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  • Earth Surface Processes
    LU Da dao
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    In the late 1970s and early 1980s, geographical science entered a new stage, which is characterized by the shift of major attention from the nature dominated environmental changes to the human dominated ones, that is, the interactions between natural process, biological process and human activity. All this shows the changing nature of geography is at the core of dramatic changes within ecosphere, the dynamic man land relationship. Unfortunately, it is the dramatic relationship that has led to the continuing destruction of resources bases as well as ecological and environmental bases upon which human being are dependant. Given the global changes, geographers are obliged to carry out theoretical and empirical studies about sustainable development and environmental protection, from both man land relationship and regional perspectives. The central issues to be concerned are the influences of global change on China and rational approaches for China to realize sustainable development. In recent years, Chinese geographers have contributed a lot to the fields of natural environment, territorial planning and regional development, providing scientific analysis and suggestions essential to China's responses to global change and sustainable development. However, the potential advantages of geography in terms of resolution of these critical issues have not been realized so far. To change such a situation, geographers have to make great efforts to synthetic theories and methodologies, giving full recognition to the theoretical studies of man land territorial system. The issues of sustainable development should remain as major concern by China's geographers in a long time. In fact, the efforts to coordinate the man land relationship aim at the realization of sustainable development. Clearly, the theories of man land territorial system should work as important theoretical bases of sustainable development. Therefore, it is a significant task for geographers to enhance the theoretical studies of man land territorial system. The prior issues regarding man land territorial system are as follows: 1) studies on regional differences from systematic perspective; 2) a deeper understanding of the characteristics of man land territorial system; and 3) studies on the approaches for comprehensive integration. Furthermore, the development of methodologies with comprehensive and systematic perspectives, territorial and dimensional perspectives as well as model building and simulation applicable to practice deserves more efforts.

  • Earth Surface Processes
    ZHENG Jing yun, HAO Zhi xin, DI Xiao chun
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    The database of environmental change during historical times is the foundation for the global change study. In this paper, the source data and computer standardization of environmental change database during historical times in China was expounded. Based on the technique of computer, database, the general design, main function and application prospect of the database was introduced. There are three kinds of source data including historical documents, instrumental data and natural evidence in the database, in which each kind of source data covers three main tables for keeping the original data (such as the document cards), raw data derived from the original data and the proxy data for environmental change which was reconstructed by the methodology for time series reconstruction during historical times respectively. The structure for the database includes two main parts,in which part one contains tables for saving the source data and part two serves as management ware for data table linkage and database running. There are four main functions for the database, including data browser and backup, data query and statistical analysis, data editing, appending, deletion and modification, and the user guide and help.

  • Earth Surface Processes
    LIU Ji sheng, CHEN Yan guang
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    It is of significance to research into nonlinear relationships between human systems and physical environment in order to explore spatial complexity, but it is of difficulty to do so in the past because of lack of effective research means and methodologies. If we develop integrated models including cellular automata(CA)which are based on geographical information system (GIS), we will be able to solve many complex problems on man land relationship. We suggest that geographers should construct a kind of metasynthetical technical systems being composed of GIS as geographical databases, GIS based CA models, integrated regional dynamic models, and other related CA based models. For the sake of making the CA models based on GIS intelligent to certain extent, artificial neural networks, which can be used to distinguish and compare between the simulation patterns and digital maps concerned, and genetic algorithms, and even genetic programming, which can be used to design and train the weights of neural nets, should be adopted into the systems. Going a step further, the multiagent systems (MAS)and the postmodern mathematics of fractal and chaos, the latter of which take the form of softwares by being compiled into some programming, should be comprised in the systems. So geographers will have an artificially intellectualized meta synthetical systems consisting of a number of integrated models based on integrated models which make it easy and convenient to expore spatial complexity on man land relationship.

  • Earth Surface Processes
    XU Jiong xin
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    The Yellow River is the most famous heavily sediment laden river of the world, its land accretion process is sensitive to influencing factors such as the changing precipitation and human activities. Thus, the Yellow River Delta provides an ideal site to study the delta development under the land ocean interactions. The development of Yellow River Delta can be regarded as the outcome of interactions between the river and marine dynamics and of interactions between the river and tide transported material fluxes. The rate of land accretion is controlled by these interactions. When the above two aspects are in equilibrium, the land accretion process of delta may be thought under the critical conditions, and the river supplied water and sediment quantities may be considered as thresholds of runoff and sediment for land accretion. By comparison between the sea charts and remotely sensed images made in different periods, the annual area of land accretion has been obtained. To identify the water and sediment thresholds for delta development, two regression equations have been established between land accretion rate and water and sediment quantities into the river mouth, based on the data from the Yellow River Delta in the period of 1955 1989. From these relationships, the threshold of river supplied sediment quantity for land accretion has been estimated as 2.78 10 8 t, and the threshold of runoff as 76.7 10 8 m 3 ; under these sediment and water supplies, the Yellow River Delta may be in equilibrium in an average sense. In other words, if the annual sediment quantity is less than 2.78 10 8 t, and the annual runoff less than 76.7 10 8 m 3 , the delta might be eroded and the land would be lost, and thus the environmental security of the delta might be seriously affected. For a better management of the environment of the Yellow River, these thresholds should be taken as one of the constraints. The meaning of ecologically needed water use in the Yellow River should be extended, in order to include the water quantity that is required for maintaining the balance of land accretion in the delta.

