Table of Content

    25 February 2014, Volume 33 Issue 2 Previous Issue    Next Issue
    Invited Paper
    Progress and prospects in research on mountain hazards in China
    CUI Peng
    2014, 33 (2):  145-152.  doi: 10.11820/dlkxjz.2014.02.001
    Abstract ( )   PDF (1231KB) ( )   Save
    In this paper, first, the research progress on fundamental theories on mountain hazards and prevention techniques are briefly reviewed. In the current research, the distribution of mountain hazards has been recognized and the hazards assessment methods for mountain torrents, debris flow and landslides have been established, and the principles and calculations of landslide stability analysis have been developed. In addition, the stress-strain relation of debris flow slurry and the formulae of velocity, discharge and impact of debris flow have been established, and a model of viscous debris flow initiation has also been proposed. We also presented the magnitude amplification effects of mountain torrents and debris flows. Meanwhile, the methods to forecast mountain hazards have been developed by analyzing both rainfall and ground factors. Based on the understanding of the physical characteristics of mountain hazards, a number of monitoring instruments have been invented, and especially the early warning methods have been used in the underdeveloped regions. Furthermore, a systematic technology for coping with mountain hazards has been developed. The topics on the formation, development, forecasting and prevention, protection strategies and risk management of mountain hazards have been proposed for future research. Finally, aiming at the requirements of the reduction of disasters for the nation and the goals of the academic progresses, we propose the topics that are worthy of more attention in the future research, such as the response of mountain hazards to ecology, the effects of climate change on mountain hazards, the prediction of catastrophe, the mesomechanic behaviors of the soil affected by water, the theories and methods of hazard risk assessment, the hazard forecasting model based on the formation mechanisms and the improvement of prediction and recovery technology.
    References | Related Articles | Metrics
    Urban and Regional Development
    Spatial organization of urban system in Central Plains Economic Region
    WANG Fazeng, ZHANG Gaisu, DING Zhiwei, LIU Jingyu
    2014, 33 (2):  153-168.  doi: 10.11820/dlkxjz.2014.02.002
    Abstract ( )   PDF (11725KB) ( )   Save
    Construction of economic region has become an inevitable trend as a result of the development of the country's multicentered economies, which is also an important support for the strategy of spatial development in each province. The State Council's guidance on speeding up the construction of Central Plains Economic Region (CPER), issued on September 28, 2011, clearly proposed that coordinating urbanization, industrialization and agricultural modernization is the main strategic theme, and optimizing urban system spatial layout and coordinating urban-rural development are the major tasks. Therefore, it is extremely important to integrate urban systems' spatial structures in order to achieve the coordinated development between growth pole and growth plate, center areas and peripheral areas, in CPER. In this paper, based on the theory of regional urban system organization optimization in urban geography, and using the methods of a spatial evaluation model, we did an in-depth analysis on the roadmap of the spatial organization of CPER. The results are as follows. (1) By the evaluation models of the scale strength and comprehensive development strength, the spatial organization levels of the 30 cities in CPER are calculated. Based on the principle of proportionality of spatial distribution and the evaluation results, Zhengzhou is identified as the core city of CPER; Luoyang, Handan, Xinyang and Shangqiu are considered as the regional central cities; Jincheng, Anyang city, Nanyang and Huaibei are the second-level regional central cities; other 21 cites are the local central cities; 201 counties are basic cities for promoting the development of rural areas. (2) Depending on the evaluation models of the spatial organization, such as fractal theory, buffer analysis, circle analysis, urban interaction model, and other quantitative methods, CPER exhibits basic spatial organization characteristics such as poly-center status, spheres radiation, regional group development, network trend. At the same time, the advantages and disadvantages of different urban system spatial organizations in CPER are discussed. (3) Based on the results of spatial organization evaluation models, combined with the basic model of urban spatial combination such as radial growth patterns of mononuclear, multicore balanced and unbalanced growth models, we proposed a spatial integration model for CPER, including one growth pole (Zhengzhou), four circle-layer, five regional cities, four sub-regional cites, five urban coordination region, and seven axis, and suggest that strategies are selected based on specific spatial integration models. From the perspective of best organization models and developmental trend, spatial organization of urban system approaches to promoting healthy development of new urbanization in CPER should be mononuclear unbalanced growth from the center Zhengzhou, sphere extending from Zhengbian metropolitan area to the outer layer, network development of core growth plate of urban agglomeration of Central Plains, five urban partitions including core growth plate, northern coordinated region, western coordinated region, southern coordinated region and eastern coordinated region, following the pattern of "junction cites(dot) + axis (line) + functional partition (side) + network organization". In summary, based on the analyses, we proposed the development methods and roadmaps of the spatial organization, which may predict the future direction of urban system spatial integration in CPER and can also provide support for the coordinated development of new urbanization, new industrialization and new agricultural modernization.
