Urban Population Data Research Articles

Modeling urban expansion in the transnational area of Changbai Mountain: A scenario analysis based on the zoned Land Use Scenario Dynamics-urban model

Modeling urban expansion in the transnational area of Changbai Mountain (TACM) is important for regional sustainable development. Nonetheless, few studies investigated future urban expansion across the whole TACM. By using the Shared Socioeconomic Pathways (SSPs) and the zoned Land Use Scenario Dynamics-urban (LUSD-urban) model, this study simulated urban expansion across the whole TACM during 2015–2050. We first analyzed the urban expansion across the TACM during 1992–2015. Then, urban land demands were calculated for the Chinese side, the Democratic People's Republic of Korea's (DPRK's) side, and the Russian side using urban population data under the SSPs, respectively. Finally, we simulated urban expansion by using the zoned LUSD-urban model. The results indicated that the urban land in the TACM will grow from 870.57 km2 to 1025.78–1386.50 km2 during 2015–2050, and the DPRK's side will become the primary region of urban expansion, where its urban land area will raise from 174.78 km2 to 232.46–357.58 km2. We also found that the urban expansion on the DPRK's side will be at the expense of cropland and natural habitats, which will cause serious consequences on the regional food security and ecological security. We recommend that urban expansion should be regulated to promote the regional sustainable development.

Urban sprawl in China: Differences and socioeconomic drivers

China's unprecedented urbanization has resulted in accelerating urban sprawl, which is threatening the country's eco-environmental quality and socioeconomic sustainability. In this study, we integrated urban land census data and urban district population data to examine the pattern of urban sprawl and identify differences, and to investigate the socioeconomic drivers of urban sprawl in China between 2006 and 2014. The results revealed that China has experienced drastic urban sprawl over almost all of the last decade with an average urban sprawl index (USI) of 3.16%. However, the rate of urban sprawl has decreased since 2010. In addition, regional distribution, urban size, and hierarchy have different effects on urban sprawl. In particular, cities with severe urban sprawl should be noted, such as large and medium cities in eastern China, large cities in central China, small-A and large-B cities in western China, and large-A cities in northeast China. We also found that urban sprawl was significantly associated with urban population density, gross domestic product (GDP) per capita, and industrial structure. Further, when the spatial heterogeneity was considered, the driving forces of urban sprawl exhibited different magnitudes and directions. Our results indicate that to formulate effective urban planning and land use policies, decision-makers should seriously consider the differences in urban sprawl depending on region, urban size, and hierarchy.

A quantitative analysis of inequality of urban cultural space distribution in Xi’an

Urban cultural space (UCS) has been of great social and economic value for sustainable development, and the existing researches about it mainly focus on some specific aspects, such as historical heritage or cultural service facility. However, UCS hasn’t been quantitatively assessed as an independent system with clear definition and comprehensive classification. Thus, we present a quantitative analysis based on the statistic of UCS provision in different categories between 44 sub-districts in Xi’an and find its inequalities. Xi’an urban land use data and population data of sub-district level are introduced in the analysis process with GIS, SPSS and MATLAB. Our results indicate that inequalities of UCS in Xi’an are mainly reflected in three aspects, including categories, geospatial and population. Among the four categories of UCS, historical heritage and cultural park account for higher percentage, while cultural service facility and religious space are lower. The inequalities in geospatial could be estimated from two indicators. The first indicator named cultural space rate ranges from 0 to 66.88%, while the other named distance between residential and cultural space varies from 100.47 m to 2004.75 m. The inequalities in population could be assessed by cultural space per capita and Gini coefficient. The results indicate that per capita ranges from 0 m2 to 214.79 m2. The Gini coefficient of Xi’an is 0.86, which means that the UCS distribution in population is extremely inequitable. Our studies would further the research on UCS and provide constructive suggestions in urban planning and policy formulation to ensure adequate UCS provision and improve its distributional order in Xi’an.

