Theoretical and Empirical Study on Urban Population Cawing Capacity： Case of Haidian District in Beijing

The measurement of urban population carrying capacity is the basis for cities＇ sustainable development. However, the traditional study on population carrying capacity which was based on food supply is not applicable to the single urban area. This paper built a model for the analysis of urban carrying capacity, and took Haidian District in Beijing as an example to calculate the urban carrying capacity of Haidian District in the future, which was the basis for the improvement of the population carrying capacity. This study would also provide a reference to the measurement of the urban population carrying capacity for other cities and districts in China.     

Theoretical and Empirical Study on Urban Population Carrying Capacity: Case of Haidian District in Beijing

Abstract

The measurement of urban population carrying capacity is the basis for cities’ sustainable development. However, the traditional study on population carrying capacity which was based on food supply is not applicable to the single urban area. This paper built a model for the analysis of urban carrying capacity, and took Haidian District in Beijing as an example to calculate the urban carrying capacity of Haidian District in the future, which was the basis for the improvement of the population carrying capacity. This study would also provide a reference to the measurement of the urban population carrying capacity for other cities and districts in China.     

经济-生态导向的城市人口空间分布优化——以无锡市区为例

城市人口分布格局不仅受经济就业、生活质量、通勤距离等自组织分布要素的引导,还受到政府管制和调控的制约,不可能完全通过自组织而实现人口分布的优化。因此,除了阐释人口分布的自组织变动机制和影响因素外,还迫切需要研究人口分布对经济社会与资源环境方面的综合影响,进而提出优化的人口空间格局。在大量查阅人口分布相关理论的基础上,研究了城市人口空间分布模式,提出了生态约束、生产挤占、生活集聚、效益综合、顾及现状等人口优化分布原则,并运用随机与目标函数方法,建立人口空间分布优化模型。以无锡市区为例,基于丰富的人口、经济、资源、环境资料,进行城市空间生态保护、生产开发、生活居住价值评价,通过模型运算,提出优化的人口空间分布格局,为无锡市区人口分布调控提供依据。     

A forecast analysis on world population and urbanization process

The continuous growth of world population and the intensification of urbanization process create a challenge to environment quality and sustainable development around the world. In this paper I tried to conduct a forecast analysis of near-future urbanization related population growth worldwide, based on recent demographic trends. Such an analysis can provide important insights into the prospects for changes in the size and composition of world population and in urbanization process. Optimal polynomial functions were used to fit historical trajectories of population dynamics, and the detailed forecasts of the population mainly over the period 2010–2030 were conducted and analyzed. If the past pattern continues, world total population would increase to 7.94–8.33 billion in 2030 and the annual growth is expected to continually decline in the forecast period. Global total population would stop increasing during the period 2050–2060 and would not exceed 9.5 billion in the future. The total population of Africa, Asia, Oceania, South America, North & Central America would separately increase to 1.35–1.41, 4.86–5.65, 0.04–0.05, 0.44–0.45, and 0.71–0.72 billion in 2030. Europe’s total population is forecast to decline to 0.64–0.67 billion in 2030. World’s rural population is expected to grow to the maximum during the period 2015–2020 and would greatly decline after that period. Global rural population would reach 3.12–3.41 billion in 2030. Rural population in Asia and Africa is estimated to increase and achieve the maximum around 2025 and decline thereafter. For other regions, the rural population would continually decline in the forecast period. Urban population in the world would continually grow and reach 4.72–5.00 billion in 2030, an increase of 48.6–57.8%. However the annual growth of urban population is expected to increase to the maximum (6.86 million/year) during the period 2020–2025 and then decline in the following years. Urban population is projected to continually grow in all regions excepting Europe. Europe’s urban population is expected to decline in the period 2010–2030. Urbanization process worldwide, represented by the ratio urban population versus total population (RUT) and the ratio rural population versus urban population, is expected to continue during the period 2010–2030. The RUT of the world is projected to reach 0.5 before 2010 and would continue to increase in the forecast period. Global RUT is estimated to reach 0.56 in 2030. However, the regional patterns of urbanization process would be diverse. Europe’s RUT is estimated to continually decline in the forecast period and reach 0.68 in 2030. The RUT for Africa and Caribbean would continually increase before 2030, while the RUTs for Asia and South America are estimated to achieve their maximums around 2025 and decline in the following years. Oceania and North & Central America would thoroughly realize urbanization (≈1) during the periods 2020–2025 and 2025–2030. The expansion of world population and urbanization will continually exert a stronger stress to environment quality and sustainable development in a near future. However we may expect this situation would start to change from mid-21st century after total population has achieved its maximum. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.     

