【作者】 周杰；

【导师】 张学儒；

【作者基本信息】 重庆交通大学 ， 地图学与地理信息系统， 2019， 硕士

【摘要】 自改革开放以来,我国的城镇化率由1978年的17.92%提高到2015年的56.1%,并将以每年一个百分点的速率继续增长,预计在2020年,中国城市城镇化率将超过60%。城镇化使农村人口转变为城市居民,给我国带来巨大的社会福利,大量人口在城市中集聚的同时,也不可避免的推动城市建成区面积的剧烈扩张。城市的发展受到了人类活动与自然因素的共同影响,同时城市的扩张也影响着人们的活动与自然环境。城市扩张的研究是一个与人类切身利益相关的研究主题。随着遥感与地理信息技术的发展,对于城市扩张的监测研究技术不断革新,尤其是夜间灯光数据的出现,极大地促进了大尺度、长时间序列的城市扩张监测研究的发展。本文利用夜间灯光数据提取了中国1992年、1997年、2002年、2007年、2012年和2017年的城市建成区。为了提高提取结果质量,对两种夜间灯光数据采用不同的方法进行预处理。DMSP/OLS数据采用相互校正和连续性校正;NPP/VIIRS数据则利用月度数据进行年度数据合成,在对数据进行对数变换。与传统的采用夜间灯光数提取城市建成区方法不同,研究中提出利用图像切割技术—Canny边缘检测方法,识别城市建成区边界,以期提升城市建成区的提取精度。依据城市建成区边界信息计算得到每个省级行政单位的城市建成区分割阈值,降低区域发展不均衡导致各区域阈值不同的影响,进一步提高建成区提取精度。根据阈值分割得到中国城市建成区,并进行精度检验。依据中国城市建成区提取结果,采用城市扩张速度和城市扩张强度方法分析中国1992-2017年间的城市面积变化特征。京津冀、长三角和珠三角是我国快速发展的典型区域,为进一步探究中国快速发展过程中的城市建成区扩张规律,选取这三大城市群分析其城市扩张的时空变化。最后依据ANN-Markov-CA复合模型模拟未来中国城市扩张情况。得到的主要结论如下:(1)Canny边缘检测算法可以有效提高基于夜间灯光数据的建成区提取精度,解译精度达到81.68%。对夜间灯光数据采取预处理措施,增强了夜间灯光数据中城市建成区信息的表达能力,提升了城市建成区提取结果的质量。依据Canny边缘检测方法,有效的检测出城市建成区边界信息。依据边界信息分区计算各区域的城市建成区阈值,降低了城市建成区提取中由区域经济发展水平不同引起的误差。将提取结果与Landsat8数据提取的建成区进行叠加,检验提取结果的精度,得到重叠区域达到了81.68%,提取精度较高,Canny边缘检测算法用于夜间灯光提取城市建成区可行。(2)1992-2017年间,中国城市建成区面积增加了5.7倍,胡焕庸线以东地区对中国城市扩张贡献最大。1992-2017年间中国城市建成区面积逐期上升,每期城市建成区新增面积都在10000km~2以上,到2017年城市建成区面积为1992年的5.7倍。胡焕庸线两侧城市建成区在面积变化、城市扩张速度和城市扩张强度上,以东区域都占据了绝对的优势。在面积变化上,两侧差距逐渐变大由1992年的16119 km~2,扩大到2017年的77792 km~2。城市扩张速度上,两侧城市扩张速度差距的最小值为1427 km~2,大于以西地区城市扩张速度的最大值823.6 km~2。在城市扩张强度上,以东地区城市扩张强度高于以西地区和中国总体扩张强度,以东地区的城市扩张强度相比于以西地区,最小值为3.5倍,最大值则达到了8倍以上。因此,胡焕庸线以东地区对中国城市扩张贡献最大。(3)中国城市扩张空间分布与自然环境条件和经济发展密切相关。中国城市扩张空间分布上,在1992-2017年间,长三角、珠三角和京津冀一直是城市扩张最为显著的区域,随着时间的推移城市扩张显著区域向西部推移。在区域发展的中心,如省会城市、直辖市城市等,城市扩张显著。同时自然条件限制了城市扩张的空间分布,东部季风气候区域和地势平坦区域的叠加地区,城市扩张显著。高寒、干旱区域则城市扩张分布较少。因此自然环境条件与社会经济发展影响了中国城市扩张的空间分布。(4)三大城市群的城市扩张主要集中在城市群内中心城市周边,城市重心的迁移与城市建成区扩张时空变化有关。1992-2017年间,三大城市群的城市建成区面积逐步增加,平均增长率为京津冀43.72%、长三角56.14%,珠三角34.60%。长三角地区城市建成区面积规模最大。城市扩张空间分布上,扩张最为显著的区域主要集中在城市群内部的中心城市,区域内的山区和山脉影响城市建成区的空间分布和城市扩张的空间分布,城市扩张分布受到了社会经济状况与自然条件的影响。三大城市群的城市重心迁移变化,受到了城市扩张空间分布的影响。(5)基于ANN模型的城市扩张适宜性评价经检验准确率为0.864,准确率较高,ANN模型适用于城市扩张适宜性评价。模拟结果显示中国城市建成扩张热点区域发生转移,但胡焕庸线的限制任然难以突破。依据K折验证方法评价ANN模型训练结果,得到准确率为0.864。采用CA-Markov模型模拟中国城市扩张情况,模拟结果经检验Kappa系数为0.78,故ANN-Markov-CA复合模型模拟精度高,适用于城市扩张模拟研究。依据模拟结果,发现城市扩张的热点区域发生转移,京津冀、长三角和珠三角地区的城市扩张规模虽然依旧可观,但是在成渝城市群、关中平原城市群、中原城市群和长江中游城市群区域扩张规模更为突出。依据现有的自然社会经济条件,中国城市扩张难以突破胡焕庸线的限制。更多还原

【Abstract】 Since the reform and opening up.China’s urbanization rate has increased from 17.92%in 1978 to 56.1%in 2015.It would continue to grow at a rate of one percentage point a year.China’s urbanization rate is expected to exceed 60%by 2020.Because of urbanization,the transformation of rural population into urban residents has brought tremendous social welfare to China.A large number of people gather in the city to promote the drastic expansion of urban built-up areas.As we known,the development of cities is influenced by both human activities and natural factors,while the expansion of cities also affects people’s activities and natural environment.With the development of remote sensing and geographic information technology,the monitoring and research technology for urban expansion is constantly innovating.The appearance of night light data promotes the development of urban expansion monitoring with large scale and long time series in particular.The study extracts urban built-up areas in China from night lighting data in 1992,1997,2002,2007,2012 and 2017.Two kinds of night light data are pretreated by different methods