern slope of the Tianshan Mountains is a transitional znoebetween mountains and plains.It is about 400 km long and 60 km broad from Wusu city to Jimusar city, appearing in three rows of folds with different morphologies and with their age becoming younger from south to north. Based on Geological Information System (GIS) and Remote Sensing (RS) methods, as well as previous research results, this paper systematically discusses the effects of foothill belt on hydro process in plain area. There are four facets of effects. Firstly, the foothill belt can prevent shallowgroundwater from flowing into plains directly, and turn it into surface water flow so as to increasestream runoff. The percentage of groundwater to surface river flow with foothill belt can reach about 47%, but percentage of groundwater to that without foothill belt is only about 37%. Secondly, the foothill belt can enhance annual adjustment abilityof surface rivers, making oasis developsteadily, e.g. the oasis area is about 7 539km 2 in ManasRiver basin with foothill belt is available, but in Sikeshu River basin, the foothill belt oasis area is only about 134km 2 . Thirdly, the foothill belt can prevent floodwateror mud rock flow from entering into plains directly and protect oasis safety. Fourthly,the foothill belt can affect distributions of aquifer'soverflow and buried depth of groundwater level in the plain area,and can control spill amount of groundwater. The foothill beltis importantto surrounding environment, as it can protect the surrounding ecoenvironment, influence land use and land cover change in the plains. Every vertical spectrum with foothill belt is100~200m lower than that without foothill belt. The purpose of this paper is to affer anew understanding about the foothill belt andits functions to environment, especially to hydro process in the plains, and a new idea about how to study interaction between highland and lowlandor mountains and plains. And it can provide scientific basis for utilizing water resources rationally and achievingsustainable development of oasis.

  • Earth Surface Processes
    LI Hai bin, LIN Zhong hui, LIU Su xia
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    In situ observations of soil moisture are invaluable means in developing land surface parameterization and studying pattern of climate change. However, the existing observations have been done only at point scale. Hence as to how to get regional soil moisture is of especially important. In this paper, geostatistical method (Kriging) is used to estimate soil moisture unknown at site A based on known soil moisture data around A. The data set of soil humidity in the top 1 m of 102 agrometeorological stations over China in 1987 is used for the estimation. In order to test how well the method works, we estimate one station's soil moisture as unknown by using other station's data. The observational data from that station is then taken as the true value. We gave the RMSE of Kriging interpolation method. and compared it with inverse distance square method The accuracy of the estimation is not high in terms of average relative error and standard deviation index For further analysis ,we took fperiod which had the maximal samples as an example.The average relative error of both methods was 0.26, the standard deviation of Kriging was 8.77 , the standard deviation of 5.17. The better results of the latter method was maybe due to itshomogenization over all the data with difference between the maximum and the minimum observed soil moisture being 42.85 that by geostatistical method being 31.25 and that by inverse interpolation method being 24.09. It is suggested that the combination of the two estimation methodsmay give better results. The inverse distance interpolation method is suitable for data with general variation characteristicswhile the geostatistical method is good for regional variable tendency. The average range calculated in this paper, around 500 km, is in agreement with the result of Entin et al. (2000) from 49 stations and 11 year records and Liu et al. (2001) with 99 stations with 3 year records.

  • Earth Surface Processes
    LI Ling
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    This paper reviews the process and researches on internal population migration in China since the economic reforms from 3aspects. They are the changes in migration process;the main reasons, choices and patterns of migration, migration and gender difference, migration and urbanization;and the participation and impression of migrants to city's economic and social life. The internal migration process in China since the economic reforms can be divided into 4 periods. The most important reason for migration is the difference of employment opportunities induced by regional economic disparities. The main migration pattern is through self organized network. Population migration has accelerated the process of urbanization. Migrants have become important part of urban labor market. But the temporary migrants in cities make them in weak status and difficult to dissolve into city life. This situation is unfavorable to the whole process of migration and urbanization in China. Large amount of positive researches give us a more and more clear knowledge to China's internal population migration, but most researches still remain within the frame of foreign country's theories. The author thinks that more researches in the following 4 fields are needed: the relation of population migration and the proceed of Hukou (registered residence)system reform, the relation of migration and the employment of urban citizens, the relation of migration and the industrial adjustment, the affection of temporary migrants to the comparing analysis of social and economic differences.