Using fine-scale satellite imagery and GIS data to help predict disease spread

Event Abstract Back to Event Using fine-scale satellite imagery and GIS data to help predict disease spread Nistara Randhawa1*, Hugo Mailhot2, Duncan T. Lang3, Beatriz Martínez-López4*, Kirsten Gilardi1 and Jonna A. Mazet1 1 One Health Institute, School of Veterinary Medicine, University of California, Davis, United States 2 University of California, Davis, United States 3 Department of Statistics, University of California, Davis, United States 4 Center for Animal Disease Modeling and Surveillance, School of Veterinary Medicine, University of California, Davis, United States Background and objectives: Emerging infectious disease outbreaks present a major public health challenge and require innovative tools for modeling their spread and impact. To address these challenges, we developed a geospatial model leveraging fine-scale satellite imagery, GIS datasets, and population mobility models to simulate disease spread via road transportation Methods: High-resolution satellite data on urban areas (~12m) and population data were used to build a geospatial network connected by roads. Mobility patterns across the resultant network were calculated with the radiation model, which used the population attributes of urban areas and the road distances between them to determine commuting rates between the road-connected urban areas. We demonstrated the above process for Rwanda and simulate the spread of 2009 pandemic Influenza A H1N1 over the created network. The results of our simulations were compared with the observed spread of the disease in 2009-10. We also determined the effects of vaccination campaigns on outbreak spread and impact across the network. Results: Our results were comparable to data collected during the actual outbreak of pandemic influenza in Rwanda with respect to outbreak length and order of urban areas infected. The probability of outbreak occurrence reduced when areas of infection origin were vaccinated, especially with increasing vaccination coverages and efficacies. At the same time, outbreak impact, defined by the number of individuals infected with influenza, was lower when larger urban areas were vaccinated. Conclusions: Our modeling approach, taking into account human mobility between urban settlements across road networks, can be valuable for future planning and control purposes in real-time disease situations. The model highlights the effectiveness of controlling outbreaks by targeting mitigation efforts at their points of origin, a process that can be made possible by increased surveillance and more rapid outbreak response times. This modeling approach can readily be applied to other infectious diseases as well, such as Ebola in West Africa. Keywords: Satellite Imagery, outbreak spread, Roads, networks, Fine-scale, mobility Conference: GeoVet 2019. Novel spatio-temporal approaches in the era of Big Data, Davis, United States, 8 Oct - 10 Oct, 2019. Presentation Type: Student senior oral presentation Topic: Spatio-temporal surveillance and modeling approaches Citation: Randhawa N, Mailhot H, Lang DT, Martínez-López B, Gilardi K and Mazet JA (2019). Using fine-scale satellite imagery and GIS data to help predict disease spread. Front. Vet. Sci. Conference Abstract: GeoVet 2019. Novel spatio-temporal approaches in the era of Big Data. doi: 10.3389/conf.fvets.2019.05.00042 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 09 Jun 2019; Published Online: 27 Sep 2019. * Correspondence: Dr. Nistara Randhawa, One Health Institute, School of Veterinary Medicine, University of California, Davis, Davis, California, 95616, United States, nrandhawa@ucdavis.edu Dr. Beatriz Martínez-López, Center for Animal Disease Modeling and Surveillance, School of Veterinary Medicine, University of California, Davis, Davis, United States, beamartinezlopez@ucdavis.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Nistara Randhawa Hugo Mailhot Duncan T Lang Beatriz Martínez-López Kirsten Gilardi Jonna A Mazet Google Nistara Randhawa Hugo Mailhot Duncan T Lang Beatriz Martínez-López Kirsten Gilardi Jonna A Mazet Google Scholar Nistara Randhawa Hugo Mailhot Duncan T Lang Beatriz Martínez-López Kirsten Gilardi Jonna A Mazet PubMed Nistara Randhawa Hugo Mailhot Duncan T Lang Beatriz Martínez-López Kirsten Gilardi Jonna A Mazet Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Analysis of Public Transportation Travel Characteristics of the Elderly based on IC Card Big Data-Taking Qingdao as an Example

Due to technical limit, it is difficult to get the public transportation orient-destination (OD) data in Qingdao. In despite of limited data, the paper introduced a new way to conduct bus passenger flow analysis, taking trip characteristics of the elderly in Qingdao as an example. Based on the analysis of IC card data in various time slots, cluster analysis of typical bus lines, combined with urban population data and person trip survey data, the paper analyzed the passenger bus travel characteristics of the elderly, especially their utilization of public transportation resources.