    References | Related Articles | Metrics
    Structure of tourist economy network and its spatial development pattern in Jianghuai Urban Agglomeration
    YU Hu, CHEN Tian, LU Lin, WANG Kaiyong, ZHU Dongfang
    2014, 33 (2):  169-180.  doi: 10.11820/dlkxjz.2014.02.003
    Abstract ( )   PDF (6854KB) ( )   Save
    Taking tourism industry as a growth pole to promote the development of the tertiary industry is becoming one of the important strategies for economic growth in urban agglomerations in the future. In the paper, using the gravity model, we measured the connection densities of tourist economies among the 11 cities, established a model for the network structure of the tourist economies in the Jianghuai Urban Agglomeration. The social network software Ucinet 6 was used to demonstrate the spatial positions and the roles of the cities in the network, which then served as a basis for constructing the spatial pattern of the tourist economies in the Jianghuai Urban Agglomeration. The results showed that: the network connections of urban tourist economies in the Jianghuai Urban Agglomeration exhibited an imbalanced pattern, with tight connections in the south and loose connections in the north. Hefei has the highest degree of centrality in all three categories: connectivity, accessibility, and intermediateness, and is also the distribution center for the tourists. So Hefei is the tourism industry center of the Jianghuai Urban Agglomeration.Wuhu and Anqing are the second-level tourist destinations, serving as important visitor centers for the greater Nanjing metropolitan areas and the Sourthern Anhui International Tourism Culture Showcase areas adjacent to the Jianghuai Urban Agglomeration. Ma'anshan, Chuzhou, and Chizhou are tourist destination portals; Chaohu, Tongling are general tourist destinations; Bengbu, Lu'an and Huainan are periphery tourist destinations. During the process of dynamic evolution, network density, number of connecting sides, and connectivity are all showing a growing trend. The intermediary ability and core function of the key cities are reducing. Most cities are showing route-dependent accumulation cycles. The level of spatial balance among the cities is improving. Based on the structural characteristics of tourist economy network, together with the location factors such as regional transportation layout, tourism resources distribution and urban economic strength, we divided the 11 cities into different levels as tourist destinations. We also proposed the concepts of spatial development axis and spatial development pattern which indicate the coordinated development with the key tourism areas nearby, namely, "three first-level tourist axes, two secondary-level tourist axes, and one potential tourist axis". The tourist economies of the Jianghuai Urban Agglomeration should be connected with one another as well as those of the cities outside the urban agglomeration. This paper aimed to understand the macroscopical regional integral structure, and offer certain theoretical references for the balanced development of regional tourism and the tourism marketing.
    References | Related Articles | Metrics
    Evaluation of Kazakhstan's urbanization during 1992-2011 and its influencing factors
    YEERKEN Wuzhati, LIU Hui, LIU Weidong
    2014, 33 (2):  181-193.  doi: 10.11820/dlkxjz.2014.02.004
    Abstract ( )   PDF (2653KB) ( )   Save
    After the collapse of the Soviet Union, Central Asia has been confronted with serious social and economic conflicts, and in urban areas, these problems are more obvious and severe. However,the 21st century is very significant to Central Asia, especially to Kazakhstan. Oil industry has promoted the rapid economic growth and lots of new oil cities have emerged in this region, but the traditional industrial cities are still struggling. The aim of this research is to analyze the degree of Central Asia's urbanization and the evolutional process from the collapse of the Soviet Union, and establish a comprehensive evaluation index system based on the case of Kazakhstan's urbanization. Through studying the essential meanings of urbanization and the characteristics of Kazakhstan, this research set up a comprehensive evaluation index system, including changes in population, economy, society and land, and othersixteen specific secondaryindicators. Moreover, using the method of information entropy to determine the weight of each indicator and calculate its comprehensive value. Firstly, the results show that the weight of social class index is the highest, andthe weight of population class index is the lowest,whichindicates that the rural-urban migration is not the main urbanization process of Kazakhstan during the past 20 years. Secondly, the comprehensive values suggest that Kazakhstan's comprehensive urbanization process can be divided into four stages, and the studies on the evolution process found that the mechanisms of population, economy, society and land present different characteristics during the four stages of urbanization. (1) In the rapid reduction stage (1992-1996), the main processes of Kazakhstan's urbanization were the rapid decline of the four aspects, especially the society index class. (2) In the slow declining stage (1997-2000), the main processes of Kazakhstan's urbanization were the rising of population index and slow declining of other aspects. (3) In the slow rising stage (2001-2004), Kazakhstan's urbanization was mainly the gradual recovery of economy and society indexes; (4) In the rapid rising stage (2005-2011), Kazakhstan's urbanization mainly witnessed a rapid economic growth. Finally, this research studied the influencing factors of Kazakhstan's urbanization based on the method of Four Dimensional Analysis on market forces, intrinsic forces, exterior forces and administrative forces. (1) The political mutation under the destruction of the urban functions was the reason for the decline of the Kazakhstan's urbanization level from 1992 to 2000. (2)A large number of urban residents with higher vocational skills and more knowledge had escaped from Kazakhstan, leading to the collapse of the urban population, and this phenomenon was even more significant from 1992 to 1996. (3) The recovery of Kazakhstan's urbanization was due to the administration power and policy implications, and these were also the reasons for the slow decline of Kazakhstan's urbanization from 1997 to 2000 and the strengthening of Kazakhstan's urbanization after 2000. (4) Driven by the oil industry and trades, Kazakhstan's urbanization improved in terms of its industrial structure and employment.