经济发达城市人口承载力预测及其经济合理性评价——以无锡市区为例

在经济发达地区资源环境约束趋紧和经济发展转型背景下,开展人口规模预测研究对协调人口、资源、经济之间的关系具有积极意义。以无锡市区为例,核算土地资源人口承载力与不同时间阶段经济合理人口规模,分析土地资源人口承载量与经济合理人口规模之间的关系,解析未来人口发展趋势和影响因素。结果表明：无锡市区人口仍将稳步增加,外来人口仍将是常住人口增量的主体,但增速趋缓;2015、2020年经济合理人口分别约为404万和434万人,逐渐超出土地资源承载力所确定的402万人的合理人口规模;经济增长引起的就业人口的需求增长是导致人口总量增长的主要因素。未来需要通过产业结构调整、劳动生产率提升、公共服务设施完善等手段调控人口发展,以减轻资源环境压力和保障经济发展     

中国低碳城市热思考:现状、问题及趋势

近年来我国掀起了一股低碳城市建设热潮。但在这股热潮背后,还有许多尚不明晰的问题需要理性思考。围绕低碳城市相关议题,开展了如下5方面工作:①解读低碳城市概念,指出低碳城市建设是一个多目标问题,要以低碳经济为基础,并实现经济发展、生态环境保护、居民生活水平提高等目标的共赢;②概括低碳城市评价指标,指出针对指标还没有建立明确的标准;③从城市规划、低碳政策、生态产业、可持续能源、绿色交通等方面总结了保定、上海、吉林、杭州等城市的低碳建设途径;④分析城市低碳发展现状水平评价结果,指出低碳城市建设还有很大的提升空间;⑤最终在分析低碳城市建设尚存不足的基础上,提出今后需深化认识的几个问题,如不能因低碳而放弃其它城市发展目标,低碳城市建设要因地制宜,低碳城市是一项长期、复杂的系统工程,需各领域专家通力协作,需从系统规划、阶段性方案实施、实施后评估与修订等环节进行全生命周期跟踪管理。希望这些思考能对我国低碳城市建设的顺利推进起到积极作用。     

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运用空间自相关的全域指标和局域指标，分析1990年和2000年上海市域及中心城区两个年份的人口密度的Moran's I和Getis's G值。结果表明：从市域的尺度上看，10年间，人口集聚增强，即城市高密度集聚、农村低密度集聚，中心城区及其内部出现的人口密度相对分散的趋势只是表现在城市内部，而市域内城市与农村之间的差异仍在不断扩大，表现为一种从农村向城市的向心型城市化过程，而且城市化还处于不断上升的阶段。从中心城区的尺度看，10年间，中心城区人口密度不断降低，城区核心人口绝对量持续减少，城区外缘绝对量持续增加，上海市城区具有明显的郊区化特点，空间上表现出一种离心型城市化的特点。研究结果的可借鉴性表明空间自相关的统计分析能更好地揭示出人口的分布模式、人口集聚及其变化的热点和内在机制，对于人口的合理布局方案、城市化政策制定等政府宏观决策具有意义。     

Study on Simulating Spatial Distribution and Varying Patterns of Urumqi＇s Population

In this paper, an approach to simulate the spatial distribution of urban population is proposed using urban land use and population statistical data through the geographical information systems （GIS）. Then, the spatial population distribution of Urumqi as a case is simulated by the approach mentioned above and its varying patterns are analyzed by the raster population surface. As a result, producing raster population surface is more accurate and natural than the traditional choropleth map of population density. Concerning the spatial population distribution of Urumqi, the population density declines from south to north and the population distribution mainly presents＇ ＂T-type＂, the population distribution presents multicentre agglomeration and the population distribution of the districts shows different features. The population density varies significantly with the increase in the distance from central business district （CBD）. Finally, it is found in this paper that the development history of districts, terrain and traffic road are main factors that have an influence Urumqi＇s population distribution. This paper tries to provide more accurate population data for the plan and management of urban land, traffic and public facilities in order to enrich the researches on urban population distribution.     

