气候变暖与城市公共安全规划

气候变暖:21世纪全球面临的最严重挑战之一全球气候变暖:一个不争的事实2007年2月2日,据政府间气候专门委员会(IPCC)发表的《第四次气候评估报告》显示,地球气候的温度在过去100年中变暖了0.74℃,主要的变暖阶段是最近50年;同时,未来20年每10年地球的气候还会变暖0.2℃。     

河南省城市化发展轨迹研究

综观世界各国城市化的历程．可以看到一定的规律性。美国著名经济地理学家诺瑟姆发现．各国城市化发展过程所经历的轨迹，可以概括为一条稍被拉平的“S”型曲线．体现出鲜明的阶段性。大致可以划分为三个阶段：低速增长阶段（城市化水平低于30％）．高速增长阶段（城市化水平在30％～60％之间）和成熟的城市社会（城市化水平高于60％）。     

城市化进程与公路发展的探讨

城市化主要表现为：城市人口增长,城市数目增加,城市体系形成和完善;城市经济在国民经济中占主要地位,并成为社会前进的主要基地;城市的经济关系广泛渗透到农村．并使农村生活方式城市化。当一个国家城市化水平达到30％时．将进入城市化飞速发展时期。     

人口城市化对我国城市发展的影响分析

在如何推进我国人口城市化进程问题上,学术界存在三种观点。第一种观点认为,在我国城市失业率逐年增长、城市就业形势严峻的情况下,应放慢我国人D城市化进程,即“放慢人口城市化论”;第二种观点认为,鉴于当前我国人口城市化进程严重滞后于工业化进程,滞后于经济社会的发展,同时,农村又面临农民收入增幅大幅回落,“三农”问题突出,因此,应加快推进入口城市化进程,即“加快人口城市化论问;第三种观点则认为,人口城市化进程应与我国的经济发展状况相适应,即“适度人口城市化论”。对此问题,笔者赞同第二种观点,即我国应加速…     

气候变暖与农作物品种的适应性栽培探索

随着全球气候变暖的不断加剧,生态环境发生了变化,农作物生长的基本环境也发生了转变。为提高农作物的经济效益,根据气候变化及作物生长特点,栽培一些与气候变暖相适应的农作物品种。本文将针对气候变暖条件下,农作物的适应性栽培进行探讨。     

城市化发展与城市环境探讨

一、城市化与城市环境在讨论城市环境与城市化战略之前,有必要对我国城市化历史作一简要回顾。因为,按照历史学家的观点,今天的发展是昨天的继续。了解过去,能使我们正确地把握现在和未来。１．城市化的历史发展。据文献记载,我国城市的产生距今已有３０００～４００...     

The interaction between buildings and the climate

Research in Japan shows that 'heat islands' in town centres can be materially reduced by expanses of grass and water. But can we do much about it, or do we always want to anyway? Yet the effect of climate on buildings is crucial, and the purpose of a recent symposium was to study the relationship of the variable factors with particular reference to the education and training of architects, engineers and meteorologists.     

浅析新型城镇化与建筑产业化发展的相互作用

对我国城镇化新的发展方向进行了分析,并结合建筑产业化的内容从正向影响和反作用两个方面进行了论述,通过分析新型城镇化与建筑产业化二者相互作用的机理,得出新型城镇化与建筑产业化相互联系、互相渗透的结论,从理论阐述上解决了在新型城镇化建设发展阶段同建筑产业"共赢"的问题。     

新农村建设与城镇化的辨证关系及其互动探析

一、问题的提出对新农村与城镇化关系的论述,代表性观点主要有三类:一是此消彼长的关系,认为新农村建设是针对片面城镇化倾向的战略调整。新农村建设的基点是立足农村,追求的是农村的发展,这种发展并不是要将农村城镇化;第二种观点认为,新农村建设是城镇化的一个重要补充,是农村城镇化或就地城镇化,是我国发展城市群和大中小城镇向农村的延伸。还有一种观点认为,新农村建设和城镇化是同时进行的,城镇化是新农村建设的助推器。如果我们把新农村和城镇化当作两个集合(系统),则第一种观点认为两个集合是相离的,第二种观点认为新农村是城镇化的…     

