If one surveys the development of wind engineering, one comes to the conclusion that the challenge of urban climatology is one of the most important remaining tasks for the wind engineers. But what distinguishes wind engineering in urban areas from conventional wind engineering? Principally, the fact that the effects studied are usually unique to a particular situation, requiring consideration of the surroundings of the buildings. In the past, modelling criteria have been developed that make it possible to solve environmental problems with great confidence, and studies validated the models: at least in a neutrally stratified atmosphere. The approach adopted in the book is that of applied fluid mechanics, since this forms the basis for the evaluation of the urban wind field. Variables for air quality or loads are problem specific, or even random, and methods for studying them are based on risk analysis, which is also presented. Criteria are developed for a systematic approach to urban wind engineering problems, including parameter studies. The five sections of the book are: Fundamentals of urban boundary layer and dispersion; Forces on complex structures in built-up areas; Air pollution in cities; Numerical solution techniques; and Posters. A subject index is included.

Spatial production is inevitably linked to climate issues. In the course of the last 15 years the debate on sustainable architecture and ecological urbanism has risen like a phoenix from the ashes. Architects and urban planners, as well as administrative bodies and developers, face a new responsibility in terms of the complexity of their conventional design and planning methods. Increasing awareness of climate issues in the design process has the potential once more to make architecture in the future more site-specific, giving it back its contextual relevancy. City and Wind - Climate as an Architectural Instrument is a call to see architecture not just as a means of protecting us against the climate, but also as a way of bringing us back to it.

In the context of urbanization and compact urban living, conventional experience-based planning and design often cannot adequately address the serious environmental issues, such as thermal comfort and air quality. The ultimate goal of this book is to facilitate a paradigm shift from the conventional experience-based ways to a more scientific, evidence-based process of decision making in both urban planning and architectural design stage. This book introduces novel yet practical modelling and mapping methods, and provides scientific understandings of the urban typologies and wind environment from the urban to building scale through real examples and case studies. The tools provided in this book aid a systematic implementation of environmental information from urban planning to building design by making wind information more accessible to both urban planners and architects, and significantly increasing the impact of urban climate information on the practical urban planning and design. This book is a useful reference book to architectural postgraduates, design practitioners and planners, urban climate researchers, as well as policy makers for developing future livable and sustainable cities.

The mixing-layer height and the average wind speed within the mixing layer were calculated twice for each day of a 5-year record of upper air observations at 62 National Weather Service stations int he contiguous United States. The times of day of these calculations are morning and mid-afternoon. A rough allowance was made for effects of the urban "heat island" on the morning mixing heights. The morning and afternoon times coincide approximately with those of maximum and secondary minimum concentrations of slow-reacting pollutants in cities. These calculations illustrate the typical large diurnal variation in atmospheric dispersion. Twenty charts present seasonal and annual, and morning and afternoon mean mixing heights and wind speeds. A model of some general dispersion features over urban areas is described in which the normalized pollutant concentration averaged over a city is a function of mixing height, wind speed, and city size (distance the wind travels across the city). Frequency values of mixing height by wind speed are used with the model to calculate average normalized concentration frequencies for each weather station. Thirty charts present isopleth analyses of seasonal and annual, and morning and afternoon normalized pollutant concentrations that were exceeded 10, 25, and 50 percent of the time for specified city sizes. The occurrence of episodes during which upper limits on mixing height and wind speed were not exceeded were determined from the daily morning and afternoon values of these parameters. Isopleths of the total number of episode-days for episodes lasting at least 2 days and at least 5 days with various limiting mixing-height and wind-speed values are presented in 20 charts.

Urban Climates is the first full synthesis of modern scientific and applied research on urban climates. The book begins with an outline of what constitutes an urban ecosystem. It develops a comprehensive terminology for the subject using scale and surface classification as key constructs. It explains the physical principles governing the creation of distinct urban climates, such as airflow around buildings, the heat island, precipitation modification and air pollution, and it then illustrates how this knowledge can be applied to moderate the undesirable consequences of urban development and help create more sustainable and resilient cities. With urban climate science now a fully-fledged field, this timely book fulfills the need to bring together the disparate parts of climate research on cities into a coherent framework. It is an ideal resource for students and researchers in fields such as climatology, urban hydrology, air quality, environmental engineering and urban design.

The majority of the world’s population live in environments with artificially weakened wind as buildings in urban areas form wind-breaks and reduce wind speeds. Anthropogenic heat is also generated and during the summer dense urban areas suffer from the urban heat island effect, a known urban climate problem. This book discusses how to evaluate the urban wind environment, including ventilation performance and thermal comfort. This book is organized in two parts; Wind Environment and the Urban Environment and Criteria for Assessing Breeze Environments. It includes chapters on sea breeze in urban areas; thermal adaptation and the effect of wind on thermal comfort; health risk of exposures; pollutant transport in dense urban areas; legal regulations for urban ventilation and new criteria for assessing the local wind environment. Keywords: urban wind environments, urban heat island, urban climate, land use change, thermal comfort, risk assessment, urban air pollution, urban ventilation