The Tibetan Plateau is a unique geomorphic unit composed of some basic geomorphic types, such as extreme high mountains,high mountains, hills, plains, and tablelands of high altitude or sub-high altitude. Different opinions for the exact scope of Tibetan Plateau exist. According to latest research achievement and the long time fieldwork, questions related to the area and boundary of the Plateau have been discussed in view of geography, and the principles taking geomorphic characters as the main rule and considering the integrity have been made to define the boundary. The 1∶1 000 000 geomorphological map was compiled based on 1∶100 000 aerial photographic map,1∶500 000 topographic map and interpretation of satellite images. By refering to the 1∶3 000 000 relief map, the boundary of the Plateau was delineated.The position of the boundary was quantitatively determined with GIS and GPS.The map of electronic version of the Tibetan Plateau was compiled. The main conclusion is that Tibetan Plateau starts from the southern edge of the Himalayan Range, abuts on India,Nepal and Bhutan,connects the northern edge of Kunlun, Altun and Qilian Mts., and joins Tarim Basin and Hexi Corridor in Central Asia.The west of it is the Pamirs and Karakorum Mts., bordering on Kirghizistan, Tajikistan, Afghanistan, Pakistan and Kashmir. The east of it is Yulongxueshan, Daxueshan, Jiajinshan and Qionglaishan Mts.as well as south or east piedmont of Minshan Mts. Tibetan Plateau joins the Qinling Mts.and Loess Plateau with its eastern and northeastern part. Tibetan Plateau in China's territory starts from the Pamirs in the west and reaches to Hengduanshan in the east. It bestrides a longitude of 31 degrees with a length of 2 945 km from east to west,and bestrides a latitude of 13 degrees with a length of 1 532 km from south to north. It ranges from 26°00′12" N to 39°46′50" N and from 73°18′52"E to 104°46′59"E, covering an area of 2 572.4×10 3 km 2. Administratively, it embraces 201 counties (cities) in 6 provinces, namely, the Tibet Autonomous Region (73 counties/cities,1 176.0×10 3 km 2, part of Cona, Mêdog and Zayü), the Qinghai Province(40 counties/cities,721.0×10 3 km 2, some counties only partially), Dêqen Tibetan Autonomous Prefecture in Northwest Yunnan Province(9 counties/cities,33.5×10 3 km 2), West Sichuan Province ( 46 counties/cities about 254.0×10 3 km 2 ,such as Garze Autonomous Prefecture, Aba Tibetan and Qiangzu Autonomous Prefecture,and Muli Autonomous County, etc.),Gansu Province(21 counties/cities, 74.9×10 3 km 2), and Southern Xinjiang Uygur Autonomous Region (about 12 counties/cities, 313.0×10 3 km 2).

Man-land relationship includes human dependent upon nature and human activity to nature. Contents of man-land relationship are changed with development of human society. Man-land relationship research is the basis for development of modern geography. Various schools of geography such as determinism, possibilism, cultural landscape and human ecology are focusing studies on man-land relationship. The earth system science should carry out interdisciplinary studies between natural and human sciences, to reveal interaction between man and nature as well as the corresponding countermeasures. Developments of information techniques and knowledge economy bring about new opportunities and challenges for human society. Characteristics of man-land relationship in information era differ from those in industrial era. The way and intensity of interaction between human activities and nature will be obviously different. The understanding to nature will be systematically deepened, and ideas of time and space are changing in information era. Knowledge and techniques are becoming main driving forces for social and economic development. Owing to the entirety of the earth, the complexity, protracted nature and potentiality of the interactions among various spheres of the earth, many global environmental issues, such as climate warming, ozonosphere depletion, environmental pollution, etc., are becoming the foci of the countries and public concern throughout the world. The realities impel us to learn lessons and experience accompanied with the traditional development models and to explore new development models for human society. Man-land relationship research covers extensive domains. The hotspots of both global environmental change and sustainable development are closely related to man-land relationship. Global environmental changes have been arisen from slow accumulation process of human impact, and sustainable development is a new development model, which has been obtained by self-examination to development course and model of the human society.The main frontiers of man-land relationship research include the following issues: global environmental change and its regional response, regional sustainable development and mechanism regulation of man-land relationship, studies on social ecological and environmental ethics, etc.

