Water is scarce in the North China Plain and the limited precipitation is not enough to satisfy the water requirement for wheat growth. In order to avoid reduction of output caused by scarcity of water, irrigation is necessary to supplement water. This paper discusses the relationship between the amount of irrigation and the yield of wheat. Statistical analysis of experimental data of irrigation indicates that the relationship between yield of wheat and irrigation presents a quadratic parabola in North China. We fit the model of wheat water production function by adopting least squares theory on the basis of field experimental data of wheat. Water production function is quadratic function and its math expression is Y=-0.0027ET 2+2.8647ET-127.91. Water productivity is divided into three different development stages according to the changing rule of water use efficiency and the relationship between yield and water consumption. Water consumtion being less than 217.66mm is identified as the first stage when yield rises with the rise of water consumption, and productivity rises gradually at this stage. Water consumption at the second stage rises from 217.66mm to 530.50mm and the yield still rises with the rise of water consumption, but the range of rise reduces. The productivity rises slowly.Water consumption at the third stage exceeds 530.50mm and the yield reduces with the rise of water consumption. Negative rise occurs and productivity declines. The analysis of wheat irrigation production function under typical irrigation system indicates that the best point of irrigation efficiency of wheat is not the highest point of utilization ratio of water or the highest point of yield. The best point of irrigation efficiency of wheat is decided by the principle that marginal revenue is equal to the marginal cost. When marginal benefit equals marginal cost, net income of irrigation of wheat is the biggest. The maximal net income is 4816.49 yuan/ha, and irrigation water is 265.00mm at this time. Compared with the irrigation of the maximal yield, it saves 17.85mm of water . Making rational use of wheat water irrigation production function and its regularity can realize the better unification of water-saving, high-yield and high-efficiency of wheat.

The pattern, process and their relationships are fundamental issues in geography. Patterns and processes in nature, such as ecosystem distribution, regional climatic changes, land use and land cover, and rainfall or runoff series, display complex behavior and often intertwine with scale problems. Many scale-dependent phenomena have been exemplified in scientific researches, and scale issues are found at the center of methodological discussions in both physical and human geography. However, some existed research works failed to make a distinction among the concepts of scale and scaling, to employ consistent scaling paradigm, and to adopt an objective criterion for assessing the scaling effects in geography. This paper attempts to calibrate those deviations and to present new branch subject of geography-Scaling Methodology of Geography. After introducing scaling approaches, upscaling and downscaling, in geography, we place a focus on the research objects, categories and contents of proposed subjects, and three basic principles, scientific principle, economic principle and operational principle, are proposed in scaling works. Finally, ten key issues are presented for establishing the scaling methodology of geography. The key questions are as follows: (1) how does spatial heterogeneity scale in scaling ? (2) how do ratio variables change with scale in scaling? (3) how do dominating processes change with scale in scaling? (4) how does property of processes change with scale in scaling? (5) how does sensitivity change with scale in scaling? (6) how does predictability change with scale in scaling? (7) what is sufficiency for simple aggregation and disaggregation in scaling? (8) how do disturbance factors change with scale in scaling? (9) can scaling transcend several scales and scale fields? (10) is noise factor changeable with scale in scaling?

This paper presents a new method to simulate the dynamics of multiple land uses based on the integration of neural networks,cellular automata and GIS. Recently, cellular automata (CA) have been increasingly used to simulate urban growth and land use dynamics. However, simulation of multiple land use changes using CA models is difficult because numerous spatial variables and parameters have to be utilized. Conventional CA models have problems in defining simulation parameter values, transition rules and model structures. In this paper, a three-layer neural network with multiple output neurons is designed to calculate conversion probabilities for competing multiple land uses. The neural-network-based CA model is directly developed in a GIS environment by using ARC/INFO GRID AML. The GIS provides both data and spatial analysis functions for constructing the neural network. Real data are conveniently retrieved from the GIS database for calibrating and testing the model. The GIS functions are also used for the neural network calculations. The neural network has multiple output neurons to generate conversion probabilities at each iteration. Land use conversion is decided by comparing the conversion probabilities. The model is carried out by iterative looping the neural network for simulating multiple land use changes. Complex global patterns can be generated from local interactions through the neural network. The simulation results are not deterministic because a stochastic variable is used and site attributes are dynamically updated at the end of each loop. The proposed method can overcome some of the shortcomings of the currently used CA models in simulating complex urban systems and multiple land use changes by significantly reducing the tedious work in defining parameter values, transition rules and model structures. The model has been successfully applied to the simulation of land use dynamics in the Pearl River Delta.

With the help of remote sensing data and GIS, by using the indices of the landscape pattern, such as fractal dimension, patch density, fragment index, landscape diversity index etc., this article presents the dynamic change of Kaifeng city from 1988 to 2002. The results show that: (1) There were a rapid increase in the patch number from 1988 to 2002 in the study area,the patch number increased from 28784 in 1988 to 32311 in 2002. The whole shape turned irregular and the fragment of the landscape degree became serious, from 1.1308 in 1988 to 1.1334 in 2002. (2)The construction area, water area, and green-land increased individually from 8049.97hm 2, 4756.86 hm 2, and 1076.31 hm 2 in 1988 to 11852.60 hm 2, 6486.21 hm 2 and 2125.52 hm 2 in 2002; the farmland (mainly the irrigable land), non-used land and orchard area decreased individually from 10937.97 hm 2, 2500.56 hm 2, and 1454.67 hm 2 in 1988 to 4206.42 hm 2, 1104.84 hm 2, and 623.83 hm 2 in 2002. (3) The center of high-density construction area was shifted to southwest, green-land to northeast and water area to southeast. (4)The high-density construction area changed rarely, but low-density construction area was mainly transformed to high-density construction area; farmland mainly to construction area and non-used land to farmland and green-land. (5)Urbanized index and landscape used degree increased a little from 20.08% to 29.57%, and the landscape used index increased a little from 293.0532 to 315.8277. (6)Human activity has important influence on the urban landscape, but the Yellow River has a great influence on the landscape pattern of Kaifeng city, because the study area is located near the Yellow River with an abnormal geographic background. Irrigation from the Yellow River made a lot of non-used land turn to farmland, and diverting water from the Yellow River made water area increase greatly.

Flood hazard is one of the most harmful disasters in the world for over 40% of the natural hazard damage are caused by flood hazard every year. With the developments of socio-economy, people come to realize that they should not only depend on engineering measures but also use non-structural measures such as flood forecasting, damage evaluation and flood regulation to reduce flood damage. At the same time, along with deepening and broadening of research content on flood control and multi-disciplinary infiltration, people pay increasingly more attention to the studies of multi-disciplinary integrated flood control measures. Meanwhile it is possible to apply computer simulation, remote sensing and GIS technologies to the research field of flood control as well as to the analysis of flood-inundated simulation by GIS on floodplain based on the research of flood prevention and reduction. In southeast China coastal areas there are many size medium or small rivers that flow into the sea separately. Because the flood regulation and storage capacities are low with short flow concentration duration, flood hazard is grave. Besides these basins are situated in the China's developed region, especially in recent years, with rapid growth of economy, enlargement of industrial and city scale, as well as expansion of population, flood losses have also drastically increased. So research on flood hazard prevention and reduction has become an urgency. As floods occur mainly on flood plain in this region, this paper, taking the lower reaches of the Fenghua river in Yongjiang basin of Southeast China as an example, discusses the application of the approaches and methods of remote sensing and GIS to flood-simulation in floodplain. It firstly explores the rainfall runoff characteristics in this basin and floodplain flood routing rules. Supported by remote sensing and GIS the rainfall runoff and two-dimension flood routing models are built, the parameters of models and coefficients of two-dimension numerical calculation models are determined with GIS. Meanwhile the evaluating model of flood submerged area and the damage assessment models are built supported by digital elevation models (DEM) as well as socioeconomic database. Finally a satisfactory calculating result of actual simulated verification is obtained by using remote sensing, telemetering and GIS information. The research indicates that geographic information system and remote sensing create favorable condition for flood-inundated simulation on floodplain. There will be great promise for the application of GIS to the studies of flood prevention and reduction. This research will also provide valuable experience for the flood preventioll and reduction decision-making studies of this region.

