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1.
《地理学报(英文版)》2017,(6)
The floating population has become the main driver of urban population excessive growth in China’s mega cities.Urban transit system(UTS)is a significant factor in population spatial distributions within urban areas,especially rapid and high-capacity transit systems.This paper analyzes the causal effects of the extension of expressways and subways between 2000 and 2010 in the Beijing Metropolitan Area(BMA),focusing on the group differences between the local residents and the floating population.Due to the endogeneity of transportation improvements and population growth,Instrumental Variable(IV)regression model is applied to avoid this problem.The results show the local residents increased in the inner suburbs but decreased in the city center,while the floating population increased in the majority areas.IV regression results show that the extension of urban transit systems had statistically significant impacts on population growth across the BMA.The results also show that the extension of urban subway system had more effects on the floating population than the local residents across the BMA.It is mainly caused by the rather low fare of urban subway system.This implies that the excessive subsidy on urban subway system could result in excessive floating population growth and residential differentiation,even residential segregation.Hence,it is necessary to plan and design reasonable and scientific urban transit systems in order to advance reasonable population size and promote residential integration.Moreover,the regional analysis shows that the effects of urban transportation improvements on the local residents are not statistically significant in the inner suburbs.It implies that urban transportation improvements had limited effects on inducing people to move to suburban areas and controlling center city’s population in Beijing.Therefore,it should be stressed the differentiated effects of urban transportation improvements on population distribution in the process of urban planning and population control. 相似文献
2.
Based on statistical data and population flow data for 2016,and using entropy weight TOPSIS and the obstacle degree model,the centrality of cities in the Yangtze River Economic Belt(YREB)together with the factors influencing centrality were measured.In addition,data for the population flow were used to analyze the relationships between cities and to verify centrality.The results showed that:(1)The pattern of centrality conforms closely to the pole-axis theory and the central geography theory.Two axes,corresponding to the Yangtze River and the Shanghai-Kunming railway line,interconnect cities of different classes.On the whole,the downstream cities have higher centrality,well-defined gradients and better development of city infrastructure compared with cities in the middle and upper reaches.(2)The economic scale and size of the population play a fundamental role in the centrality of cities,and other factors reflect differences due to different city classes.For most of the coastal cities or the capital cities in the central and western regions,factors that require long-term development such as industrial facilities,consumption,research and education provide the main competitive advantages.For cities that are lagging behind in development,transportation facilities,construction of infrastructure and fixed asset investment have become the main methods to achieve development and enhance competitiveness.(3)The mobility of city populations has a significant correlation with the centrality score,the correlation coefficients for the relationships between population mobility and centrality are all greater than 0.86(P<0.01).The population flow is mainly between high-class cities,or high-class and low-class cities,reflecting the high centrality and huge radiating effects of high-class cities.Furthermore,the cities in the YREB are closely linked to Guangdong and Beijing,reflecting the dominant economic status of Guangdong with its geographical proximity to the YREB and Beijing's enormous influence as the national political and cultural center,respectively. 相似文献
3.
Urban land cover has major impacts on a city’s ecosystem services and the inherent quality of its urban residential environment. The spatio-temporal distribution of impervious surface area and green areas in Chinese cities has exhibited a significantly marked difference in comparison with USA cities. This study focused on monitoring and comparing the spatio-temporal dynamics, land cover patterns and characteristics of functional regions in six Chinese(n=3) and USA(n=3) cities. The study data were collated from Landsat TM/MSS imagery during the period 1978–2010. Results indicate that Chinese cities have developed compactly over the past three decades, while development has been notably dispersed among USA cities. Mean vegetation coverage in USA cities is approximately 2.2 times that found amongst Chinese urban agglomerations. Land use types within Chinese cities are significantly more complex, with a higher density of impervious surface area. Conversely, the central business district(CBD) and residential areas within USA cities were comprised of a lower proportion of impervious surface area and a higher proportion of green land. Results may be used to contribute to future urban planning and administration efforts in both China and the USA. 相似文献
4.
