GOVERNMENT INTERVENTION,LAND MARKET,AND URBAN DEVELOPMENT: EVIDENCE FROM CHINESE CITIES

This article investigates how government intervention in land market affects China's urban development, using data from prefecture‐level cities between 2000 and 2010. We find that government intervention enlarges the impact of positive productivity shocks on housing price appreciation, through mainly the government control over residential land supply. However, we find no significant evidence that high government intervention constrains population growth and leads to wage increase. Such patterns of urban dynamics can be explained by the fact that migrant workers are the driving force behind China's urbanization, but they have limited housing demand and are not well compensated. (JEL P52, R12, H11)     

Land fragmentation under rapid urbanization: A cross-site analysis of Southwestern cities

Explosive population growth and increasing demand for rural homes and lifestyles fueled exurbanization and urbanization in the western USA over the past decades. Using National Land Cover Data we analyzed land fragmentation trends from 1992 to 2001 in five southwestern cities associated with Long Term Ecological Research (LTER) sites. We observed two general fragmentation trends: expansion of the urbanized area leading to fragmentation in the exurban and peri-urban regions and decreased fragmentation associated with infill in the previously developed urban areas. We identified three fragmentation patterns, riparian, polycentric, and monocentric, that reflect the recent western experience with growth and urbanization. From the literature and local expert opinion, we identified five relevant drivers ?C water provisioning, population dynamics, transportation, topography, and institutions ?C that shape land use decision-making and fragmentation in the southwest. In order to assess the relative importance of each driver on urbanization, we linked historical site-specific driver information obtained through literature reviews and archival analyses to the observed fragmentation patterns. Our work highlights the importance of understanding land use decision-making drivers in concert and throughout time, as historic decisions leave legacies on landscapes that continue to affect land form and function, a process often forgotten in a region and era of blinding change.     

范式与特点：全球知识城市案例分析

伴随知识经济发展起来的知识城市,是21世纪城市可持续发展的一种全新理念。作为西方后城市化时代对城市空间结构的一种新认识,知识城市很大程度上是全球城市、文化城市、技术城市及经济中心、政治中心、文化中心和金融中心的高度统一。要使知识城市上升为一种理念和模式来指导今天的城市建设,就必须在全面了解知识城市的构成要素和模式的基础上,归纳出具有一般特性的指导原则和共同特征。本文分析了知识城市理念演绎城市空间结构的新变化,归纳出衡量知识城市的标准,总结了全球知名知识城市的典型范式及其特点,可供我国在城市化进程中借鉴这一全新的理念,拓宽新的思路。     

A comparative study of urban fragmentation patterns in small and mid-sized cities of Idaho

Urbanization has a massive impact on ecological function and impedes the provisioning of environmental services. The interaction between urbanization and the environment has been researched extensively. However, the existing research focused on the urbanization characteristics of large metropolitan areas. In this paper, we investigate the urban fragmentation patterns of small and mid-sized cities in Idaho, USA. To capture the urban morphology for each site within the study we use both concentric ring and transect analysis as well as several spatial/landscape metrics. Our results show that the characteristics of urbanization in small and mid-sized cities (and those in second-tier regions that attract relatively little scholarly attention) are consistent with growth phase theory of urbanization, urbanization along a gradient, and urbanization patterns of metropolises.     

Urbanization,migration, and Vietnam's spatial structure

In North Vietnam during the war years from the mid-1960s to the mid-1970s, cities were evacuated to minimize damage from bombing. As such, the urbanization process was checked. In the South, however, urban areas grew rapidly as people fled the fighting in the villages. Reunification of the country led to an outflow of residents from the largest southern cities back to the North or into new economic zones. From the mid-1970s to the early 1980s, Vietnam's total urban population remained static before beginning to increase slowly during the latter half of the 1980s. The rate of urbanization accelerated in the first half of the 1990s, although that process is not reflected in the available statistics. During 1979-89, the smaller cities grew faster than the larger ones, while most interprovincial migration occurred from North to South. Unemployment is a major problem in Vietnam's growing cities. The country's economic reforms require a more fluid labor market with fewer restrictions upon labor mobility. These needs are gradually undermining the strategy designed to contain urbanization, forcing planners to rethink urban development. The author discusses developing Vietnam's three main urban development corridors.     