The impact of urbanization on CO2 emissions in China: an empirical study using 1980-2014 provincial data.

Towns and cities are not only the focus of attention for their consumption of energy and resources; they are also scrutinized closely for their emissions of greenhouse gases. China's urbanization level now exceeds 50%, but there is still much disparity compared with the level of urbanization in developed countries. This study selects China's urban population and carbon emissions data for the years 1980-2014 and discusses the timing and cause effect of urbanization and the corresponding carbon emissions using the Granger causality test and an error correction model (ECM) then uses STIRPAT models to extract six indicators to measure the quality of urbanization, namely, the level of urbanization, area of built-up regions, added value of tertiary industries, disposable income per capita, green areas per capita, and energy intensity. These six indicators represent population agglomeration, the expansion of urban areas, industrial agglomeration, quality of life improvements, ecological conservation, and technological improvements, respectively. The study divides 29 provinces in China into three groups based on the quality of urbanization and analyzes the impacts of the six indicators of urbanization quality on carbon emissions. The findings show that the impacts of different factors on carbon emissions vary substantially among the provinces. Finally, the study uses the findings to give suggestions on how to develop low-carbon urbanization.

Zipf law analysis of urban scale in China

<p>In this paper, by using China's urban population data from 1990 to 2010 and double logarithmic regression model to test China’s urban scale and urban rank through Zipf law, we found that China’s urban scale distribution is relatively balanced, virtually conforming to Zipf's law. Researching and analyzing urban scale distribution of China’s every province’s, we also found that the urban scale distributions of China’s all provinces are relatively complicated and they are not even close to 1. The increase of Zipf index means that urban scale distribution is transiting from primacy degree distribution to ideal Zipf distribution. Further analyzing and categorizing every province’s Zipf index, we can conclude that China’s urban scale distribution can be categorized four mainly: achieved ideal Zipf law; approaching to ideal Zipf distribution; The transition state from the primacy degree distribution to the Zipf law distribution; typical primacy degree distribution.</p>

Spatial-temporal characteristics and determinants of PM2.5 in the Bohai Rim Urban Agglomeration

Ambient particulate matter (PM) pollution of China has become a global concern and has great impact on air quality and human health. This paper adopts the PM2.5 concentration data obtained from 241 newly located observation points in the Bohai Rim Urban Agglomeration (BRUA), as well as economic, urban and industrial working population data in the study area, revealing the spatio-temporal distribution of PM2.5 and its determinants with the help of a spatial data model. The results indicate that: 1) The BRUA was the core area of PM2.5 pollution in China in 2014, the average PM2.5 concentration of which reached 74 μg/m3, which is 13 μg/m3 higher than the country average (61 μg/m3); 2) The PM2.5 concentration distribution had a characteristic of high in winter and autumn but low in spring and summer, presenting a U-shaped monthly profile and a U-impulse type daily profile; 3) The urban PM2.5 concentrations showed obvious spatial variation and agglomeration. The highest hot-spot was observed in spring, while the lowest was in summer. High concentration cities were mainly located in southern Hebei and western Shandong, and low concentration cities were in the coastal area around the Bohai Sea and the mountainous areas in northern Hebei. High hot-spot areas demonstrated an M-shaped change, with two cycles of advance and retreat from west to east. 4) The Geographically weighted regression (GWR) model shows that the GDP per capita, urbanization rate and construction of the cities were closely related to PM2.5 concentrations in the BRUA.

From sequential to parallel growth of cities: Theory and evidence from Canada

This paper examines city growth patterns and the corresponding city size distribution evolution over long periods of time using a simple New Economic Geography (NEG) model and urban population data from Canada. The main findings are twofold. First, there is a transition from sequential to parallel growth of cities over long periods of time: city growth shows a sequential mode in the stage of rapid urbanization, i.e., the cities with the best development conditions will take the lead in growth, after which the cities with higher ranks will become the fastest-growing cities; in the late stage of urbanization, city growth converges according to Gibrat′s law, and exhibits a parallel growth pattern. Second, city size distribution is found to have persistent structural characteristics: the city system is self-organized into multiple discrete size groups; city growth shows club convergence characteristics, and the cities with similar development conditions eventually converge to a similar size. The results will not only enhance our understanding of urbanization process, but will also provide a timely and clear policy reference for promoting the healthy urbanization of developing countries.

