This paper is devoted to introducing the concept and ideas of GeoComputation (GC) to Chinese geographers. GC is regarded as the application of computationally intensive approaches based on high performance computing to solving geographical problems and to explaining geographical phenomena. One of the origins of GC is linked to computational science with a principle of the use of models to gain understanding. GC includes all the tools of quantitative geography, but it is not the development of quantitative geography. GC was covered in some GIS books, but it is not another name for GIS. In addition to the greater computational efficiency and fuzziness provided by computational intelligence technologies, GC can improve the quality of study results by using computationally intensive methods to reduce the number of assumptions and eliminate the irrelevant simplifications imposed by computational constrains. A problem is that we don’t know what ‘core GeoComputation’ is. In order to make the diverse research efforts on GC convergent, we should have computational geography become the principal part of GC, which seems to exceed the limit of geography.
Taking the upper reaches of the Shuhe River in Juxian County of Shandong Province as a case study, this paper analyses the spatial distribution and environmental characteristics of Dawenkou, Longshan and Yueshi cultural sites. Then a GIS-based logistic regression predictive model is built for the archaeological sites in the upper Shuhe River so that the quantitative relationships of the sites distribution with the altitudes and rivers distribution are identified. Results show that the archaeological sites in the upper Shuhe River were located in areas with lower elevation and slopes less than 3°, indicating that the sites were distributed in areas that were more suitable for local agricultural activities. In terms of the direction of the site selection, there was a more balanced distribution, with the west, southwest, east and southeast dominating the entire study area. The settlements in pre-historical periods were mainly located along the tributaries but far away from the mainstream so as to avoid flood disasters. With the elapse of time, the altitudes and slopes of the sites as well as their distances to the rivers tended to increase, which were related with the increased human ability to overcome environmental constraints.
The traditional economic data expression is based on the administrative regions at county or province level, which conceals the inner difference of the calculation area. It cannot satisfy the requirement of the study of resources and environmental sciences.Land use data integrate lot of information of factors affecting economic distribution. A close spatial relation between land use and economic distribution can be established using the data of the nature of land, the production mode of primary industry, the input and output of industry, and the proportion of service in China. After analyzing the characteristics of the regional economic development, we consider the GDP of counties separately and constructed the model based on land use for three types of industries to simulate the difference of GDP in arid area using 1 km × 1 km grid-cells. To the primary industry, we considered the influence of land-use type and land quality, the area weightiness method is adopted, using linear equation to fit it; According to the influence of road on secondary industry, a road-based counter-distance weighted model is built to calculate the secondary industry output indices, and then the spatialization of the secondary industry output is implemented. For the output of tertiary industry, a power exponential model based on the scale of town and the distance from the center of town is derived from distance decay function. We take the GDP data in the northern piedmont of the Tianshan Mountains in Xinjiang in 1995, 2000, 2007 as a case. The results show that the precision of each simulation result is high both at industries and counties level, the relative errors between the simulation results and the statistical ones are all below 1%. From the distribution map, we can see that the high value areas are mainly distributed from Miquan to Shawan, and dispersed radially from Urumqi, Karamay and Shihezi to their surrounding areas. In city area, the GDP density is decreased from the inner city to the outskirts, and the downtown GDP density is much higher than the suburban one. This is highly matched the fact. The time series analysis reflected the process of regional economic development and fit the distribution characteristics of regional economy well. Compared with other models, the simulation method we used in this case is more practicable and effective.
From the 1990s onwards, human geographers in Western countries have done a lot of research on cultural/creative industries with other disciplines, such as sociology, communication and media, urban planning, and economics. The researches involved many subjects including the agglomeration of cultural industries, the relationship between industries and city environment, and the methodology of study in this field. As cultural/creative industries are a new phenomenon in economy, there are many disputes in these subjects. Geographers in western countries have gained great success in the area, and given actual impact on urban policy and cultural policy. Compared to the progress in cultural/creative studies made by western geographers, studies in the field in China are just starting up. Thus geographers in China are suggested to focus their current research in the field on several subjects which include the policy of creative cluster, the impacts of local milieu to the development of cultural/creative industries, and the combination of the theories from cultural studies, economics and geography.