  • Earth Surface Processes
    LU Jin fa
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    More than 50 river basins with gauging stations were chosen for an analysis on relationships between sediment yield and basin morphological characteristics in the middle reaches of the Yellow River. They have drainage areas ranging from 500 to 2500 km 2 each and can be categorized into 6 types of basins with different physiographical backgrounds:the loess hilly basins and highly weathered mudstone & siltstone basins north to Wuding River,loess hilly basins in north Shaanxi, west Shanxi and east Gansu provinces, loess hill + bedrock mountain basins, bedrock mountain + loess hilly basins, loess yuan basins and bedrock mountain basins. A set of data on river basin morphology were obtained by using morphometric method, including drainage density, percentage of inter gully area with slope steepness less than 15°, relief ratio, basin roughness, basin circularity etc. Different relationships between sediment yield and basin morphological characteristics were obtained for different types of river basins by plotting and multi variate analyses. The results showed that the best correlation exits between sediment yield and drainage density, but the relations between sediment yield and the other morphological characteristics are not as good as expected due to heavy disturbance of surface material, vegetation coverage, morphological development from various types of river basins. If taking the basin types as parameters, different fitness, intercept and slope of correlation lines were observed between sediment yield and drainage density for different types of river basins, showing a control of other basin characteristics, such as surface material, vegetation, landform development etc., on the relationships of sediment yield and basin morphological characteristics. The intercepts and slopes of lines tend to increase from loess hilly basins through loess hill + bedrock mountain basins and bedrock mountain + loess hilly basins to bedrock mountain basins subsequently. It indicates that basin morphology is an important factor affecting sediment yield of a river basin but can exert substantial influence on sediment yield of the river basin only when the basin characteristics are more homogeneous. Therefore a classification of river basin types is necessary before a correlation between sediment yield and basin morphological characteristics is established.

  • Earth Surface Processes
    CHEN Hao, ZHOU Jin xing, LU Zhong chen, CHEN Jin rong
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    In the last decades, especially since the 1980s, variations in runoff and sediment yield have occurred to the trunk stream and the tributaries of the Yellow River. As a consequence of drastic decline of runoff volume and sediment load, downstream channel shrinkage and dried up as well as disasters induced by a minor flooding event happened. In order to understand these new problems and new situations, a great deal of research work and investigations on impacts of climate and human activities on variations of runoff and sediment yield as well as variation characteristics and causes of changes were carried out in China. At present, runoff and sediment change investigations are mainly focused on studies of hydrologic method and water conservation method in the middle reaches of the Yellow River. Since the middle reaches of the river have distinct natural zonal distribution characteristics, both runoff and sediment processes in the drainage system are synthetically affected by environmental factors. Based on observational data of the controlled primary tributary from Hekou to Longmen at midstream section, this paper analyses the variations and causes of runoff and sediment load by using method of geographic environmental factors. The results indicate that runoff volume and sediment load in the Hekouzhen Longmen section of the drainage basin are closely related to the impact of geographic environmental factors. Runoff and sediment variations are a product of synthetic action of natural environmental factors and human activities. In the 1970s, runoff and sediment reduction is mainly affected by decrease of precipitation as control and management practices then are inadequate. In the 1980s, impact of human activities plays a leading role in reducing runoff and sediment load in the basin as control measures of reservoir and dam projects are effective in reducing water and silt load on the Loess Plateau. Since the 1970s, precipitation has played a less role in reducing runoff and sediment but human activities played an increasing role as a result of improvement in soil and water conservation measures. The average water and silt reduction impacted by climate fluctuation and human activities in the 1970s and 1980s is respectively 53.4%, 28.6% and 46.6% and 71.4%.