Moving towards urban sustainability in Kenya: a framework for integration of environmental,economic, social and governance dimensions

Global urban development is increasingly becoming an aspect of focus as nations fight sustainability challenges. A review of the current literature on urban sustainability suggests that research on development of cities, in both developed and developing countries, is growing fast, with an emphasis on sustainable development. However, very little of this research contains an integrated framework to systematically identify and examine the various dimensions of urban sustainability and to measure and evaluate them appropriately. Cities are more than the sum of their sectors, and are complex and interdependent systems on whose dynamics the quality of life of millions of human beings and a good part of the economy depend. Environmental, economic, social and governance problems can create formidable barriers to urban sustainability. Governance remains a critically important dimension of urban sustainability, especially when discussing urbanization in developing countries, given rapid population movements and imbalances in socio-economic development. Understanding how cities function is fundamental to resolving these imbalances. The aim of this paper is to provide a review and analysis of the concept of urban sustainability and to propose the development of a holistic framework through integration of environmental, economic, social, and governance dimensions of sustainability. Such a review would make it possible to understand the complex dynamics of the four dimensions and to assess the progress and challenges in moving towards urban sustainability, taking the case of Nairobi, Kenya, as an example. The paper argues that, for urban sustainability in developing countries, more emphasis should be placed on the governance dimension, because this is where the biggest challenge exists, with increasing needs for immediate management of rapid urbanization.     

Study on Simulating Spatial Distribution and Varying Patterns of Urumqi's Population

Abstract

In this paper, an approach to simulate the spatial distribution of urban population is proposed using urban land use and population statistical data through the geographical information systems (GIS). Then, the spatial population distribution of Urumqi as a case is simulated by the approach mentioned above and its varying patterns are analyzed by the raster population surface. As a result, producing raster population surface is more accurate and natural than the traditional choropleth map of population density. Concerning the spatial population distribution of Urumqi, the population density declines from south to north and the population distribution mainly presents “T-type”, the population distribution presents multi-centre agglomeration and the population distribution of the districts shows different features. The population density varies significantly with the increase in the distance from central business district (CBD). Finally, it is found in this paper that the development history of districts, terrain and traffic road are main factors that have an influence Urumqi's population distribution. This paper tries to provide more accurate population data for the plan and management of urban land, traffic and public facilities in order to enrich the researches on urban population distribution.     

基于SLEUTH模型的滇池流域城市扩展模拟分析

通过滇池流域1992～2010年城市扩张研究,发现城市建设用地增长主要表现为两种形态：一是边缘增长,表现为城市建成区范围不断扩大;二是道路影响增长,表现为环滇池道路两边新城市单元的产生。基于滇池流域城市扩展变化遥感数据,对SLEUTH城市扩展模型进行校准,模拟30 a间（2010～2040年）3种预案下的昆明城市扩展变化过程,并对模拟结果进行分析。3种模拟预测结果表明：任意管理预案下城市无序扩张,大量农林用地被城市建设用地占用,人口和城市建设用地呈现爆发式增长,滇池沿岸被城市包围,会对滇池水环境产生极大的压力;土地总量控制预案下城市的发展完全按照城市总体规划内容进行,没有考虑城市实际发展过程中的经济、人口等因素影响,没有达到滇池生态环境保护的需要;生态环境保护预案下,能相对有效控制建设用地,减少对农林用地、湿地的侵占,利于滇池环境保护。预测发现,从滇池流域水资源现状来看,即使实施了环境保护模式,人均水资源量仍处于“严重短缺”状态。需要通过调整昆明城镇体系和产业布局,降低城市首位度和人口;采取更为严格的空间管制策略,有效控制城市空间扩展,以减少对滇池流域的环境压力     

我国中部地区城市群多中心结构的增长效应

多中心城市群是要素在经过多重集聚扩散后形成的空间均衡,已成为城市群发展的政策目标。我国城镇化水平发展时间较短,地区差异较大,因此需结合具体城市群的发展阶段研究其空间优化问题。基于2005~2014年中部六大城市群的市域数据,从人口规模分布和产业空间布局两个维度出发,定量分析其城市群空间结构对地区经济增长的影响。研究结果表明：（1）在控制了其他影响因素之后,城市群人口空间结构会对经济增长的影响呈现倒“U”型曲线特征,即由单中心向多中心结构转变;（2）产业布局的空间集中对城市群经济增长具有正向促进作用。这一结论对中部地区如何合理有效引导要素等资源流动来拓展发展新空间、优化发展新格局和提升经济发展效率和城镇化质量具有一定的参考价值和政策意义。     

