This paper firstly derived urban information from Defense Meteorological Satellite Program/Operational Linescan System （DMSP/OLS） data in 1992, 1996 and 1998 with the support of statistical data, and then developed ...This paper firstly derived urban information from Defense Meteorological Satellite Program/Operational Linescan System （DMSP/OLS） data in 1992, 1996 and 1998 with the support of statistical data, and then developed three basic urban models of polygon-urbanization, line-urbanization and point-urbanization in urban agglomerations from viewpoint of spatial analysis. The conclusions are as follows： （1） Urban patch numbers in the Bohai Rim increased from 1659 to 2053 with an annual average increase number of about 66. Meanwhile, the small urban patches accounted for a larger proportion in the region and the patch density increased fast. In addition, the urban barycenter of the region showed a moving trend toward northwest from 1992 to 1998. Urbanization in the Bohai Rim in the 1990s is fast and obvious. （2） Urbanization in the Bohai Rim can be reflected by three basic processes, i.e., the polygon-urbanization around the big cities, the line-urbanization around the transportation lines and the point-urbanization emerging in large areas. Of them, the polygon-urbanization has been in dominance. It is obviously within an effective range of 3-4 km surrounding the urban patches. The line-urbanization and point-urbanization in the region was relatively small, both of which showed an obvious increasing trend.展开更多
Electric power consumption(EPC)is one of the basic indices for evaluating electric power use.Obtaining timely and accurate data on the spatiotemporal dynamics of EPC is crucial for understanding and practical deployme...Electric power consumption(EPC)is one of the basic indices for evaluating electric power use.Obtaining timely and accurate data on the spatiotemporal dynamics of EPC is crucial for understanding and practical deployment of electric power resources.In this study,an EPC model was developed using stable nighttime lights time-series data from the Defense Meteorological Satellite Program Operational Linescan System(DMSP/OLS).The model was used to reconstruct the spatial patterns of EPC in Chinese Mainland at the county level from 1995 to 2008.In addition,the spatiotemporal dynamics of EPC were analyzed,and the fol-lowing conclusions were drawn.(1)The EPC model reliably represented the spatiotemporal dynamics of EPC in Chinese Mainland with approximately 70%accuracy.(2)The EPC in most regions of Chinese Mainland was at low to moderate levels,with marked temporal and spatial variations;of high-level EPC,58.26%was concentrated in eastern China.Six urban agglomerations(Beijing-Tianjin-Tangshan region,Shanghai-Nanjing-Hangzhou region,Pearl River Delta,Shandong Peninsula,middle-south of Liaoning Province,and Sichuan Basin)accounted for 10.69%of the total area of Chinese Mainland but consumed 39.23%of the electricity.(3)The EPC of most regions in Chinese Mainland increased from 1995 to 2008,and 64%of the mainland area showed a significant increase in EPC.Moderate increases in EPC were found in 61.62%of eastern China and 80.65%of central China from 1995 to 2008,whereas 75.69%of western China showed no significant increase in EPC.Meanwhile,77.27%,89.35%,and 66.72%of the Shanghai-Nanjing-Hangzhou region,Pearl River Delta,and Shandong Peninsula,respectively,showed high-speed increases in EPC.Moderate increases in EPC occurred in 71.12%and 72.13%of the Beijing-Tianjin-Tangshan region and middle-south of Liaoning Province,respectively,while no significant increase occurred in 56.34%of the Sichuan Basin.展开更多
DMSP/OLS nighttime light （NTL） image is a widely used data source for urbaniza- tion studies. Although OLS NTL data are able to map nighttime luminosity, the identification accuracy of distribution of urban areas （...DMSP/OLS nighttime light （NTL） image is a widely used data source for urbaniza- tion studies. Although OLS NTL data are able to map nighttime luminosity, the identification accuracy of distribution of urban areas （UAD） is limited by the overestimation of the lit areas resulting from the coarse spatial resolution. In view of geographical condition, we integrate NTL with Biophysical Composition Index （BCl） and propose a new spectral index, the BCl Assisted NTL Index （BANI） to capture UAD. Comparisons between BANI approach and NDVl-assisted SVM classification are carried out using UAD extracted from Landsat TM/ETM＋ data as reference. Results show that BANI is capable of improving the accuracy of UAD extraction using NTL data. The average overall accuracy （OA） and Kappa coefficient of sample cities increased from 88.53% to 95.10% and from 0.56 to 0.84, respectively. Moreover with regard to cities with more mixed land covers, the accuracy of extraction results is high and the improvement is obvious. For other cities, the accuracy also increased to varying de- grees. Hence, BANI approach could achieve better UAD extraction results compared with NDVl-assisted SVM method, suggesting that the proposed method is a reliable alternative method for a large-scale urbanization study in China＇s mainland.展开更多