Sequential city growth: Theory and evidence from the US 总被引：2，自引：1，他引：1
City growth patterns are attracting more attention in urban geography studies. This paper examines how cities develop and grow in the upper tail of size distribution in a large-scale economy based on a theoretical model under new economic geography framework and the empirical evidence from the US. The results show that cities grow in a sequential pattern. Cities with the best economic conditions are the first to grow fastest until they reach a critical size, then their growth rates slow down and the smaller cities farther down in the urban hierarchy become the fastest-growing ones in sequence. This paper also reveals three related features of urban system. First, the city size distribution evolves from low-level balanced to primate and finally high-level balanced pattern in an inverted U-shaped path. Second, there exist persistent discontinuities, or gaps, between city size classes. Third, city size in the upper tail exhibits conditional convergence characteristics. This paper could not only contribute to enhancing the understanding of urbanization process and city size distribution dynamics, but also be widely used in making effective policies and scientific urban planning. 相似文献
5.
ZHAO Rongqin HUANG Xianjin LIU Ying ZHONG Taiyang DING Minglei CHUAI Xiaowei 《地理学报(英文版)》2014,24(1):159-176
Urban carbon footprint reflects the impact and pressure of human activities on ur- ban environment. Based on city level, this paper estimated carbon emissions and carbon footprint of Nanjing city, analyzed urban carbon footprint intensity and carbon cycle pressure and discussed the influencing factors of carbon footprint through LMDI decomposition model. The main conclusions are as follows： （1） The total carbon emissions of Nanjing increased rapidly since 2000, in which the carbon emission from the use of fossil energy was the largest Meanwhile, carbon sinks of Nanjing presented a declining trend since 2000, which caused the decrease of carbon compensation rate and the increase of urban carbon cycle pressure. （2） The total carbon footprint of Nanjing increased rapidly since 2000, and the carbon deficit was more than ten times of total land areas of Nanjing in 2009, which means Nanjing confronted high carbon cycle pressure. （3） Generally, carbon footprint intensity of Nanjing was on de- crease and the carbon footprint productivity was on increase. This indicated that energy utilization rate and carbon efficiency of Nanjing was improved since 2000, and the policy for energy conservation and emission reduction taken by Nanjing＇s government received better effects. （4） Economic development, population and industrial structure are promoting factors for the increase of carbon footprint of Nanjing, while the industrial carbon footprint intensity was inhibitory factor. （5） Several countermeasures should be taken to decrease urban carbon footprint and alleviate carbon cycle pressure, such as： improvement of the energy efficiency, industrial structure reconstruction, afforestation and environmental protection and land use control. Generally, transition to low-carbon economy is essential for Chinese cities to realize sustainable development in the future. 相似文献
6.
《地理学报(英文版)》2017,(7)
China's economy has undergone rapid transition and industrial restructuring. The term "urban industry" describes a particular type of industry within Chinese cities experiencing restructuring. Given the high percentage of industrial firms that have either closed or relocated from city centres to the urban fringe and beyond, emergent global cities such as Shanghai, are implementing strategies for local economic and urban development, which involve urban industrial upgrading numerous firms in the city centre and urban fringe. This study aims to analyze the location patterns of seven urban industrial sectors within the Shanghai urban region using 2008 micro-geography data. To avoid Modifiable Areal Unit Problem(MAUP) issue, four distance-based measures including nearest neighbourhood analysis, Kernel density estimation, K-function and co-location quotient have been extensively applied to analyze and compare the concentration and co-location between the seven sectors. The results reveal disparate patterns varying with distance and interesting co-location as well. The results are as follows: the city centre and the urban fringe have the highest intensity of urban industrial firms, but the zones with 20–30 km from the city centre is a watershed for most categories; the degree of concentration varies with distance, weaker at shorter distance, increasing up to the maximum distance of 30 km and then decreasing until 50 km; for all urban industries, there are three types of patterns, mixture of clustered, random and dispersed distribution at a varied range of distances. Consequently, this paper argues that the location pattern of urban industry reflects the stage-specific industrial restructuring and spatial transformation, conditioned by sustainability objectives. 相似文献
7.