基于适度人口容量的生态文明城市建设研究——以广东省惠州市为例

生态文明城市是新型城镇化建设的目标,是实现经济发展、民生改善与生态保护协调统一的最佳方式。适度的人口容量、科学的城市规划和有效的城市治理是避免和减轻城市病的根本途径。本文从生态经济学和系统工程学跨学科的视角出发,构建了一个基于适度人口容量,人口流动和城乡均衡发展的生态文明城市建设路径的理论分析框架,并以广东省惠州市为例,根据土地功能定位和主体功能区定位,分别测算了惠州市的适度人口容量;基于人口自然变动和人口机械变动的趋势,预测了惠州市未来人口发展状况。研究发现,惠州市常住人口已略微超过基于土地功能定位测算的适度人口容量,但基于主体功能定位的人口密度模型测算表明,惠州市未来人口发展规模远低于适度人口容量,进而从总体上剖析了惠州市生态文明城市建设中适度人口容量和人口均衡发展方面带有普遍性的问题和原因。由此,揭示出生态文明城市的创建,必须基于人口承载力,走动态规划调控路子,协同推进经济建设、民生改善、生态保护、环境优化和制度改革,真正地促进流动人口市民化、城乡公共服务均等化和社会保障公平化。     

北京城市人口增长调控研究

北京城市人口的增长是必然的 ,但必须对人口规模进行必要的调控 ,这是北京实现可持续发展的需要。北京城市人口增长调控要运用市场化的方式 ,辅之以必要的行政措施 ,以结构调整为导向 ,适度控制城市人口数量的增长 ,重点优化城市人口结构 ,合理调整城市人口空间布局     

Climate variability and changes in the major cities of Bangladesh: observations,possible impacts and adaptation

High population density, inadequate infrastructure and low adaptive capacity have made the urban population of Bangladesh highly vulnerable to climate change. Trends in climate and climate-related extreme events in five major cities have been analyzed in this paper to decipher the variability and ongoing changes in urban Bangladesh. An analysis of 55 years (1958–2012) of daily rainfall and temperature data using nonparametric statistical methods shows a significant increase in annual and seasonal mean daily maximum and minimum temperatures in all five cities. A significant increase in climate-related extreme events, such as heavy rainfall events (>20 mm), hot days (>32 °C) and hot nights (>25 °C), is also observed. Climate model results suggest that these trends will continue through the twenty-first century. Vulnerability of urban livelihoods and physical structures to climate change is estimated by considering certainty and timing of impacts. It has been predicted that public health and urban infrastructures, viz. water and power supply, would be the imminent affected sectors in the urban areas of Bangladesh. Adaptation measures that can be adopted to mitigate the negative impacts of climate change are also discussed.     

城市旅游发展的动力:理论分析与案例研究

20世纪80年代之初，深圳和珠海旅游发展的内外部条件极为类似，但是20年来两个城市旅游的发展模式却完全不同。本文研究发现：城市旅游发展取决于需求结构和相对优势两个因素的共同作用。基于旅游体验本质的需求结构的变化，决定了同一类型的旅游城市具有相似的变化规律；不同类型的旅游城市变化规律差异较大。另一方面，城市旅游驱动机制决定了相对优势的变化，旅游驱动机制演变轨迹的不同正是建成各个城市旅游目的地旅游发展模式差别的主因。由此可见，城市旅游要实现可持续发展就必须用随外部环境的变化（主要是需求结构的变化），适时培育和转变驱动机制。     

农村人口转移趋势及空间指向研究

农村人口转移及城市集群发展加速城镇化进程,把握农村人口转移趋势,导引农村人口有序转移是推动新型城镇化建设的关键。长株潭城市群一体化发展具有典型性和代表性,基于此,本文选择湖南省和长株潭城市群作为研究对象,探讨农村人口转移趋势及其空间指向。本文选择人口发展方程和回归分析两种常见的人口总量预测方法测算湖南省2016—2030年人口总量,比较测算结果发现人口发展方程虽然在年增长率的预设上具有一定的主观性,但在长期人口预测中表现出更好的适用性。在城镇化率预测上,Logistic增长模型具有广泛的适用性。因此本文选择人口发展方程和Logistic增长模型,预测湖南省和长株潭城市群2016—2030年的人口总量和城镇化率,在此基础上计算出人口城乡分布的大致状况,进而估算农村人口转移趋势。预测结果显示2016—2030年间,湖南省和长株潭城市群分别有大约980万和567万农村人口向城市转移,长株潭城市群城镇化率和农村人口转移进程均领先于湖南省平均水平,尤其是城市群中心城市。据此,可得出结论:城镇化进程中的城市群发展在推动农村人口转移中的作用突显,农村人口转移空间指向城市群集聚,即城市群是引领城镇化进程的空间经济主体形态,是农村人口转移的"牵引力",是农村人口转移空间指向的"内聚力"。同时,农村人口加快向城市群聚集的趋势也呼吁城市治理理念和治理模式的创新,智慧城市或是这一变革的最优方案。     

