Spatial heterogeneity and driving mechanism of urban climbing and its impact on regional environment in varied landform types in the middle reaches of the Yellow River

Urbanization research is essential for the sustainable use of regional land resources and ecological environment protection.The expansion process and driving factors of urban construction land at different scales in the middle reaches of the Yellow River(MRYR)have not been comprehensively elucidated.In this study,we explored the distribution pattern of urban construction land on different slope gradients at different scales and analyzed its influencing factors.The main findings were as follows:(1)There has been significant expansion of urban construction land in the MRYR over the past 20 years.Spatial heterogeneity was observed in the regional urban construction land expansion process among different geomorphic regions.(2)The urban construction land in the MRYR was expanded vertically to areas with slopes of>5°,particularly in 2005–2010.Significant slope climbing of urban construction land was observed in the loess hilly-gully and rocky mountain areas.(3)In MRYR,68.45%of the counties were categorized as the slope-climbing types,including 37.38%high-slope-climbing types.(4)The regional population density and economic development level were closely associated with regional urban construction land area variability.(5)The climbing process of regional urban construction can effectively alleviate farmland encroachment and pressure on the regional ecological environment.The urban expansion of the metropolitan distribution areas in the Plain region(such as Xi'an,Taiyuan)had a relatively significant impact on the local carbon storage.

Spatial patterns and driving forces of urban vegetation greenness in China:A case study comprising 289 cities

Urban vegetation in China has changed substantially in recent decades due to rapid urbanization and dramatic climate change.Nevertheless,the spatial differentiation of greenness among major cities of China and its evolution process and drivers are still poorly understood.This study examined the spatial patterns of vegetation greenness across 289 cities in China in 2000,2005,2010,2015,and 2018 by using spatial autocorrelation analysis on the Normalized Difference Vegetation Index(NDVI);then,the influencing factors were analyzed by using the optimal parameters-based geographical detector(OPGD)model and 18 natural and anthropogenic indicators.The findings demonstrated a noticeable rise in the overall greenness of the selected cities during 2000-2018.The cities in northwest China and east China exhibited the rapidest and slowest greening,respectively,among the six sub-regions.A significant positive spatial correlation was detected between the greenness of the 289 cities in different periods,but the correlation strength weakened over time.The hot and very hot spots in southern and eastern China gradually shifted to the southwest.While the spatial pattern of urban greenness in China is primarily influenced by wind speed(WS)and precipitation(PRE),the interaction between PRE and gross domestic product(GDP)has the highest explanatory power.The explanatory power of most natural factors decreased and,conversely,the influence of anthropogenic factors generally increased.These findings emphasize the variations in the influence strength of multiple factors on urban greenness pattern,which should be taken into account to understand and adapt to the changing urban ecosystem.

Influence of Transportation Accessibility on Urban-rural Income Disparity and Its Spatial Heterogeneity

Transportation accessibility has been treated as an important means of reducing the urban-rural income disparity.However,only a few studies have examined the effects of different types of transportation accessibility on urban-rural income disparity and their spatial heterogeneity.Based on data from 285 prefecture-level(and above)Chinese cities in 2000,2005,2010,2015,and 2020,this study uses spatial econometric models to examine how highway accessibility and railway accessibility influence the urban-rural income disparity and to identify their spatial heterogeneity.The result reveals that highway accessibility and railway accessibility have‘coreperiphery’ring-like circle structures.The urban-rural income disparity exhibits strong spatial clustering effects.Both highway accessibility and railway accessibility are negatively associated with urban-rural income disparity,and the former having a greater effect size.Moreover,there is a substitution effect between highway accessibility and railway accessibility in the whole sample.Furthermore,these associations differ in geographic regions.In the central region,highway accessibility is more important in reducing the urban-rural income disparity,but its effect is weakened with the increase of railway accessibility.In the western region,railway accessibility has a larger effect on narrowing the urban-rural income disparity,and this effect is strengthened by the increase of highway accessibility.We conclude that improving transportation accessibility is conducive to reducing the urban-rural income disparity but its effect is spatial heterogenetic.Highways and railways should be developed in a coordinated manner to promote an integrated transport network system.