The spatial distribution of marine economy in China includes 11 provinces having littoral zones, islands and vast expanse of sea areas. China has taken marine resources development as an important content in the national development strategies and regarded marine economic development as a great action to revitalize the national economy since the 1990s. China has proposed the plan of forming several marine economically strong provinces by 2010,which can provide relevant conditions not only for building China into a well-to-do society, accommodating workforce, alleviating the employment problems but also for developing western regions and revitalizing old industrial base in Northeast so as to promote overall development of the national economy and quicken the pace of economic growth. In the research, some quantitiative methods and models for analysing regional space differentiations are used to analyse the spatial agglomeration and diffusion degree of marine industry and marine tertiary industrial structure of various provinces for the purpose of revealing the mechanisms and laws for the formation of the marine economy of every province. Countermeasures for building marine economically strong provinces in China are put forward.

By using the multi-stage nested Theil decomposition method and the wavelet analysis of the Theil index sequence, this paper studies the spatial and temporal scales of regional economic disparities in China from 1952 to 2000. The main conclusions are: (1) the regional economic disparities in China, including the disparities within-province, between-provinces, within-region (the eastern, central and western regions) and between-regions, have existed since 1952. (2) The first stage decomposition of Theil index shows that the dynamic trend of disparity in the eastern region is consistent with that of whole China. The disparity in the central and western regions remains small, and the evolution is rather slow. The disparity between the three regions has been continuously increasing. (3) The second stage decomposition of Theil index reveals that the within-province disparities is the most significant component of all in the overall regional inequalities, which is more significant than that of the between-province and between-region disparities components, constituting the important part of the overall regional inequalities. In addition, the influence of within-province disparities in the eastern region on the overall regional inequalities is more significant than that of in the other two regions, and, the influence in the western region is more significant than that of in the central region. (4) Based on the decomposition and approximation of Theil index sequence using wavelets by different time scales, we elicit a conclusion that the evolutionary process of regional economic disparity in China is not a simple inverted U-shaped pattern but a compound of several U-shaped patterns. The result tells us the evolutionary process of regional economic disparity in China does follow the inverted U-shaped patterns a time scale of 16 years. That is to say that the regional inequality tends to rise in the first stage of economic development, and falls slowly over the peak in the second stage of economic development. However, if we shorten the time scale to 8 or 4 years, then a link of several U shaped patterns will appear.

As a concept based on greenway development, heritage corridor, which combined recreation and tourism development with ecological restoration and cultural conservation, has come into being in the United States since the 1980s. With rapid development in the study of greenway network, plans of heritage greenway network were proposed for heritage conservation as part of ecological infrastructure in regional scale in recent years worldwide. As many cases have shown, suitability analysis is the key in greenway planning study. Some approaches of greenway suitability analysis given in the former cases were too complicated and too much data dependent to be applicable in the Chinese condition. With GIS (geographic information system) technology and MCR (minimum cumulative resistance) model being used, a new approach of heritage corridor suitability analysis is designed to analyse and identify the suitability of potential areas for heritage corridors. This approach is featured in the following aspects: 1) A heritage corridor is defined as a linear landscape element that combines the function of recreational activities, heritage protection and ecological processes. 2) In addition to the physical faccors of heritages, the process of recreational use is the major concern in the definition of the suitability of a heritage corridor. 3) Recreational activities associated with heritages are considered as a horizontal process going across the landscape. This process is taken as an active process which overcomes the cumulative landscape resistance affected by land uses and covers. The less accumulative resistance a user is going to experience across the landscape, the more suitable the landscape is designated as heritage corridors. 4) The suitability of a landscape for a heritage corridor is therefore represented through the relative accumulative resistance in the process that a user experiences across the landscape towards or between heritage sites. 5) The calculation of accumulative landscape resistance is based on the cost-distance from the sources (heritage sites) to any points in the landscape.Different land uses and covers contribute differently to the resistance, and their weights are based on the evaluation by experts and inquiry of the local people. A case study in a rapidly urbanizing region, Taizhou City of Zhejiang Province, is presented.

Urban housing spatial structure can be viewed as the substantial expression of urban development history. The housing spatial structure of Guangzhou city is typical in that it lies on the front of opening zone and, furthermore, it is one of the three largest cities in China. Basing on the housing data of Guangzhou's 5th Census, the paper employs factor and cluster methods to analyze 5 key factors taking from 40 variables of 77 sub-districts (F>70%). They are housing constructed years, housing sources, kitchen equipments, toilet equipments and housing floors. The results of the factor scores help to divide the houses in urban built-up area of Guangzhou city into four types with different features: Ⅰ) Pre-establishment Housing Area (in which houses constructed before the founding of P. R. China); Ⅱ) Government Welfare Housing Area (Ⅱa: in which houses constructed for public servant from the time of the founding of P. R. China to the Reform and Opening) and Enterprise Welfare Housing Area (Ⅱb: in which houses constructed for people serving public owned enterprises from the time of the founding of P. R. China to the Reform and Opening); Ⅲ) 1980s Housing Area (houses with relatively rough equipment constructed during the 1980s); Ⅳ) 1990s Housing Area, in which Commercial Houses (Ⅳa) and Privately Constructed Houses (Ⅳb) centralized. The results can be used to explain the formation mechanism of Guangzhou's housing spatial structure. 1) As a result of Guangzhou's development, housing spatial structure turns on concentric circles from inside to outside. The quality of houses in the former urban area (inside circles) is poorer than that in the outer because they are the origin of the city. Some underdeveloped villages were surrounded by built-up area with urban expansion, while some of them were developed apart from the urban. 2) City planning distorted the concentric circle structure. 3) City reconstruction changed the homogeneous situation of the former urban area. 4) Although the housing reform institute changed houses' tenure, their public-owned attribute has not been broken. 5) Outskirts of the city become the hot area of real estate development, which result in the highest ratio of commercial housing in the outside of the built-up area. As a conclusion, the paper deduces the structure mode of housing spatial structure in the large cities of China: The Pre-establishment Housing Area normally lies in the inner circle. The second circle is the Welfare Housing Area. The Commercial Housing Area mainly centralized in the 3rd circle, which surrounds those relatively underdeveloped villages originally far from urban built-up area and some special function area constructed in the culture and education areas in the 1980s. The broad suburban housing area and industrial area together formed the 4th circle.

The origin and development of cities of Northeast China have a long history along with the formation of their peculiar civilization. But, before the 20th century, the level of urbanization in Northeast China lagged behind that in Central China for a long period of time due to some historical reasons. Modern cities of Northeast China originated in the early 20th century. Since the 20th century, Northeast China had gone through the immigrating and opening-up policies of the Qing government, later been invaded and occupied by the imperialist nations such as Russia and Japan for several decades. After the founding of the People's Republic of China, Northeast China has ever been the key region of China's industrialization. Today, due to economic growth and dramatic reform of economic structure, Northeast China's urban development has stepped into the rapid developing period, and been one of the regions with the highest standard of urbanization in China except for several municipalities directly under the central government, and made the great contribution to Chinese economy. Compared with other cities of China, cities of Northeast China have a special political and economic background, and clearly reflect the feature of synchronous developing and mutual promoting in the course of both urbanization and industrialization. In the paper, the authors identify the development mechanism of cities of Northeast China in the 20th century by revealing the relationships between the development of cities of Northeast China and their economic and social development. Simultaneously, the authors also analyze the historic role of the development of cities of Northeast China and some current major problems restricting their development in the course of renewing the old industrial base of Northeast China.