  • Earth Surface Processes
    ZHANG Ou yang, XU Jiong xin
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    The Yellow River is the Mother River of the Chinese nation literally, but it is also a disastrous river with excessive sediment that cannot be easily harnessed. The eco environment is highly vulnerable to the hazardous erosion by water and wind in the middle reaches while channel aggradation, flood menace and frequent change of course occur in the lower reaches. Although great achievements have been made in the Yellow River harnessing and resources utilization, hazards of erosion in the middle reaches and the potential failure of the channel in the lower reaches still exist and the conditions still need to be improved. It is generally accepted that solving the Yellow River problems fundamentally needs systematic considerations. The concept of the fluvial system proposed by Schumm in the 1970s provided a theoretic basis for this issue. The Yellow River system needs to be divided further into subsystems for utilizing the concept of the fluvial system to solve the problems. The Yellow River system is decoupled based on morphological and hydrological data in this paper following Schumm's theory. It meets well with the idealized fluvial system model, thus, an example of the Schumm's idealized fluvial system mode is offered. On the whole, the upper reaches up stream Hekouzhen is the water producing zone (subsystem); the middle reaches between Hekouzhen and Taohuayu section is sediment producing zone; the section from Taohuayu to Lijin is transfer zone;and downstream Lijin is deposition zone. The Yellow River system is a hierarchic structural system. Within the upper reaches of the Yellow River up stream Hekouzhen, upstream Longyangxia is the water producing subzone, the section between Longyangxia and Qingtongxia is the sediment producing subzone, and that between Qingtongxia and Hekouzhen is the transfer subzone. In the middle and lower reaches downstream Hekouzhen, the section from Hekouzhen to Longmen is the sediment producing subzone, that between Longmen and Taohuayu is the water producing subzone, and between Taohuayu and Lijin is the transfer subzone. This decoupling of the Yellow River system is not exclusive, actually, the subsystems are in the dynamic status from the long term point of view. Each subsystem has its characteristics of geomorphologic process. The subsystems from the upstream to the downstream form a cascading system by materials (water and sediment, etc.) movement and energy dissipation. The Yellow River system is also a process response system because the subsystems are closely related with the input and output of the material and energy. These subsystems need to be coupled as a whole. The coupling of the sediment producing zone (the Loess Plateau) and the transfer zone (the channel of the lower reaches) is primarily important to the Yellow River harnessing.

  • Earth Surface Processes
    WU Chen, XU Qing hai, YANG Xiao lan
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    Zhangshiyan of Hebei Province is a national tourist scenic spot. It has many strange, perilous, graceful and beautiful geomorphic types. They were formed since 37 MaB.P., and experienced three major geomorphic cycles during the Early Tertiary, the Late Tertiary and the Quaternary eras and left many geomorphic types of different evolutional stages of infancy, youth, maturity and old age. The major evolution patterns were strong tectonic uplift, collapse, side and headward erosion, and raze. The rocks of sandstone and limestone also played an important role in landform evolution. The predominant geomorphic evolution situation in future will still be infancy stage to youth stage for a long period of time. But as tourism developed, the strange and beautiful scenic spots of maturity stage development level are more liable to be destroyed by tourists. So, how to prevent these geomorphic types from being destroyed is a pressing issue.

  • Earth Surface Processes
    LI Xue ming
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    Research on grain size of seashore loess in Liaodong Peninsula indicates that kind of loess was the product of frigid climate in Quaternary ice age Due to geographical locations adjacent to coastal zone, the loess has distinctive formation process compared with loess in other areas Divulged alluvium and sands of Bohai seabed in the last glacial period constitute another important material source of this loess which are transported by sand saltation mode Grain size of this seashore loess bears a great deal of formation about changes of Bohai sea level Sedimentary process of this seashore loess is controlled by two factors, which are wind power and Bohai sea level's fluctuation in the last glacial period Wind deposits derived from adjacent source of materials make grain size distribution of this loess from normal to abnormal Goodness of fit of grain size distribution and 2 3Φ size percentage content reflect history of transgression and regression of Bohai Sea and strong and weak Mongolian high pressure of the last glaciation. These changes are identical with paleo environment reflected by sporo pollen assemblage, and also corresponding to sea leeventsl changes in the neighbouring areas and stage of δ 18 Ο/ 16 Ο Goodness of fit of seashore loess grain size distribution is a major substitutional index of paleo environmental changes Heinich events are recorded in Rosin's grain size distribution There are 5 high values of goodness of fit of Rosin's grain size distribution in profile of this seashore loess These events of high values occurred in transgression period of Bohai Sea during early and later phase of the last glacial period, and are records of extreme cool events which occurred during the last glacial period It is difficult to compare these events with Heinich events due to limitations of precision of chronological orders

