For a given region, internal accessibility and external accessibility should be considered to assess accessibility of each point in the region. Using MapX component and Delphi programming tool, regional accessibility calculation and analysis information system based on minimal pass-time is developed, with which mark diffusing figure could be generated. From the view of time-distance, the present and approaching regional internal accessibility and regional external accessibility of 16 major cities in the Yangtze River Delta are analyzed according to land traffic network. The result shows that, the regional accessibility of the Yangtze River Delta radiates a fan-shaped pattern with Shanghai as the core. The top two cities are Shanghai and Jiaxing. The bottom two cities are Taizhou and Nantong. With the completion of Sutong Bridge, Hangzhouwan Bridge and Zhoushan Bridge, the regional internal accessibility of all cities in the Yangtze River Delta will be improved. Especially for Shaoxing, Ningbo and Taizhou, the regional internal accessibility will be one hour decrease. At the same time, the regional internal accessibility of other cities will be about 25 minutes decrease averagely. As the accomplishment of the Yangkou seaport in Nantong, regional external accessibility with the node of seaport of cities in Jiangsu province will be increased with an average decrease in accessibility by about one hour.
Geographic concentration of industries is very important to decision making and regional economic development. Based on data from the second census of basic units and input-output table of Beijing, this paper researches the spatial distribution structure of manufacturing industries in Beijing by means of improving distance-based industrial geographic concentration method -M' function. Efforts are further made to investigate co-location of 14 sector groups. The results suggest that the 25 manufacturing sectors concentrate at various levels, and decline at longer distances. The studies also indicate that factor endowments and labor favorite sectors concentrate highly, while capital/technology intensive industries show lowly concentrative pattern. Statistical results imply that comparative advantages and industries linkage are the most important locational determinants of Beijing manufacturing industries, and have reinforced the spatial concentration level. However, market competition, utilization of foreign investments and technological spillover have strengthened its dispersion. Concerning the co-location phenomenon, inter-industry concentration levels are lowly concentration, even dispersion. Pairs of labor favorite and factor endowments sectors show highly co-location concentration, while industries between capital/technology intensive and other sectors generally show dispersion pattern. Further studies indicate that more input-output imitates the high inter-concentration between two sectors of activity. The results have important policy implications for industrial restructuring in Beijing.
The purpose of this paper is to investigate the systematic forces that determine the sectoral distribution of foreign investment. Unlike the existing literature, this study highlights the importance of industrial agglomeration and industrial linkage in attracting foreign investment. Using a panel dataset of two-digit manufacturing industries in Beijing during the period 1999-2004, this study finds that geographically agglomerated industries with strong intra-industrial linkages attract much foreign investment. Previous foreign investments have demonstration effects, information spillover effects and linkage effects, leading to industrial concentration of foreign investment. Investors also highly favor capital and technology intensive industries and are drawn to the most profitable and exporting industries, but avoid industries with high effective wage rates and high entry barriers. This study provides strong evidence to support that competitive and comparative advantages of local industries are critical to allure foreign investment. The existence of industrial clusters certainly heightens a city's attractiveness to foreign investment.
Tourism is acknowledged as one of the effective means to balance inter-regional economic disparity in the world. This paper uses Theil coefficient which can be decomposed multiply, to measure temporal changes of inter-provincial, inter-regional and intra-regional disparity in Chinese inbound tourism from 1990 to 2004. Just as the result suggests, regional gap in Chinese inbound tourism from 1990 to 2004 can be summarized as follows: First, on the whole, regional disparity in Chinese tourism becomes smaller and smaller and its speed is slower as well. Secondly, intra-regional disparity is larger than that of inter-regional. Intra-regional disparity is the main contributor to inter-provincial tourism disparity. Thirdly, inter-provincial disparity remains large in the early 1990s, shrinks sharply in the mid-1990s, and continues declining in the early 21st century. Fourthly, inter-regional disparity shrinks all the time except in 1991 and 2003. Fifthly, eastern intra-regional disparity decreases sharply. Western intra-regional disparity is smaller and fluctuates slightly. Middle intra-regional disparity keeps large and has increasing trends. This paper further analyzes the factors influencing temporal changes of regional inbound tourism disparity. By comparison with other researches on temporal changes of regional economy, this paper has two meaningful discoveries: one is based on the shrinking trends of regional inbound tourism disparity and the widening trends of regional economic disparity. We think our research provides a good proof that tourism can help to balance regional economic disparity and thus help to narrow the regional economic gap. The other is that Chinese inter-regional tourism disparity becomes smaller and smaller. However, in the meantime Chinese inter-regional economic disparity becomes larger and larger. So inbound tourism can also help to balance inter-regional economic disparity.