The Digital City is a multi-resolution, multi-scale, multi-space and time, multi-kinds description of a city in three dimensions with techniques such as 3S, telemetry, simulation and Virtual Reality (VR) based on such techniques as computer, multimedia and large-scale storage, and taking the wide band web as vinculum. By this technique, the modern city's information can be collected, collated and generalized,and the complete spatial data model can be established on the geographical coordinate system so as to facilitate each person's acquaintance of the past, present and future of the city rapidly, entirely and visually through the web. At the present time, studies on Digital City at home and abroad make no substantive advancement, but still remain at building hardware and software conditions, or at most, at the preliminary stage of the study. The paper mainly probes into the key techniques such as Virtual Reality, Urban Spatial Data Infrastructure, integrated model study of many kinds of GIS systems, 3D-GIS, the urban planning in three dimensions, city simulation and digital society supported by VR and Digital City, etc.

The small watershed management information system is an integrated system of GIS and erosion model, land productivity model and cost-benefit analysis model. It can be applied in watershed planning and management in Loess Plateau.The system is developed for decision support in soil and water conservation with the functionalities of data management, data query, database updating, displaying, output and model analysis. The basic geographic unit for system integration is land-unit. The land-unit was defined as a piece of land with the homogeneous geographic characters such as elevation, soil type, land-cover, slope, aspect, etc. Based on the land-unit, three model groups were integrated with GIS. In order to realize those functions, basic integration methods were analyzed and the integration method of DLL and its extension was adopted. Then based on the method accompanied with Avenue programming language, the system was fully integrated in Arcview environment. A landunit based flow network model was developed for simulating the processes of drainage and sediment transportation among land-units, and it provides parameters for erosion model, economic model and yield model. The soil erosion model calculates soil loss for each land-unit in a watershed. Yield model and socio-economic model estimate crop productive and economic benefit in the watershed, such as river beach, check dam, agro-forest, terracing, etc. These three models are integrated with each other and fully linked to database system. Based on the result of model simulation, the soil and water loss, land productivity and economic benefits in a watershed can be estimated for different land planning and engineering strategies. The optimized management for watershed can be done through comparisons of varied planing. The arithmetic process and parameters of each model are also described in this article.

Based on previous research on spatial conceptual data model of GIS, the authors present an object-oriented holistic GIS data model, and discuss data organization, data storage and access mechanism of holistic GIS system. Firstly, six features of holistic data model are introduced, and a conceptual data model is presented with a key concept, Complex Object, which is introduced in detail. Secondly, data organization means of holistic GIS are introduced. Several basic concepts such as Object Set, Layer, Database, Map or Map Window, and Workspace are introduced into the data organization system. Object Set has three types: Simple Object Set, Compound Object Set and Continuous Field. A Layer is a concept related to map display in our holistic GIS software. A Database is defined as a set of stored objects, which is either a small size file or a large-scale database. Map is a frame used to load layers, and can contain multiple layers.A Workspace is a warehouse, which stores basic data info, Maps, Point, Line and Region Symbols,etc. Thirdly, data storage and access mechanism of holistic GIS are introduced. In respect of storage, database table structures of Simple Object Set, Compound Object Set and Field are analyzed, and table structure of 3D data structure and time attribute is also introduced. In order to quicken the pace of accessing to database tables,the spatial index mechanism based on quadtree data structure is built. Further data access mechanism is discussed. Fourthly, SuperMap Deskpro, a GIS software based on holistic data model, is introduced. This software is fulfilled through completely using object-oriented thinking. It can effectively store and access to geographic entities' information including location, attribute, topological relationship and semantic relationship. In respect of Layer Organization, it not only accords with users' direct apperception of geographical world,but also supports users to rationally organize data to meet actual needs. SuperMap Deskpro supports users to use files to store small amount of data, and at the same time users can also use large-scale business database such as SQL Server and Oracle to manage large amount of data.