to improve the quality of extraction results.DMSP/OLS data are processed by mutual correction and continuity correction,while NPP/VIIRS data are synthesized by monthly data and logarithmic transformation is performed.The segmentation thresholds of urban built-up areas of each provincial administrative unit are calculated based on the boundary information of urban built-up areas,which can reduce the impact of different thresholds caused by unbalanced regional development and further improve the extraction accuracy of built-up areas.According to threshold segmentation,urban built-up areas in China are extracted and their accuracy is verified.Based on the extracted results,the urban expansion speed and urban expansion intensity were used to analyze the characteristics of urban area change in China from 1992 to 2017.In order to further explore the expansion law of urban built-up areas in the process of rapid development in China,the three urban agglomerations,Beijing-Tianjin-Hebei,Yangtze River Delta and Pearl River Delta are typical areas of rapid development in China,are selected to analyze the spatial and temporal changes of urban expansion.Finally,simulation of China’s Urban Expansion in the Future Based on ANN-Markov-CA Composite Model.The main conclusions are as follows:(1)The interpretation accuracy reaches 81.68%,which indicates that Canny edge detection algorithm can effectively improve the accuracy of building area extraction based on night light data.Pre-processing measures are adopted for night lighting data,which enhances the expressive ability of urban built-up area information in night lighting data and improves the quality of urban built-up area extraction results.According to Canny edge detection method,the boundary information of urban built-up area can be effectively detected.The threshold values of urban built-up areas are calculated according to the boundary information partition,which reduces the errors caused by different levels of regional economic development in the extraction of urban built-up areas.In order to verify the accuracy of the extraction results,the overlap area is 80.06%by superimposing the extracted results with the built-up area extracted from Landsat8 data.The Canny edge detection algorithm is feasible for night lighting extraction of urban built-up areas.In terms of urban expansion intensity,the urban expansion intensity in the region of East of Hu Huanyong Line is higher than that in the area west of Hu Huanyong Line and China as a whole.Compared with the region of West of Hu Huanyong Line,the urban expansion intensity in the region of East of Hu Huanyong Line is 3.5 times as low as that in the region of West of Hu Huanyong Line,and the maximum is more than 8 times.(2)The area of built-up urban areas in China increased by 5.7 times between 1992and 2017.The region of East of Hu Huanyong Line contributes most to China’s urban expansion.From 1992 to 2017,the area of urban built-up areas in China increased steadily,with the newly added area of urban built-up areas exceeding 10,000 km~2 in each period.In2017,the area of urban built-up areas was 5.7 times that of 1992.The area of East of Hu Huanyong Line has absolute advantages in area change,urban expansion speed and urban expansion intensity.In terms of area change,the gap between the two sides gradually increased from 16119 km~2 in 1992 to 77792 km~2 in 2017.In terms of urban expansion speed,the smallest gap between the two sides is 1427 km~2,which is larger than the maximum of 823.6 km~2 in the region of West of Hu Huanyong Line.Therefore,the region of East of Hu Huanyong Line contributes most to China’s urban expansion.