The theory of urban spatial interaction is an important basic theory in urban geography. For the theoretic models come from occident， our country correspondingly lags and research mainly on there demonstration， more research should be done in theory. This paper analyzes the principle of the noted theoretic models of urban spatial interaction. Considering breaking-point model has been applied widely and verified in practice. Its limitation, evolvement and expanded form were principally studied.Reily put forward Law of Gravitation on Zero-Sale in 1931 according to Newton’s Law of Gravitation. Converse expanded the theory， brought forward Breaking Point Theory and gave the computational formula in 1949. Because the theory just gives only one breaking point between two cities， many methods for partitioning space are used， for instance， making vertical line through the breaking point on the linked line between the two nearby cities and linking the nearby breaking points with smooth lines. In fact, ， these are not feasible and not rigorous. Other conventional theoretic models of urban international action, including Gravitation Model and Potential Model， also have obvious limitations.
Although geographical boundary is usually fuzzy and uncertain， it is still valuable in theory and actual application if we can find an advantageous and correct method for delimiting the urban abstracted regions. Considering Voronoi diagram’s geometric particularities， the rationality for dividing up space and the solvability by computer， some researchers tried to apply it in expanding and validating classical Breaking Point Theory. The method of compartmentalizing urban influential space based on ordinary Voronoi diagram ignores urban compositive strength， and the method based on weighted Voronoi diagram doesn’t take the geographical principle into account. The scientific meaning and rationality is demonstrated in theory about integrating breaking-point model and Voronoi diagram. The expanded breaking points model shows that in a well-proportioned plane， the boundary between two city’s abstracted regions is the vertical bisector of the connected line with them if the cities’ weights are equal; the boundary is an arc if the weights are not equal; the orbit of all the breaking points in the plane forms ordinary Voronoi diagram and weighted Voronoi diagram accordingly; and each city’s weight equals to the square root of its central strength value in the second situation.
Apocalypses can be received from analyzing the principle and evolvement of the theoretic models of urban spatial interaction， which geography is an intersecting and practicing subject which sets the complicated natural and human phenomenon as studying objects， it is necessary that geography should use the new theories， techniques and methods for reference， which is the keys for developing itself.
City spatial cognition research included cognition of place name, city image, cognitive distance and cognitive distortion. The national research of spatial cognition began in the 1980s, focusing mainly on the city image. Research of place name is more focused on the origin and meaning, less involved in the form of space. The purpose of this paper is to analyze the pattern of cognitive space based on a large number of questionnaires, then explored it’s genesis deep. The main methods are spatial interpolation of ARCGIS and spatial autocorrelation of Geoda095i. Four conclusions were obtained as follows: Firstly, the type of cognitive point is not the influencing factor of cognitive rate. Secondly, the spatial cognitive pattern showed a ">-shaped pattern". The two peaks of Beijing Railway Station and Peking Zoo uplifted in the northwest - southeast direction, and saddle lied in lower Sogo Department Store in low recognition rate area. Thirdly, the cognition of residents had clear spatial relevance and scale-dependent. Cognition among sites is high-high, low-low comparability in less spatial level, but it is high-low otherness in larger spatial level. 6km is their boundary. Fourthly, cognitive space can be divided into four sub-regions: Beihai Park, Zhongyou Department Store, Peking Zoo, and Chengxiang Entrepot. The sub-region is homogeneously high cognition area, and contains many cognition peaks.
Most economic activities occur in cities. A city, as a regional pole of growth, drives the whole regional economics to develop. There is such a situation especially in the region of Zhujiang Delta in the medium-term of industrialization. But what is the cause of urban growth? In this paper we utilize the framework of new economic growth and new economic geography and try to study the effects of increasing scale return of the density of economic activity. The paper starts by discussing the related literature and points out that there are some puzzled things at the studies about sources of urban scale’s growth in the economic theoretical circles. In Section 2, we analyze three models about the relation of city size of population and urban growth and the relation of the density of economic activity and urban growth under different hypotheses. In Section 3, we utilize the data of the region of Zhujiang Delta and Hong Kong to make regression analysis and comparison analysis. The main result is summarized in Section 4, that is: from the perspective of the external-economic approach, the monopolistic competition approach or the human capital approach under the premise of external-economy, the spatial density of economic activity is the result of agglomeration on one hand and on the other hand it can also promote the returns of scale economics and accelerate urban growth. So the density of economic activity can become the main endogenous source of aggregate increasing returns in the certain increasing range to promote urban growth.This paper both gives a theoretical basis for August Losch’s way to determine the location of city system in market density and shows a very effective path to drive the regional economic integration through the point-axle economic system for regional economic development.