The Zipf theory is the law to study the relation between word frequency and word sequence which is now extensively used in city size structure, city spatial fractal, economics, sociology, and so on. From supposition to discussion, this paper proves that tourist flow size grading structure is in conformity with the Zipf theory in aid of the Zipf and difference degree index. The scaling section feature and internal structural difference in each scaling range of domestic and inbound tourist flow size grading structure in Sichuan province were studied in this paper based on statistic data of domestic tourist flow from 1996 to 2004. The result shows that tourist flow size grading structure has possessed the Zipf feature, even could be sectioned by fractal dimension scaling in certain years, and the bifurcation points of each scaling range can be determined by regression equations. The scaling section may be divided into two types, which are effective and ineffective scaling sections. Viewing from the tourism development in Sichuan province, the space distribution area of tourist flow ineffective scaling section is reducing and effective scaling section area is increasing. The Zipf index can be used to divide the scope of each scaling section and analyze the internal structural feature of effective scaling section and the changing law of the tourist flow size grading structure. For the region without the unobvious Zipf feature, equilibrium degree and difference index can be used to study the difference of the internal structure. The study shows that the results of effective scaling section being analyzed by the Zipf index and ineffective scaling section by equilibrium degree and difference index accord with the objective reality, also clearly reflect the structure scaling section feature, the internal structural difference of each section and the changing law of the total structure system. This is very important to enrich the methods of analyzing tourist flow size grading structure. Concerning the tourist flow size structure in Sichuan province, the Zipf index "q" of domestic tourist flow is mostly between one and two before 2002, and the size grading structure system assumes Pareto distribution pattern; after 2003, the Zipf index "q" further reduces and the tourist flow size structure is turning to logarithmic regular distribution pattern.
The solutions to spatial optimal search are complex and important. Since combinatorial optimal problems are computationally difficult, brute-force search can hardly solve the problems. As a result, a novel approach is necessary to deal with them. Particle swarm optimization (PSO) is a new kind of optimal technique, which can solve complex nonlinear spatial optimal problems. This paper demonstrates that PSO solves the spatial optimal search based on GIS under the constraint conditions of population distribution and shortest path. The PSO treats each solution as a particle searching in D-dimensional hyperspace. Different from other optimal problems, the spatial optimal search is in 2-dimensional geographic space, in which each point includes X, Y coordinates. D is equal to 2n. Where n is the number of marketplaces. So the position vector of the particle i is (xi/1, yi/1, xi/2, yi/2, …, xin, yin). Each particle flies over search space and its velocity vector is (vxi/1, vyi/1, vxi/2, vyi/2, …, vxi/n, vyi/n). The particles can adjust their positions and velocities according to the current optimal value p(t) and global optimal value pg/. The work in this paper makes use of the control MapObject2.3 to extract the centroid coordinates, area and population density of each cell in the map of population distribution by means of the computer programming language. It initializes the parameters, computes the fitness value of each particle and finds the current optimal value and global optimal value which adjust the position and velocity of each particle until they satisfy the condition of maximal number of iterations or precision. Finally, it identifies the position of the particle with the global optimal value is the optimal location of the marketplaces. The contents of this paper include: first, this paper introduces the characteristic and research progress about PSO and spatial search. Secondly, the paper elaborates on the implementing procedure and method of spatial optimal search by using PSO and GIS under the constraint condition of population distribution and shortest path. Thirdly, the paper utilizes the 4×4 spatial regions as an example to prove the correctness and effectiveness of the proposed method. Finally, the paper further verifies this method by a case of Fangcun District, Guangzhou. It is concluded that particle swarm optimization is a robust method of solving spatial optimal search under complex conditions.
Currently, in northern China, the impact of aridification on land system is not very clear, which would, to some extent, restrict the rational development and utilization of land resources. Therefore, based on the principle and method of system dynamics (SD), a SD model aims at simulating land use changes in northern China under different aridification scenarios and designed socio-economic status is developed in this paper. The accuracy assessment with historic data covering 1989 to 2001 indicates the SD model is helpful and reliable to understand the complex change process of land use system. The aridification scenarios in the next 30 years are defined as three types, from the reversal of aridification, gradual aridification to the acceleration of aridification with the increment of aridification degree. The results suggest that, in northern China, future aridification has great impact on the water resource, leading it to decline from 468.6 to 388.8 million m3 under different aridification scenarios. In other words, water resource is gradually becoming a rare resource restricting regional sustainable development. Furthermore, the results show that, under the pressure of population growth and economic development, the construction and traffic land will expand obviously and the conflict between cultivated land and construction and traffic land will be prominent. In all, in the future development, such issues as how to arrange land use structure and pattern rationally, and how to adapt to the pressures of climate change and socio-economic development together will be the main problems which would be faced and should be solved in the regional sustainable development in northern China.
This paper brings forward the concept for the first time based on central place theory and fractal theory by creating the model of centricity exponent firstly, and then integrates centricity exponent and fractal dimension with each other to measure the stability. Before the assessment, we select K = 4 as a parameter to calculate centricity exponent and fractal dimension, and suppose that it is right to select central place system as the frame of reference. The Result shows that spatial structure stability is in direct proportion with the value of central index, the number of nodes, the value of network dimension, and comparability of urban agglomerations' spatial structure with that of central place structure system. We classify urban agglomerations in China into five types according to the value of centricity exponent and the spatial contact direction, and then divide the level of stability into five grades according to the value of semi-trapezoid fuzzy membership function. According to the number of urban agglomerations in different grades of stability, we find that the degree of spatial structure stability is low for urban agglomerations in China on the whole. This study is valuable to promote the development and exertion of spatial operation efficiency for urban agglomerations following on reasonable spatial allocation of nodes.