    Related Articles | Metrics
    Coordinative relationship between tourism and urban development in Beijing during 1995-2011
    DU Ao, LIU Jiaming, SHI Huichun
    2014, 33 (2):  194-201.  doi: 10.11820/dlkxjz.2014.02.005
    Abstract ( )   PDF (825KB) ( )   Save
    Today, tourism and urban development, both promoting and affecting the urban economic and social development, have become the two focuses of the economic social development studies. At the same time, there is an obvious relationship between tourism and urban development. Beijing is one of the most representative city of tourism and urban development. This paper, taking the capital Beijing as a case, and drawing on the coupling theory in physics, constructs evaluation index system of tourism and urban development. The results show that: (1) Both the level of tourism and urban development in Beijing have increased greatly from 1995 to 2011, and there is a coordinative relationship between them. (2) The coordinative degree is increasing continuously, progresses gradually from imbalance stage to high coordination stage from 1995 to 2011. The period from 1995 to 1997 was the imbalance stage, the period from 1998 to 2004 was the coordination stage, and the period from 2007 to 2011 was the high coordination stage. According to types of the coordinative degree, it was urban development lagged behind before 2001 and was tourism lagged behind after 2001. Particularly, although the general trend of tourism development is positive, there still are some great fluctuations in the year of 2003 and 2008, caused by SARS, Beijing Olympic Games and international financial crisis, suggesting that some accidental events, with direct or indirect effects on the tourism industry, are inevitable during the process of tourism industry development. The coordinative relationship between tourism and urban development linked with urban scale, geographic location, economic development, national policy, etc. The mechanism needs more in-depth studies in the future. In order to make tourism and urban development more coordinative, three advices are given in this paper, including improving infrastructure construction, promoting the development of suburban tourism and urban redevelopment, and exerting the effect of tourism industry chain. Besides, in this paper we just discuss the relationship between the tourism and urban development through macro perspective. In the meantime, tourism has become one of the driving forces of new urbanization, and a number of new tourist cities are emarging along the water and land transportation arteries. In addition, a lot of historical urban districts have been revitalized and have become tourism business districts. The researches that explore how the tourism industry affects urbanization in the cities at different levels with the progress of social economies, from a microcosmic perspective, need to be strengthened in the future.
    References | Related Articles | Metrics
    Vector-based multi-agent simulation of urban expansion:a case study in Panyu District in Guangzhou City
    ZHOU Shuli, TAO Haiyan, ZHUO Li
    2014, 33 (2):  202-210.  doi: 10.11820/dlkxjz.2014.02.006
    Abstract ( )   PDF (21940KB) ( )   Save
    Urbanization has great potential to stimulate China's domestic demand and is an important driving force of building a well-off society in an all-round way. However the limited land resource in the process of urbanization has caught great attention of the government. So, research on the mechanisms of urban land expansion can offer effective guidance for urbanization. Multi-agent modeling provides a new method to study urban land expansion. And it is of theoretical and practical significance to adopt multi-agent modeling, a bottom-up approach, to explore the characteristics and mechanisms of urban land expansion. However, the existing multi-agent models are mainly based on raster, where grid size has a major impact on the simulation results, and grid size, neighborhood shape and neighborhood size also lead to different simulation results. As a result, it is a big challenge to choose an appropriate size for better simulation results. In order to overcome the limitation of the traditional raster-based multi-agent simulation, a vector-based multi-agent system of urban land expansion dynamic simulation was developed, in which household agents selected their own optimal places of living based on evaluation indices of urban residential suitability in the human-environment science. The evaluation indices mainly include the following four aspects: traffic accessibility, living convenience, land price and landscaping. The indices of traffic accessibility are obtained by calculating the distance from road and subway station based on exponential distance decay function. The indices of living convenience are obtained by calculating the distance from the public facilities such as school, hospital and so on, based on the same function. The indices of land price depend on the average price of the land in the neighborhood. The indices of landscaping are obtained based on the distance to rivers or the green in the same way. Finally, the four indices are summed up, by a weighted factor, to indicate the living suitability. The model runs as follows: household agents select their ideal residential package to live based on their preferences of living environment, the four evaluation indices as mentioned above. The land type of this package will be converted to urban land when the total number of household agents that select this package exceeds a certain threshold. At this point household agents can choose to stop selecting and settle down, or continue to select until they find their ideal residential package. This vector-based model was used to simulate urban land expansion process from 2003 to 2008, taking the district of Panyu of Guangzhou City as a study area and using the GIS-Extension module of NetLogo platform. Eventually, the simulation results were compared to the actual land use situations, showing that the conversion accuracy is 63.09%, the non-conversion accuracy is 90.74%, and the total accuracy is 86.04%. The simulation shows that vector-based multi-agent simulation of urban land expansion not only can eliminate the impact of the scale on the simulation results, but also has high simulation accuracy. At the same time, to some extent the vector-based multi-agent simulation is useful for understanding and discussing the mechanisms of urban expansion, and offers effective support for making the decisions on the construction of new urbanization.