Study of a historic sediment in the south margin of the Tarim Basin, where is influenced by the Westerlie force evidently, shows that the mass susceptibility correlates positively with carbonate δ¹³C and strongly with the components of 56.37-224.4μm(especially with components of 70.96-200μm), but correlates negatively with the components of 0.56-35.57μm (especially with components of 17.83-31.70μm.). The correlation among three proxies bears profound significance of climate and environmental changes. When temperature declined in the extreme arid area, the relative humidity increased greatly, resulting in restrains of evaporation and prosperity of vegetation, protecting the land surface from erosion, and only relative finer debris can be carried to deposit in lake, carbonate δ¹³C declined. Less oxidation strength during a relatively cold period led to lower mass susceptibility. Conversely, when temperature increased, relative humidity declined sharply and resulted in increase in evaporation, the vegetation cover reduced so that the erosion intensity on the land surface increased, leading to coarser component being loaded and deposited in lake and rise in carbonate δ¹³C. Strengthened oxidation during a relatively warm period resulted in an increase in mass susceptibility. Based on the interpretation of the proxies and widely regional comparison, this paper identifies 8 characteristic climatic periods during the last 4.0ka. Most significantly, the similarity which can be observed between the fluctuation of climate proxies in this paper (especially the proxies of grain size ) and the Greenland GISP2 ice core δ¹⁸O record shows that climate change of the studied area may have global background, and on the other hand, it also incarnates evident regional characteristics.

The south coastal plain of Laizhou Bay is one of the typical salt-water intruded areas, whose occurrence and development have a close relation with the environmental evolution since late Pleistocene. This paper deals mainly with the systematic palynological, microfossil, granularity research and ¹⁴C dating on more than 29 samples from a column core with a depth of 29m of core A1 for the purpose of revealing the characteristics of paleoenvironmental evolution since late Pleistocene.According to the systematic study, 7 phases of the paleo-climate fluctuations and paleo-vegetation successions since late Pleistocene are identified. And 7 climate periods can be listed in the ascending order for the convenience of correlation: ①120-85kaBP, the analysis of spores,pollens and sediments shows that the then climate evolved from cold into warm and a little dry gradually;②85～76kaBP,obvious manifold pteridophyte and exiguous granularity of sediments showed a local humid environment with swamps and lakes developed in the lower reaches of the Weihe River; ③76～50kaBP,equal to the secondary Ice Age of Dali, characterized by grassland vegetation type with conifer in domination, and coarse sediments showed a barren terrestrial environment;④50～24kaBP,cold,wet-resistant hydrophyte such as bulrush lived on the coastal wetlands where the sea interacted with rivers, being a littoral environment; ⑤24～10kaBP,the worst period of Quaternary natural environment, the south coastal plain of Laizhou Bay was dry grassland and loess deposition environment; ⑥10～4kaBP,owing to the warm and wet weather, sea level was high and transgression occurred; the local marine-deposited stratum embodied exuberant hydrophyte and aquatic plants. The maximal transgression of Holocene ended at 4kaBP;⑦4～0kaBP,the modern sedimentary environment which inclines to dry. Three warm and wet periods and two cold periods can be found. Of which, the warm period of 85-76 kaBP is corresponded with the late Yangkou seawater transgression and there is no evidence of early Yangkou seawater transgression, the warm period of 50-24kaBP is corresponded with the Guangrao seawater transgression and the warm period of 10-4kaBP is corresponded with Kenli seawater transgression, the duration of the latter one is longer than Bohai and east of Laizhou Bay. The three periods formed the foundation for the salt-water intrusion in this area.

This study has chosen the shrubs of Caragana opulens Kom., a natural zonal vegetation in the semiarid area on northwest Loess Plateau, and compared its soil moisture from 0⁹.9m to those of re-vegetated shrubs of C.korshinskii Kom., re-vegetated almond forest, natural grassland （protected） dominated by Stipa breviflora, intensively grazed grassland and continuous cropland. Soil moistures were measured at the depth over 3m with an interval of 0.2m beneath and with an interval of 0.3m. The purpose was to testify the hypothesis that the zonal natural shrub vegetation consumes less soil water than re-vegetated shrub and forest vegetations. The results show that the soil moisture of natural shrub of C.opulens Kom. was largely higher than those of re-vegetated shrub of C.Korshinskii Kom. and almond forest beneath 1m in soil profile, close to those of intensively grazed grassland and cropland,but slightly lower than cropland. The average soil moisture in 0⁹.9m soil profiles of natural shrub of C.opulens, re-vegetated shrub of C.korshinskii, re-vegetated almond forest, natural grassland, intensively grazed grassland and cropland were 9.5%, 7.4%, 7.7%, 8.5%, 9.3% and 9.8%, respectively.and the average soil water moisture from 1⁹.9m are 10.2%, 7.6%, 8.1%, 9.0%, 10.6% and 10.0% respectively. The soil moisture of natural shrub land of C.opulens was higher than the soil moisture of natural grassland between the soil layer of 0⁴m, but beneath 4m, their soil moistures were essentially the same. All vegetation types have resulted in a continuous dry soil layer within which the soil moistures were hard or unavailable to vegetation. The thickness of hard or unavailable water moisture layers of natural shrub of C.opulens , re-vegetated shrub of C.korshinskii,re-vegetated almond forest, natural grassland, intensively grazed grassland and cropland were 2, 5.6, 4.2, 3.6, 3.3 and 1.0m, respectively. According to previous studies, the layer of unavailable soil moisture above 2m in soil profile is rechargeable by annual precipitation in the study area, but it hardly can be recharged by precipitation for unavailable soil water layers beneath 2m. From this initial study, we concluded that the natural shrubs of C.opulens consumes less soil water than re-vegetated shrubs of C.korshinskii, re-vegetated almond forest, underlining the importance of the role of zonal vegetation in the vegetation reconstruction in the study area.

On the basis of analyzing ecogeographical models and studying those methods being realized at the present time, a new research method integrated by ARC/INFO and VC++ is put forward, which can overcome those limitations existed in the previous methods and techniques. In the operational process of our methods , before the Holdridge life zone model and ecological diversity model are simulated, the original data are interpolated and become grid data. Based on the daily surface air temperature and precipitation data observed at 735 stations in China from 1960 to 2002, and through runing these models with our available methods and techniques, we obtained the serial maps of temporal and spatial distribution of Holdridge life zones and the value of Holdridge life zone diversity in China. After finishing all simulations, we carried out a series of analyses with these results. First, according to the serial maps of temporal and spatial distribution of Holdridge life zones, we found changes in spatial distribution of Holdridge life zones correspond well with the changes of the climatic factors and land cover. Second, through comparing and analyzing Holdridge life zone diversity, annual mean biotemperature and annual mean precipitation in our research period of time, some rules and phenomena are archived in China: 1) The fluctuated changing pattern occurs in the Holudridge life diversity, biotemperature and precipitation. 2) While the fluctuated directions of precipitation and biotemperature are the same, the fluctuated direction of the Holdridge life diversity accords with them. However, 3) while the fluctuated directions of precipitation and biotemperature are reversed,more intensive fluctuated changing pattern would occur in the Holdridge life zone diversity and the fluctuated intensity and scope would increase with the enlargement of the reversed ratio. Furthermore, through analysing the Holdridge life zone diversity, shape index of patches and patch connectivity of the Holdridge life zone in China during the 1960s, 1970s, 1980s and 1990s, we attained the analytical results that the Holdridge life zone diversity, the number of patches and the number of patch types present a decreasing trend at ratios of 0.0692%, 1.7293% and 1.3515% in every ten years, respectively. Whereas the shape index of patches and the patch connectivity present an increasing trend at ratio of 0.2526% and 3.7928% in every ten years. Finally, we discuss the relationship between life zone diversity and eco-environmental stability according to the above results.

The Ejin natural oasis landscape lies in the lower reaches of the Heihe river basin in the arid inland regions of northwestern China. With decreasing water resources from the upper reaches of the Heihe river basin, many serious ecological and environmental issues in the Ejin natural oasis have become more and more pressing in recent years. Using remote sensing techniques, GIS, and landscape pattern analysis software APACK, the landscape patterns changing characteristics, and the eco-environmental effects for Ejin natural oasis landscape are studied based on Landsat Thematic Mapper data in 1987 and Landsat Enhanced Thematic Mapper Plus data in 2001. The main results show that: 1) During the past 15 years, both the water area and main oasis area sharply decreased. The degree of oasis desertification process, at present, is more serious than before. 2) The most intense conversion among different landscape types was occurring in the transitional zone between oasis landscapes and desert landscapes. 3) As a result of the change of Ejin natural oasis landscape, the landscape patches shape complexity and its heterogeneity were obviously reduced. Moreover, the landscape texture became more and more coarser, the landscape diversity was decreasing and the landscape stability turned into unsteady. 4) Sharply decreasing surface water from the upper reaches of Heihe river basin is the vital factor for Ejin natural oasis landscape degradation in the past 15 years. The eco-environmental effects for Ejin natural oasis landscape induced by landscape change include the acceleration of groundwater mineralization degree, the degeneration of groundwater quality, the degradation of natural oasis vegetation, the decrease of species diversity, the increasing threats of sandstorms, the increasing quantity of ecological refugee and so on. In conclusion, the landscape condition of Ejin natural oasis landscape, today, is much worse than in the past years, with bad unsustainable developing trend.