Climate change is a global environmental crisis, but there have been few studies of the effects of climate change on cereal yields on the Tibetan Plateau. We used data from meteorological stations and statistical yearbooks to assess the impacts of climate change on cereal yields in Tibet. Three types of statistical models were selected: fixed-effects model, first-difference models, and linear detrending models. We analyzed the impacts of climate change(including the minimum temperature, precipitation, growing degree days and solar radiation) on cereal yields in Tibet from 1993 to 2017 at the county, prefecture-level city, and autonomous region scales. The results showed that the sensitivity of cereal yields in Tibet to temperature(minimum temperature and growing degree days) was greater than their sensitivity to precipitation and solar radiation. The joint impacts of climate variables were positive, but the sensitivity and significance varied in different regions. The impacts of minimum temperature, precipitation, and solar radiation were positive in all cities, apart from the negative impacts of growing degree days on cereal yields in Lhasa. The impacts of climate trends on cereal yields in Tibet were positive and the results were in the range of 1.5%–4.8%. Among the three types of model, the fixed-effects model was the most robust and the linear detrending model performed better than the first-difference model. The robustness of the first-difference model decreased after adding the interaction terms between different climate variables. Our findings will help in implementing more spatially targeted agricultural adaptations to cope with the impacts of climate change on the agro-ecosystem of the Tibetan Plateau. 相似文献
8.
This study presents an analysis of the spatial-temporal distribution of 230 archaeological sites in Guizhou Province, Southwest China for three selected time periods from the Paleolithic Age to the Shang-Zhou Dynasties. The relationship between archaeological sites distribution and environmental changes is also discussed based on paleo-environmental proxies of δ18O and δ13C recorded in stalagmites from Southwest China. The results show that: in the Paleolithic Age(260–10 ka BP), archaeological sites were concentrated in the central, northwestern and southwestern parts of Guizhou, where the high-altitudinal karst landforms with many natural caves suitable for human habitation are developed. In the Neolithic Age(10–3.6 ka BP), most of human settlements were concentrated in the central, northwestern and southwestern parts, while, a fewer sites were found on river terraces in the southern and eastern parts, and the intermontane basins in the central and western Guizhou. During the Shang-Zhou Dynasties(3.6–2.2 ka BP), the sites were mainly distributed in the intermontane basins and on river terraces, which were suitable for primitive aerial farming. The analysis of paleo-environmental proxies of δ18O and δ13C since 260 ka BP suggested that climate fluctuations had little impact on human settlements in this study area. The distinct physical environment, especially the spatial patterns of karst landforms and arable land played an important role in the archaeological sites distribution of Guizhou. 相似文献
9.
中国城市绿色发展效率时空演变特征及影响因素 总被引：1，自引：3，他引：1
To resolve conflicts between development and the preservation of the natural environment,enable economic transformation,and achieve the global sustainable development goals(SDGs),green development(GD)is gradually becoming a major strategy in the construction of an ecological civilization and the ideal of building a"beautiful China",alongside the transformation and reconstruction of the global economy.Based on a combination of the concept and implications of GD,we first used the Slacks Based Model with undesirable outputs(SBM-Undesirable),the Theil index,and the spatial Markov chain to measure the spatial patterns,regional differences,and spatio-temporal evolution of urban green development efficiency(UGDE)in China from 2005 to 2015.Second,by coupling natural and human factors,the mechanism influencing UGDE was quantitatively investigated under the framework of the human-environment interaction.The results showed that:(1)from 2005 to 2015,the UGDE increased from 0.475 to 0.523,i.e.,an overall increase of 10%.In terms of temporal variation,there was a staged increase,with its evolution having the characteristics of a"W-shaped"pattern.(2)The regional differences in UGDE followed a pattern of eastern>central>western.For different types of urban agglomeration,the UGDE had inverted pyramid cluster growth characteristics that followed a pattern of"national level>regional level>local level",forming a stable hierarchical scale structure of"super cities>mega cities>big cities>medium cities>small cities".(3)UGDE in China has developed with significant spatial agglomeration characteristics.High-efficiency type cities have positive spillover effects,while low-efficiency cities have negative effects.Different types of urban evolution processes have a path dependence,and a spatial club convergence phenomenon exists,in which areas with high UGDE are concentrated and drive low UGDE elsewhere.(4)Under the framework of regional human-environment interaction,the degree of human and social influence on UGDE is greater than that of the natural background.The economic strength,industrial structure,openness,and climate conditions of China have positively promoted UGDE. 相似文献
10.