Are breast cancers in India different from Western populations? Results of a tertiary center retrospective analysis.

e12039 Background: Breast cancer is the commonest cancer in the urban Indian female population but comprehensive data on the details of tumor types, outcomes post treatment and comparison with Western data is not readily available. We present a robust database of Eastern Indian breast cancers reported from a tertiary center. Methods: Retrospective analysis of 407 unselected medical records of breast cancer cases between June 2011 and October 2012 were undertaken. Clinico-pathological details, Nottingham Prognostic Index (NPI) Score post surgery (conservation and mastectomy) and follow-up were analyzed. Adjuvant chemotherapy details were recorded. Following Institutional guidelines a hypofractionated Radiotherapy (RT) schedule was delivered (40Gy in 15 Fractions over 3 weeks), with boost delivered in patients receiving conservation surgery. Acute radiation toxicity following hypofractionation was recorded. Results: Mean age at presentation was 52.42 years. 383 (94%) underwent surgery; breast-conservation in 37%. 34% received neo-adjuvant anthracycline-taxane sequential chemotherapy prior to surgery. For those who underwent upfront surgery, 12% patients had pT3 disease and 83% pT1/T2. 41%, 31%, 16% and 12% had pN0, N1, N2 and N3 disease respectively. 89% cases had infiltrating ductal carcinoma with 57% Grade III disease. 73% were ER positive and 35% were Her-2 positive. 31% patients were intermediate risk and 36% high risk (>5.5) by NPI Score. After upfront surgery 54% received adjuvant chemotherapy of which 63% received both anthracycline and taxanes sequentially. 67.4% patients received adjuvant RT where the median time between date of surgery and starting of RT was 5 months. Median post hypofractionated RT follow-up was 6 months when 7 out of 97 patients had > Grade 0 Skin toxicity, 4 had breast edema, 6 shrinkage, 8 patients had Grade I Lymphedema. Conclusions: Indian patients were younger and had advanced stage at presentation and higher NPI scores requiring more combined systemic chemotherapy. Hypofractionated RT schedule was tolerated well and further hypofractionation could now be investigated in clinical studies to improve throughput in moderate resource countries like India.

Poor Municipal Spending for Infrastructure Development and Gap for Investment: A Case of Bangladesh

The study aims at assessing (Bangladeshi) municipal financial capabilities in meeting growing demands forinfrastructure facilities and other services. Determining municipal financial capacities is important mainlybecause the factors such as around 3.1 percent (Note 1) annual urbanization growth, 40-50 percent (Note 2)urban service gap and creation of new urban bodies put tremendous pressure on municipal authorities to meetthe growing demand for infrastructure facilities and citizenry services. By analyzing sampled municipal annualbudget documents along with urban population data, and questionnaire survey, the study finds thatmunicipalities are as poorly capable as to spend less than US$10 per person annually. The study also finds 18-97percent shortage of estimated transfer revenues, which are generally being used for building infrastructurefacilities that literally requires huge capital investment. So vacuum for investment is found. Around 70 percentrespondents interviewed are dissatisfied with the service qualities and quantities they receive. Thus, the studysuggests that government should give immediate attention to find alternate financing options forinvestment-hungry municipal infrastructure development sector.

The prevalence and distribution of non-communicable diseases and their risk factors in Kasese district, Uganda : cardiovascular topics