Since 1996, China has ranked the first place in producing crude steel. As iron and steel industry in China has been rapidly developing, its spatial pattern has evolved a lot. In the early 1980s, when China launched the Reform and Opening-up policy, the majority of iron and steel industry concentrated in few provinces such as Liaoning, Shanghai and Hubei, displaying an unbalanced spatial pattern. During the years of 1985-2002, Chinese iron and steel industry spread to North China and East China, because industrialization and urbanization developed rapidly in these regions. However, the spatial pattern of Chinese iron and steel industry turned back to the unbalanced state after 2002, because more and more steel production capacity concentrated in the coastal areas, especially in the Bohai-Rim and the Yangtze River Delta. By calculating the Coefficient of Variation(Cv), the evolution of spatial pattern of Chinese iron and steel industry can be demonstrated. In addition, changes of concentration ratio can be used to investigate the evolution of spatial pattern on an enterprise scale. This paper analyzes the factors which have affected the evolution of spatial pattern. In different periods of time, factors exerted different influences. Domestic supply of iron ore once determined the spatial pattern of Chinese iron and steel industry from the founding of P.R.China to the late 1970s. In the last 20 years of the 20th century, due to rapid industrialization and urbanization, large demand for steel products led to the spatial pattern to spread in China. In the context of globalization, overseas market and iron ore supply are playing a more and more important role in affecting the spatial pattern of Chinese iron and steel industry. In conclusion, domestic and global factors, such as market demand, investment, raw materials, and policies, have influenced the spatial pattern of Chinese iron and steel industry. As a result, it tended to be concentrated in the coastal areas.
The study of regional ecology focuses on socioeconomic metabolism as one of the important issues by International Human Dimension Programme of Global Environment Change. Combining the idea with emergy synthesis, originally established by H.T.Odum, this paper analyzes and updates the social metabolism of Guangdong province on the aspects of the variety, efficiency and metabolic status of resource utilization in 2006. Through decades of emergy indicators, the conclusions are drawn as follows: Guangdong developed well as a whole in 2006. It had high level of emergy welfares with per capita 1.60×1016 sej and the emergy surplus was about 57.31×1022 sej, showing the increase of its real wealth, but the imported emergy was 0.73 times of total emergy use and the waste ratio was 0.26, while the environmental loading ratio was 14.36 in 2006. Some problems has emerged such as the excessive use of resources, the over-dependence on import, the overfull output of wastes and the serious environmental load. The emergy sustainability index is also decreasing year by year. At present it still presents a linear operational pattern and will have negative effects on its environment and development. Therefore, it is necessary to optimize and reform the metabolic course to the circular mode. In order to improve the harmoniousness between the nature and the society of Guangdong Province, the paper proposes to set up low-cost and high-benefit industrial systems, to increase the development of alternative resources and new energy, to enhance the capacity of waste treatment and to perfect the metabolic mechanism in the future.
From the mechanism of river flow and sediment movement, this paper built a model for forecasting sediment concentration of an alluvial river by combining stable sediment nonequilibrium transportation model with discharge distribution model along channel which was derived from the assumption that the amount of river water regulation for the linear reservoir regulator. The observations of water and sediment from the Huayuankou to Jiahetan section and from the Longmen to Tongguan section at the Yellow River had been used to verify the proposed model, which indicated that since the change of discharge along channel has been considered, the proposed model made better forecasting performance than stable nonequilibrium transportation model used solely and the forecasts were reasonably satisfied.