Factors Influencing the Spatial Variability of Air Temperature Urban Heat Island Intensity in Chinese Cities

Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling factors.In this study,the data generated by an urban climate model were used to investigate the spatial variations of the AUHI across China and the underlying climate and ecological drivers.A total of 355 urban clusters were used.We performed an attribution analysis of the AUHI to elucidate the mechanisms underlying its formation.The results show that the midday AUHI is negatively correlated with climate wetness(humid:0.34 K;semi-humid:0.50 K;semi-arid:0.73 K).The annual mean midnight AUHI does not show discernible spatial patterns,but is generally stronger than the midday AUHI.The urban–rural difference in convection efficiency is the largest contributor to the midday AUHI in the humid(0.32±0.09 K)and the semi-arid(0.36±0.11 K)climate zones.The release of anthropogenic heat from urban land is the dominant contributor to the midnight AUHI in all three climate zones.The rural vegetation density is the most important driver of the daytime and nighttime AUHI spatial variations.A spatial covariance analysis revealed that this vegetation influence is manifested mainly through its regulation of heat storage in rural land.

Temporal and spatial differences in human activities performed in Urban Green Spaces of Vilnius(Lithuania)

Urban green spaces(UGS)are relevant to city well-being,as recognized by the United Nations’Sustainable Development Goals(SDGs).However,few studies have studied the temporal use of UGS.This work assessed the seasonal,weekly,and daily use of three urban green spaces(Vingis Park,Bernardino Garden,and Jomantas Park)in Vilnius(Lithuania).The study is based on an on-site observation-based survey,which recorded users’characteristics,activities,and weather conditions during summer and winter.The results showed that UGS’s seasonal,weekly,and daily use differed according to park and users’characteristics.Parks with a higher diversity of facilities had a high seasonal difference in the number of observed activities.User numbers were higher in the summer for activities with children,social activities,sports,and water activities than in the winter.Jomantas Park had the lowest variability in user characteristics.Weather variables were linked to changes in users’activities.Higher precipitation and lower temperature were associated with reducing the number of users and the diversity of registered activities.Most of the stationary activities were observed during summer.The diversity of the observed activities was associated with the available facilities rather than the park size.The distribution of stationary activities was spatially correlated with facility/equipment(benches,playgrounds,sports,and fitness equipment)and proximity to water features.The results of this study are relevant for UGS design,planning,and management.

Spatiotemporal Differentiation of Urban Spatial Form and Carbon Emissions in Poyang Lake City Group

In response to the inherent requirements of low-carbon land spatial planning in Jiangxi Province and the lack of existing research,this paper explored the mechanism of spatial form elements of Poyang Lake urban agglomeration on urban carbon emissions.Based on generalized linear regression and geographically weighted regression models,this paper analyzed the spatiotemporal distribution characteristics of carbon emissions,the spatiotemporal relationship between urban form index and carbon emissions,and the spatial differentiation of the intensity of dominant factors from 63 county-level administrative units in the Poyang Lake city group from 2005 to 2020.The results showed that:①The carbon emissions of urban agglomerations around Poyang Lake are generally increasing,and the spatial distribution of carbon emissions is characterized by high-value concentration in the middle and low-value agglomeration in pieces;②The main driving factor for the spatial heterogeneity of carbon emissions was the expansion of built-up area;③Improving urban compactness and optimizing urban form could effectively reduce urban carbon emissions.The results showcased the correlation between urban spatial landscape pattern and the spatiotemporal distribution of carbon emissions,which could make the low-carbon land spatial planning in the Poyang Lake city group more reasonable and practical.

Urban Spatial Form Optimization Strategies Based on the Principle of Climate Adaptability of Regional Architecture: A Case Study of Traditional Cave Dwelling Villages in Northern Shaanxi Province