Urban growth patterns and growth management boundaries in the Central Puget Sound, Washington, 1986–2007

Many regions of the globe are experiencing rapid urban growth, the location and intensity of which can have negative effects on ecological and social systems. In some locales, planners and policy makers have used urban growth boundaries to direct the location and intensity of development; however the empirical evidence for the efficacy of such policies is mixed. Monitoring the location of urban growth is an essential first step in understanding how the system has changed over time. In addition, if regulations purporting to direct urban growth to specific locales are present, it is important to evaluate if the desired pattern (or change in pattern) has been observed. In this paper, we document land cover and change across six dates (1986, 1991, 1995, 1999, 2002, and 2007) for six counties in the Central Puget Sound, Washington State, USA. We explore patterns of change by three different spatial partitions (the region, each county, 2000 U.S. Census Tracks), and with respect to urban growth boundaries implemented in the late 1990’s as part of the state’s Growth Management Act. Urban land cover increased from 8 to 19% of the study area between 1986 and 2007, while lowland deciduous and mixed forests decreased from 21 to 13% and grass and agriculture decreased from 11 to 8%. Land in urban classes outside of the urban growth boundaries increased more rapidly (by area and percentage of new urban land cover) than land within the urban growth boundaries, suggesting that the intended effect of the Growth Management Act to direct growth to within the urban growth boundaries may not have been accomplished by 2007. Urban sprawl, as estimated by the area of land per capita, increased overall within the region, with the more rural counties within commuting distance to cities having the highest rate of increase observed. Land cover data is increasingly available and can be used to rapidly evaluate urban development patterns over large areas. Such data are important inputs for policy makers, urban planners, and modelers alike to manage and plan for future population, land use, and land cover changes.     

对我国城市化健康发展的理论思考——城乡统筹发展的视角

本文简要回顾了我国近10年来城市化快速发展的理论和政策背景,指出快速城市化进程中存在土地、能源等自然资源过渡消耗和浪费问题,也存在重城轻乡等突出社会问题;采用人口供需平衡的方法,分析评价了我国人口城市化水平同经济发展水平、工业化水平和土地城市化的关系;对城市化加速理论进行剖析,认为我国当前工业化技术体系不适用于机器技术体系下城市化加速的经验规律,应该结合我国新型工业化的要求走资源节约型的新型城市化道路;建议适当降低城市化发展目标与速度,纠正城市化过程中＂城市偏向＂和＂以物为本＂的做法,体现国家赋予城市化带动农村发展的重任,实现城乡统筹发展。     

Urban growth management-the Saudi experience

Saudi Arabia experienced a high rate of urbanization during the period 1970–1986 resulting in accelerated annual growth rates for Saudi cities averaging more than 6.4%. Higher than usual growth rates created demand for the opening up of huge areas to meet housing, commercial, industrial and other land uses. Government's land grant policy and liberal interest free loans resulted in massive expansion of cities and towns all over the country with major cities of Riyadh, Jeddah, and Dammam having the biggest share. Lack of planning frameworks and weak city institutions could not direct the growth properly leading to sprawl and lop-sided development. This meant rapid extension of road network and utilities with high financial outlays. The slow-down in the economy and ever-increasing demand for infrastructure provision forced the government to initiate growth boundaries to tackle these problems in 1986. The paper discusses the methodology adopted and the process of devising urban limits and evaluates their impact on urban structures of Saudi cities. The paper draws some conclusions in the realization of objectives of the exercise with respect to, (a) control urban sprawl by encouraging infill development where utilities were generally available; (b) reduce cost of provision of infrastructure through better coordination tied to commonly agreed phasing; (c) maintain natural environment around the cities.     

新加坡土地综合利用效率探讨

新加坡经济发达、人口密集、土地狭小。、但有限的土地并没有成为新加坡经济社会发展的制约。相反,通过借鉴世界城市规划发展的成功经验和自身的创新土地管理,新加坡在土地空间利用上展现了其面对住房、交通、环境、水资源利用等城市发展共同挑战问题时独特的解决方法。长期稳定的综合规划、短期局部的灵活应变和土地效益的综合考量成为新加坡土地政策的三大特征。新加坡在土地管理中对土地使用效率和社会公平兼顾的政策理念与效果,对中国快速城市化进程中的土地管理有非常有益的借鉴。     

Temporal effects on biodiversity and composition of arthropod communities along an urban–rural gradient