    References | Related Articles | Metrics
    Influencing factors of land price in Nanjing Proper during 2001-2010
    GAO Jinlong, CHEN Jianglong, SU Xi
    2014, 33 (2):  211-221.  doi: 10.11820/dlkxjz.2014.02.007
    Abstract ( )   PDF (1717KB) ( )   Save
    As one of the most representative and sensitive elements, land price has always been the core of the land market and the focus of the studies. Especially in recent years the land finance provides important support for rapid urbanization in China, which has made the land market and the pricing mechanism a focus of academic research. Current studies have achieved a lot, but most of these studies are based on either a single type, or a single year. Also, most of these studies lack scientific theoretical frameworks. In order to further affirm the main factors influencing the different types of land prices during the developmental process, this paper builds an analysis framework for influencing factors of land price based on the theory of supply and demand. In a perfectly competitive market, the curve of supply-and-demand has great effects on the land pricing process together with its corresponding supply-and-demand amount. From a geographical perspective, the demand amount of urban land is mainly affected by the factors such as market, location, facilities and so on, whereas the natural supply amount of urban land is mainly affected by the factors such as local landscapes, geological features and any other natural conditions. Meanwhile, monopoly behaviors, government regulation controls also have impacts on urban land prices all the time. In this paper, we take the 96 towns of Nanjing Proper as basic analysis units, and use the transaction data of residential, industrial, commercial land during 2001-2010 to simulate the main factors influencing the three different types of land prices with the Hedonic model. The results demonstrate that the demand factors such as economic, demographic, location and facilities, as well as the supply factors such as geological features and natural landscape, both have impacts on the land prices. But the impacts on the different types of land prices are not the same: the residential land price is more affected by demand factors. The larger the population size, the better the potential for economic development, the more favorable geographic conditions, the more opportunities to have higher residential land prices; the industrial land is relatively weakly influenced by the demand factors, and more influenced by the supply factors; the commercial activities require a relatively higher scale, but with less environmental impact. So the commercial land price is mainly affected by the level of demand factors, such as the local economy, population size, distance to the CBD and other traffic conditions, and the supply factors had no significant effects. Compared with the previous studies focusing on natural and geographic conditions, this study considers more humanity factors. And the theoretical framework built in our study may be of great significance for urban land pricing both in theory and in practice. One drawback is that we just take the towns as the basic analysis units. So, we cannot take the land area of each transaction into account. As a result, the scale benefit might be ignored. And that is just what should be taken into consideration in our future work.