On the basis of taking into account the main feedback relations of carbon cycle terestrial surface system,the authors employ highly integrated and simplified methods to establish a carbon cycle zero-dimension model of land surface system (CCZDM),and study carbon fluxes among four carbon reservoirs (land biota, litter carbon, soil carbon and atmospheric carbon), by taking impact of human activities and ocean influence as external factors. The CCZDM supposes that Human Being's impacts are not enough to break the natural balance of carbon cycle before the year 1860, but since then the balance has been broken owing to the industrial revolution. A large quantity of CO 2 was emitting into the atmosphere by burning fossil fuels, intensifying agriculture and destroying segments of the vegetation cover of the earth. With the increase of atmospheric CO 2 , the global temperature increased accordingly, which, in turn , affects carbon cycle of terrestrial system. The changes of four carbon reservoirs and temperature are simulated through CCZDM from the year of 1860 to 1997 and the results show that the simulated data are compatible with observational as well as other research findings. This demonstrates that the model is reasonable and the parameter values are correct. The study of CCZDM can provide theoretical guides to that of two-dimension carbon cycle of land surface system.

The vulnerability of eco-environment and its sensitivity to global environmental change characterize the transitional area of farming and pasturing in Northeast China. The moisture regime is a principal factor, by which the spatial differentiation and variation of the physiographical environment are influenced directly. The temperate and precipitation changes in the last 45 years (1951～1995) were analyzed using wavelet analysis method, mainly on the multi-scale properties and law of the changes. The result of the wavelet analysis indicates that changes of the precipitation at each sampling site were dynamic and the distribution of the relative higher and the lower period was in alternation. During the 45 years, the variation trend of the precipitation was impalpable. The temperature changed periodically but rose gradually in the 45 years. An important reflection to regional environmental change is desertification. The relation between the temporal and spatial distributions of precipitation and the plant growth also was analyzed. The result shows that the fluctuation coefficient of plant output is greater than that of precipitation. This phenomenon has a significant effect on the structure and the function of the regional system and the expansion of desertification. By using the vegetation index (NDVI), the result of comparison of land cover for two periods of time indicates that under the impact of the natural conditions and the human activities, regional change of land cover is obvious. The seasonal change of NDVI values of different vegetations shows that the correlation between monthly average NDVI and precipitation is 0.871～0.953, and the correlation between monthly average NDVI and the temperature is 0.832～0.895. For the study area, the trend of land desertification and salinization did not change at all from the 1950s to the 1990s. The vulnerable soil parent materials, strong wind force as well as concentrated precipitation and its great annual variations have effective impact on the desertification in the area. So the temperature and precipitation change is the major driving force for the land degradationand the environmental change.

This article summarizes research progress in some basic problems on paleogeographic revolution of the Tibetan Plateau in the last 50 years, especially recent decade. Based on reviews of current viewpoints and analysis of Miocene and Pliocene paleogeographies, it was suggested that altitude of the Tibetan Plateau was less than 1000m before 3.6Ma BP and intense uplift of the plateau began at that time. The ages of last three glaciations in the plateau are 725～581,289～136 and 82～10ka BP respectively, which are comparable with oxygen isotopic stages in deep sea. Large ice sheet did not exist in the Tibetan Plateau in the Maximum Glaciation of Pleistocene. Environmental changes were frequent with high amplitude and desiccation occurred in the Tibetan Plateau since the last interglacial period. Important phases and events of paleogeographic evolution in Cenozoic are: tropical and subtropical lowland controlled by planetary wind system between 38 and 22Ma BP, appearance of paleo-monsoon and development of main planation surface between 22 and 3.6Ma BP, intense uplift resulting in the formation of the modern monsoon and development of water system between 3.6 and 1.7Ma BP, entrance of cryosphere and maximum glaciation between 1.1 and 0.6Ma BP, and intense uplift and desiccation of climate in the inner plateau. Finally, some important problems need to be researched in future are suggested. It is indicated that key to breakthroughs in paleogeographical research lies in analysis of depositional basins and stratified landforms in and around the plateau, precise dating and explanation of high-resolution environmental information.

This paper systematically discusses the impacting factors on human height development from fetus to adult and the future trend. The results show that development of body's height is progressing according to certain time series, and it is the function of time. The stature of fetus increases with the month age, which has no obvious difference in various regions and from various mother's bodies.However, the heights of newborn babies have no clear difference in different regions and sex, and there are statistical differences between city and countryside. The clear difference of body's stature between city and suburb appears from infancy to preschool period,and this kind of difference will last to adult period. These indicate that spatial environmental factors and socio-economic factors are mainly factors affecting body's stature after newborn period. The impact of spatial environment on body's stature is an extensively diverse factor which has many meanings and can be controlled, which includes the effects of natural environment and social surrounding. With the development of socio-economy, there is increasing effect of social environment on body's height and weight, which brings a series of social medical and public health problems. It has theoretical and practical importance on development of human physique (including body's stature and weight) to study the relation between spatial environmental factors and body's stature.