Global urbanization is rapidly increasing, yet the prevalence of single order and time point studies likely miss important temporal effects of urbanization on entire communities. We studied three sites along a rural–urban gradient in the Seattle metropolitan area with three sampling periods from 2009–2011 to examine how arthropod communities respond to increasing levels of urbanization in a similar habitat type through time. Consistent with previous studies, urban areas contained altered environmental conditions relevant for litter arthropods, and arthropod biodiversity decreased with urbanization. However, urban arthropod biodiversity was not influenced by environmental measures, supporting the idea of an “urban-filter”. Urbanization was not a factor influencing how communities responded to the effect of time, suggesting that other factors (e.g. disturbance) may ultimately be more important for determining patterns of biodiversity through time in urban areas. Finally, our study illustrates urbanization forces can structuring entire arthropod communities similarly through time, having important consequences for our understanding of urbanization’s temporal effects and indirect influence on community interactions and ecosystem processes. As the effects of urbanization will inevitably vary through time, we suggest that multiple time point studies are required to increase our ability to accurately describe arthropod community responses to increasing urbanization.     

Are plant communities mainly determined by anthropogenic land cover along urban riparian corridors?

Often used as a mitigation tool to landscape fragmentation, urban riparian corridors also suffered from the effects of the urban expansion. This study explored the relationships between plant riparian communities and two major environmental variables (land cover, soil characteristics) and analyzed the floristic change along an urbanization gradient. Fifteen sites were surveyed on both riverbanks of two riparian corridors characterized by contrasting water regimes in Strasbourg, North Eastern France. Data of spontaneous species abundance was collected from 180 quadrats using (i) all plant species, (ii) herbaceous stratum and (iii) ligneous stratum (bush and tree). The diversity and compositional patterns of riparian plant species were analyzed within each corridor according to three levels of urbanization (urban, suburban, peri-urban). Relationships between riparian communities, land cover and soil chemical properties (pH, nitrogen and carbon content, moisture) were established by between-class co-inertia analyses. Land cover emerged as the main factor explaining changes in riparian communities along the rural–urban gradient while soil chemical properties discriminate water stress and fluvial dynamics of the two corridors. Similar compositional patterns were found within the most urbanized sites with the establishment of ubiquitous species. The herbaceous stratum is best linked to the level of urbanization, whereas the tree stratum is primarily correlated with corridor attributes (hydrological regime, soil properties). Although riparian species and communities are mainly determined by land cover, urban riparian corridors maintain native biodiversity up to the urban center.     

Spatial disintegration and arable land security in Egypt: A study of small- and moderate-sized urban areas

While commonly associated with regional ‘mega-cities’, rapid urbanization in the less-developed world has also begun to define growth in small- and moderate-sized settlements on the periphery of major metropolitan areas. The dispersal of population growth to these smaller areas holds significant implications for environmental, economic, and social health, and threatens local food security, increases congestions, and induces difficulty in service provision. This study examines the effects of spatial disintegration and rapid urbanization in the stock of arable land in Egypt. To assess this issue, the study will meet three objectives. First, we evaluate the relationship between population growth and urban land cover expansion in small- and moderate-sized settlements in Egypt. Second, we consider the role of selected geographic determinants in influencing the growth of these areas through the use of a regression model. The selection of an appropriate model type is a sub-objective and will be discussed further. Third, these drivers of growth will be assessed through their effects on the country’s stock of arable land. These objectives will be met through the development and application of the regression models, in order to examine the relationship between urban land expansion and several independent variables. An increase in population is found to have a positive and statistically significant effect on corresponding urban land cover area. Surprisingly, the variables commonly associated with urbanization in Egypt - proximity to major roads, the capital of Cairo, and the Nile River - though exhibiting a positive relationship with urban growth, are not statistically significant in the selected case studies. This research underlines the necessity for a combined approach to policy formation - with input from policy fields as varied as agriculture, urban planning, and land reclamation - to slow outward growth and maintain arable land stocks.     