    References | Related Articles | Metrics
    Mechanism of tourism investment decision-making and its spatio-temporal responses:a case study in Zhangjiajie
    MA Xuefeng, HE Yingyi, SUN Gennian
    2014, 33 (2):  222-231.  doi: 10.11820/dlkxjz.2014.02.008
    Abstract ( )   PDF (1769KB) ( )   Save
    Tourism investment has become a new topic in the academic community of tourism research in recent years. In this paper we analyzed tourism investment decision-making mechanism and corresponding consequences, and, taking Zhangjiajie as an example, explored the evolution of tourism investment decision-making mechanism and set up a model for the response strength of the tourism industry. The model helped study the characteristics of temporal responses of Wulingyuan scenic spot and analyze specifically the temporal responses and the reconstruction of the evolutional process of Zhangjiajie tourism industry under the effects of local government and the market. The results showed that: (1) From the viewpoint of tourism investment decision-making mechanism, tourism investors have been changing dynamically and directly affected the growth of the industry in the different stages, and the changes of tourism investors in the different growth stages of Zhangjiajie tourism industry were determined by tourism investment policies and regulations. In addition, tourism investors played different roles in the different stages of the tourism industry growth along with the evolution of the tourism investment system itself. Government and state-owned enterprises at all levels were the main sources of the investments in the emergence stage of the tourism industry growth in Zhangjiajie, with the government investments together with private investments as the main source in the initial stage, and private investments as the major source and government investment as the complementary source in the developmental stage. (2) From the viewpoint of the temporal responses in Zhangjiajie, the calculated response coefficient was overall in a rising trend with periodic fluctuations, showing the increasingly positive effects of the tourism investments on the growth of the tourism industry. Response coefficient of the tourism industry growth had a slow and steady increase of 0.006 from 0.1282 in 1989 to 0.1341 in 1992 because of a relatively small tourism investment in the emergence stage. The response coefficient enjoyed a sharp increase of 421.83% from 0.1631 in 1993 to 0.8511 in 1999 as a result of diversified tourism investments and optimized investment and financing environment in the growth stage, an increase from 0.8767 in 2000 to 1.1214 in 2012 with enhanced popularity and further optimized tourism investment environment and system. (3) From the viewpoint of the spatial responses, the "core-edge" pattern of Zhangjiajie tourism industry growth and reconstruction were formed under the combined efforts of local government, the world heritage management system and the market. The tourism spatial pattern includes two of the National 5A Scenery Sites, Wulingyuan scenic spot and Tianmen Mountain, as the center. After industry reconstruction the ranking order of the tourism services density is: Sangzhi County References | Related Articles | Metrics
    Urban and Regional Development
    Spatial pattern of coupling development between real estate development and housing condition at prefectural level in China
    ZHANG Yingjia, LI Xueming, XIA Chunguang
    2014, 33 (2):  232-240.  doi: 10.11820/dlkxjz.2014.02.009
    Abstract ( )   PDF (6188KB) ( )   Save
    Chinese real estate industry has been developing very quickly, but imbalanced, since the start of real estate reform three decades ago. Most of the investments have been focusing on the regions with well-developed urban economies, attractive economic environment, better infrastructures and public services, and better living conditions, which gradually lead to bigger and bigger spatial differences in real estate development among the different regions. Rational real estate development can provide people with moderate housing condition, but irrational and imbalanced development will hinder the efforts to improve housing condition. It is important to explore the relationship between real estate development and housing condition. In this paper, we first established a number of comprehensive assessment indicators for real estate development and housing condition, and then calculated the degree of coordination and coupling development between real estate development and housing condition improvement. The spatial pattern of the degrees of coordination and development of the 286 prefectural cities showed that: (1) Coordination degree between real estate development and housing condition in most prefectural cities is at medium level, with an average number of 0.59, indicating that the two subsystems are still in an adjustment phase and have not yet established a coordinated and mutually reinforcing dynamic relationship. (2) Coupling development degree between two subsystems in most prefectural cities is still at a lower level. There are significant disparities between eastern coastal areas and western inland areas. Based on degrees of coordination and coupling development, the 286 prefectural cities can be divided into nine categories, namely, well developed and coordinated area, well developed and adjusting area, well developed but conflicting area, developed and coordinated area, developed and adjusting area, developed but conflicting area, under developed but coordinated area, under developed and adjusting area, under developed and conflicting area. (3) One of the key tasks for the economy in 2013 is to actively and steadily promote urbanization, strive to improve the quality of urbanization, and firmly adhere to the real estate control policies. These seemingly contradictory and complex tasks should be undertaken with prudence and flexibility as well as positive and moderate attitude. Considering the significant disparities among the different regions in China, the government can take the measures that suit the local conditions, such as different financial policies, price guidelines and administrative decisions. The central and local governments should play different functions but work together and establish an effective information-sharing mechanism. In other words, to make joint efforts to achieve coordination between the real estate development and housing condition improvement, the central government should formulate the policies, determine the objectives, and monitor the results; local governments should have the right to choose the suitable means and ways to achieve specific goals, and accept supervisions from the higher level government and respond to the attentions from the public for evaluation of the policies and fulfillment of the obligations.