To date there has been no population-based survey of the major risk factors for non-communicable diseases (NCD) in Uganda. Hospital-based data from urban centres report an increasing burden of NCDs in Uganda. This population-based survey aimed to describe the prevalence of risk factors for NCDs in a rural Ugandan district. The survey was conducted using the WHO STEPwise approach to surveillance of non-communicable diseases (STEPS) methodology. Participants (n = 611) were residents of the Kasese district selected in a one-step, complete survey of a rural district. Standardised international protocols were used to record history of disease, and measure behavioural risk factors (smoking, alcohol consumption, fruit and vegetable consumption, physical activity), physical characteristics [weight, height, waist and hip circumferences, blood pressure (BP)], fasting blood glucose (BG) and total cholesterol (TC) levels. Data were analysed using simple descriptive analysis. In this sample, the prevalence of hypertension (systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg) was 22.1% for men and 20.5% for women. Fifteen per cent of men and 16.8% of women were overweight [body mass index (BMI) ≥ 25 kg/m(2)] and 4.9% of men and 9.0% of women were obese (BMI ≥ 30 kg/m(2)). Nine per cent of participants were diabetic, 7.2% ate five or more combined servings of fruit per day while only 1.2% ate five or more combined servings of vegetables per day. Fifty-one per cent of the population were physically inactive and 9.6% were daily smokers. Thirty-one per cent of females had fasting blood sugar levels (FBS) ≥ 6.1 mmol/l while 10% of males had FBS > 6.1 mmol/l. This study presents evidence on the magnitude of NCDs, their risk factors and gender distribution in a rural population in Uganda, a poor country in east-central Africa. These data, when combined with urban population data, could be useful in the formulation and advocacy of NCD policy and plans of action in Uganda.

西安太阳总辐射时空变化特征及对城市发展的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 西安太阳总辐射时空变化特征及对城市发展的响应 DOI: 10.5846/stxb201112312017 作者: 作者单位: 陕西省西安市气象局,中山大学地球科学系,陕西省西安市气象局,陕西省西安市气象局,陕西省西安市气象局,陕西省西安市气象局 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(70901043);教育部人文社科基金(09YJC630130);全国统计科研计划项目(2011LY033);国家重大基础预研项目(2005CCA05300) Characteristics of spatial and temporal variations of global solar radiation in Xi'an and relevant response in urban development Author: Affiliation: Xi''an Bureau of Meteorology,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:根据西安辐射站太阳总辐射资料和周围23个气象台站日照百分率资料,建立1961-2009年西安市太阳总辐射资料时间序列,运用模糊聚类分析法将全市分为3个区,采取滑动t检验法进行突变检验及阶段分析,研究西安太阳总辐射的时空分布及变化特征。同时引用西安历年城区人口数据,对城区太阳总辐射与城市发展进行了相关性分析。结果表明:西安太阳总辐射具有东部多、西部次之、中部少的分布特征;1961-2009年呈波段减少的变化趋势,线性倾向率为-2.01%/10a,其中1977-1991年为显著减少阶段,以中部减少幅度最大;其间出现两次突变,突变年分别为1977年及1992年;城市发展带来大气污染物的增加,造成西安城区太阳总辐射对城市发展有较大的响应,西安城市发展对太阳总辐射季节影响上表现为冬、夏季远大于春、秋季。 Abstract:Variations in the distribution of solar radiation on the earth surface can fundamentally alter characteristics of temperature, humidity, precipitation and atmospheric circulation, and are thus considered important indicators in the evaluation of climate change. All Intergovernmental Panel on Climate Change (IPCC) Assessment Reports contain special chapters that illustrate how solar radiation variations have been used to indicate or deduce global climate change. Given the current global trend of energy intensity triggered by over-exploitation of fossil fuels and global warming caused by excessive greenhouse gas emissions, energy from solar radiation represents the cleanest form of energy that can be used directly by humans. Therefore, solar radiation is a priority within the area of research on natural energy resources. Xi'an is the political, economical and cultural center of Shaanxi Province. The city is located at the center of the Central Shaanxi Plain. This location has the Weihe River to the north and the Qinling Mountains to the south. It has a total area of 10,108 square kilometers, an urban area of 369 square kilometers, and a population of over 8.4346 million. Xi'an was one of the four great capital cities of the ancient Chinese civilization. Research on solar radiation in Xi'an and its impact involves data from only a single point, which were analyzed in the 1990s. This research was on natural resources in Northwest China. Therefore, there has been no systematic and in-depth investigation of solar radiation characteristics in the area around Xi'an. According to data on global solar radiation from Xi'an radiation stations along with percentage of sunshine data from 23 nearby national meteorological stations, this paper presents time series ofglobal solar radiation data from the period 1961 to 2009. We apply fuzzy cluster analysis methods to divide the city of Xi'an into three sections-middle (section I), eastern (section II), and western (section III). We use the sliding T method to conduct mutation testing and phase analysis, and we study temporal and spatial distributions as well as variation of the global radiation. We also perform correlation analysis of the global urban solar radiation and urban development, with reference to Xi'an urban population data over the years. The results show that Xi'an global solar radiation had the greatest distribution features in the eastern section, less in the western section, and least in the middle section. The time series from the period 1961 to 2009 reveal a band decrease trend, which has a linear rate of decrease at -2.01%/10a. There was a period of reduction from 1977 to 1991. In this period, the greatest band reduction extent was found in the middle section. There were two years of mutation, 1977 and 1992. With urban development, there was an increase in the contamination of the atmosphere. This in turn caused urban global solar radiation in Xi'an to have a relatively large impact on such development. This was demonstrated by the seasonal patterns. The impact was more evident in winter and summer seasons, compared with the spring and autumn seasons. 参考文献 相似文献 引证文献

