Exploring indicators for quantifying surface urban heat islands of European cities with MODIS land surface temperatures

The term urban heat island describes the phenomenon of altered temperatures in urban areas compared to their rural hinterlands. A surface urban heat island encompasses the patterns of land surface temperatures in urban areas. The classical indicator to describe a surface urban heat island is the difference between urban and rural surface temperatures. However, several other indicators for this purpose have been suggested in the literature. In this study, we compared the eleven different indicators for quantifying surface urban heat islands that were most frequently used in recent publications on remote sensing-based urban heat island assessments. The dataset used here consists of 263 European cities with monthly mean temperatures from MODIS data products for July 2002, January 2003 and July 2003. We found that (i) the indicators individually reveal diurnal and seasonal patterns but show rather low correlations over time, and (ii) for single points in time, the different indicators show only weak correlations, although they are supposed to quantify the same phenomenon. Differentiating cities according to thermal climate zones increased the relationships between the indicators. Thus, we can identify temporal aspects and indicator selection as important factors determining the estimation of urban heat islands. We conclude that research should take into account the differences and instabilities of the indicators chosen for quantifying surface urban heat islands and should use several indicators in parallel for describing the surface urban heat island of a city.     

市政设施管理信息系统的面向对象设计与实现

根据对面向对象分析,设计与建模及可复用构件理论的研究,结合在软件开发中的实践经验,采用当前面向对象领域最为流行的统一建模语言进行系统的建模,开了一套科学,的“市政设施管理系统”从而使得市政部门能迅速掌握市政设施的基本情况,产能及时,准确地作出科学的决策。     

Sustainable Development and Management of Water Resources for Urban Water Supply in Hong Kong

Abstract

Hong Kong, now a Special Administrative Region of China, is a very special and unique place in the world. Although the territory is located in the humid subtropics, local water resources are very limited because of its geographical setting and physical environment. Hong Kong's urban water supply has its uniqueness and has gone through a history of developing local resources and transferring water from the East River (Dongjiang) basin in mainland China over the past half century. This paper aims to present the experience and challenges in developing water supplies and managing water resources in Hong Kong. First, the availability of local water resources is evaluated in the context of the territory's geographical setting. Second, the approaches adopted for developing urban water supply from local resources and more importantly, by making use of water imported from the Dongjiang, are presented and reviewed. Finally, a number of sustainability issues in Hong Kong's urban water supply are addressed with an emphasis on the problems and prospect of the Dongjiang water resources in the future     

城市群区域公共基础设施网络的协调模式浅析

针对现在我国城市化发展进程,城市群的发展已迫在眉睫,本文主要分析了城市群区域公共基础设施网络体系的协调发展对城市群经济建设的重要性,以及协调发展的模式,并对我国未来城市群发展的方针提出自己的看法。     

面向城市规划的三维地理信息系统设计与实现

随着计算机、地理信息和虚拟现实技术的发展,将三维数字技术应用到城市规划工作中已经取得了较好的效果,开发建立三维地理信息系统服务于城市规划已经成为了城市规划信息化工作的新的方向标,获得了很多成功的经验。本文以面向城市规划的三维地理信息系统建设为研究对象,从三维建模要求、流程、构建过程等方面对三维场景的内容进行了说明,对建立面向城市规划的三维地理信息系统的设计与实现进行了论述,并对具体应用进行了介绍。     

中小山水城市绿地系统塑造城市特色的途径和方法

绿地是形成城市特色的重要组成部分,城市绿地系统与城市自然人文环境相结合是城市特色构建的一个重要方面。中小山水城市绿地系统规划在塑造城市特色方面具有独特的代表性。文章总结了中小山水城市的特色,提出绿地系统塑造城市特色的手法,并且以泾县为例来分析绿地系统塑造中小山水城市特色的手法。首先分析整理城市特色资源,对主要的关键词进行抽取比较,得到主要的城市特色;然后从整体出发为绿地系统定位,通过城市绿地系统结构布局强化城市山水环境;通过绿道体系的构建打造城市特色的展示体系;最后从树种规划的角度出发塑造城市的宣纸之都的城市特色.     

A hybrid model for real time simulation of urban traffic

In this paper a hybrid model is presented to predict the behavior of traffic in urban area. Intersections and on/off-ramps are modeled by Colored Timed Petri Nets while road links are modeled by a stochastic discrete time model. It is assumed that vehicle routings at each intersection are stochastic. A Particle Filter algorithm based on the hybrid model is developed to estimate the system state. The validation of the model by using real data is discussed. The limited computational effort required makes the model suitable to be used in simulation-based control schemes for urban traffic.     

径向基函数网络与GIS/RS融合的UGB预测

针对城市空间增长特点,探究城市扩展的规律,研究城市增长边界的计算和预测模型,这对于城市的发展规划具有重要的意义。然而,在国内外,关于城市增长边界方面的研究较少,首次提出利用人工神经网络、地理信息系统和遥感相结合的技术建立具有复杂几何形状的城市增长边界模型。通过数值实验结果表明,模型对城市未来增长边界的计算和预测准确度达80%～84%,结果表示直观、真实,能够为当前精明增长模式下的城市用地规划工作提供决策参考。     

E-Society Portal: Integrating Urban Highway Construction Projects into the Knowledge City

Community involvement is an important factor for sustainable highway construction. Information and communication technologies provide a new and more effective approach to facilitate community involvement. However, there are too many parameters with conflicting and subjective definitions related to sustainability and too many stakeholders with varying degrees of interest and sophistication. There is a need for an effective tool to communicate project impacts on sustainability to local communities. This paper presents an ontology for stakeholder management and sustainability in highway construction. An ontology is a conceptual semantic model that attempts to capture human knowledge (both explicit and tacit) in a consistent manner. Ontologies include three main elements: a taxonomy (common vocabulary presented in concept trees), set of relationships (linking concepts across trees), and axioms (limitation/constraints on the behavior of concepts). The ontology was used to develop a portal for broadcasting highway design features to local communities. By browsing through the portal, a user can learn about project elements, the impacts of each element on sustainability issues, who is sponsoring such element, and what efforts have been made to reduce any impacts of such elements on local communities.