A multitude of climate-adaptive design approaches are embedded in regional architecture,which have a positive impact on addressing the deformed development of urban spatial patterns and the dual challenges of climate and resources.This paper examines the principles of climate adaptability embedded in the site layout and spatial organization characteristics of traditional cave dwelling villages in northern Shaanxi Province.The extracted climate adaptability principles are summarized,and the resulting design strategies that are well-suited to the contemporary urban space form are presented.Through analysis,it can be observed that traditional cave dwelling villages in northern Shaanxi are predominantly situated on south-facing slopes in proximity to water at low altitudes.These villages are characterized by compact building groups and east-west development,which is constrained by the elements of mountains and rivers.A two-level street system is generated,comprising streets parallel to the contour line and roadways perpendicular to the contour line.This results in the formation of a courtyard form enclosed by mountains.Such site layout and spatial organization exhibit excellent climate adaptability with regard to heat,ventilation,and wind storage.In light of the aforementioned considerations,the following urban spatial form design strategies are put forth:①the topographic height difference can be exploited to obtain sufficient sunshine;②the group shape can be optimized in order to reduce building energy consumption;③the best orientation of the building can be chosen to take account of both winter and summer conditions;④the height and length can be combined in order to form natural masking;⑤the D/H ratio of streets and roadways should be controlled to achieve a balance between heat gain and cooling of groups;⑥vents should be set appropriately to optimize group ventilation;⑦climate buffers should be established to increase the level of climate response.

The Study on the Evolution of Urban Spatial Structure in Zhuhai City Based on Spatial Syntax

With the deepening of the Guangdong-Hong Kong-Macao Greater Bay Area strategy and the accelerated integration and development of the east and west sides of the Pearl River Estuary,Zhuhai’s hub position is becoming more and more prominent.The city of Zhuhai has a dense water network and is divided into two urban areas,the east and the west,under the influence of the Mordor Gate waterway.Based on the theory of spatial syntax,this paper carries out an analytical study on the urban spatial structure of Zhuhai,identifies the distribution characteristics of urban POIs,and provides theoretical support for the urban development of Zhuhai.

Geospatial Analysis of Urban Heat Island Effects and Tree Equity

In recent decades, Urban Heat Island Effects have become more pronounced and more widely examined. Despite great technological advances, our current societies still experience great spatial disparity in urban forest access. Urban Heat Island Effects are measurable phenomenon that are being experienced by the world’s most urbanized areas, including increased summer high temperatures and lower evapotranspiration from having impervious surfaces instead of vegetation and trees. Tree canopy cover is our natural mitigation tool that absorbs sunlight for photosynthesis, protects humans from incoming radiation, and releases cooling moisture into the air. Unfortunately, urban areas typically have low levels of vegetation. Vulnerable urban communities are lower-income areas of inner cities with less access to heat protection like air conditioners. This study uses mean evapotranspiration levels to assess the variability of urban heat island effects across the state of Tennessee. Results show that increased developed land surface cover in Tennessee creates measurable changes in atmospheric evapotranspiration. As a result, the mean evapotranspiration levels in areas with less tree vegetation are significantly lower than the surrounding forested areas. Central areas of urban cities in Tennessee had lower mean evapotranspiration recordings than surrounding areas with less development. This work demonstrates the need for increased tree canopy coverage.

Spatial Pattern and Process of Urbanization in Karst Area——A Case Study in Guiyang City

ObjectiveKarst area is one of ecological fragile regions in China, where the economic and social development is lagged heavily. In recent years, with the constant development of the west regions, economy and society are developed rapidly and urbanization speed is accelerated. This study aims to investigate the spatial pattern and process of urbanization in karst area of Guiyang City, which has important significance for land management and urban planning in karst area. MethodBased on RS and GIS technologies, TM satellite images in 1986, 1995 and 2000 and CBERS-01 satellite image in 2006 were adopted to obtain the data of urban land utilization in Guiyang City in the four years. The spatial pattern and process of urbanization in Guiyang City were investigated using urbanization proportion index （UPI）, urbanization intensity index （UII） and absolute expansion intensity （AEI）. ResultThe urbanization process in Guiyang City was significant, exhibiting polygon-urbanization, line-urbanization and point-urbanization. From the perspective of spatial pattern, the urbanization in Guiyang City displayed the cluster development; from the perspective of urbanization process, the urbanization speed in some secondary central areas was higher than that of central areas. ConclusionThe spatial pattern and process of urbanization in karst area were unique and were mainly influenced by terrain, transportation, economy, society and so on.