  • Earth Surface Processes
    ZHU Hong, SITU Shang ji
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    The topographic conditions of high center and low peripheries of Hainan Island result in vertical and horizontal zonal characteristics of Hainan's climate,plants and soil geographic factors, and influence the development of Hainan culture. During the development of Hainan Island, the northern and northwestern parts of the Island were developed at first; with the increase of Hainan immigrants , the northeastern part was developed then, followed by the souteastern and southwestern plain areas around the Hainan Island; and finally, the central tablelands,and mountainous and hilly areas were developed. The development sequence took the form of the circular distribution characteristics of the present overall Hainan culture along the altitude. Based on the analysis of the spatial distribution characteristics of Hainan regional culture and regional differences, geographical differences of Hainan cultural landscapes, regional distribution of talented people of Hainan and agricultural landscapes, this paper points out that the spatial distribution of Hainan culture is related to its geographical factors such as topography, climate, etc. and the distribution of all kinds of cultural landscapes also appears the circular distribution characteristics along the altitude. In other words, there are more cities and more population, and developed industries and better traffic system in the coastal plain areas around the Island than in the central areas. And the degree of literacy in the coastal plain areas around the Island is the highest in the Hainan Island, and the culture of the center falls behind the whole Island.

  • Earth Surface Processes
    HAN Zeng lin, YOU Fei, ZHANG Xiao jun
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    Distributing models along varies traffic lines for economic development are significant in regional development. economic zone along expressways(EZAE) is one of the most important models among them. Based on the observations of a number of cases and the investigations of authentic instances, this article systematically presents a preliminary study upon EZAE and planning methods of its economic distribution. (1) Although it shares the same features in many aspects with other Traffic Economic Belts (TEB), such as TEB of railways, TEB of rivers etc., it has some unique characteristics. They are TEB's major features attributed to expressway's transportation traits, such as the rapidity of EZAE's expansion, the original features of regions adjacent to expressways, evolution and formation features. As a combination of the previous studies about TEB and economic activities related to EZAE, its definition is delivered. It is supposed as the major contribution of this article. (2) The mechanism of formation and evolution of EZAE are dilated in this article in two facets: The spatial system and the economic system. During the growing process of its spatial system, it falls into three stages: germination period, expansion period and mature period. Each has distinctive characteristic and is supported by examples. As an economic system, its formulation and evolution follow the common laws of TEB's and has its distinctive characteristics as well. (3) The major application of these theories are included in EZAE's economic allocation planing. The characteristics and contents of the plan are emphasized. The characteristics are summarized in the following aspects: the scope,the spatial feature, the relationship between the EZAE and the expressway. The contents of the plan can be laid down upon such fields: the evaluation of physical and economic conditions; boundary division; directions and strategies of development etc. At last, planning of EZAE of Shenyang Shanhaiguan is presented as a supporting case.

  • Earth Surface Processes
    WU Zong qing, CHAI Yan wei, DAI Xue zhen, YANG Wu yang
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    To initiate the study on consumers'behaviors in China, the authors, based upon quantities of questionnaires and field surveysin Tianjin, analyze the urban residents' shopping trip space. An aggregated ring shape of shopping trip space of Tianjin's residents, which also reflects the hierarchy of urban region, shows a decay in shopping space (distance) from the higher level merchandises to the lower ones, and prove that the 400 to 500 meters'radius of the trip space for convenient merchandises is applicable and boasts its common meanings throughout the world. More creatively, to describe and analyze the hierarchy of shopping trip space in detail and mathematically, a new mode, which is based upon Central Place Theory, is introduced, upon which some new details are found and analyzed. For the market segment, the authors cluster the residential cases into four groups by income levels, and bring out three kinds of hierarchical distribution of shopping trip space, which differentiates the income groups in shopping trip distance and the preference to the hierarchical central places and with some possible accounts for the structures followed.