北京远郊区城镇化与小城镇产业发展关系研究

本文以平谷区的多个城镇为例,分析了在城镇化过程中,面对城乡二元体制的矛盾与冲突,不同城镇在产业发展方面做出的不同选择。文章指出,在北京城市化进程中,郊区小城镇在产业发展思路上应从自身特点出发,将比较优势转化为竞争优势,选择适宜的主导产业,从而切实壮大城镇经济实力,吸引农村剩余劳动力就业,同时为中心城疏解人口和集聚新产业做好准备。     

波浪与多孔介质结构相互作用的数值分析

采用比例边界有限元方法(SBFEM)研究波浪与圆环柱形多孔介质结构(碎石填充)的相互作用。将整个计算域分成两个有限域和一个无限域,通过变分原理,推导出各子域的SBFEM控制方程,并进一步研究各参数对结构与波浪相互作用的影响。     

Estimating the impacts of climate change and urbanization on building performance

Over the past 15 years, much scientific work has been published on the potential human impacts on climates. For their Third Assessment Report in 2001, the United Nations International Programme on Climate Change developed a set of economic development scenarios, which were then run with the four major general circulation models (GCM) to estimate the anthropogenesis-forced climate change. These GCMs produce worldwide grids of predicted monthly temperature, cloud, and precipitation deviations from the period 1961–1990. As this period is the same used for several major typical meteorological year data sets, these typical data sets can be used as a starting point for modifying weather files to represent predicted climate change. Over the past 50 years, studies of urban heat islands (UHI) or urbanization have provided detailed measurements of the diurnal and seasonal patterns and differences between urban and rural climatic conditions. While heat islands have been shown to be a function of both population and microclimatic and site conditions, they can be generalized into a predictable diurnal and seasonal pattern. Although the scientific literature is full of studies looking at the impact of climate change driven by human activity, there is very little research on the impact of climate change or urban heat islands on building operation and performance across the world. This article presents the methodology used to create weather files which represent climate change scenarios in 2100 and heat island impacts today. For this study, typical and extreme meteorological weather data were created for 25 locations (20 climate regions) to represent a range of predicted climate change and heat island scenarios for building simulation. Then prototypical small office buildings were created to represent typical, good, and low-energy practices around the world. The simulation results for these prototype buildings provide a snapshot view of the potential impacts of the set of climate scenarios on building performance. This includes location-specific building response, such as fuel swapping as heating and cooling ratios change, impacts on environmental emissions, impacts on equipment use and longevity comfort issues, and how low-energy building design incorporating renewables can significantly mitigate any potential climate variation. In this article, examples of how heat island and climate change scenarios affect diurnal patterns are presented as well as the annual energy performance impacts for three of the 25 locations. In cold climates, the net change to annual energy use due to climate change will be positive – reducing energy use on the order of 10% or more. For tropical climates, buildings will see an increase in overall energy use due to climate change, with some months increasing by more than 20% from current conditions. Temperate, mid-latitude climates will see the largest change but it will be a swapping from heating to cooling, including a significant reduction of 25% or more in heating energy and up to 15% increase in cooling energy. Buildings which are built to current standards such as ASHRAE/IESNA Standard 90.1-2004 will still see significant increases in energy demand over the twenty-first century. Low-energy buildings designed to minimize energy use will be the least affected, with impacts in the range of 5–10%. Unless the way buildings are designed, built, and operated changes significantly over the next decades, buildings will see substantial operating cost increases and possible disruptions in an already strained energy supply system.     

浅论农业与城镇化的关系

一 中国农业发展的特点 1.农业的现代化程度不高,从总体上说,农业还没有能够摆脱靠天吃饭的情况,科技含量不高,粗放型农业生产仍然占有很大部分,对农产品的再加工和精加工不够。 2.农业人口数量巨大且综合素质有待提高。十三亿人口,九亿在农村,一方面造成人均资源的匮乏,另一方面农业劳动力的转移滞后造成人力资     