Numerous domestic scholars have argued that a remote location is the major factor preventing the transformation and sustainable development of resource-exhausted cities. Research to date, however, has not presented relevant evidence to support this hypothesis or explained how to identify the concept of ‘remoteness'. Resource-exhausted cities designated by the State Council of China were examined in this study alongside the provincial capital cities that contain such entities and three regional central cities that are closely connected to this phenomenon: Beijing, Shanghai, and Guangzhou. Spatial and temporal distances are used to calculate and evaluate the location remoteness degrees(LRDs) of resource-exhausted cities, in terms of both resource types and regions. The results indicate that resource-exhausted cities are indeed remote from the overall samples. Based on spatial distances, the LRDs are α_1 = 1.36(i.e., distance to provincial capital city) and β_1 = 1.14(i.e., distance to regional central city), but when based on temporal distances, α_2 = 2.02(i.e., distance to provincial capital city) and β_2 = 1.44(i.e., distance to regional central city). Clear differences are found in the LRDs between different regions and resource types, with those in western China and forest industrial cities the most obviously remote. Finally, the numbers of very remote resource-exhausted cities based on spatial and temporal distances(i.e.,α 1.5 ∩β 1.5) are 14 and 19, respectively, encompassing 17.9% and 24.4% of the total sampled. Similarly, 25 and 30 not remote resource-exhausted cities based on spatial and temporal distances(i.e.,α≤1.0 ∩β≤ 1.0) encompass 32.1% and 38.5% of the total, respectively. This study provided supporting information for the future development and policy making for resource-exhausted cities given different LRDs. 相似文献
11.
In addition to socio-economic factors,major landforms may affect the city structure and urban form. Here we show that landforms have significant effects on the city shape and street patterns of the fast-growing Iranian cities of Dezful (a river) and Khorramabad (mountains and valleys),but no clear effects on the cities of Yazd and Nain. Also,where the street orientation is peaked,the Gibbs/Shannon entropy (a measure of dispersion or spread) is low,but increases as the distribution becomes more uniform because of landform constraints. The streets in the old inner parts of all the cities are,on average,shorter and denser (more streets per unit area) than the streets of the newer outer parts. The entropies of the outer parts are also greater than those of the inner parts,implying that the street-length distribution gradually becomes more dispersed or spread as the city expands. All these cities have been fast growing in the past decades,with the newer outer parts expanding rapidly. As shown here,the rapidly formed outer parts (with greater dispersion in street patterns) have significantly different textures from those of the older inner parts,indicating different functionality and growth processes. These quantitative methods for street-network analysis can be used worldwide,particularly for analysing the effects of landforms on city shape and texture. 相似文献
12.
In addition to socio-economic factors, major landforms may affect the city structure and urban form. Here we show that landforms have significant effects on the city shape and street patterns of the fast-growing Iranian cities of Dezful(a river) and Khorramabad(mountains and valleys), but no clear effects on the cities of Yazd and Nain. Also, where the street orientation is peaked, the Gibbs/Shannon entropy(a measure of dispersion or spread) is low, but increases as the distribution becomes more uniform because of landform constraints. The streets in the old inner parts of all the cities are, on average, shorter and denser(more streets per unit area) than the streets of the newer outer parts. The entropies of the outer parts are also greater than those of the inner parts, implying that the street-length distribution gradually becomes more dispersed or spread as the city expands. All these cities have been fast growing in the past decades, with the newer outer parts expanding rapidly. As shown here, the rapidly formed outer parts(with greater dispersion in street patterns) have significantly different textures from those of the older inner parts, indicating different functionality and growth processes. These quantitative methods for street-network analysis can be used worldwide, particularly for analysing the effects of landforms on city shape and texture. 相似文献
13.