  • Earth Surface Processes
    TAO Wei, TIAN Yin sheng, Wu Xia
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    World Heritage belongs to all the peoples of the world, irrespective of the territory on which they are living. The World Heritage List draws attention to the wealth and diversity of the Earth's cultural and natural heritage. Historic Cities in World Heritage List agglomerate the elite of the noblest stage in human civilization history, whose outstanding history, artistic and scientific values make them the living fossils of urban historic study. To the end of January 2000, the total number of ancient cities in World Heritage List is 94. They are 1/7 of the total world heritage sites. These ancient cities are distributed in 56 countries of the four continents. Of which 42 cities of 24 countries are in Europe, 22 cities of 11 countries are in Africa and Arabian region, 16 cities of 11 countries are in Asia and Pacific region,and 14 cities of 10 countries are in America. The paper firstly analyses the study significance of these ancient cities, then exploringly sets up a suit of research system including research methods and main contents. The research methods are demonstration method, holistic and systematic method, dynamic and evaluative method, as well as comparative method. These methods are the main ways in studying the ancient cities in World Heritage List. At the same time, the main research contents of these cities include the value study of many sides, the protection study and the development study. Finally the paper takes the world cultural heritage-the Chinese ancient city of Lijiang as an example to reveal its special research value and significance covered mainly in the three aspects.

  • Earth Surface Processes
    FANG Chuang lin, YANG Jie
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    Regional development planning of risk type, which is called risk planning in short, is considered as a new management pattern of planning. When implementing it, the development and the harmony among economy, society, population, resources, and environment in a certain space and at a certain time should be arranged, all the risks that may come out should also be undertaken, then measures should be taken to solve all the problems, and the synthetical benefits after implementing the risk planning can also be shared. Under the market economy of the social democracy, risk planning should be advocated in order to improve the quality of formulating and implementing the planning, remedy all kinds of pathologies step by step, strengthen the control of the whole process, and obtain the best synthetical benefits in implementing it. Beginning with the conception and the rise of risk planning, the authors discuss the creation of the bid, bargain, blind checkup, decision making, insurance, marketing, holding values and increment of risk planning, as well as the management pattern. In order to implement a risk planning successfully, it is suggested that the legislation guaranteed system, the investment fund system, the public consultation and supervisal system, and the occupation system of risk planning should be constructed. Finally, taking the economic and social development planning of Zhanyi County, which is located at the headstreams of Zhujiang River, as a case study, the authors analyze the whole process of formulating and implementing the risk planning of Zhanyi County, such as compiling the bid book of the risk planning and organizing the bid, endorsing the bargain and implementing the risk planning according to it, compiling the process verbal of the risk planning and consulting the public, organizing the blind checkup, the final examination and the appraisal of the risk planning, tracing the decision making and the implementation of the risk planning, making the risk planning hold its value or even get increments, and so on.

  • Earth Surface Processes
    LI Guo-ping, LU Ming-hua
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    Based on the theory and practice of high tech industrial division, especially of regional division based on value chain, this paper verifies the different requirements for factors and location of main value added parts of high tech industry's value chain and the spatial distribution of main value added activities of some high tech enterprises in Zhongguancun by analyzing the questionnaires for them, and draws a conclusion that Beijing's high tech industry has formed rudimental regional division based on value chain. The R&D departments of many high tech enterprises mostly agglomerate in Beijing, especially in Zhongguancun; the manufacturing departments of them are distributed all over China, even overseas, and the marketing departments of these enterprises mainly agglomerate in Beijing and global network is forming, which means Beijing has become a special region with headquarters, R&D departments and marketing departments of high tech enterprises concentrated in China. The rudimental regional division based on value chain of high tech industry in Beijing reflects the condition of Beijing's factor endowment in our country, shows Beijing's advantages in developing high tech industry, and verifies that different value added activities of high tech enterprises have different locational preferences. The R&D departments are generally located in the places where there are plenty of professionals with high ability, scientific research institutions, and convenient information acquiring and communicating. Locating the manufacturing departments, the enterprises think a good policy environment, a strong industrial cluster, convenient transportation, cheap land price and convenient provision with raw and processed materials and components are important. The marketing departments are often located in the places with convenient transportation, perfect marketing network, convenient communication network and large demands. This paper summarizes the different value added activities of the value chain such as headquarter, R&D, manufacturing and marketing, and the mode of high tech industrial regional division based on value chain, which is divided into basic activities and assistant activities according to Michael E.Porter's Value Chain Theory. Based on the condition of Beijing's high tech industrial regional division and the difference of factor endowment among districts in Beijing, the paper discusses the developing trend of Beijing's high tech industrial regional division based on value chain in future.