Impact of climate warming on passive night cooling potential

Night-time ventilation is often seen as a promising passive cooling concept. However, as it requires a sufficiently high temperature difference between ambient air and the building structure, this technique is highly sensitive to changes in climatic conditions. In order to quantify the impact of climate warming on the night-time ventilative cooling potential in Europe, eight representative locations across a latitudinal transect were considered. Based on a degree-hours method, site-specific regression models were developed to predict the climatic cooling potential (CCP) from minimum daily air temperature (T _min). CCP was computed for present conditions (1961–90) using measured T _min data from the European Climate Assessment (ECA) database. Possible time-dependent changes in CCP were assessed for 1990–2100, with particular emphasis on the Intergovernmental Panel on Climate Change (IPCC) ‘A2’ and ‘B2’ scenarios for future emissions of greenhouse gases and aerosols. Time-dependent, site-specific T _min scenarios were constructed from 30 Regional Climate Model (RCM) simulated data sets, as obtained from the European PRUDENCE project. Under both emissions scenarios and across all locations and seasons, CCP was found to decrease substantially by the end of the 21st century. For the six Central and Northern European locations (>47°N) CCP was found to decrease in summer (June–August) by 20–50%. For the two Southern European locations (Madrid and Athens), future CCP was found to become negligible during the summer and to decrease by 20–55% during the spring and the autumn. The study clearly shows that night-time cooling potential will cease to be sufficient to ensure thermal comfort in many Southern and Central European buildings. In Central and Northern Europe, a significant passive cooling potential is likely to remain, at least for the next few decades. Upper and lower bound estimates for future CCP were found to diverge strongly in the course of the 21st century, suggesting the need for flexible building design and for risk assessments that account for a wide range of emissions scenarios and uncertainty in climate model results.

La ventilation nocturne est souvent considérée comme un concept de refroidissement passif prometteur. Toutefois, cette technique nécessitant une différence de température suffisamment élevée entre l'air ambiant et la structure du bâtiment, elle est très sensible aux changements des conditions climatiques. Pour quantifier l'impact du réchauffement climatique sur les possibilités de refroidissement par ventilation nocturne, on a considéré huit emplacements représentatifs sur une transversale latitudinale en Europe. Sur la base d'une méthode ‘degrés-heures’, on a développé des modèles de régression spécifiques à des sites pour prévoir le potentiel de refroidissement climatique (CCP) à partir de la température quotidienne minimale de l'air (T _min). On a calculé le CCP pour les conditions présentes pendant la période 1961–90 en utilisant les données T _min de la base de données ECA (Evaluation du climat européen). On a évalué de possibles changements du CCP liés à la durée pour la période 1990–2100, en mettant l'accent sur les scénarios A2 et B2 du GIEC (Groupe d'experts intergouvernemental sur l'évolution du climat) relatifs aux futures émissions de gaz à effet de serre et aux aérosols. Des scénarios liés à la durée, avec T _min spécifiques aux sites ont été élaborés à partir de 30 ensembles de données de modèles de climats régionaux simulés obtenus dans le cadre du projet européen PRUDENCE. Pour les deux scénarios d'émission et pour tous les emplacements et saisons, on a constaté que le CCP diminuait de façon substantielle dès la fin du XXIe siècle. Pour les six emplacements en Europe centrale et en Europe du Nord (>47° nord), on a constaté que le CCP diminuait de 20–50% (juin–août). Pour les deux emplacements en Europe du Sud (Madrid et Athènes), on a constaté que le futur CCP devenait négligeable pendant l'été et diminuait de 20–55% pendant le printemps et l'automne. Cette étude montre clairement que le potentiel de refroidissement nocturne cessera d'être suffisant pour assurer le confort thermique dans de nombreux bâtiments construits en Europe du Sud et en Europe centrale. En Europe centrale et en Europe du Nord, un potentiel significatif de refroidissement passif va vraisemblablement durer pendant au moins les prochaines décennies. Il s'est avéré que les estimations supérieures et inférieures du futur CCP divergeaient nettement dans le courant du XXIe siècle, ce qui suggère la nécessité de concevoir les bâtiments avec souplesse et d'évaluer le risque en tenant compte d'une large gamme de scénarios d'émission et de l'incertitude des résultats des modèles climatiques.

Mots clés: changements climatiques, scénarios climatiques, potentiel de refroidissement climatique, ventilation nocturne, refroidissement passif, Europe     

衡水市加速城镇化进程的思路与对策研究

城镇化是全面建设小康社会的重要组成部分,也是全面建设小康社会的重要途径,在保持国民经济长期快速增长、促进经济与社会协调发展、增进人与自然的和谐发展等方面都起着重要的作用。