The water and nitrogen applications are the two main factors that affect the nitrate leaching on farmland. The field experiment was conducted to analyze the nitrate leaching and yield under different nitrogen and water application rates in summer maize field. The result indicated that there was no distinct yield difference between the higher water treatment (with soil moisture controlled between 70%FC and 100%FC in 0～50cm) and the lower one (between 55%FC and 85%FC), while the nitrogen rate had evident effect on yield with the yield reaching the maximum at about 200 kg N ha^-1,and significant effect on nitrate leaching. Higher water application could accelerate the leaching of nitrate evidently. Under higher water level, the soil nitrate concentration peaks appeared at deep layers more easily than those under lower water level as an indication of nitrogen leaching, meanwhile the nitrate concentrations of soil water at depth of 200 cm were all higher than the national drinking water limit (10 mg NO^-3-N L^-1). Comparatively, under lower water treatment the nitrate leaching depths are all less than those under higher water treatment, but NO^-3-N L^-1 concentrations of soil solution under level of 200 and 300 kg N ha -1at the depth of 200 cm still exceeded the national drinking water limit (10 mg NO^-3-N L^-1). When NO^-3-N in 100cm soil profile came to about 450 kg N ha^-1 the soil NO^-3-N concentration at soil depth of 200cm would rapidly rise to 130 mg L^-1 from 40 mg L^-1 ,at the same time the nitrogen rate just reached 230kg N ha^-1,which mean that the nitrogen rate should be under about 230kg N ha^-1.

Intake excess of arsenic (As) can damage human health and may cause diseases. Routes of As intake are respiratory for dust and fumes, and oral for As in water, soil, beverage, and food. Consumption of vegetables from contaminated soils may be harmful to consumers health. In 1999, a serious As poisoning incident due to As contamination happened, more than 300 people were hospitalized in Dengjiatang, Chenzhou City, Hunan Province. Some 50 ha of paddy fields were contaminated and the farmlands were wasted for 4 years, though the source of As contamination had been cut off by local authority in time. Only a few vegetable fields can still be cultivated on the fields. There are few reports on revegetation or potential risk study of wasted As-contaminated farmland.We investigated the As concentration of plants and soils on the fields with different levels of As contaminations. Processes of natural revegetation of waste paddy and health risk of cosumed vegetables cultivated were investigated in the As-contaminated erea. It was found that revegetation in As-contaminated soil was significantly affected by the As-contaminated level. The amount of plant species was small and the weed biomass was the greatest in soil contaminated with low arsenic. The weeds grown on soil contaminated with medium level of As had the highest amount of plant species. The amount of plant species was the least and biomass of weed was the lowest in soil contaminated with high level of As. The species diversity was reduced by the present of Paspalum sp., a dominated weed, in the wasted fields. As concentrations in the edible parts of most vegetables were higher than the maximal permissible limit of As in food. Intake of As from consumed vegetables was 4.1 μg/kg body wt. per day in spring and summer, and 2.9 μg/kg body wt. per day in autumn and winter, respectively, both of which exceeded the level (2.1 μg/kg body wt. per day) set by World Health Organization (WHO).

The human race made great progress in science and technology and created unprecedented civilization in the 20th century. However, at the beginning of the new century, there are a number of challenges such as population, resources, environment and development etc. that have to be dealt with. Underlying all these challenges is the question of correctly understanding the relationship between humans and the environment and well coordinating the relationship between man and nature. The relationship between man and nature is reflected in man's dependence on and conscious activity in nature. Man cannot survive without nature, yet he is a force that can change nature. Man wants to change nature, but he is also restricted by nature. The relationship between man and nature is dependence, adaptation, conflict and harmony. The content of the relationship between man and nature changes as the human society changes. Man began to rethink his development pattern. The cruel reality requires that man should carefully examine the process of societal development, summarize the experience and lessons of traditional development patterns, seek new development patterns that reflect harmony between man and nature and responsibility to future generations. Strong anthropocentrism ignores the survival and development need of the ecological system and the long-term value of the ecological system to the human race. This approach over-emphasizes man's position and disregards natural objects, which runs into conflict with sustainable development and has been losing ground as a major paradigm. Biocen-trism weakens man's position and is too radical to be acceptable. Therefore it is necessary to build a system of environmental ethics fit for our times. The humans are a part of the natural world on the earth. Only when environmental protection starts from enhancing the overall interest of the earth can there be greater safety and tolerance. Human activities should be regulated by respect of natural laws and the intrinsic values of natural laws. And this is the basis of building the development pattern of civilization in the new time. Therefore, it is the duty of the scientific community to make publicity to and educate decision-makers and the general public on how to understand, respect and protect nature. Ecological and environmental impact should be taken into account in studying morality issues and in scientific research activities such as project evaluation and appraisal. Government regulation, market mechanism and moral regulation can work together. As to the conducts of enterprises and local governments, from a humanistic point of view, social price should be taken into consideration and as social interest is more important than corporate interest, we should not abuse non-renewable resources and should resist consumerism; from a naturalist point of view, we should carefully handle fragile environment, respect life, species and nature. Projects that utilize and change nature should be appraised and evaluated before hand. Government decision-makers may be influenced by scientists and attach importance to the opinions of scientists. Environmental ethics covers a wide area, including specific norms of conducts like birth control, resource conservation, ecological restoration, environmental improvement, clean production, reduction in pollution, appropriate development, rational consumption and protection of nature. We must pay attention to publicity and education to improve the citizen's awareness of environmental ethics. From the point of view of regional sustainable development more attention should be paid to environmental effects in regional resources utilization and exploitation as well as coordination and overall planning in development between various regions.

Recent geo-researches display two significant features. First, most research projects are centered on revealing the implications for regional sustainable development and ecological security; and second, these projects try to employ an integrated approach to taking both physical and socio-economic factors into consideration. Indeed, the implementation of sustainable development strategy demands a classification of territorial systems based on such an integrated approach. To be integrated, a key scientific issue is how to synthesize the physical and socio-economic factors in the process of classification. Based on a new indicator system, which involves mainly physical indicators at the macro level and socio-economic indicators at micro level while employing both at the middle level, this paper tries to develop a new integrated approach to the classification of territorial systems to reveal the features of human-nature relationship at various spatial levels. The new system of classification is a hierarchy consisting of five levels: class zero realm; class one ecological zone (and/or) sub-zone; class two land-human region; class three eco-economic division; and class four economic districts. The classification at the first three levels is a "top-down" process; that at the fifth level is a "bottom-up" process; and that at the fourth level is a matching process from both the top and the bottom. The paper further tests the new approach of classification via a case study of the Tibetan Plateau. By the approach, the Plateau is divided into 3 zones, 15 regions, 22 divisions and 29 districts. Such classification results have profound implications for regional sustainable development.