  • Earth Surface Processes
    WU Yu ping, DONG Suo cheng, SONG Jian feng
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    This paper empirically examines Environmental Kuznets Curve (EKC) with time series data from 1985 to 1999 and provides a basis for the environmental policy evaluation of Beijing. The results lead to two main conclusions:1) The environmental policy and the environmental investment of Beijing municipal and central governments have made the turning point of EKC come early, being around 10000 15000 yuan at constant price of 1978, or 25000 40000 yuan at present price of 1999, or 3000 5000 US dollars by exchange rates of middle price in the year end of 1999, or 15000 20000 US dollars calculated in Purchasing Power Parity (PPP) way,and if the GDP per capita grows at the rate of 8%, the turning point will come true during 2005 2010. 2)The relationship between economic growth and environmental degradation takes on an inverted U, but different regions may have different turning points, different time spans for realizing the turning point of EKC, and different slopes for the rising declining pattern. Four points are identified from this examination of the EKC for Beijing: First, this analysis suggests that it is not appropriate to generalize the emergence of EKC for all environmental indicators. Among the 12 main environmental indicators of Beijing, only two do not have enough explanatory meaning for the EKC. On the whole, the relationship between economic growth and environmental degradation in Beijing has an obvious EKC character. Second, the efficient environmental policy and the huge environmental investment of the Beijing municipal and central governments have made its turning point of the EKC arrive early. Third, the EKC should not be widely assumed and it is necessary to refer to various and more flexible explanations. In other words, economic factors may be important, but social and natural factors should also be taken into account, such as environmental policy, environmental awareness of residents and the spread of environmental technology. Finally, the relationship between economic growth and environmental degradation theoretically takes on an inverted U, but different regions may have different turning points, different time spans of reaching the EKC turning point, and different slopes of rising declining pattern.

  • Earth Surface Processes
    REN Dong ming, FAN Jie, HU Bao qing
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    Taking Chongqing reservoir site as an example, this paper analyzes the characters of dual economic structure in the Three Gorges Reservoir Area firstly from static and dynamic state The static characters represent the dualities in capital accumulation, productivity and urban rural income standard The dynamic characters represent the proportion of industrial investment being much higher than that of agriculture, comparative productivity of industrial sector higher than that of agricultural sector, the income and consumption standard of urban producers higher than that of rural producers Additionally, in the Three Gorges Reservoir Area, besides the agro industrial or urban rural duality, there exists duality in the division of industrial sector and the grade of technology, which makes the duality in the Three Gorges Area go beyond the bound of agro industry or urban rural area given by the traditional dual economic theory, hence putting up a multi termed character Secondly, this paper discusses the four reasons which lead to the duality in the area, including: 1) accompanying capital economy before liberation made the duality come into being immediately; 2) after liberation, the adoption of Super Industrialization Model enhanced the dual constriction between urban and rural areas in the Three Gorges Area, making the duality expand swiftly and taking on an extra intensive state; 3) relatively close productive structure and the shift to an earlier time lead to the lower acceptance for surplus labor forces, this makes the dual economic structure appear an excessively stable state; and 4) the large span between inter industries or inside industries leads to the clear dual structure in the division and the grade of technology Finally, the paper gives the pipelines for changing the dual economic structure in the Three Gorges Area The method is to strengthen the economic relation between central urban areas and rural area around, exert the driving effect of central cites to reservoir areas, realize the industrialization in urban and rural areas at the same time Thus starting in light of economic relation and seeking the mutual compensative chain to establish the industrial contacts is a good and practical pipeline to reduce the dual discrepancy in the Three Gorges Area

  • Earth Surface Processes
    ZHEN Feng, GU Chao lin
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    Spatial structure is the core topics of geography and planning research. Since the 1970s, information technology has begun to affect urban and regional socio economic development. Especially since the 1990s, global informatization characterized by Internet and mobile telecommunication has made urban and regional development face more rapid and more comprehensive transformation. Western academic fields have done lots of research on this new topic. Based on western literatures, this paper reviews relative research on spatial structure under information era from three points, which are: 1) new research topics; 2) shift of research paradigms;and 3) main research contents. With rapid advancement of information technology and its application, geography begins to face continuous challenge, and attention to information activities makes new research topics and new branches emerging. Meanwhile, interaction between information and society also leads to changes in traditional research paradigm. The main research contents are summarized as follows: 1) Cyber space-new spatial logic; 2) location research; 3) decentralization & centralization and even & uneven development of space; 4) innovation network and regional spatial structure; 5) spatial outcome of information development mode; and 6) new spatial polarization.