During the last two decades, a lot of innovations have appeared in the field of urban and regional research. New paradigms and approaches such as dynamics of complex systems, self-organization, evolution theory, have been recognized for better understanding the evolutional process of regional spatial structure. It can be seen as a cumulative and aggregated order which results from numerous locally made decisions. Therefore the basic force driving the evolution of regional system is inherently microscopic. Regional system is an evolving complex system which grows from simple to intricacy. Inspired by the concept of biology, regional system also evolves into a complex, multiplex and vitality state by certain natural selection and adaptation. The understanding that the region is a complex adaptive system (CAS) means that microscopic simulation emphasizing the way in which locally made decisions and interaction between all kinds of local agents such as households and enterprises give rise to global patterns is highly appropriate. The methodology of CAS model is a part of theory of CAS. The CAS such as urban and regional system is conceived as societies of autonomous agents who are able to act both on themselves and on their environments. The general behavior of the regional spatial evolution is produced by the combination of actions of the households and enterprises. The determinants of an agent's behavior have a local character and there is no global constraint on the system's evolution. These agents can adapt to other agents and environment continuously by learning from their own experience. The classifier system is a good learning algorithm for representation of the agent's adaptation. Therefore, it is a good alternative way of simulating the evolutional process of the regional spatial structure by modeling behaviors of these local active agents and their interactions. It is easy to build and understand the CAS model. The CAS model can overcome the limit of perfect rationality by introducing learning algorithm and integrate any qualitative or quantitative description of an agent, whose behavior may be very complicated. The flexible modeling method allows for a much more detailed representation of spatial interactions and of some local properties and also makes it possible to introduce new agents or new rules in the model without changing the other parts. This paper basically reviews the simulating ideas and methodology aiming at two types of traditionally modeling strategy on the study of regional spatial evolution, in addition, primarily introduces the theory of complex adaptive system, one of the most important achievements of studies of complexity, and besides, discusses the general characteristics of the region as a complex adaptive system, expounds the technical problem of regional simulation based on the CAS and the original idea of the CAS model.

Urbanization process has come into a rapid growth period since the 1990s. Beijing, the capital city of China, is stepping into a metropolitan developmental stage. The investment for city construction and real estate will be more than 50 billion yuan each year within next 5 years based on Beijing International Metropolitan Planning for holding Olympic Games in Beijing, 2008. However, Beijing's real estate market has entered a booming period in 2001 when a new real estate project opened out each day in average. Moreover, up to 100 real estate projects have been developed in some of the spatial points within the central city fringe. According to characters of location in urban land development, this paper tries to find a growing pattern which is more suitable to describe spatial characteristics of urban land development. Based on analyzing more than 2000 land samples in Beijing's land market from 1992 to 2000, a logistic growing pattern of urban land development has been illustrated in Beijing metropolitan area both in concentric areas and radiate sectors. Four stages, i.e.,preliminary, accelerated, decelerated and saturated stages, are in the life circle of spatial land development within a limited area based on the principle of diminishing marginal benefit. Although some of the areas,such as old downtown and Shijingshan fun-shaped area, have been in a pre-saturated stage, most parts are in an accelerated stage according to the results of analysis and prediction in the paper.

According to the targets and action plans towards sustainable development set up in China's Agenda 21-Shanghai Action Plan, based on seven principles, this paper selects ten indicators including total population, total GDP, total fixed investment, water quality index etc.to study Shanghai's regional development process during 1978-1998 through correlation coefficient and regression analysis. The aim of the study is to approach the characteristics and regulations of Shanghai's regional development and to provide bases for future needs. Research showed that the confliction between economic growth and environmental improvement has come to relax in the latest 20 years especially during the period with moderate economic growth rate at 7-8%. More close correlation occurred during 1990-1998 compared with that in 1979-1989. From the regression analysis, GDP was an indicator that can be forecasted with a relatively small error.