(3)The spatial distribution of urban expansion in China is closely related to natural environment and economic development.From 1992 to 2017,the Yangtze River Delta,the Pearl River Delta and Beijing,Tianjin and Hebei have been the most prominent areas of urban expansion in China.With the passage of time,the prominent areas of urban expansion have shifted to the west.In the center of regional development,such as provincial capital cities and municipalities directly under the Central Government,urban expansion is significant.At the same time,natural conditions restrict the spatial distribution of urban expansion.Urban expansion is significant in the overlapping areas of Eastern monsoon climate and flat terrain.Urban expansion is less distributed in cold and arid regions.Therefore,the natural environment conditions and socio-economic development affect the spatial distribution of urban expansion in China.(4)The urban expansion of the three metropolitan agglomerations mainly concentrates on the periphery of the central cities in the urban agglomeration,and the transfer of the urban center of gravity is related to the spatial and temporal changes of urban built-up area expansion.From 1992 to 2017,the built-up area of the three metropolitan agglomerations gradually increased,with an average growth rate of 43.72%in Beijing,Tianjin and Hebei,56.14%in the Yangtze River Delta and 34.60%in the Pearl River Delta.The Yangtze River Delta has the largest urban built-up area.In the spatial distribution of urban expansion,the most prominent areas are mainly concentrated in the central cities within the urban agglomeration.The mountainous areas and mountains in the region affect the spatial distribution of urban built-up areas and urban expansion.Urban expansion distribution is affected by social and economic conditions and natural conditions.The change of the center of gravity of the three metropolitan agglomerations is influenced by the spatial distribution of urban expansion.(5)The accuracy of ANN model in evaluating the suitability of urban expansion is0.864,which is higher.The ANN model is suitable for evaluating the suitability of urban expansion.The simulation results show that the hot areas of urban construction and expansion in China have shifted,but the limitations of Hu Huanyong Line are still difficult to break through.The accuracy of K-fold validation method in evaluating the training results of ANN model is 0.864.The CA-Markov model is used to simulate urban expansion in China.The Kappa coefficient is 0.78.Therefore,the ANN-Markov-CA composite model has high simulation accuracy and is suitable for urban expansion simulation research.According to the simulation results,it is found that the hot areas of urban expansion have shifted.Although the scale of urban expansion in Beijing-Tianjin-Hebei,Yangtze River Delta and Pearl River Delta is still considerable,it is more prominent in Chengdu-Chongqing urban agglomeration,Guanzhong Plain urban agglomeration,Central Plains urban agglomeration and the middle reaches of Yangtze River.According to the existing natural and social economic conditions,it is difficult for China’s urban expansion to break through the restrictions of Hu Huanyong Line.更多还原