Susceptibility spatial analysis of debris flows is to evaluate triggering factors for debris flow occurrence and divide the land surface into zones of varying degrees of susceptibility, based on spatial analysis technology. For the purposes of assessing debris flow susceptibility, a GIS spatial analysis combined with condition probability model of susceptibility analysis can estimate the probability of possible occurrence of debris flows. This paper discusses the potential of combining GIS technology with susceptibility modeling in debris flow analysis and also outlines the special advantage of GIS application for susceptibility mapping. The study area is located in the Nujiang River Basin of Yunnan, where is seriously suffering from debris flow hazards. Seven factors impacting debris flow susceptibility are analyzed: slope angle, rock and soil type, rainstorm distribution, trainage density, land use, seismic acceleration and human activities. According to the susceptibility spatial analysis of these factors,the susceptibility evaluation map was generated using GIS to conduct factor integration analysis. Then we classified each factor into three grades based on results of susceptibility calculation. With regard to debris flow susceptibility index, the study area is divided in to three susceptibility zones. The debris flow susceptibility zona-tion map shows that the high susceptibility zone covers an area of 4147 km2 or 12. 8% of the total study area; the middle susceptibility zone covers an area of 13931 km2 or 42. 9% and the low has an area of 13931 km2or 44. 3%. The susceptibility zonation map can help planners or engineers to choose the optimum construction locations for implemen-ting land development schemes in order to reduce the impact of debris flow on the study area.

Stone forest is a kind of rarely-seen karst landscape, which has its own unique e-volution process. Based on the analysis of stone pillar-the individual component of stone forest, this paper, by discussing different combinations of the rates of edaphic corrosion, soil erosion and aerial erosion, puts forward the model of "triplex erosion" to explain the development of stone forest and studies the current development stage and evolutional prospect of the Lunan Stone Forest. The research reveals that the scope of edaphic corrosion, which is the basic driving force for the heightening of stone pillars, is limited within about 10 m below ground surface, and the depth best for the development of stone forest is observed to be usually less than 1.5m under the current natural conditions in the area. Since the top of stone pillars is lowering at a rate of 10. 4 mm/ka, and the bottom deepening 26. 17 mm/ka, therefore, the actual height increase of stone pillars is 15. 77 mm/ka; considering that the soil erosion rate in the area of Lunan Stone Forest is 650 mm/ka, the visible height of stone forest is increasing at a rate of 639. 6 mm/ka, and soil, an extremely significant factor for the heightening of stone pillars, is rapidly becoming thinner and thinner at a rate of 623. 83 mm/ka. All this shows that the best time for the development of Lunan Stone Forest has gone, though the visible height of stone forest is still increasing at present. The study result of the paper attaches great importance to the reduction of soil erosion in Shilin area. Therefore, it is necessary for the local people to take effective measures to prevent soil from being rapid eroded, especially, considering the stone forest in Lunan area a precious natural heritage owned by all human beings as well as local people.

By applying the isotopic technique on the water circulation study arisen in the middle of the 20th century, which is a new technology through the study on macroscopic changes of water molecules in the water circulation to achieve the combining study of macroscopic and microscopic water circulation mechanism. It is of very interest theoretically and practically for the study on the water resources characteristics in the basin to investigate the temporal and spatial variable rules of isotopes in the precipitation and the correla-tivity of the precipitation elements. Because stable isotopic technologies are being used all over the world to provide better links between the water cycle elements and the water resources characteristics. Much work has been done world-wide on δ¹⁸O and δD in rainfall, the best famous work is the precipitation sampling and stable isotope analyzing contribution of IAEA, which offers valid theory basis and practicing experiences to isotopic hydrology study. This paper takes Dongtaigou experimental basin at Tanghekou town Huairou district Beijing city in North China as study object, analyses the spatial and temporal change of the oxygen isotope in the precipitation from July to August in 2003, and then illustrates the correlativity between oxygen isotope ratio δ¹⁸O and rainfall, and the correla-tivity between oxygen isotope ratio δ¹⁸O and altitude. At last, this study evaluates the influence and effect of rainfall and altitude factors on the precipitation processes, illuminates the spatial and temporal distribution of δ¹⁸O in the precipitation during the sampling period, and offer basis for the later on study of water cycle in basin in the study area. This study draw some conclusions as follows: the δ¹⁸O spatial gradient in the basin is 0. 58‰/ 100m, the direction of the water vapor moving in the study period of time is from the south-east to the north-west.

Based on remote sensing imageries of 1967,1987 and 2000, and a digital elevation model with a scale of 1:250000, the key forces driving land use change and controlling land use pattern in the upper reaches of the Dadu river are found out from such biophysical and socioeconomic factors as terrain, elevation, roads, water system, urban and rural residential areas, and then the probability maps for each land use type are created by using Logistic stepwise regression, of which the goodness of fit is evaluated for all equations with the ROC (Relative Operating Characteristics) method. In this study, CLUE-S model which has the capability of modeling changes in quantity and location simultaneously, is applied to simulate temporal and spatial changes in land use from 1967 to 1987 and from 1987 to 2000 for an area of 18665 km2 which covers the counties of Rangtang, Jinchuan and Barkam. Comparisons for validation between simulated land use maps and actual land use maps of 1987 and 2000 find that Kappa index reaches to 0. 86 and 0. 89 respectively, indicating a successful simulation. For a better understanding of the future land use changes in the region, the same model is further put into application to predict spatial distribution of land use changes in 2010 for three scenarios associating with current governmental policy of "grain to green". The results of scenario analysis demonstrate that CLUE-S model can play key roles in land use planning and ecological construction, and is also a key part of decision-support system. In the scenario analysis, the changes in quantity are specified on purpose, and thus the simulation is focused on land use changes in location. This is because land use and cover changes in the upper reaches of the Dadu river are mainly driven by policies, especially for forest land and cultivated land, and changes in area are usually determined by government. Therefore, such an application of CLUE-S model is more suitable to regions characterized by policy-driven land use change, in which once the changes in quantity, such as areas of forest cutting, afforestation, grazing-forbidden, or planned reserves, are specified, then their changes in locations can be predicted with the same model. Furthermore, the spatial resolution of modeling can reach to a level of single grid cell.

Land use changes can not only change land cover, but also influence a variety of natural phenomena and ecological processes, including soil conditions, water runoff, soil erosion and biodiversity. The rational land use can improve soil structure, strengthen resistance to the environmental change, and the irrational land use can lead to land degradation, such as water and soil loss, land desertification. Daxing District located to the south of Beijing, was taken as a case study for illustrating the effects of land use change on soil fertility. The 1:50,000 soil map produced in the Second National Soil Survey (SNSS) in 1982 was digitized with GIS supporting. Top soil samples were collected from the same soil sampling sites of the 1:50,000 soil map with GPS reference locations, from May to June 2000. Three samples collected around each sampling point were mixed and a quarter of each sample was kept for laboratory analysis. At the same time, farmers were interviewed for fertilizer input, irrigation, yield, land management, etc. The soil samples were air-dried and ground to pass 0. 15 to 1 mm sieves in the laboratory. Chemical properties of soils were analyzed using standard methods. The content of organic matter, total N, available N and available P increased by 31. 02%,50%, 37.89% and 177% respectively, but that of available K decreased at the same time. The order of content changes of organic matter, total N and, available P is different between different land use types in 1982 and 2000, which is horticulture land> water land>irrigable land>vegetable land>dryland>forest land. Due to the transition of water land into irrigable land, vegetable land and horticulture land, the order of changes of organic matter, total N and available N is dryland> horticulture land> irrigable land> vegetable land, the order of the available P is horticulture land>irrigable land> vegetable land >dryland, the available P increased in horticulture land and dryland, but decreased in vegetable land and irrigable land to some extent. The order of organic matter and the available P is horticulture land> irrigable land> dryland, that of total N is dryland> horticulture land>irrigable land, and the available N is irrigable land > horticulture land > dryland, with the dryland transiting into irrigable land and horticulture land. The extent of the available K decreased, but the other nutrients of soil increased at the same time when sandy wasteland were transited into such land types as irrigable land, horticulture land, dryland, forest land and vegetable land.