This paper makes an in-depth analysis on the type, process and effect of enterprises' spatial transfer in Chongqing municipality after a comprehensive investigation. At present, the enterprises transfer from urban region to the outside mainly focuses on such sectors as auto and motorcycle accessory, food and beverage, textile and garment industries.From now to the near future, its transfer area mainly involves outskirts, then ambient cities and medium-sized cities, finally up to farther cities and counties in the Three Gorges Area. On the basis of the analysis of enterprises' spatial transfer,the paper makes a key study on the spatial amalgamation and cooperation pattern between the urban enterprises and the enterprises in the Three Gorges Area. Meanwhile, the analysis and discussion are made to the different patterns. Now, the spatial transfer of the enterprises in Chongqing is at the fledgling stage and only involves outskirts of the urban area. The amalgamation and cooperation of the enterprises between urban area and Three Gorge Area is mostly exogenous with a characteristic of vertical cooperation in the link between enterprises. Endogenous network for the spatial link between enterprises has yet to be established. The amalgamation and cooperation between urban enterprises and the enterprises in the Three Gorges Area has boosted the development of the enterprises in the Three Gorges Area as well as the improvement of their production technology and played an active role in the development of the socioeconomy in the Three Gorges Area.

In this paper the areal model of agricultural integration is defined as the major model of agricultural integration adapted to the sort of leading products, marketing orientation, the degree of rural economic development and the organization level of farmer household in different regions. The formation mechanism of areal models of agricultural integration is as follows:1) sort of leading products is the fundamental factor; 2) marketing orientation is the key factor; 3) the degree of rural economic development is the restrictive factor ; 4) the organization level of farmer household is an important factor; and 5) location,resources and environment are the external conditions. There is great intraprovincial imbalance of social and economic development within Jiangsu Province,and the areal models of agricultural integration should be differentiated with concret conditions of each region.The processing factory driving model,special market radiation model and leading products based model are recommended as the major areal models of agricultural integration in Southern Jiangsu, and the intermediary organization servicing model and the plural participation model are recommended as the major areal model of agricultural integration in Northern Jiangsu. Some typical examples of areal model both in Southern and Northern Jiangsu are analysed in detail: 1) the dairy integration model in Nanjing city region;2)the model of Yangchenghu crab integration in Wuxian county;3)the pearl integration model of China's Weitang Pearl Market; 4)the model of garlic integration in Dafeng county; 5)the model of egg integration in Hai'an county;and 6)the model of laver integration of Yucheng Group Company.

The emergence and recent rapid growth of rural industry in China is a striking and in many ways unique phenomenon. How to explain it with the approach of locational analysis is a very important and interesting topic to economic geographers. However, for more than a century, the phenomenon of spatial agglomeration of economic activities has been occupying the central position in the study of economic and industrial geography, so it is very difficult to provide powerful explanations to China's highly dispersing rural industrialization with normative or modern locational analysis. Based on the hypothesis of "economic man", this paper integrates a new set of theoretical tools involving new economic and industrial geography, new institutionalist and evolutionary economics and normative locational analysis, and advances an integrative framework of locational analysis which synthesizes four location factors: institutions, technology, market and resource endowment. In this framework, each location factor affects the industrial location behaviors through affecting the transaction costs or the production costs. In particular, the paper argues that the institutional factors and the mechanism of transaction costs are critical for understanding the high speed and scattering distribution and great regional imbalance of China's rural industrial development.

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.

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.

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.

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.

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.

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%.

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.

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.

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

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.

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.

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.

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.

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

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.