Sediment (also called total suspended solid) river loads and associated particulate nutrients (POC, PN and PP, etc.) greatly influence the ecology and biogeochemistry of estuary and coastal marine environment, leading to water eutrophication. River transport of particulate nutrients is important from regional and global biogeochemical perspective, as POC, PN and PP constitute major portions of C, N and P transported from land to sea. In this paper, the authors summarize progress in river transport of sediments and particulate nutrients in both global and regional scales. In methodology, the study on estimates of particulate nutrients is based on the river sediment load. During the 1950s-1990s, most researches were focused on the impacts of natural processes on the transport of sediments in rivers, and the global river sediment load to the sea was estimated to vary between 8.8 and 64 Pg yr-1. But at present, more attention is paid to the impacts of human activities, and the estimates of global river sediment load to the sea ranged from 11 to 27 Pg yr-1. For the models of river sediment and particulate nutrients reported, most of them were built on global scale. The global river export of POC, PN and PP varied between 170-210 Tg yr-1, 21-30 Tg yr-1 and 9-20 Tg yr-1, respectively. Further calibration and test would be required for these global models to be applied in a specific basin.
Overland flow is the main cause for slope erosion, which has unique hydrodynamic characteristics. This paper made a systematic and thorough discussion on the flow pattern, frictional resistance, mean flow velocity measurement and runoff energy of sediment-laden overland flow, sediment concentration as well as the impacts of the above. Reynolds number (Re) and Froude number (Fr) are used to express flow pattern. The branch point of Re exists in the definition of “laminar flow”, and raindrop splash is the main reason for its specificity. Fr of overland flow free of sediment on bare soil is generally considered to be >1. Different flow pattern results are also obtained in the meager literature of sediment-laden flow. However, most scholars believed that sediment-laden flow belonged to tranquil flow. There are different values of Darcy-Weisbach Friction Coefficient (f) in different experiments on hillslopes, and the factors that affect f are Re, water depth, Fr and sediment concentration. On the study of sediment-laden flow, f is closely related to Re, but the tendencies are quite different. In addition, f is inversely proportional to Fr, and on the contrary, it is directly proportional to sediment concentration. Many measurements of surface flow velocity have their respective advantages and disadvantages. Exact instrument is characterized by high price, required routine maintenance and harsh work conditions, which is usually used to measure overland flow free of sediment. So, exact instrument is not suitable for sediment-laden flow temporarily. The accuracy of flow measurement with tracers is not high, but the process of tracers diffusing would be slower through the effect of sediment concentration. As a result, using tracers to measure the velocity of sediment-laden flow is still applicable. Formulas for velocity of overland flow are usually simulated by a power function of discharge and slope gradient, and there are a negative relationship existing between flow velocity and sediment concentration. Runoff energy is synthesis of hydrodynamic characteristics of sediment-laden flow on hillslopes. Most scholars use different formulas of water potential energy to express runoff energy. Generally speaking, the runoff energy consumption of shallow flow on slope increases as sediment concentration increasing. On the basis of reviewing recent research at home and abroad, deficiencies from experimental device and skill and experimental content are also discussed. The main problems of experimental device and skill include low-precision of velocimeter and poor comparability of data. Besides, results of every hydrodynamic parameter acquired by experiment are almost about its average values of the whole hillslopes, and most experiment has been done under the condition of overland flow free of sediment on gentle slope. Finally, the corresponding suggestions are put forward to provide a theoretical basis for slope erosion mechanism and slope erosion model perfection.
The prediction accuracy of a distributed hydrological model depends on how well the model input spatial data describe the characteristics of the watershed. Especially, in a large scale catchment, could a higher resolution of input data contribute to a more accurate result? As an important component of input data, soil information directly impacts the accuracy of the simulation of hydrologic model. In this study, surveyed soil data with two different spatial resolutions were used as input data for a SWAT model simulation in a large scale catchment of Xinjiang River basin (15535km2) in China. Simulations of stream flow, soil water storage and evapotranspiration using the two soil datasets were compared, and the applicability of fine resolution of soil data was analysed. The results indicate that the different resolutions of soil data have a great impact on the distribution of hydrological response units in the SWAT model, but show no obvious differences in stream flow simulation and evapotranspiration (ET). Our observations also show that the lower resolution data improved slightly in average monthly stream flow simulation before and after calibration, but there is no substantial difference. The finer resolution data produced a higher monthly soil water storage (SW) simulation than the lower resolution data across the whole watershed during the simulating period. Results also show that the evapotranspiration calculation method in the SWAT model is insensitive to soil resolution. The implications of this study are that improvement of the resolution of soil data does not necessarily contribute to a more accurate prediction of streamflow in large scale catchments. In practical studies, modellers need to select an appropriate resolution of soil data depending on the scale of watershed and the level of accuracy required, and also need to consider the principle of the model and the physical meanings of some key parameters to explain the simulation result.