Adopting the simplified water balance model, the average infiltration coefficient of precipitation and specific yield in the Hebei Plain between 1985-1995 are simulated, and the annual average groundwater level dropping down by water use sectors and crops is calculated on the basis of the above simulations. The results show that the water use in agriculture is the main factor resulting in the decline of groundwater level in the Hebei Plain, and the industrial and domestic factors are the secondary. In the piedmont plain, agriculture has led to a decrease of 0. 63 m per year, industry of 0. 08 m and domestic of 0. 03 m, with the individual ratios being 85. 1% , 10. 8% and 4. 1% respectively. While in the low plain, the order of the decrease is 0. 23 m, 0. 005 m and 0. 015 m per year with the ratios being 92. 1%, 2. 0%, and 5. 9% accordingly. In both areas, as to the major role causing the decline of groundwater level among the crops, wheat is the first, being 0. 33 m and 0. 127 m per year, while millet is the least, being 0.01m and 0. 004 m annually. As for water consumed in producing unit output value, wheat also occupies the first place, being 1. 35m3/yuan and 0. 91m3/yuan, or resulting in the largest decline of 0. 02 m and 0. 008 m in producing 100 million yuan of wheat each. While vegetable is the least, being 0. 25 m3/ yuan and 0. 19 m3/yuan, or 0. 004 m and 0. 002 m decline per 100 million yuan. With the decline of groundwater level, a series ecological and environmental disasters have been caused which have become the key factors restricting the socio-economic sustainable development of the Hebei Plain. Therefore, it is high time to adjust planting structure in order to achieve sustainable use of the groundwater in the Hebei Plain.

Differences in land use and land cover comprise a complicated process, which involves conversion of the natural soil ecosystem to an artificial ecosystem. This process may affect the accumulation of heavy metals in soils. The knowledge of the heavy metal concentrations for different land use types, which has been infrequently investigated, is of critical importance to assess human impact on heavy metal concentration in soils. Arsenic is a toxic heavy metal with an ADI (acceptable daily intake) of 2. 14 jug/kg body b. w. / day, according to the WHO. In this study, 500 samples were collected from 6 land-use types, including vegetable plot, paddy field, orchard, greenbelt, wheatfield, and natural soil, to compare differences between As concentrations of these soil-use types in Beijing. In comparison with background, the concentrations of As in the different land-use types increased to different extents. The accumulation of As in soils was widespread. Through ANOVA analysis, it was found that land-use type obviously influenced soil As concentrations. The natural soil type had the lowest concentration of As. The vegetable and paddy fields had the greatest concentrations of As. The intensity of anthropogenic activities, such as the use of pesticides, chemical fertilizers, and fuel combustion, was identified as an important factor affecting the concentration of As in soils. Using a baseline concentration as a reference, the ratio of all soil samples above this limit was 1. 8%, among which the ratios of soil samples from vegetable plot, orchard, and wheatfield were 2. 6%, 2. 7%, and 0. 7%, respectively. According to the mean concentrations of As, the order of the 6 land-use types, from the highest to the lowest As concentration, was paddy field > greenbelt > vegetable plot > orchard > wheatfield > natural soil. The environmental quality of paddy field and vegetable plot soils needs to be closely considered because of the high accumulation of As in these soil-use types.

Dissolved inorganic nitrogen of soil is liable to be transferred into surface or subsurface waters with surface or subsurface runoff. So it is important to measure ammo-niac(NH₄⁺) and nitrate(NO₃^-) in soils for estimating non-point pollution nitrogen load in a drainage area. Commonly, saturated CaSO₄ solution and 2M KCl solution are respectively used as soil extractant for NO₃^-and NH₄⁺ Their efficiencies are high and experimental results are stable. But it is uncertain whether the two methods are fit for non-point pollution research because the output characteristic of soil-soluble inorganic nitrogen is not only related with soil content but also is influenced by soil solution environment. Characteristic of natural rainfall and irrigation water is respectively similar to deioned water and 0. 01M CaCl₂ solution. So deioned water and 0. 01M CaCl₂ solution can be used as soil extractants to simulate actual soil solution environment when rainfall and irrigation take place. In this paper, measured results extracted by deioned water and 0. 01M CaCl₂ solution are compared with results extracted by saturated CaSO₄ and 2M KC1 solutions in order to clarify the relations among them. Four soil samples, which were gathered in the suburb of Beijing, were blended and shaken for 30 minutes with four extractants (6 extracting forms) (According to traditional methods of soil extraction, the ratio of water to soil is 5 : 1 when saturated CaSO4 solution and 2M KC1 solution were used. The ratios are 20 : 1 and 100 : 1 when deioned water and 0. 01M CaCl₂ solution are used. ). Then the extracted solutions were filtrated by 0. 45μm filter paper. The concentrations of NH₄⁺ and NO₃^- in the filtrate are analyzed with Salicin-hypochlorite Method and Griess-Ilosvay Method by Autoanalyzer Ⅲ Colorimeter (BRAN LUEBBE). According to the measured results, such conclusions are drawn: (1) the measured values of NO₃^- by different extracting methods are coincident with each other; (2) the measured values of NH₄⁺ are obviously different. The values of NH₄⁺ extracted by deioned water (ratio of water to soil is 100 : 1) surpass the others by far; and (3) the measured values of NH₄⁺ extracted by deioned water and 0. 01M CaCl₂ solution are not as stable as the ones by saturated CaSO₄ and 2M KC1 solutions. On the basis of these, four kinds of extractants are fit when a research is centred only on NO₃^-. Or else, fit extractant and ratio of water to soil must be selected according to the goal of the research and characteristics of the researched system.

Nowadays, in an open economic system, due to the increasing integration process in capital, financial and product markets, economic interaction across regions is becoming more and more important. The economic growth of one region is not just decided by its endogenous factors as before, but increasingly affected by its surrounding regions. Economists call this influence as "spillover". It is the mutual spillover of regions that brings the economic development of whole China. So, to know the spillover will obviously do great help to understand the economic developing question of China and to make effective regional economic policy. In fact, many scholars have conducted researches on this topic. For example, Mckibbin established Mundell-Fleming model between two countries; Douver set up GDP-spillovers models on multi-countries; and Conley advanced a complete framework to analyse spillovers based on all these ideas. In this paper, according to the new growth theory and the spatial interactions, we calculate the cross-province spillovers in China with the ameliorated statistical analysis model of the regional spillovers presented by Conley and Ligon(2003). The results indicate that: Most of the cross-province spillovers in China are positive, and those in the western part of China are negative except Yunnan and Xinjiang. Shanghai has the highest level of spillovers, so we call Shanghai as the economic center of China. Hubei province is key in regional spillover, hence developing Hubei economy can promote economic development in central and western China. As a result, we suggest that it is an important stratagem to promote the integrated development of Western and Eastern economy. Further we also think that an effective measure to revitalize Northeast China's economy is to offer some preferential policies which were given to Xinjiang now to Northeast China.

This article aims to explore the formation of the new industrial space in the Suzhou area in China driven by recent trans-border investment of Taiwanese IT companies in the last eight years and investigate the governance mechanisms of the local supply chains as well as its implication to regional development. We observed that the foreign brand-name companies had played important roles in propelling this wave of Taiwanese IT companies' trans-border investment in the Suzhou area. Although the strategic cooperation between Taiwanese OEM/ODM companies and foreign brand-name companies was consolidated, but the pressure from the foreign brand-name companies has changed the governance mechanisms of Taiwanese companies' supply chains and forged the dynamics of spatial agglomeration. We argue that the production networks' trans-border extension interweave with the exercise of power between enterprise organizations; and as to the new industrial space in the developing countries that were formed by the global production networks' transplantation, besides the essence of interdependence that characterized the industrial district's inter-firm relationship, economic geographers shouldn't ignore the asymmetric power relations that were embodied in the global commodity chains.

In recent years, the interaction between commercial development and population growth is a new active research area in human geography. This paper basically reviews the theories in the study on the spatial structure of urban commercial activities and discusses the several quantitative methods in commercial spatial analysis. However, the GIS and many other important spatial models have not been used very well in such a research. Based on the retrospection of domestic research concerned, the paper gives a detailed discussion on the analytical framework of the application of spatial interactive models in geographic distribution patterns between population and commerce in Haidian District of Beijing. As a matter of fact, the spatial interactive models including potential model and Lashmanan-Hansen model are successful analytical tools in transportation planning as well as urban and regional research, but these traditional models are seldom used in commercial spatial allocation and planning. In this paper, the calculation of population potential and the retailing probability (Lashmanan-Hansen model) in different areas in Haidian District generates two different spectrums. This kind of spatial spectrums are a significantly important way for better observing the spatial consistency between population distribution and commercial distribution. Therefore, the commercial spatial planning decision can be made according to the consistency and population growth forecast. This paper indicates that, since the 1980s, both population and commercial growth in Haidian District has been dramatically rapid than before. However, the quantitative analysis shows that there is little consistency between the development of population distribution and commercial distribution in Haidian District, which is the biggest administrative area in Beijing. The fact is that the commercial growth always lags behind population growth. In 2001, we can divide the commercial centers into four grades. Based on the results of population growth forecast and the spatial consistency, the commercial allocation for different areas in Haidian District has been calculated for spatial planning in the future.