The author reviews the development process of territorial planning since the 1980s in China. According to statistical data, up to 1993,30 provinces (autonomous regions, municipalities), 223 cities and 640 counties had accomplished the compilationof territorial planning. In this process, the functions of "authority, decision making and service" were fully brought into play to serve the compilationof regional economic social developmentplanning. Meanwhile, the principle of "from top to bottom, from bottom to top" was followed in combination with that of "leaders, local operators and experts", and made a point of the study of basic theories. However, some problems were also revealed, i.e., the features of territorial planning are not distinct, having many similarities withregional economic social development planning; the planned economy still played an important role; the maneuverabilityof planning was not good; and the qualitative analysis was not so closely combined with quantitative research. Aiming at the current situations of economic globalization and informalization,China's Accession to the World Trade Organization, and the improvement of socialist market economic system, the paper puts forward basic thought to promote the new roundterritorial planning and accomplish four changes as follows: to change planned type to market and guidancetypes; to change resources exploitationand utilizationto integration of resource exploitation, utilizationand conservation; mono goal for economic development to multi goal for sustainable development which should coordinate economy,society,population,resources and environment;and to change planning focus from industrial planning to spatial locational planning that coordinates regional economic social construction.Based on the above thoughts, the improving waysare proposed, including: importanceshould be attachedtothe inter provincial territorial planning or trans urban and trans prefectural territorial planning of a province; the land use planning should be the core of basicterritorial planning; spatial policyresearch in cooperation with territorial planning should be strengthened; planning method should be evolved toward informalization and scientization; legislation of territorial planning should be formulated as soon as possible; and publicparticipation should be widely admitted in the process of planning.

Air transportation is a unique and increasingly important perspective in studying spatial structure of urban system This paper illustrates the framework of urban system by analyzing structural features of air transportation network based on the data of the amount of airport passenger transportation and the number of weekly flights (1)Since open to the outside world, the nodes in China's air transportation network increased quickly accompanied with the expansion of air transportation network scale which presents positive correlation with the scale rank of urban system (2) On the whole, dispersion dominates the evolution of airport's spatial structure But in the variant periods and zones, the newly built airports and the increase of transportation capacity of the existing airports exert different influences on the expansion of air transportation network (3) Network linkage intensity differs in various provinces But the eastern coastal zone is still the core region of domestic and international airline linkage in which the international hub function of Beijing Tianjin Hebei and Jiangsu Shanghai is distinctive while Guangdong mainly acts as home hub (4) The capital city of a province is still of vital essence to this province's outward connection, but more and more developed cities of some provinces have partly substituted the capital cities (5) The spatial distribution of intensity and tightness of air network linkage separate from each other, which manifest that the spatial network structure of China's urban system is still in the process of dynamic evolution (6) The factors such as the change of airline structure, the airline linkage with foreign countries and the cooperation and competition of domestic airport cities will all influence urban system structure in future

There are many advantages to construct a base of energy and heavy/chemical industries in the contiguous area of Shaanxi Gansu Ningxia On one hand,the area is not only rich in resources ofoil, coal and natural gas, which form a combinative superiority ofenergy resources, but also rich in resources of bauxite and nonmetal minerals On the other hand, with the change of supply demand situation of China in recent years,a heavy task forChina'senergy industry in the future is to increase the productionand supply of the secondary energy with high quality suchas electricity,refined oil from coal,etc Therefore, there is a large market in China for the area to exploitits energy resources and to establish the processing industry ontheseresources Although the area has got a primary development in its energy and heavy/chemical industries, there are still many problems, such as the low level of technology, weak ability of competition and the lackof further machining The article holds thata general strategy shouldbe workedout, whichis "large in size, high in technology and new in mechanism to setup a conversional production system anda regional production complex", so astofoster the superiority of industrialcompetition, toextend the industrial chainas soon as possible, to cultivatethemulti industriespositively, and to step on the road ofsustainabledevelopment In order to carry out the strategy, it is necessary toformulate and implement somemeasures and policies Firstly, we should found an inter provincial management committee to get successful development of resources and harmoniousdevelopment of the region Secondly,we should build up a market of mining right actively and raise the local portion in resource division Thirdly,we should attach importance to protect environment, transformingouter negative effectof enterprises into interior Fourthly, it is significant to establish the supporting system of finance Finally, the role of the government should be changed so as to offer favorablesystem surroundingsfor the base of energy and heavy/chemical industries

Firstly, the paper predicted future food productive capacity of agricultural resources including cultivable and non cultivable land resources; secondly, the food demand was respectively forecasted in the coming three periods, based on the different nutrition supply amount according to the population forecast program; lastly, the comparison between the productive capacity and the demand was analyzed in the coming three periods The results shows that the grain productive capacity will be slightly greater than the demand because the food structure of prosperous level is as the demanding standard in 2010, however, in 2030 and 2050 the productive capacity will be smaller than the demand because the food structure of hypo affluent and affluent level is as the demanding standard So it would be difficult to satisfy the food demand during the period converting from the prosperous level to the affluent level if only depending on the limited cultivable land resources The balance analysis of supply and demand based on the comprehensive productive capacity of agricultural resources shows: the comprehensive productive capacity of agricultural resources would be higher than the food demand in the three coming periods The productive potential of non cultivable land resources should be exploited during the course of using limited cultivable land resources efficiently The food demand could be satisfied during the period converting from prosperous level to affluent level and the living standard could be improved only by depending on the comprehensive productive capacity of agricultural resources