    References | Related Articles | Metrics
    Development level and coordination of highway networks of prefecture-level administrative regions in China
    LIU Dong, JIN Fengjun
    2014, 33 (2):  241-248.  doi: 10.11820/dlkxjz.2014.02.010
    Abstract ( )   PDF (2980KB) ( )   Save
    The study of regional transport development in different scales is one of important areas in transport geography research. There are big differences among the regions of China in highway network development. Examining the differences in the scale of prefecture-level administrative region (PAR) is more accurate than in provincial scale. In this paper, taking the 333 PARs in China as a research object, we studied the differences among the regions in highway network development and evaluated the degree of coordination between highway network development and economic development. Firstly, we selected 9 indicators reflecting the scale, quality, accessibility and transportation volume of highway networks and, by using the weighted average method, established a comprehensive evaluation model to evaluate the levels of highway network development and calculate highway indicators for the 333 PARs. Secondly, we selected 7 economic indicators to establish a comprehensive evaluation model for the regional economic development, and calculated the economic indicators for the 333 PARs. Thirdly, by using Pearson formula, we calculated the correlation coefficient between the highway index and the economic index. Finally, we established a coordination evaluation model and calculated the coordination index between the highway network development and the economic development for each PAR. The results and conclusions are as follows. (1) There are big differences among the different regions in highway network development; the highway indicators of the 333 PARs varied from 0.361 to 5.992, with Dongguan City and Shenzhen City being the highest and Ngari Prefecture and Nagqu Prefecture the lowest. Based on the highway index, the 333 PARs are classified into three levels, including 104, 121 and 108 PARs respectively, which shows a ladder-like distribution in a large scale, corresponding to the spatial pattern of Eastern, Central and Western China. It is worth pointing out that the 108 PARs in the third, or the underdeveloped, level of highway network development are mainly located in Western China. (2) The correlation coefficient between the highway index and the economic index was calculated to be 0.8328, which shows a highly positive correlation between the two index systems. (3) The coordination index of the 333 PARs varied from 0.223 to 1.634, with Dongguan City being the highest and Alxa League the lowest. Based on the coordination index, the 333 PARs are classified into three categories, namely, the advanced, coordinated, and lagged, including 90, 85 and 158 regions respectively. Here "advanced" means that the highway network development is ahead of the regional economic development; "coordinated" means highway network development is coordinated with the regional economic development; "lagged" means the highway network development is lagged behind the regional economic development. The spatial distribution of the three categories is different from the distribution of the three levels, but 92 PARs are in both the lagged category and the third level, mainly located in West China. For the lagged and underdeveloped PARs, the measures should be taken to optimize and upgrade the highway networks and meet the needs of the regional economic development.
    References | Related Articles | Metrics
    Urban and Regional Development
    Review and enlightenment of overseas urban amenity research
    WEN Ting, CAI Jianming, YANG Zhenshan, SONG Tao
    2014, 33 (2):  249-258.  doi: 10.11820/dlkxjz.2014.02.011
    Abstract ( )   PDF (702KB) ( )   Save
    Traditional theories of urban development have been outmoded in the era of globalization and knowledge economy, and urban amenities are now considered as a more and more important factor promoting urban growth. Urban amenities have become an increasingly hot topic in the western countries, to which the researchers in China seem to have not paid too much attention. This article aims at obtaining a comprehensive understanding of overseas research in the field of urban amenities, in order to provide references for urban amenity research in China. By collecting and analyzing related publications, this paper gives a systematically review of overseas research on urban amenities from several aspects: (1) the theoretical basis, including human demand theory, capital theory and sciences of human settlement; (2) concepts of urban amenities defined by different researches, and three types of urban amenities, i.e. natural amenities, modern amenities and social amenities; (3) urban amenities and amenity migration; (4) the influence of urban amenities on location decisions of talents, companies and urban growth; (5) commonly used research methods of urban amenities including survey, Hedonic price model and structure equation model. After that, the author makes comments on the current research progress and research trends. At the same time, comparisons between domestic and foreign researches on urban amenities are also discussed. The main conclusions from the review are as follows. (1) Quite a few of Western scholars have demonstrated that urban amenities work as an promoter to urban development through attracting talents and companies, whereas the concept of urban amenity has been studied just as a component of the livability of a city, which has not been closely related to urban development; (2) the focus of the scholars on urban amenities has changed from natural factors previously to modern elements now, such as restaurants, museums and bars, because a city, after all, is man-made; (3) the theory of urban amenities is more concerned with the needs of talent and the creative class, so it is a demand oriented developmental theory, which can not only help make a city successful in economic growth but also facilitate continuous urban development. With the influence of globalization, there is a strong necessity of carrying out studies on urban amenities in China from the three aspects: (1) it has been widely proved that urban amenities have a strong relation with urban growth, and China will lose more profit if we ignore it, especially for super cities as Beijing and Shanghai. With the rapid progress of urbanization and economic development in China, more people come to urban areas, so it is of great significance to take urban amenities into consideration in the process of making developmental strategies; (2) urban planning system can also benefit from urban amenity studies, since it is concerning people's needs; (3) the Twelfth Five-year Plan of China has proposed to speed up economic restructuring from traditional industries to high-tech industries. Considering that the developmental theory of urban amenities lies in attracting human capital and technical enterprises, it may very well provide guidance for the economic restructuring of the cities in China. Above all, from the perspective of both perfecting related research and promoting urban growth, the research of urban amenities in China is needed.