Study on Spatial Heterogeneity of Urban Green Land Based on ETM+ Image in Shenzhen City

[Objective] To discuss the influence of the spatial heterogeneity of different green land types on their corresponding ecological efficiency and functions. [Method] ETM+ Images are utilized to classify urban green land into three categories, i.e. park green land, affiliated green land and other green lands; the principles of geostatistics are adopted to analyze their spatial heterogeneity. [Result] Spatial heterogeneity of different green land types differs greatly, which follows the scale law of 'affiliated green land < other green lands < park green land'. [Conclusion] The ecological functions and process of different green land types are different in scale; and the shapes of semi-variance functions are closely related to the spatial range, size and variety of ground objects, which however differ slightly in different directions, look similar or tend to isotropy.

Analysis of Spatial Configuration of Wenshufang in Chengdu City from the Perspective of Urban Design

Figure-ground theory,linkage theory and place theory of Roger Trancik were applied,field investigation,photo-taking and inductive analysis combined to analyze spatial configuration of urban historic blocks,physical environment,wills of people and also interaction between human behavior and environment in Wenshufang,Chengdu City of Sichuan Province.The results showed that on the basis of a clear bidimensional virtual-real structure,"linear parameters" and "dynamic structures" of spatial connection were established for Wenshufang,environment elements and humanistic needs of the place were respected,connection vitality of lane and yard spaces maintained.In this way,Wenshufang successfully inherited Buddhist cultures and folk cultures,providing a useful reference for the protection and research on historic blocks in other cities.

Research on Spatial Influence Mechanism of Chongqing Urban Growth Management

After illustrating the concept of Urban Growth Theory and Urban Growth Management,by taking relevant theoretical research literatures for reference,based on the specific conditions of Chongqing City,the paper had analyzed the spatial growth and evolution of Chongqing City,and the spatial influence mechanism for urban growth management.The spatial influence mechanism of Chongqing urban growth had been divided into four aspects including natural environment,economic development,urban traffic organization and regional policy planning,which were considered as the primary mechanism,driving mechanism,essential condition and driving force of urban spatial growth and development,respectively.From the perspective of analyzing problems,the comprehensive analysis had been conducted on the urban growth management in economy and planning,and corresponding urban growth space management strategies had been formulated.From the perspective of combining theory with practice,it had studied and revealed the spatial influence mechanism for urban growth management,which was of practical guiding significance to the development of Chongqing urban space pattern,and also vital significance to the construction of theoretical system of Chinese urban management and guidance of further development and renovation of specific urban planning.

Study on Spatial Structure of Rural Tourism in Wuhan Urban Agglomerations

Spatial structure of rural tourism in the urban agglomerations of Wuhan was analyzed by comprehensively studying relevant documents about rural tourism,and reviewing previous researches on the concept and spatial structure of rural tourism.Through investigating rural tourist resources in the study area,resource advantages and characteristics of 9 cities were introduced,and the Gini Coefficient was taken to quantitatively analyze spatial patterns of its rural tourist villages,the obviously imbalanced concentration of these villages was pointed out.By measuring connectivity and accessibility of regional spaces in the study area,its traffic connectivity was proved moderate,and accessibility of each tourist village and town was fine.Then an optimized spatial structure was proposed for the rural tourism development in Wuhan Urban Agglomerations,that is,"one core,one belt and three districts".

Spatial and Temporal Differences of Urban Land Comprehensive Carrying Capacity in Guangxi

The comprehensive carrying capacity of urban land can reflect the re- source level, economic scale, social development and environmental pressure of ur- ban land carrying. The assessment indicator system of urban land comprehensive carrying capacity was constructed from the 4 aspects of resource, economy, society, environment, and principal component analysis and cluster analysis were used to evaluate the urban land comprehensive carrying capacity of Guangxi and the 14 cities in 2005-2014, and analyzed its spatial and temporal characteristics as well as the driving forces, with the aim to provide references for improving the urban land comprehensive carrying capacity. The results showed that, the overall urban land comprehensive carrying capacity in Guangxi increased in 2005-2014, and there were significant differences in the land comprehensive carrying capacities among the cities in Guangxi in 2005-2014, in which Liuzhou, Guilin, Nanning belonged to the regions with the highest carrying capacity, while Beihai, Yulin, Wutong belonged to the regions with high carrying capacity, and the carrying capacities of the other cities changed with the changes of time. The economic development degree was an important factor influencing urban land comprehensive carrying capacity, but could not directly represent the urban land comprehensive carrying capacity level.