The number of overseas tourists has been on the increase since the reform in China. During this period, there has been a distinct change in the status of urban Chinese destinations: new urban destinations have obviously attracted more overseas tourists; while the number of overseas tourists attracted to traditional ones have been decreasing. In the meantime, some cities tend to have either fewer overseas tourists or no obvious increase of overseas tourists. This paper explains the two reasons for the above change: one being the change in demand, the other being the transfer of the driving mechanism in urban tourism. The current research aims to analyze the latter reason. This paper uses Dalian, Shenzhen and Zhuhai as case studies to discuss the process and principles of the transfer of the driving force of urban tourism, and to testify the assumption this paper makes: that is, each urban destination has its own driving force mechanism, while the mechanisms can be different during different periods of development for the same destination. It is the transfer process of the driving force of the destination that changes the relative advantage of the urban destinations, which in turn causes the change in the relative status of the destinations. Accordingly, the paper concludes that the sustainable development of urban tourism depends on the change of its main driving force in response to it outside surrounding (mainly the change in the demand structure), so as to construct its new advantage before its earlier advantage is gone. Since the paper uses the number of incoming overseas tourists as the indicator, limitation of the study is unavoidable. Moreover, the three cities in the studies are all coastal ones, leaving room for further studies for its applicability.

The tourism in Beijing is the core and representative of the tourism development in China. But now the imbalance in the spacial and temporal distribution of the visitor flow in Beijing is getting worse. Therefore, it is very important to analyze the spacial and temporal distribution of the visitor flow in Beijing quantitatively, and take some action to alleviate this complexion. An on-site survey of Beijing's 12 typical scenic spots of different types, including Badaling Great Wall and the Imperial Palace etc, was carried out from May 2001 to May 2002. The real visitor flow condition was ascertained on the basis of the statistics of the on-site survey of these scenic spots to investigate the distribution of visitor flow in these scenic spots. Then an overall investigation of 183 important scenic spots was made, including monthly vistor reception, annual vistor reception and other static space configuration data. This paper analyzes the overall trend as well as the distributing character of visitor flow in scenic spots of city centre, suburbs and outskirts. We concluded that the spacial and temporal distribution of the visitor flow in Beijing is obviously imbalance; and to a certain extent, the supply of the tourism products can't meet the demand of the tourist market. Four maojor conclusions are: Firstly, the visitor flow mainly concentrates in the city proper and the mountainous area of northern Beijing, and the number of the visitors in the suburbs increases faster than that in the city proper. Secondely, the centralization of tourism time is intensified with the appearance of "the tourism golden week", which added the burthen to the senic spots during the midseason, especially caused the problem of the serious hotspot overcapacity. Thirdly, both amount of the senic spots and the competition are increasing, which is responsible for the decreasing of the vistor reception amount of some theme senic spots and traditional senic spots in the suburbs. At the same time, museums and a large amout of resembled new spots are facing a problem of the visitor shortage. Finally, the overall adjusting and controlling countermeasure for development direction, the spatial pattern of Beijing's tourist products, including improving the creativity of tourism product, attaching importance to the dragon-head effect and the centralization effect of the new product, leading the leisure tourism demand of the citizen to the suburbs, is presented. Besides, the adjusting and controlling countermeasures of visitor flow in scenic spots of the city proper, suburbs and outskirts is also proposed.

Based on the data of tourism sampling check from 1999 to 2003 in China, and in the context of spatial field effect,this psper uses factor analysis to show the basic character of domestic tourist flows origin, distribution, centralization, decentralization and their relativity of tourist flows spatial network. The results are as follows: (1) Economy is the main driving force of the tourist flows origin, the effect of cultural driving force is intensifying and tourist resource is the main driving force of the tourist distribution. Now, China has formed four tourist flows original fields and five tourist destinations. (2) Influenced by market principle, the hierarchical structure of tourist centralization fields and decentralization fields represents the spatial sequence model of K = 3. (3) The regional structure of tourist centralization fields show the character of "U" form, and the regional structure of tourist decentralization fields represent the pattern of "third class ladder". (4) The spatial network indexes of β and γ indicate that the relativity of tourist flows spatial network is feebleness. Finally, the paper regards that China should expedite the tourism development of the "two zones & three regions", namely the two zones of the Yangtze and Yellow river drainage areas and the three regions of the south coastal provinces, the north coastal provinces and northeast provinces in China. They are the key directions to push energetically the cooperation among tourist regions, endeavor to construct the tourist spatial network system, adjust and optimize the directions and quantity of tourist flows, as well as the key factors to enhance the network level of tourist flows.

This paper introduces the design and realization process of electronic sand table system for regional planning of Chongqing under the platform of ArcGIS by ESRI through secondary development by Visual Basic for Application (VBA). That it is called electronic sand table, sometimes digital sand table or virtual sand table, is contrast with traditional material sand table model. Unlike material sand tables, electric sand table is new high-tech product with integration of computer application, visual reality, Geographical Information System, virtual reality and multimedia. It can give users a real-time and interactive operation circumstance. Electronic sand tables break the limits of traditional sand tables such as large area, inconvenient for carrying, single content, and difficult to update. It has practical functions towards regional planning apart from the functions of traditional material sand table, such as assisting design planning scheme, managing spatio-temporal attribute of planning objects, analysing spatial affects and evaluating the planning blueprint, etc. In this paper, also, we analyse great significance of applying electronic sand table to regional planning and the profound effects that electronic sand table brings to regional planning. In the recent years, electronic sand table has been applied in many fields to a certain extent, such as military affairs, irrigation works, real estate, fire protection, but little in regional planning. From this article, we provide a new mode in which we carry on regional planning and we successfully test it through taking the Chongqing city as a case. This mode breaks the traditional idea, its vividness and third dimension can help geographers and regional policy decision-makers to gain a better understanding of the regions, and electronic sand table will become their right hand some time later.

This paper studies the principles and method of fast remote-sensing information extraction for urban built-up land, taking Fuzhou city as an example. With the detailed analysis and clarity of several existing normalized difference indices, the study selects three indices, Normalized Difference Built-up Index (NDBI), Modified Normalized Difference Water Index (MNDWI) and Soil Adjusted Vegetation Index (SAVI) to represent three major urban land use/cover classes, i. e. , built-up land, water body and vegetation, respectively. The three index images are generated from a Landsat ETM + subscene of Fuzhou city and then used as three bands to compose a new image. This dramatically compresses the original eight-band ETM+ image into a three-band image, reduces band correlations and data redundancy, thus significantly simplifiying the band spectral analysisprocedures. The spectral signature analysis only needs to be performed on this three-index composite image and the signature differences among the three major urban land use/cover classes are revealed much easier than being done with multi-bands. Based on the revealed signature differences, the built-up land is finally extracted through a simple logic calculation. The result achieves a 91.3% overall accuracy. Therefore, the method is a fast and accurate one for the remote-sensing information extraction of urban land use without human interference. In addition to the above built-up land information extraction study, the paper proposes a Modified Normalized Difference Water Index (MNDWI) based on the NDWI of Mcfeeters (1996) , which uses MIR wavelength (ETM + band 5) instead of NIR wavelength to construct the index. The replacement largely enhances the contrast of the water bodies with the other land use/cover classes and reduces the spectral confusion with the other classes. Therefore, the MNDWI is more suitable for delineating features of polluted urban rivers/lakes. The advantages of using SAVI instead of NDVI in the urban study are also discussed in this paper.