    References | Related Articles | Metrics
    Pedogeography and Hydrology
    Prediction of distribution of soil organic matter based on qualitative and quantitative auxiliary variables:a case study in Santai County in Sichuan Province
    LI Qiquan, WANG Changquan, YUE Tianxiang, LI Bing, ZHANG Xin, GAO Xuesong, ZHANG Yi, YUAN Dagang
    2014, 33 (2):  259-269.  doi: 10.11820/dlkxjz.2014.02.012
    Abstract ( )   PDF (9653KB) ( )   Save
    Soil organic matter (SOM) is one of the most important indicators of soil quality. Accurate spatial information about SOM is critical for sustainable soil utilization and management and environmental protection. Spatially correlated auxiliary information was widely used to improve spatial prediction accuracy. However, the qualitative variables such as soil type, land use type are not being used often as auxiliary variables. In this paper we proposed a spatial prediction method (ST+RBFNN) based on radial basis functional neural network model, using both qualitative and quantitative variables as auxiliary information, to predict the spatial distribution of soil organic matter in Santai County in Sichuan Province, located in the hilly region of mid Sichuan Basin. To establish and validate this method, 2346 soil samples were collected and randomly divided into two groups, as modeling points (1877) and validation points (469). With the modeling points, a radial basis function neural network model was trained using the average content of SOM of each soil genus, topographical factors and vegetation index as auxiliary information to predict the spatial distribution of SOM content within each soil genus. Results showed that, the SOM content ranged from 4.20 to 47.60 g kg-1, with an average value of 17.97 g kg-1, a moderate variability. The nugget/sill ratio was 0.742, indicating a weak spatial dependence for SOM. Elevation and slope showed significantly negative correlation with SOM content while topographic wetness index and vegetation index showed significantly positive correlation with SOM. Analysis of variance indicated that there were significant differences in average content of SOM among the different soil types (P<0.01), suggesting that soil types also had significant impact on the spatial distribution of SOM, and soil genus types were better predictors than soil groups. Slope, topographic wetness index and vegetation index showed significant correction with the residuals of average content of SOM (computed by subtracting the average SOM content of the relative soil genus from the original value of each soil sample), indicating that the above three quantitative factors further resulted in the spatial variation of SOM besides soil types. The prediction map obtained by the proposed method was more consistent with the true geographical information than ordinary Kriging (OK), regression Kriging (RK) and neural network combined with ordinary Kriging (RBFNN+OK). Moreover, ST+RBFNN method significantly reduced the prediction errors. Compared to OK, RK and RBFNN+OK, the mean absolute error (MAE) of ST+ RBFNN method was reduced by 31.76%, 28.45% and 26.68%, the mean relative error (MRE) was reduced by 35.90%, 32.55% and 30.75%, and the root mean squared error (RMSE) was reduced by 22.60%, 19.88% and 18.43%. Moreover, this method also showed better capability of predicting the extremum of the validation data. The prediction errors were reduced by 6.88% to 43.70% than the other three methods in predicting the extremum of the validation points (10% of normal distribution of the data). This result suggested that it is helpful for improving the prediction accuracy to employ both qualitative and quantitative variables as auxiliary information in spatial prediction of soil properties, and this proposed method provides a useful research idea for digital soil mapping.