Spatial Conformation Analysis of Urban Complex as Wanda Plaza in Chengdu City of China

Through analyzing the overall spatial conformation of Wanda Plaza in Chengdu City, a typical urban complex, the whole space was classified into external plaza space, internal business space and its connection with external space. Characteristics of such an urban complex and its contained correlation were elaborated from the perspectives of spatial conformation, organization technique and connotation. And it was proposed that the urban complex should be regarded as an organic whole with dynamic changes and mutually-influenced units, attractiveness of external space and cohesion of internal space, so as to define the organization techniques influencing regional spatial conformation and also practical significance of these techniques.

Spatial-temporal changes of Tianjin urban spatial morphology from 1978 to 2004

Taken fractal dimension, compact ratio, urban centroid and urban principal axis as the urban spatial characteristic indices, Tianjin city＇s urban area is investigated in the last 26 years in a quantitative perspective, and its traits and changes during different periods are also analyzed. It is clear that these indices can not only scientifically and explicitly assess the urban morphology, urban direction and its changes and trends, but also uncover long-term effects of economy and urban planning on urban morphology.

Spatial patterns of urban land use growth in Beijing

By using digitized land use maps of Beijing in 1982, 1992 and 1997 and employing GIS spatial analysis techniques, this paper conducts an empirical study on the spatial differentiation and spatial patterns of urban land use growth in Beijing in the period of 1982–1997. It is observed that urban land use growth in Beijing went beyond the control of urban planning, in terms of the extraordinary high growth rate and undesired spatial pattern. The rate of urban expansion after 1982, which was predominated by growth of industrial land, was extraordinary high compared to its historical period. While its growth centers have been actively shifting toward the northern part, rather than toward the southern and eastern parts as designated by the latest General Plan (1991–2010) of Beijing, its spatial pattern of urban land use growth in general was in distinct concentric sprawl, which seriously violated the General Plan of Beijing.

Evolution and Spatial Patterns of Spheres of Urban Influence in China

This article presents the findings of a study of the spheres of urban influence with regard to all cities in China(not including Hong Kong,Macao and Taiwan Province of China)in the years 1990,2000 and 2009.An optimized gravity model with comprehensive time distance was used to carry out a detailed analysis of the spatial patterns of Chinese spheres of urban influence and the spatial characteristics of urban agglomerations.Such urban agglomerations are characterized by high density population and a developed economy,which are also considered as the national competition unit.This paper initially identifies four spatial patterns of urban agglomerations based on the spatial layout of city groups during their evolution.Some basic characteristics of urban agglomerations are outlined,including the number of cities,the size of cities and the functions of urban centers.These characteristics are examined by using statistical methods and Geographic Information System(GIS).The main findings from this research are that the development stages and structures of urban agglomerations in China vary significantly.It is also clear that the stages and evolution of spatial patterns are strongly affected and dominated by both policy and location factors.

Spatial Impact of High-speed Railway on the Urban Scale:An Empirical Analysis from Northeast China

The emergence of rapid transit,primarily represented by high-speed railway(HSR),while reshaping the regional traffic patterns,leads to the reconstruction and redistribution of population and industry.This leads to either shrinkage or expansion of urban scale.However,research on the influence mechanisms of the urban scale has mostly concentrated on historical,economic and social factors.The influence of traffic factors is rarely mentioned in current research.Therefore,this study examines Northeast China,where the change in urban scale is most significant,to discuss the spatial impact of high-speed railway on the urban scale.This is of great significance in terms of enriching current understanding of the factors affecting the urban scale.The results included the following:1)The high-speed railway produced considerable space-time convergence effects,however,simultaneously aggravated the imbalance in traffic development in Northeast China.The increase in accessibility presents attenuation characteristics from the high-speed railway.Additionally,the high-speed railway has changed the mode of cooperation between cities in the provinces,inter-regional and inter-provincial cooperation models gradually become popular.2)The change rate of accessibility and the urban scale present significant spatial coupling phenomena,with the change rate of the Harbin-Dalian trunk lines and its surroundings being more significant.3)There are predominantly four modes of the influence of high-speed railway on the urban scale,which make difference city present expansion or shrinkage.