  • Earth Surface Processes
    LIU Hui
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    Poverty problem is very common and serious in the west of China where human development level is very low, and poverty of income, poverty of knowledge and poverty of human ability coexist After solving the problem of adequate food and clothing at the end of the last century, there are still some new problems in poverty alleviation in the west of China, such as how to eliminate poverty steadily, how to overcome backward human resources development problem, and overload tax and fees on farmers, etc On the basis of studying the poverty characteristics and some new problems in poverty mitigation in western China, this paper raises some new policies and suggestions for shaking off poverty strategy in the 21st century The basic tentative plan for poverty stricken area's development objectives implemented at three stages was proposed too, i e , 2001~2005, achieving stable poverty elimination,2005~2010,creating various conditions for achieving comparatively well off and 2010~2030, making most of the poverty stricken farmers's living standards to approach to or achieve comparatively well-off It also suggested that poverty alleviation measures should be taken to turn human resources investment as the dominant factor from material investment gradually As the central government has put forward a series of policies for the great development of the western areas, it needs to combine eliminating poverty plan with these polices closely, which will be much effective in implementing poverty ridding of plans in China

  • Earth Surface Processes
    MA Li, PANG Xiao min
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    As the regional problems are usually regarded as a result of'market failure', traditional regional economic policies are basically based on the assumed rationality of 'government intervention'and concerned mainly the benefit of objective area. Considering the fact that many regional policies aiming at enhancing the benefit of the objective area have resulted in the negative effect on the benefit of non objective area at the same time, we attempt to study the regional policy issue with application of game theory. Firstly, we analyze the driving forces for regional division. Based on the hypothesis that the motivation for a region to take part in the regional cooperation and division is the increased benefits, we compare the ratio of benefits to cost, and find that the exchange ratio of specialized products of two regions is the main decisive element. Then, we probe into the effect of economic policy on the dynamics of regional competition and regional division. Different regional policies will change the game model of regional competition and division through changes of regional benefits. Also, we find that the reasonable exchange ratio of specialized products in division should be based on the ratio of product cost before division. At last, we give a game theory analysis of the effect of China's regional policy. Many regional problems in the development of China's regional economy were largely the result of playing games at regional level in order to maximize each region's own benefits. Especially, unreasonable price system gave limitations to the development of regional cooperation and division.As a whole, some conclusions have been achieved as follows: (1)It is the economic benefit that motivates a region to take part in regional division. (2)The price ratio on of the specialized products is the main element that works on the process and result of regional competition and division. (3)The regional policy particularly set out for one area will influence all areas that have economic relations with it.

  • Earth Surface Processes
    ZHANG Xiao dong, CHI Tian he
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    Based on the theory of economic development and environmental protection, the paper first offers a Coordinated Degree Model (CDM) on the relation between the stage of economic development and the capacity of environment. The authors expound the notion of coordination degree and believe that there exists the best harmonizing range at different economic development periods. The optimization of economic & environmental system does not mean optimization of all parts , the whole optimizations based on both harmony are more important. Environment carrying capacity is the most important factor which will affect optimization.It also makes differentiating classes for provinces (regionsf) according to economic & environment coordination degree, regardingeconomic development and resources & environment as a unified entity, it is fit for sustainable development thought. The result of the demonstrative analysis on the provinces (regions) in China by using the CDM revealed that the relation of the economic development and the environment is in line with the "U shaped" curve. The "U shaped" curve demonstrated that the pattern of the economic development in China was not ideal, which is brought by the decrease of the capacity of the environment. The most serious area is middle west China. This conclusion will help forecast turning period in differents regions, so people can adjust it on time, avoid uncover effect of economic development on resources & environment.