    References | Related Articles | Metrics
    Environmental risk evaluation of shallow groundwater and its spatial auto-correlation in lower reach of Liaohe River Plain
    SUN Caizhi, ZHU Jing
    2014, 33 (2):  270-279.  doi: 10.11820/dlkxjz.2014.02.013
    Abstract ( )   PDF (5861KB) ( )   Save
    As the economies are in the fast development, disasters occur more frequently. Evaluation, monitoring, and early warning of disaster risks are an important way to reduce the losses caused by the disasters. So it is one of the key topics in the current disaster research. As a major source of water in northern China, groundwater provides resource and ecological and geo-environmental functions. However, groundwater systems in northern China are being threatened by high population density, rapid urbanization and industrialization. Generally speaking, groundwater has been damaged to different degrees, which resulted in the decrease or complete loss of the functions of groundwater systems. So the research of groundwater environmental risk has great practical significance. In this article, the lower reach of Liaohe River Plain was chosen as a study area, and the shallow groundwater system was taken as a research object. The study area contains a large Quaternary groundwater system with characteristics typical of northern China. Social-economic and water environmental data of the Liaohe River Plain in 2012 were used in the study. Although many studies on groundwater have been conducted, few theories of groundwater environmental risk and methods of protection were developed at the groundwater system scale. Drawing lessons from modern hazard and environmental risk theories and methods, based on the definitions of groundwater environmental risks, we built an evaluation index system and an evaluation model for groundwater environmental risks from the aspects such as vulnerability, functionality, stress and adaptability. Using GIS spatial analysis method to evaluate the groundwater environmental risks in this region, we carried out spatial auto-correlation analysis. The results show that: 63.12% of the whole groundwater environment is facing a mid-level risk. In detail, the areas with extreme high risk accounts for 6.79%, the areas with high risk 18.96%, the areas with moderate risk 37.37%, the area s with light risk 21.98%, and the areas with slight risk 14.90%. Most high risk areas are mainly in the northeast of Xinmin City, Dengta City, west of Liaozhong County, parts of Heishan County and southeast of Linghai City. The risk of the study area shows a relatively high degree of positive correlation. The high correlation areas are mainly distributed in mid-east and mid-west of the high-risk areas and the northeast and southeast of low-risk areas. Uncertainty evaluation is an important part of the environmental risk analysis. But due to limited data, we didn't consider the indexes of randomness and fuzziness, which to a certain extent affects the scientific nature and reliability of the evaluation results. With constant improvement on the information sources, more studies will be done to include uncertainty index of groundwater environmental risk evaluation. The specific purpose of this study is to investigate measures to protect the three functions of the groundwater systems based on groundwater system risk evaluation. This study is of great significance to the enrichment of groundwater environmental risk theories and methods, and it also helps with making scientific decisions for the protection of the groundwater system of the lower reach of Liao River Plain and similar areas.
    References | Related Articles | Metrics
    Pedogeography and Hydrology
    Soil spectrum characteristics and information extraction of salinization:a case study in Weigan-Kuqa Oasis in Xinjiang
    ZHAO Zhenliang, TASHPOLAT Tiyip, SUN Qian, LEI Lei, ZHANG Fei
    2014, 33 (2):  280-288.  doi: 10.11820/dlkxjz.2014.02.014
    Abstract ( )   PDF (7622KB) ( )   Save
    Soil salinization is a process of global land degradation, which hazards the environment. It is caused by inefficient irrigation and the excessive use of water. It reduces the productivity of land. Xinjiang is the typical area of arid and semi-arid region. The monitoring of soil salinization timely and effectively is not only beneficial to the production of agriculture, but also in favor of sustainable development of agricultural land. The purpose of this study is how to improve the classification accuracy. In this paper, the author uses Spectral Angle Mapper method extracting the information of soil salinaztion. In order to improve the accuracy of classification, the author determines the appropriate soil and vegetation spectral library. The appropriate soil and vegetation spectral library decide the accuracy. The use of field measurements of soil spectral reflectance is used to study the soil spectral characteristics. It is combined with hyperspectral data of the Chinese environmental and disaster monitoring and forecasting of small satellites and classified soil salinization based on hyperspectral image. In the first part of this paper, according to the definition of degree of soil salinaztion, four classed of soil are classified, namely non-salined soil, slight-salined soil, moderate-salined soil and heavy-salined soil. The data from four classes of soil can be converted to fourteen transforms of soil spectral reflectance. There are fifteen transforms of soil spectral reflectance. They are the original and the converted fourteen transforms of soil spectral reflectance. According to the findings of the correlation analysis of fifteen transforms of soil spectral reflectance with soil salt content, regression analysis are done. The equations are chosen to estimate soil salt content. And root mean square error (RMSE) is employed to verify the accuracy of the equations. The best equations of estimating soil salt content are decided. In the second part of this paper, the author decides the soil spectral library according to the result of spectral characteristics. The vegetation spectral library is based on field measurements and actual survey. In the final part of this paper, the author uses the SAM method to classify the hyperspectral image based on the soil spectral library and vegetation spectral library. Such a classification is proved good, laying the foundation for the region's hyperspectral applications, giving warning to regional farmers for appropriate farming methods, provided the data for the region's sustainable development. This article identifies the soil and vegetation spectral library of the study area. This helps to further study on spectral characteristics in this region. Environmental and disaster monitoring and forecasting of small satellite is designed and developed by our country. China centre for resources satellite data and application provided for our researchers free. HSI hyperspectral data is also China's the only hyperspectral remote sensing images. This study attempts to contribute to our development of hyperspectral remote sensing images. To speed up the satellite for the applications of environmental monitoring. It is better for the country's environmental monitoring services. The development of hyperspectral remote sensing images will bring a new opportunity and challenge to remote sensing technology. Our researchers should strive for the development of hyperspectral remote sensing technology. The development of hyperspectral remote sensing will promise a better future.
    References | Related Articles | Metrics