Analyzing urban population data using generalized gamma model and wave-spectrum relation: A case study of Kaohsiung

A quantitative understanding of complex urban growth patterns and processes is crucial to sustainable land management and urban development planning in cities. The spatial organization of urban patterns can be treated as fractals and can be characterized with fractal dimension. However, the calculation of fractal dimension of urban form is often constrained by imperfect and incomplete higher temporal resolution land-use data. Because census data are easily acquired, this study aims to provide a systematic investigation of the relationships between population and urban growth by analyzing changes in urban form that are characterized by fractal dimensions. If the population density in cities follows the negative exponential distribution in proximity, we can use the generalized gamma model and wave-spectrum relation to indirectly estimate the fractal dimension of land-use form in cities. Correlogram analysis is performed to consolidate the results from wave-spectrum relation. Information entropy of the city’s population distribution profile along the radial is calculated to measure the degree of spatial dispersion. The schematic framework is applied to the city of Kaohsiung to get significant insight in the dynamics of pattern formation of the urban population. This is critical for further computer-simulated experiments on urban growth and spatial complexity.

Estimating Urbanization Levels in Chinese Provinces in 1982—2000

SummaryNo consistent and reliable annual data series on the urbanization level for provincial regions of China is available. Making use of urban population data from the 1982 and 2000 population censuses, this paper estimates an annual data series of the urbanization level for provincial regions using an estimation approach developed on the basis of a conceptual model of dual‐track urbanization. Based on such estimated new urban data of provincial regions, the major trends of urbanization in Chinese provinces and the relationship between urbanization and economic development are analysed for the period 1982–2000.RésuméOn ne dispose pas de séries de données annuelles cohérentes et fiables sur le niveau d'urbanisation des régions de province chinoises. En utilisant les données de population urbaine des recensements de 1982 et 2000, cet article estime une série annuelle du niveau d'urbanisation des régions de province grâce à une approche développée sur la base d'un modèle conceptuel d'urbanisation différenciée. Sur la base de nouvelles données urbaines ainsi estimées pour les régions provinciales, on analyse les grandes tendances d'urbanisation dans les provinces chinoises et la relation entre l'urbanisation et le développement économique pour la période 1982–2000.

China's Urban Population Statistics: A Critical Evaluation

The paper assesses major problems that have made China's urban population statistics confusing and temporally incomparable: lack of geographically standardized areas; absence of a set of consistent criteria for the enumeration of urban population in censuses; and availability of diverse sources of urban statistics published by different government agencies for different purposes. After identifying seven major sources for China's urban population statistics, the authors focus on serious problems with the urban population data collected, adjusted, and published by the National Bureau of Statistics. The need for frequent post-censal adjustments and questionable procedures used to derive intercensal annual urban population growth rates make these data unsatisfactory. The authors demonstrate that a different method of adjustment produces an urban population time series that is internally more consistent and coherent. Journal of Economic Literature, Classification Numbers: C80, J10, O18. 2 figures, 4 tables, 25 references.