Methods for spatial and temporal land use and land cover assessment for urban ecosystems and application in the greater Baltimore-Chesapeake region

Understanding contemporary urban landscapes requires multiple sets of spatially and temporally compatible data that can integrate historical land use patterns and disturbances to land cover. This paper presents three principal methods: (1) core analysis; (2) historic mapping; and (3) gradient analysis, to link spatial and temporal data for urban ecosystems and applies their use in the Baltimore-Chesapeake region. Paleoecological evidence derived from the geochronology of sediment cores provides data on long-term as well as recent changes in vegetative land cover. This information, combined with contemporary vegetation maps, provides a baseline for conducting trend analyses to evaluate urbanization of the landscape. A 200-year historical land use database created from historical maps, census data, and remotely sensed data provides a spatial framework for investigating human impacts on the region. A geographic information system (GIS) integrates core analyses with historic data on land use change to yield a comprehensive land use and land cover framework and rates of change. These data resources establish the regional foundation for investigating the ecological components of an urban ecosystem. Urban-rural gradient analyses and patch analyses are proposed as the most appropriate methods for studying the urban ecosystem as they link ecological and social patterns and processes for varying degrees of urbanization.     

Spatial configurations of urban forest in different landscape and socio-political contexts: identifying patterns for green infrastructure planning

Rapid urbanisation and climate change have motivated the development of urban green infrastructure (UGI) as a planning strategy to support the wellbeing of urban people and ecosystems while parallel adapting cities to climate change. Forest (tree-covered areas >0.5 ha) is a key UGI component that afford a wider range of ecosystem services and mitigate urban heat islands more effectively than non-wooded green spaces. However, understanding of spatial configurations (variation in patch size and frequency) of forests across the gradient of urbanisation and between cities is limited to case studies. This represents a considerable knowledge gap for identification of general patterns that can inform integration of forest resources in UGI planning that have value beyond the individual city level. In this study we used Geographic Information Systems to explore the spatial configuration of forests across cities located within landscapes characterised by different levels of anthropogenic modification (degree of forest cover) and socio-political contexts, i.e. all Danish and Swedish cities >10,000 inhabitants (n = 176). We applied general linear modelling to investigate the relationship between forest cover, patch size and frequency with 1) regional landscape type, 2) demographic trends 1960–2010, and 3) the gradient of urbanisation (measured in three zones: urban core (0.2 km from city boundary), urban fringe (0.2–2 km), and urban periphery (2–5 km)). Regardless of demographic trends, forest cover was lowest in cities settled in large-scale agricultural regions, higher in regions with mosaics of forest and farming, and highest in forest-dominated regions. However, in all cities forest cover was lowest in the urban zone and peaked on the urban fringe rather than on the urban periphery. Furthermore, pocket woods (0.5–2 ha) accounted for over 50 % of patches in all three urban zones, irrespective of regional landscape type. We conclude by discussing how these general patterns could inform strategies for integration of urban forests in UGI planning.     

Urban policy,economic policy,and the growth of large cities in China

It is argued that despite a Chinese national urban policy large cities are still growing rapidly. Policy implementation is considered weak. It is suggested that a better strategy for increased urbanization in large Chinese cities would include integrating urban with economic policy, improving urban facilities, and planning and managing large cities. A short review is given of theories on city size and development in developing countries. Chinese economic reforms and their impact on urban growth are described. During 1978-90 the level of urbanization rose from 17.9% to 26.4%. Five periods during 1949 to present are identified as exhibiting distinct development profiles. Over the 40 year period, policies pertaining to cities of a particular population size changed constantly. During the early 1950s, development focused on major coastal cities and newly expanding industrial centers. After the 1950s and the Great Leap Forward (1958-60), rural areas and small urban places were the focus of Maoist development. Large cities were de-emphasized. The early 1970s emphasized the development of rural industries and small urban places in order to reduce rural-urban inequalities. A national urban policy was prepared in the early 1980s. The aim was to control the size of large cities, to develop medium sized cities, and to develop small cities. This policy was amended later and is now China's Urban Planning Law. However, the percentage of the nonagricultural population (NAP) living in cities of a million or more persons increased from 37.5% in 1978 to 41.6% in 1990. The share of NAP living in small cities increased to 21.5% in 1990. Temporary migrants were an estimated 5-15% of large city populations. Most cities were beyond their population control limit. Large cities had served important roles in development: greater efficiency in the industrial labor force and more profits; centers for culture, education, politics, and transportation; and links to foreign countries. Economic reforms fueled growth. At present controlled growth is an obstacle to economic development in large cities. Improvement is needed in urban management.     

