Improved concepts and methods in analysis and evaluation of the urban climate for optimizing urban planning processes

Planning processes are strongly influenced by an increased awareness of env ironmental issues concerned by projected land-use transformations. A resear ch project was carried out to produce climate maps for the region of Basel/ Switzerland to enable planning authorities taking care of the urban climate and its interrelations with urban structures. Main focus was given to deve lop and implement a methodology meeting not only the regional requirements of Basel. The new approach is not depending on subjective criteria or manua l interventions and ensures its applicability for other regions. Three basi c concepts were developed or improved in this study. A new definition of 'c limatopes' was introduced, and methods were developed for their digital det ermination by objective criteria. This definition of climatopes requires ad equate information on land-use, which is provided by introducing the concep t of 'areal types'. In contrast to 'traditional' land-use classes directly derived from satellite images, areal types are complex aggregates reflectin g not only different physical surface properties, but also socioeconomic as pects of land-use. 'Ventilation classes' are the second component required to delineate climatopes. They summarize the combined influencing factors of terrain features and land-use structures on wind field and urban ventilati on. Their determination is based on topographic information and surface pro perties derived from a digital terrain model and from land-use data. The sp atial distribution of climatopes was computed for Basel. Various quality as sessment procedures and the application of climatopes for an automated gene ration of planning guidelines demonstrate the applicability of the concepts . Climate maps containing the results of the analysis and evaluation of the urban climate of Basel were estimated by the involved planners to be a val uable tool meeting their practical requirements to a high degree. (C) 1999 Elsevier Science Ltd. All rights reserved.