Understanding the dynamics of urbanization is essential to the sustainable development of cities. Meanwhile the analysis of urban development can also provide scientifically and effective information for decision-maki...Understanding the dynamics of urbanization is essential to the sustainable development of cities. Meanwhile the analysis of urban development can also provide scientifically and effective information for decision-making. With the long-term Defense Meteorological Satellite Program’s Operational Linescan System(DMSP/OLS) nighttime light images, a pixel level assessment of urbanization of China from 1992 to 2013 was conducted in this study, and the spatio-temporal dynamics and future trends of urban development were fully detected. The results showed that the urbanization and urban dynamics of China experienced drastic fluctuations from 1992 to 2013, especially for those in the coastal and metropolitan areas. From a regional perspective, it was found that the urban dynamics and increasing trends in North Coast China, East Coast China and South Coast China were much more stable and significant than that in other regions. Moreover, with the sustainability estimating of nighttime light dynamics, the regional agglomeration trends of urban regions were also detected. The light intensity in nearly 50% of lighted pixels may continuously decrease in the future, indicating a severe situation of urbanization within these regions. In this study, The results revealed in this study can provided a new insight in long time urbanization detecting and is thus beneficial to the better understanding of trends and dynamics of urban development.展开更多
This paper intends to investigate the urban spatial patterns of Hubei Province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime ligh...This paper intends to investigate the urban spatial patterns of Hubei Province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime light imagery of cities in Hubei Province, the viewpoint of ′point-axis-area′ in the ′point-axis system′ theory, and employs light index model, gravity model and social network analysis. The findings are as follows: 1) In terms of urban nodes, the urbanization process of Hubei has been carried out mainly on the basis of external expansion rather than internal increasing. The polarization trend of urban connection network is strengthening. 2) As for urban connections, the estimation of urban connections using light index model is capable of containing various actual flow, and the connections are getting increasingly closer. 3) In regard to urban groups, seven urban groups of varying sizes have formed. On that basis, three stable and relatively independent urban groups as the centers, namely Wuchang, Yichang and Xiangyang emerge as well. But the structures of ′Wuhan Metropolitan Area′, ′Yichang-Jingzhou-Jingmen City Group′ and ′Xiangyang-Shiyen-Suizhou City Group′, which are defined by local development strategy in Hubei Province, are different from the above three urban groups.展开更多
基金National Natural Science Foundation of China, No.40501001
文摘This paper firstly derived urban information from Defense Meteorological Satellite Program/Operational Linescan System （DMSP/OLS） data in 1992, 1996 and 1998 with the support of statistical data, and then developed three basic urban models of polygon-urbanization, line-urbanization and point-urbanization in urban agglomerations from viewpoint of spatial analysis. The conclusions are as follows： （1） Urban patch numbers in the Bohai Rim increased from 1659 to 2053 with an annual average increase number of about 66. Meanwhile, the small urban patches accounted for a larger proportion in the region and the patch density increased fast. In addition, the urban barycenter of the region showed a moving trend toward northwest from 1992 to 1998. Urbanization in the Bohai Rim in the 1990s is fast and obvious. （2） Urbanization in the Bohai Rim can be reflected by three basic processes, i.e., the polygon-urbanization around the big cities, the line-urbanization around the transportation lines and the point-urbanization emerging in large areas. Of them, the polygon-urbanization has been in dominance. It is obviously within an effective range of 3-4 km surrounding the urban patches. The line-urbanization and point-urbanization in the region was relatively small, both of which showed an obvious increasing trend.
基金The National Basic Research Program of China,No.2010CB950901National Natural Science Foundation of China,No.40971059
文摘Electric power consumption(EPC)is one of the basic indices for evaluating electric power use.Obtaining timely and accurate data on the spatiotemporal dynamics of EPC is crucial for understanding and practical deployment of electric power resources.In this study,an EPC model was developed using stable nighttime lights time-series data from the Defense Meteorological Satellite Program Operational Linescan System(DMSP/OLS).The model was used to reconstruct the spatial patterns of EPC in Chinese Mainland at the county level from 1995 to 2008.In addition,the spatiotemporal dynamics of EPC were analyzed,and the fol-lowing conclusions were drawn.(1)The EPC model reliably represented the spatiotemporal dynamics of EPC in Chinese Mainland with approximately 70%accuracy.(2)The EPC in most regions of Chinese Mainland was at low to moderate levels,with marked temporal and spatial variations;of high-level EPC,58.26%was concentrated in eastern China.Six urban agglomerations(Beijing-Tianjin-Tangshan region,Shanghai-Nanjing-Hangzhou region,Pearl River Delta,Shandong Peninsula,middle-south of Liaoning Province,and Sichuan Basin)accounted for 10.69%of the total area of Chinese Mainland but consumed 39.23%of the electricity.(3)The EPC of most regions in Chinese Mainland increased from 1995 to 2008,and 64%of the mainland area showed a significant increase in EPC.Moderate increases in EPC were found in 61.62%of eastern China and 80.65%of central China from 1995 to 2008,whereas 75.69%of western China showed no significant increase in EPC.Meanwhile,77.27%,89.35%,and 66.72%of the Shanghai-Nanjing-Hangzhou region,Pearl River Delta,and Shandong Peninsula,respectively,showed high-speed increases in EPC.Moderate increases in EPC occurred in 71.12%and 72.13%of the Beijing-Tianjin-Tangshan region and middle-south of Liaoning Province,respectively,while no significant increase occurred in 56.34%of the Sichuan Basin.