Arid land agriculture in northern China is located to the north of the line from Kunlun Mountains through Qinling to Huaihe River. The agriculture of this area is rain fed in nature, so its development is greatly restricted by the water resources. And also this means there are great potentials in agricultural development in the light of the status quo of resources utilization and production practice in northern China where the level of agricultural production is low and the eco environment is execrable. As China has put emphasis on food security, eco system and economy, it is necessary for us to develop arid land in northern China with comprehensive methods and strategies. This paper recounts the research status of the arid land agriculture in China and other countries. On the basis of the analysis, the paper concludes that the same experience of the foreign countries in research and practice is that they attach importance to the combination of the amelioration of environment and the increase of crop output. Remarkable achievements have been gained in these aspects: 1) under conditions of water scarcity, most of the countries paid more attention to the collocation of the water and soil resources, especially to the durative increase of the efficiency of water use; 2) in the past several years many countries increased the level of mechanization and got rapid development of the research on the industrialization of technique. The production efficiency is 2.5 times as much as that of ten years ago; and 3) the benign circulation between the mechanization and industrialization of technique has been formed. At the same time, Chinese arid land agriculture has also gained great achievements. Firstly, on the basis of the 5 first level districts and 57 second level districts, the structure of agricultural products and planting system which are suitable for different types of arid land have been established in China. Secondly, both the protection and reasonable exploitation of the renewable resources and the artificial replacement of nonrenewable resources have made rapid progress. For the future development of China's arid land, we have to recognize the demerits of our strategies. So finally the strategies of the development of arid land agriculture in northern China are put forward.

This paper reveals spatial characteristics of the recent inter provincial(municipal,regional) flow of social economic elements in China. Firstly, thepaper reviewsthe studies on the trans regional flow of social economic elements in China Then, based on the survey data,it conducts a comprehensive analysis of the spatial characteristics of the productive element flow such as the inter provincial migration, passenger railway flow, airborne passenger flow,railroad freight flow and information flow, by adopting GIS spatial analysis and visualization techniques. The spatial distribution of the inter provincial flow is influencedevidently by the provincial economic status and the pattern of inter provincial economic relations The eastern China shows its great importance on the distribution of the inter provincial flow The three economic heartlands of China, Jing Jin Tang (Beijing, Tianjin, Hebei), Hu Su Zhe (Shanghai, Jiangsu, Zhejiang) and Guangdong also act as the main centers of inter provincial flow The gravity centers of all the inter provincial flows are relatively close to the population and economic centers of China, but deviate far more from the geometric center of the territory This means the spatial distribution of inter provincial flow is basically consistent with the socialand economic situationof China Further, the paper concludes the spatialdistribution of the flow of social economic elements as four fundamental patterns, which are tested in each type of the flow and two holistic styles are deduced

Being the core and frontier issue in the global environmental change and sustainable development disciplines, studies on land use/cover change (LUCC) has gained increasingly attention. China, restricted by its large population and less land, is one of the developing countries facing serious ecological and environmental problems in the world. Many problems of sustainable development confronting China have inherent and inevitable associations with LUCC. Therefore, systematic LUCC researches, aiming at the implementation of sustainable development strategies in China, have great significance in both academic and practical respects. Their relations between the problems of sustainable development and LUCC, and the research objects, contents, investigative methods and key issues of LUCC based on sustainable development in China are briefly discussed in this paper. The interrelationship between LUCC and sustainable development in China is very complex. Generally speaking,the linkage can be shown as the balance between land water resources demand and supply. Thus, the orientation and content of LUCC and sustainable development researches should be developed along with the critical issues for sustainable development driving force of human being scenarios of LUCC optimized decision making for sustainable development. Meanwhile, different situations under different temporal and spatial dimensions should be incorporated into the researches. The key issues to be studied are how to reveal the land supply and demand relationships under the multiple driving forces, as well as its changing extents and influences. Upon them, the framework of scientific decision making and comprehensive management for LUCC in China, which is confined by the sustainable development relationship between food and resources supply, ecological protection and economic growth, is proposed.