Counting urban population in chinese censuses 1953-2000: changing definitions, problems and solutions

The level of urbanisation in many developing countries such as China has remained at less than 50%, despite rapid urban population growth since the 1950s. Obtaining accurate information on urban population is essential for monitoring and studying the ongoing urbanisation process that is restructuring the societies of less urbanised countries. The difficulties in counting China's urban population have arisen from the accelerated urbanisation in China under a model of dual-track urbanisation since the early 1980s. Institutional settings for urbanisation have also been altered with the revision of criteria for city and town designation. These developments make it increasingly difficult to count urban population in China, causing frequent changes in the definition of urban population in five censuses from 1953 to 2000. Two approaches have been adopted to estimate urban population data series for inter-census periods. This paper proposes a third approach based on the concept of dual-track urbanisation, counting and estimating urban non-agricultural and agricultural populations separately. After thorough examination and comparison of the definition of urban population and data quality from five censuses, this paper obtains a set of more consistent urban population data after a series of adjustments. A new series of urban population data is estimated for 1982–2001. The results provide reliable urbanisation data for further study on urban transition and development in China. Copyright © 2005 John Wiley & Sons, Ltd.

Urban Productivity in China

In this empirical study, we test the relationship of Chinese urban productivity and city size. Using over 119 790 firm-level production data cross 28 industries from the Third National Industrial Survey, along with the urban population data of 224 cities, we find strong and prevailing significant agglomeration economies in Chinese urban areas. The estimated average agglomeration elasticity is around 0.051, implying that every doubling of city size will provide a 3.6 per cent gain in firm productivity. The breakdown analysis suggests that, based on current data, the major source of the agglomeration advantage comes from localisation economies-benefits from the concentration of firms of the same industry within one geographical area-rather than urbanisation economies-externalities from urban development itself. The maximum size study also suggests that, while most Chinese cities have yet to grow to demonstrate the full strength of agglomeration economies, many Chinese industries have reached the 'optimal' industry size within a 'given' urban area.

Re-examining China's “Urban” Concept and the Level of Urbanization

China is experiencing rapid growth in urbanization in the current transitional period, but the real level of China's urbanization remains unclear, although no longer mysterious. The problem stems not from deficiency of published data, but from inconsistencies and ambiguities in China's official data on the urban population. In China, four major factors affect the size of urban population and therefore the urbanization level: the criteria for designating a settlement as urban, the physical and administrative boundaries of places so demarcated, the household registration (hukou) system and the urban status of floating people. The controversies related to these four factors include what kind of settlements should be included in the urban territory and what kind of people should be included in the urban population. Our objectives in this paper are: (1) to clarify current understandings on and to examine the weaknesses in China's urban concept and official data; and (2) to readjust China's urban population data and hence the level of urbanization in line with both the international practice and the situation found in China. Drawing on a comprehensive review of the official criteria for urban designation and the official indicators for urban population, we first identify the important issues that create confusion and controversies. This background is then used to develop a conceptual framework for an estimate of China's urban population. Finally, based on a series empirical studies, China's urban population and urbanization level adjusted.

The Use of NOAA AVHRR Data for Assessment of the Urban Heat Island Effect

A vegetation index and a radiative surface temperature were derived from satellite data acquired at approximately 1330 LST for each of 37 cities and for their respective nearby rural regions from 28 June through 8 August 1991. Urban–rural differences for the vegetation index and the surface temperatures were computed and then compared to observed urban–rural differences in minimum air temperatures. The purpose of these comparisons was to evaluate the use of satellite data to assess the influence of the urban environment on observed minimum air temperatures (the urban heat island effect). The temporal consistency of the data, from daily data to weekly, biweekly, and monthly intervals, was also evaluated. The satellite-derived normalized difference (ND) vegetation-index data, sampled over urban and rural regions composed of a variety of land surface environments, were linearly related to the difference in observed urban and rural minimum temperatures. The relationship between the ND index and observed differences in minimum temperature was improved when analyses were restricted by elevation differences between the sample locations and when biweekly or monthly intervals were utilized. The difference in the ND index between urban and rural regions appears to be an indicator of the difference in surface properties (evaporation and heat storage capacity) between the two environments that are responsible for differences in urban and rural minimum temperatures. The urban and rural differences in the ND index explain a greater amount of the variation observed in minimum temperature differences than past analyses that utilized urban population data. The use of satellite data may contribute to a globally consistent method for analysis of urban heat island bias.