采用城市形态发生学研究方法,在实地调研的基础上,利用历史文献、考古调查,结合古地图、航片、遥感影像等资料,对河南商丘归德府古城的城市形态进行了复原与分析。研究结果显示,归德府古城呈圆形的外边缘带,与呈方形的内边缘带,分别修筑于不同时期,具有不同的功能,“外圆内方”的空间形态实际上是城市变化的结果,反映了文化与自然环境两方面的作用。归德府城市形态各组成部分的变化并不一致,其中外郭城的变化最大,内城的变化相对较小,内城的街道、街区格局基本与清代的格局一致。内城的城墙-城门-护城河、棋盘格式街道格局、标志性建筑物（如文庙、府学等）,以及少量的呈点片状分布的古建筑和民居,构成了归德府城市形态主体,在中原地区具有典型性和唯一性,值得特别关注和保护。 相似文献
14.
Bin Jiang 《International journal of geographical information science》2013,27(8):1033-1048
Urban streets are hierarchically organized in the sense that a majority of streets are trivial, while a minority of streets is vital. This hierarchy can be simply, but elegantly, characterized by the 80/20 principle, i.e. 80% of streets are less connected (below the average), while 20% of streets are well connected (above the average); out of the 20%, there is 1% of streets that are extremely well connected. This paper, using a European city as an example, examined, at a much more detailed level, such street hierarchies from the perspective of geometric and topological properties. Based on an empirical study, we further proved a previous conjecture that a minority of streets accounts for a majority of traffic flow; more accurately, the 20% of top streets accommodate 80% of traffic flow (20/80), and the 1% of top streets account for more than 20% of traffic flow (1/20). Our study provides new evidence as to how a city is (self‐)organized, contributing to the understanding of cities and their evolution using increasingly available mobility geographic information. 相似文献
15.
Location factors are vital elements for describing housing price variation. However, limited studies have explicitly illustrated the relationship between urban design and the heterogeneity of housing price patterns. This article specifically evaluates how the interactions between the spatial layouts and land-use system at various scales through street network affect the valuation of the residential properties and the segmentation of housing markets in a network-based Mixed-scale Hedonic Model (MHM) where the submarkets pattern are determined and annotated by the spatially varying estimates on streets. The application of the delivered method in the case of Shanghai City, China, confirms the necessity of using the non-Euclidean distance metric and represent the coexistence between the stationarity and the non-stationarity of the introduced street accessibility variables. The results provide evidence that the impacts of street accessibility measures on the local levels showcase significant spatial variation. It is common for all the places that the properties located on the streets with the higher levels of angular closeness, smaller values of angular betweenness and longer angular distance to the nearby land-uses at the larger scales will be bided higher. It is proven that our delineation of submarket performs better in prediction accuracy than the traditional submarket specifications. The detected submarkets pattern yields that reachable land-use diversity at the pedestrian level is not a preferred factor in the housing submarkets located in the developed city centres. The signs of the price effects of the angular distance to local land-uses distinguish the developing submarkets as two main groups with different degrees of geometrical walkability. It is suggestive that continuously developing pedestrian-oriented neighbours in the walkable areas could contribute to decelerating the growth of house price in Chinese cities. The productions of this study can enrich the understanding of the socioeconomic effects of urban design with greater spatial precision across submarkets. 相似文献
16.
Quantitative research of urban geography has benefited greatly from the rapid development of big geo-data. Spatial assembly is an essential analytical step to summarize and perceive geographical environment from individual behaviours. Most research focuses on the methodology of how to utilize the big data, while the adopted spatial units for data aggregation remain areal in nature. This article conceptually proposes an idea of sensing cities from a street perspective, emphasizes the significance of street units in quantitative urban studies. Using a three-month taxi trajectory dataset and the major streets in Beijing, we explore the spatio-temporal patterns of urban mobility on streets, cluster streets into nine types based on their dynamic functions and capacities. Additionally, we discuss the differences and connections between the linear street unit and traditional areal units, investigate the possibility of uncovering urban communities using streets, and point out the complexity of streets. We conclude that street unit as a supplement to areal units, is able to effectively minify the modifiable areal unit problem (MAUP), sense urban dynamics, depict urban functions, and understand urban structures. 相似文献
17.