How small cities affect the biodiversity of ground-dwelling mammals and the relevance of this knowledge in planning urban land expansion in terms of urban wildlife

Fundamental principles regarding urban biodiversity are based on studies conducted in large cities. However we cannot know whether the same phenomena occur in smaller cities or how small cities affect biodiversity. Small cities are an inherent element of urbanization and in the future, most global urban growth is expected to take place in small and medium-sized cities. Understanding the effects of small cities on biodiversity will be an important aspect in planning urban land expansion. Our study examined the effects of a small city on communities of small ground-dwelling mammals on 41 sites arranged in a four step gradient of urbanization. In 6700 trap-days, we caught 2333 individuals comprising 15 species. In the downtown area the same phenomena as those described for large cities were observed: a reduction in species richness and diversity, a decline in the abundance of urban sensitive species and an increase in synurbic species. However, in contrast to large city studies, green areas outside the downtown area did not differ from rural sites in small mammal population parameters. This phenomenon of relatively unchanged fauna outside the downtown area shows that small cities have the potential to maintain a high level of diversity of small ground-dwelling mammals if appropriate planning of further building expansion is implemented. More studies of small cities are needed to better assess their impact on biodiversity. This knowledge can then be applied in better planning for urban wildlife. Generalizations based solely on large city studies are inadequate and may lead to incomplete or inappropriate conservation strategies for small cities.     

Monitoring and modeling the urban growth of two mid-sized Chilean cities

Chile's economic development model changed drastically in 1973. Public policy liberalization ended and the market became the principal entity for regulating growth, including urban growth. The implementation of this new model resulted in unprecedented urban growth, markedly impacting the landscape. In mid-sized cities, this spatial growth has been especially significant. Two examples of such mid-sized cities are Chillán and Los Ángeles, located in the Biobío Region, in the so-called Central Valley. This research analyzed the land use/cover change in Chillán and Los Ángeles from 1978 to 1998, identified the patterns of urban growth and the fragmentation of the urban space, applying GIS and remote sensing tools. The main driving forces of the urban changes were analyzed and the model to predict the land use/cover changes was applied. Our results show the importance of monitoring and modeling rapid urban growth for attaining sustainable mid-sized cities in developing countries that are strongly dependent on export of natural resources. Monitoring and modeling could also help to avoid a repetition of the errors that produced the unsustainable growth characteristic of large Latin American cities.     

The influence of land use type and municipal context on urban tree species diversity

Recent research has focused on the ways urban forest patterns vary in relation to level of urbanization and socioeconomic characteristics, with most studies limited to one urban land use type or multiple non-differentiate land uses. Additionally, the majority of studies examining urban forest patterns focus on canopy cover extent, with less attention given to patterns of species diversity. This study explores how tree species diversity varies across different urban land uses and municipal boundaries to better understand the role of land use types in shaping urban forest patterns. The goal is addressed through an exploration of plot-level tree data in the urban municipalities of Peel Region located in the Greater Toronto Area (Ontario, Canada). Species composition and standard diversity metrics are calculated for eight land use types and four municipalities. Our results show that differences in diversity metrics and species composition are greater between urban land uses than municipalities. Moreover, Peel’s urban forest has relatively high alpha diversity but many species are present on only one land use type. The results suggest that different causal processes are associated with each land use type, and that urban forest managers should adopt land use-specific strategies to meet species composition goals within the urban forest.     

英国城乡统筹政策对我国城乡一体化战略的启示

工业革命后,英国迅速开启了城市化进程,在经历了早期城市化带来的城乡失衡、城市居住环境恶化和生态系统破坏的教训后,英国政府开始了对城乡统筹政策的探索。在探索过程中形成的一系列理论和实践成果,为世界的城市化进程提供了宝贵经验。随着我国城镇化步伐的快速推进,城乡之间长期存在的二元结构矛盾逐渐凸显,这些矛盾的解决需要我们走出一条以城带乡、以乡促城、城乡统筹、联动发展的城乡一体化道路。当前处于工业化后期的中国,面临着与工业化时期的英国几乎相同的城市化问题,因此,有必要学习英国的城乡统筹经验,以为我国的城乡一体化战略服务。     

“宜居之城”建设中水资源的开发与利用研究——以重庆为例

“宜居之城”理念,既是城市化和后城市化时代城市转型升级的必然产物,也是提升城市核心竞争力的重要途径。实践证明,宜居城市的打造需要多方面的努力,而且必须依赖于城市自身的各种资源,其中水资源的作用不可小觑。本文以重庆为例,分析和探讨了江河水资源在构建“宜居之城”中的作用,并针对存在的问题提出了建议。