Based on social and economic statistical data, general surveys, detailed surveys and analysis as well as field surveys and investigations of land in rural areas of the Bohai Rim since the 1980s, firstly, this paper analyses the trend of cultivated land occupation inevitably related to population growth, urbanization, development of industry, development of transportation facilities and water conservancy, construction of environment, and natural disasters in the surroundings of the Bohai Sea. Secondly, it examines the position of cultivated land quantity degradation and quality improvement related to less support of farmland resources, low quality of opened up land, greater exploitation difficulty, and necessity of making intensive use of farmland in the study area. Thirdly,it puts forward measures for farmland protection such as strict management of land use, strict control of farmland occupation for construction purposes, achieving overall balance of farmland quantitatively, protection of basic farmland and cultivated land in key region, transformation of middle low yield farmland, controlling of groundwater exploitation, protection of farmland eco environment, and adjustment of agricultural structure in the surroundings of the Bohai Sea. Fourthly, it discusses land increment potentials and ways of exploitation related to policy of land use management, farmland and village consolidation for sustainable land use, land reclamation and land exploitation in Bohai Rim.

Based on the statistical data at provincial and county levels from 1949 to 1998, the dynamic change of grain production and regional differences are discussed In the last 50 years, the total grain production took on an increasing trend on the whole In the period of 1949～1998, the total grain production increase was 24480 thousand tons with an annualaverage increase of 489 6 thousand tons and the per capita grain production increase was 320 8 kilograms Because of the differences in natural conditions and agricultural history, the spatial difference in grain production increase is very notable The regions with higher annualaverage increase rate of grain production are mainly distributed in the piedmont plains where irrigation conditionsand agricultural base are better such as Shijiazhuang, Handan, Xingtai, Baoding. However, the regions with lowre annualaverage increase rate of grain production are mainly located in the mountainous and hilly areas such as Zhangjiakou, Chengde and the easternplain with poor naturalconditions According to the grey systemtheory, factors affecting grain production are analyzed and correlative degree between factors and grain production is quantitatively measured The results show that per unit area grain yield, effective irrigated area and grain sown area are the most important factors that affect grain production Moreover, the countermeasures to realize the sustainable development of grain production are discussed such as relying on scientific progress to increase per unit area grain yield, protecting arable land and stabilizinggrain sown area, popularizing technology of intercropping and improving multi crop index, strengthening capital constructionof farmland and enhancing the synthetic ability of agricultural production This paper provides a scientific basis for sustainable agricultural development in Hebei Province

The Internet is a major symbol of the contemporary world that is predominated by two interwoven tendencies, i e., globalization and informationalization. It is now widely accepted that the world is moving fast towards an information age and the Internet is a major channel to such a historical change. Indeed, no technological progresses in the last several decades can match the advent of the Internet in term of its profound and extensive influences. The increasingly wide use of the Internet is causing fundamental changes in people's daily life and hence probably in the entire socio economic system of the world as well. In particular, the Internet makes the propaganda of information and knowledge much easier and faster than ever. In such a sense, its development as an industry is not only a part of the knowledge based economy but also an accelerator of the development of the latter. The explosion of electronic business/commerce (e com) on the Internet is a result of the fast and vast information and knowledge flows. The implications of such developments for industrial spatial changes are very important and interesting research topics for economic and industrial geographers. It is reported that the Internet economy has been a major contribution to the US's recent economic growth. In Asia, the recent recovery from the 1997 98 financial crisis has also been attributed partially to the rapid growth of business to business (B2B) e com. In China, the development of the Internet in the last several years has been incredibly fast. The number of domains registered under ".CN" increased from 4,066 in late 1997 to 127 thousand by the end of 2001, and that of the Internet users rose from 620 thousand to 33.7 million. The rapid development of the Internet has also led to fast growth of e com in the country. This paper will investigate the development of the Internet in China with special attention to its geographical features and then analyze the spatial implications of such development. It hopes to offer a general background to and be a stepping stone for future more detailed studies on the issue.