In this paper, the scope of land reclamation is defined to be below the mean high tide level of the coastal zone. The dynamic changes of reclamation in Shenzhen have been analyzed by extracting single-band images and converting binary Images, on the basis of a series of remote sensing images(MSS,1978), Landsat TM(1986), Landsat TM(1995), Landsat TM(1999), Spot(2004). The reclamation rate of 1978-1985 is 146.31 hm2/a， that of 1986-1994 is 304.55 hm2/a, 1995-1998 is 337.16 hm2/a, and 1999-2004 is 273.59 hm2/a. The reclamation rate in Shenzhen was fast, ecperiencing a faster to the fastest period, but it became slowed down recently. This paper not only shows the different rates and distributions, but also discusses the different roles of the four periods of land reclamation in Shenzhen. As the reclamation may induce great changes to the coast zone, it requires serious considerations. Therefore, the driving forces of the dynamic change are analyzed combining with the progress of urbanization of Shenzhen city in the period of 1979-2004. This paper establishes a comprehensive driving forces system of reclamation, including four aspects of change: location, policy, socioeconomy and coastal natural conditions (environmental problems). Shenzhen is near Hong Kong, which is the key factor to improve the reclamation projects of Shenzhen and also the driving force for the development of Shenzhen city in the early years. The changes of the policy and laws of land use in China since 1979 make great profit of reclamation, but the laws of protecting against destroying coastal zone limit the projects of reclamation. In the regression of relationship between the reclamation and the economic factors, it is found that the growth of population improves the reclamation, but the growth of infrastructure investment decreases the reclamation. The coastal natural conditions limit reclamation project. The reclamation has affected the environment of Shenzhen and Hong Kong, limited by the problems of reclamation, the growth of reclamation in Shenzhen has decreased. The system of Shenzhen reclamation is complex but evolves to a more scientific direction.
The research on driving mechanism of land use change has been a hot spot in geography， and the research on relationship between land use change and influencing factors is a key for revealing driving mechanism of land use change. Jiaodong region in China witnessed rapid socical and economic development from the 1980s to 2000. Study on relationship between land use change and influencing factors in this region has important theoretic and practical significance. Vector data of land use of Jiaodong region in the 1980s and 2000 were overlaid each other， and the regions of land use change were obtained. The area of major land use conversion types and their proportion to total change area were calculated and the matrix of land use change samples was constructed. The data of land use change and the data of urban site， road， DEM， population density， GDP and coastal line were overlaid respectively， influencing factors of land use change spots were obtained， and the matrix of influencing factors of land use change was constructed. Based on these data， Canonical Correspondence Analysis (CCA) was used for revealing the relationship between land use change and influencing factors. The study result showed that urbanization， expansion of construction land and substantial decrease of farmland were the main characteristics of land use change in Jiaodong region from the 1980s to 2000. Population density， the distance between land use change site and urban site， elevation， and the distance between land use change site and main road were the main influencing factors for distribution of major land use conversion types， and the next were GDP and the distance between land use change site and costal line. The conversions of farmland to urban land and rural residential land to urban land were mainly in the areas near urban sites and main roads with high population density and high GDP. The conversions of farmland to rural residential land were mainly in the areas near urban sites and main roads with lower elevation.
Under the support of GIS spatial model building, the traditional land potential production degression model has been used to compute photosynthetic productivity, photosynthetic thermal productivity, climatic productivity and cultivated land potential productivity step by step. The paper uses RS data to drive model building: first, the research estimates evapotranspiration through GMS-5 to compute climatic productivity; second, the research extracts spatial location of cultivated land and its type to compute cultivated land potential productivity. The results show that the quantity difference between cultivated land productivity estimated by the model and grain output is 10%, while cultivated land potential production is 30% higher than the present yield. At the same time, the research indicates the cultivated land potential production is highly affected by elevation, slope and water source.
The compensation for requisitioned land has become a hot question concerned by land managers and our society. Establishing integrated section price of land expropriation and "requisite land by value" is the direction of expropriation compensation system in China.