DP半岛街头抢劫犯罪案件热点时空模式 总被引：10，自引：4，他引：6
选取H市中心城区DP半岛作为研究区域,以岛上2006-2011 年发生的街头抢劫案件（共373 起） 作为研究对象,将DP半岛内街头抢劫案件的时空分布特征分别从宏观和局部微观两个尺度层面进行系统的分析。首先,对岛上的街头抢劫案件按年、月和小时进行统计分析,总结其在不同时间尺度上的变化规律：2007 年开始的严打使案件数量逐年减少,直到2010 年才略有回升;春节期间（二月前后） 的案件数量明显高于其他月份;晚上22:00-23:00 期间是案件高发时段。其次,利用Kernel 密度方法对研究区街头抢劫犯罪的宏观空间分布进行整体的辨别,剥离出犯罪热点空间分布,分析热点与道路网和土地利用的关联性,结果表明热点多分布于主干道、通达性高的节点或土地利用混合度高的地方。最后,选出4 个最主要的热点从微观尺度进行分析,PAI 指数表明这4 个热点在时间上是稳定的,从2006 年到2011 年一直存在。依据“热点时空类型矩阵”的时间分布和空间分布模式,将这4 个稳定热点归类到不同微观时空模式,并对每类模式下的街头抢劫犯罪提出有针对性的防控对策,以便优化警力资源的配置、最大限度抑制和减少犯罪的发生。 相似文献
18.
The association between spatial patterns of retail activity and the spatial configuration of street networks was examined by means of the space syntax methodology in eight Israeli cities that represent two city types, characterized by different planning approaches and urban growth: (i) new towns, which were established according to a comprehensive city plan and modern planning concepts of “tree-like” hierarchical street networks and “neighborhood units”; (ii) older cities, where street networks and the spatial patterns of retail activity were formed incrementally during their growth. Unlike in older cities, retail activity in new towns concentrates in relatively less-accessible and intermediate locations. This is indicated by a weak correlation between retail activity and the street network’s Integration and Choice centrality measures. The comparison between Israeli cities illustrates the influence of urban growth and planning approaches on the formation of retail activity and its interaction with the structure of the street network. 相似文献
19.
利用基于计算流体力学（CFD）理论的数值模拟软件,在不影响街道连续性面貌的前提下,通过控制变量法分别改变街道贴线率、街道界面密度、街道高宽比3个关键要素的数值来观察街道风环境的变化情况。结论主要有： 街道内的风速大小随着街道贴线率的增大呈抛物线趋势变化,先增大后减小,在街道贴线率接近70%时,城市街道内风速达到最大; 随着界面密度的不断减小,城市街道内各个测点的风速变化的幅度越来越大,这样会让在其中行走的行人感受到强烈的风速变化,舒适度大为下降; 城市街道内的平均风速和街道高宽比成反比例关系。 相似文献
20.
研究基于空间句法理论与方法,结合不同时期的数字化历史地图,从街道网络显型、“局部—整体”层级关系及运转效率等三方面探讨民国以来北京老城的街道网络演变进程。结果表明：① 政权更替是其演变的分水岭。民国时期,老城街道网络由封建隔离结构向现代通达结构转型,环环相扣、中轴对称式的整合、穿行核心格局同时被打破。1949年中华人民共和国成立后,街道网络的几何格网特征越发明显,“环形+大格网”式的核心运动骨架凸显,不同街道段的可达性与穿行频率则逐渐趋同。② 老城各子区域的可达性层级关系在百余年来持续变化,穿行频率层级关系则保持稳定,与其他区域相比,东城的可达性与穿行频率优势明显。③ 政权更替之际新结构的集中嵌入与随后规划建设的路径依赖使得老城全域的运转效率历经“下降→上升→下降→上升”的起伏演变过程。这一过程同样出现在东城、西城与外城,但更强的几何格网特征促使前者的两次上升幅度较大,运转效率也相对较高,而皇城的运转效率则随小规模封闭系统的日益开放呈阶梯式下降。概括来讲,研究不仅运用数字化手段系统梳理了北京老城的街道发展史,为如何更好地保护古都风貌,传承历史文脉提供了街道网络视角的逻辑支撑,对于空间句法的理论算法体系也进行了一定拓展。 相似文献