城市规划中人口空间分布模拟方法研究

城市人口空间分布是影响社会经济活力、基础设施建设、公共服务配置以及城市交通、住宅、生态环境问题等方面的重要因素之一,是科学开展城市规划的基础与前提.传统的等值区域图法只能描述一个地区总体城市分布状况,难以准确反映城市内部人口的实际分布.本文通过综述国内外23篇研究成果,将城市人口分布空间模拟方法总结为城市人口密度模型、内插法空间分布模型、地理因子相关性模型(包括光谱估算法、土地利用密度法、居住单元估算法、夜间灯光强度估算法、硬化地表估算法)3大类7种,分析了它们各自的特点及改进措施.人口空间分布模拟在我国城市规划体系中有较大应用价值,重点讨论了在城镇体系规划、城市总体规划以及详细规划等不同规划层面人口空间分布适用模拟技术.最后指出为提高我国城市规划的科学性和预测精度,综合运用多种方法对城市人口空间分布进行估算模拟将成为该领域研究趋势,以期为城市规划管理提供技术参考.     

南京市秦淮区昼夜人口空间分布估算与分析

人口时空分布研究对于城市规划管理、土地利用布局优化以及生态资源环境评价具有重要的现实意义。以南京市秦淮区为研究区,选择Google Earth平台提供的2014年空间分辨率为0.27 m的高分辨率遥感影像,结合统计资料和实地调查,根据人们日常活动的时空位移规律,获取“人口-昼夜-土地利用”匹配关系,借助地理信息系统建模和空间分析技术,实现100 m格网单元尺度下的昼夜人口空间分布定量模拟,并从街道和建筑斑块尺度对人口空间化结果进行验证,进而分析昼夜人口空间分布格局。结果表明：(1）利用高分辨率遥感影像目视解译和街景地图等多源数据,可有效克服城市复杂下垫面的土地利用类型和建筑物图斑数据较难获取的困难,提高城市人口估算的空间分辨率;(2）利用土地利用类型和建筑物空间属性信息,能够合理地估算建筑物尺度上的昼夜人口空间分布;（3)由于中心城区建筑物功能布局以及城乡发展差异等诸多因素影响,城市中心城区昼夜人口的空间结构存在显著差异,白天人口分布范围较为广泛且部分区域具有显著的集聚特征,而夜晚人口的高值分布则相对分散,高值集聚区向城区周边推移。 关键词： 昼夜人口;时空分布;遥感;地理信息分析;南京市;秦淮区     

Urban meteorological modelling for nuclear emergency preparedness

The main objectives of the current EU project “Integrated Systems for Forecasting Urban Meteorology, Air Pollution and Population Exposure” (FUMAPEX) are the improvement of meteorological forecasts for urban areas, the connection of numerical weather prediction (NWP) models to urban air pollution and population dose models, the building of improved urban air quality information and forecasting systems, and their application in cities in various European climates. In addition to the forecast of the worst air-pollution episodes in large cities, the potential use of improved weather forecasts for nuclear emergency management in urban areas, in case of hazardous releases from nuclear accidents or terror acts, is considered. Such use of NWP data is tested for the Copenhagen metropolitan area and the Øresund region.The Danish Meteorological Institute (DMI) is running an experimental version of the HIRLAM NWP model over Zealand including the Copenhagen metropolitan area with a horizontal resolution of 1.4 km, thus approaching the city-scale. This involves 1-km resolution physiographic data with implications for the urban surface parameters, e.g. surface fluxes, roughness length and albedo. For the city of Copenhagen, the enhanced high-resolution NWP forecasting will be provided to demonstrate the improved dispersion forecasting capabilities of the Danish nuclear emergency preparedness decision–support system, the Accident Reporting and Guidance Operational System (ARGOS), used by the Danish Emergency Management Agency (DEMA).Recently, ARGOS has been extended with a capability of real-time calculation of regional-scale atmospheric dispersion of radioactive material from accidental releases. This is effectuated through on-line interfacing with the Danish Emergency Response Model of the Atmosphere (DERMA), which is run at DMI. For local-scale modelling of atmospheric dispersion, ARGOS utilises the Local-Scale Model Chain (LSMC), which makes use of high-resolution DMI-HIRLAM NWP model data provided to DEMA by DMI four times a day under operational surveillance and covering Denmark and surroundings. The integration of DERMA in ARGOS is effectuated through automated on-line digital communication and exchange of data. The calculations are carried out in parallel for each NWP model to which DMI has access, thereby providing a mini-ensemble of dispersion forecasts for the emergency management.