According to analysis on the research progress of land expropriation price, combining the composition of agricultural land price, applying the theory of land expropriation integrated section price, adopting quantitative and qualitative methods, the author discusses that the integrated section price of land expropriation should include the following four parts: the quality price, the social security price, the social stability price and ecology price. The methods of division of the expropriation blocks and calculation of the expropriation land price are discussed.
Taking the commercial center of Hohhot as a basic point, the space distribution shows that the grade of expropriation section and the integrated section price of land expropriation reduce with the increase of the distance, and spatial variation is evident. Comparing it with the standards of expropriation compensation surrounding counties, we validate that the integrated section price of land expropriation evaluation system is rational. The research results can serve the requisite land process and perfect the rural land market in Hohhot.
The characteristics of inter-annual, inter-regional and regional agricultural land use intensity are studied based on the production cost. The German classical formula is used to compute the intensive use degree of Luancheng, Zunhua and Zhangbei counties of Hebei Province, based on the database of Hebei. Intensive use of arable land in Hebei Province experienced a four-stage development progress of "two-speedy and two-steady". The intensity distribution of regional agricultural land is Luancheng≈Zunhua＞Zhangbei, the proportion of labor-intensity to the agricultural land use intensity is Zhangbei＞Luancheng＞Zunhua. With the economic and technological development the agricultural land use intensity is rising, and the inter-regional land use intensity is affected by the location of plots, resources and other conditions such as micro topography.
This paper tried to explore the comprehensive evaluation system of regional urban land intensive utilization from land use intensity, land use investment, land use benefit,etc. Based on the actual conditions, using principal component analysis and clustering analysis, this paper made comprehensive evaluation on the intensive land-use level of Shandong Province, analyzed the changing situation in space and time, provided reference for macro guidance in urban land intensive use and changing land use pattern. The results showed: (1) The level of urban land intensive use of Shandong Province constantly improved from 2000 to 2005, while decreased a little in 2006; (2) the level of urban land intensive use declines from coastal cities to inland cities, with the southwest cities having the lowest level; and (3) economic development level is the most important external factor affecting the level of urban land intensive use. The level of urban land intensive use is higher in developed areas, like Jinan and Qingdao, than other areas.
Along with the degradation of the global environment, restoration ecological research and restoration practices for degraded ecosystem have been developed as one of the scientific hotspots and public focuses around the world. China, whose ecosystem has degraded drastically, is one of the earliest countries which carried out the research and practice of ecological restoration. Since the 1950s China has authorized and put a number of ecological conservation and restoration projects in practice. The evaluation of ecological restoration effects is not only an indispensable element of these ecological restoration projects, but also can provide important information to modulate and optimize the further implementation of these projects. According to a systematic summary of the study progress on effects evaluation of ecological restoration in China, the paper supplies a brief account of effects evaluation from the aspects of its content, approach, method and technology, and based on analyzing problems of restoration ecological research and restoration practices for degraded ecosystem in China, five proposals are suggested to promote ecological restoration research in China.
China's water issues are mainly manifested in threats of floods and drought disasters, shortage of water resources and deterioration of the eco-environment of the 21st century. Among the three problems, the shortage of water resources has become the important restrict factor for the sustainable development of society and economy. Therefore, it is essential to evaluate the degree of the drought of a district and work out the drought preparedness plans. Using data of annual precipitation and evaporation, river runoff and drought disaster affected cropping areas, the temporal distribution of regional drought in Hunan Province during 1960-2005 is analyzed by fuzzy comprehensive evaluation, M-K test, wavelet analysis, abrupt change analysis, cluster analysis, EOF and REOF. In addition, the responses between regional drought-flood in Hunan Province and global change are studied.
(1)Using an appropriate evaluation system, the fuzzy comprehensive evaluation model was established, and the level of regional drought-flood was identified.
(2)The results showed that the composite indicator in Hunan Province has a weak increasing trend in the past 36 years, of which the 1970s and 1990s were in flood periods, the 1980s were in drought period. There was a decreasing trend upon entering the 21st century, and there was an abrupt change from dry to wet in the early 1990s. Generally, the composite indicator presented variations of three periods. In the late 2000s, Hunan Province will be in a period of drought, after that it will be in a period of flood.