The modern regionalization in China has attained plentiful and substantial achievements in recent 50 years and has made important contributions to the socio-economic construction. Meanwhile, great changes have taken place in the natural and socio-economic patterns in China. So it is indispensiable to develop comprehensive regionalization as the basis of the sustainable socio-economic development for China. The main scientific issues to be discussed are as follows: 1) the target of service and the mission of research; 2) the theory and system of comprehensive regionalization; 3) the changing processes, patterns and their interactions of the main elements in regional system; 4) the identification of the boundaries between the regional systems in China; 5) the identification of typical regions and the analysis on their characteristics; 6) the interaction between the global geographical patterns and the comprehensive regional system in China; 7) data mining, processing and dimensioning; 8) the integrative methodology of comprehensive regionalization; 9) scenario analysis for the future evolution of regional system in China; and 10) the dynamic demonstration system for the comprehensive regionalization.

Based upon a review on foreign regionalization work, this paper summarized the characteristics of the regionalization work in different stages, gave a brief introduction to the methodology in the regionalization of China, and discussed some issues on the regionalization work. Since the latter half of the 20th century, the regionalization in China has entered a stage of systematic research and all-around development. The main characteristics of the regionalization work in this stage are as follows. First, the various regionalization schemes are based on their historical background respectively. They are the scientific work closely related to the economic development and social demands at the time. Roughly speaking, research on the regionalization in China had mainly served agricultural production since the 1950s. Since the 1980s, the research had been concentrated on economic development. Since the 1990s, the regionalization work has been focused on sustainable development. Second, the work was mostly static and was not able to reflect the dynamics of the changing natural and social factors. And several important boundaries were identified with some assumption and presumption. In recent years, some trends of overemphasizing models and quantification have appeared in regionalization studies. Third, the regionalization studies were inclined to physical geography. The economic geographical regionalization studies were relatively weak. Moreover, current physical and economic regionalization studies are not well related, which has become a limitation to the research of regional sustainable development. Fourth, current regionalization studies focus on terrestrial system, and haven't paid enough attention to marine system. Fifth, the confirmation of regionalization schemes is not institutionally assured yet. So the research results have not been well absorbed by the economic planning of local governments, and the purpose of serving the sustainable socio-economic development has not been realized. Finally, the necessity and importance of carrying out comprehensive regionalization in China was analyzed, and some key scientific issues related with the comprehensive regionalization of China were discussed. The paper pointed out that as a new growing point of regionalization researches, comprehensive regionalization with an integration of natural and social factors will be an important contribution of the human-earthsystem research to the sustainable development.

More and more attention is paid to the combination of global and regional issues in the sutdy of global environmental change (GEC). The GEC research emphasizes that the global environmental problems should be probed through regional studies. Resources and environmental problems have become one important issues of GEC research. The geographical environment of China has significantly changed during the past 50 years due to the intense anthropogenic activities and the global environmental changes. The main changes of the physical processes and environment elements are as follows: 1) the shift of climate zones in response to global warming; 2) the uneven precipitation changes inducing more floods in southern China and more severe droughts in northern China; 3) serious pollution and enormous demand on materials and energy; and 4) the significant changes in natural hydrological process. As to the geographical patterns, the economic geographical pattern has changed in the process of industrialization, which brought changes as well to the patterns of population, urban system, and supply-demand of natural resources. As a result, the land cover pattern has been greatly modified. The urban and transportation area has expanded quickly and occupied a great deal of farmland, causing farmland reduction in core agricultural area and cultivation increase in marginal agricultural area. The natural forest area is reducing while the forest plantation is expanding. The grassland is shrinking and has seriously degraded. The area of lakes and wetland has decreased, and the sea farming area has remarkably increased. The above-mentioned remarkable environmental changes indicated that some irreversible changes on environmental elements have taken place, and the resources and environment have become key limiting factors to national security. The future development of China is facing critical challenges from various risks on resource and environment issues, e.g. climate risk under the global warming, the risk of farmland and food supplies, the risk of water resources, the risk of energy, the risk of mineral resources, the risk of environmental quality, and the potential risk of some great projects. The geographical environment of China should be studied from the global views.

Though the Bohai Sea hydrodynamic processes have been investigated and researched for a long period, because of its transpositional meteorological forces, its natural environment and the nonlinear interaction within the water column, it is impossible to thoroughly understanding of the hydrodynamic characteristics, especially those related to the sediment transport, i.e., the Lagrangian residual circulation （LRC hereafter） in the Bohai Sea, which is the key hydrodynamic processes we concern. By using the three-dimensional baroclinic model-ECOM, driven by the monthly-mean wind stresses calculated by Helleman and Rosenstein, the general circulation patterns and spatial-temporal variations are simulated, in which, three possible states, i.e., net wind-driven LRC, net tide-induced LRC and the coupling result of the above two factors, are considered. The tide-induced LRC of M₂ constituent bears an identical pattern in four seasons in the Bohai Sea: the amplitude of the surface one is weak, and non-directional; however, there exists a southeast current from the Bohai strait to the Laizhou Bay, and a weak anticlockwise gyre in the south of the Bohai strait for the bottom constituent. The amplitude of bottom tide-induced LRC is larger than the surface one, and moreover, it bears a significant contribution in the whole LRC in the Bohai Sea. Unlike the identical structure of the tide-induced LRC, the wind-driven LRC varies seasonally under the controlling wind field. It forms a distinct circulation under the summer and winter monsoons in January and July respectively, but it seems weak and non-directional in April and September. The amplitude and direction of the wind-driven and tide-induced coupling LRCs are controlled by monsoon, which is one of the most significant factors in the Bohai Sea. There exists an anticlockwise gyre from the west coast of the Bohai Sea to the Laizhou Bay, a clockwise gyre within the Liaodong Bay, and a weak clockwise circulation in the middle of the Bohai Sea in winter. And there is a clockwise circulation along the shelf of the Bohai Sea, and an anticlockwise gyre in the Liaodong Bay in summer. Furthermore, the tide-induced LRCs, whose bottom component is the dominant one, plays an important role in local LRCs, especially at the Laotieshan waterway, east of the Liaodong Bay, top of the Bohai Bay and the estuary of Huanghe River.

Karst rocky desertification is a kind of land degradation which has happened in fragile karst mountain ecosystem in Southwest China. The unsuited matching at vertical direction and unreasonable special distribution at horizontal direction of landscape use make the landscape degradation a major problem in karst mountain areas. But little is being understood about the interrelation between the spatial distribution of rocky desertified land and the rocky desertification processes. This paper analyzes the ecological conditions of 5 special peak cluster-depressions which are at different desertification degrees on the southern slope of Huajiang karst gorge based on field investigation, the change of landscape pattern indexes and their ecological significance, in order to understand the ecological spatial character and evolving procedure of karst mountains from landscape ecological viewpoint. Results indicate that the diversity index, dominance index and evenness index relate closely to the landscape matrix of peak cluster-depressions, and show different ecological significance in different rocky desertified peak cluster-depressions. With the increase of rocky desertification intensity, the diversity index is in a decreasing trend while dominance index in an increasing trend significantly, the evenness index decreases firstly and then increases when rocky desertification develops further, the isolation and patch area of naked rock increase gradually but isolation of grasslands, shrub and woodlands increases while their patches area in a reduction. The landscape of potential rocky desertified peak cluster-depressions is even more seriously fragmentized than light and moderate rocky desertified peak cluster-depressions, and fragmentation is most in all peak cluster-depressions. The landscape patterns and development modes of potential rocky desertified and strong rocky desertified peak cluster-depressions represent two typical types of rocky desertification in southwest karst mountain areas. This paper shows that the processes of karst ecosystem rocky desertification depends on the distribution, fragmentation and conjunction, not merely the absolute quantity scale of naked rocks and vegetation. The analysis of landscape pattern emphasizes not only area, but also the relations and influence among rocky desertification processes, the spacial pattern of rocky desertification and landscape element character, therefore, landscape should not be neglected in the studies of rocky desertification degree and indexes, landscape patterns, landscape diversity and patches closely correlating with rocky desertification process must be taken into account in the assessment of the karst rock desertification degrees.