文摘DMSP/OLS nighttime light （NTL） image is a widely used data source for urbaniza- tion studies. Although OLS NTL data are able to map nighttime luminosity, the identification accuracy of distribution of urban areas （UAD） is limited by the overestimation of the lit areas resulting from the coarse spatial resolution. In view of geographical condition, we integrate NTL with Biophysical Composition Index （BCl） and propose a new spectral index, the BCl Assisted NTL Index （BANI） to capture UAD. Comparisons between BANI approach and NDVl-assisted SVM classification are carried out using UAD extracted from Landsat TM/ETM＋ data as reference. Results show that BANI is capable of improving the accuracy of UAD extraction using NTL data. The average overall accuracy （OA） and Kappa coefficient of sample cities increased from 88.53% to 95.10% and from 0.56 to 0.84, respectively. Moreover with regard to cities with more mixed land covers, the accuracy of extraction results is high and the improvement is obvious. For other cities, the accuracy also increased to varying de- grees. Hence, BANI approach could achieve better UAD extraction results compared with NDVl-assisted SVM method, suggesting that the proposed method is a reliable alternative method for a large-scale urbanization study in China＇s mainland.
基金Under the auspices of State Scholarship Fund of China Scholarship Council(No.201706320300)。
文摘Understanding the dynamics of urbanization is essential to the sustainable development of cities. Meanwhile the analysis of urban development can also provide scientifically and effective information for decision-making. With the long-term Defense Meteorological Satellite Program’s Operational Linescan System(DMSP/OLS) nighttime light images, a pixel level assessment of urbanization of China from 1992 to 2013 was conducted in this study, and the spatio-temporal dynamics and future trends of urban development were fully detected. The results showed that the urbanization and urban dynamics of China experienced drastic fluctuations from 1992 to 2013, especially for those in the coastal and metropolitan areas. From a regional perspective, it was found that the urban dynamics and increasing trends in North Coast China, East Coast China and South Coast China were much more stable and significant than that in other regions. Moreover, with the sustainability estimating of nighttime light dynamics, the regional agglomeration trends of urban regions were also detected. The light intensity in nearly 50% of lighted pixels may continuously decrease in the future, indicating a severe situation of urbanization within these regions. In this study, The results revealed in this study can provided a new insight in long time urbanization detecting and is thus beneficial to the better understanding of trends and dynamics of urban development.
基金Under the auspices of National Natural Science Foundation of China(No.41001100,41371183)Humanities and Social Sciences Foundation of Ministry of Education in China(No.15YJCZH174)+1 种基金Humanities Sciences Foundation of Ministry of Hubei Province(No.15YJCZH174)Fundamental Research Funds for the Central Universities(No.CCNU15A06069,CCNU15ZD001)
文摘This paper intends to investigate the urban spatial patterns of Hubei Province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime light imagery of cities in Hubei Province, the viewpoint of ′point-axis-area′ in the ′point-axis system′ theory, and employs light index model, gravity model and social network analysis. The findings are as follows: 1) In terms of urban nodes, the urbanization process of Hubei has been carried out mainly on the basis of external expansion rather than internal increasing. The polarization trend of urban connection network is strengthening. 2) As for urban connections, the estimation of urban connections using light index model is capable of containing various actual flow, and the connections are getting increasingly closer. 3) In regard to urban groups, seven urban groups of varying sizes have formed. On that basis, three stable and relatively independent urban groups as the centers, namely Wuchang, Yichang and Xiangyang emerge as well. But the structures of ′Wuhan Metropolitan Area′, ′Yichang-Jingzhou-Jingmen City Group′ and ′Xiangyang-Shiyen-Suizhou City Group′, which are defined by local development strategy in Hubei Province, are different from the above three urban groups.
