Mapping urban climate zones and quantifying climate behaviors – An application on Toulouse urban area (France)

Facing the concern of the population to its environment and to climatic change, city planners are now considering the urban climate in their choices of planning. The use of climatic maps, such Urban Climate Zone‑UCZ, is adapted for this kind of application. The objective of this paper is to demonstrate that the UCZ classification, integrated in the World Meteorological Organization guidelines, first can be automatically determined for sample areas and second is meaningful according to climatic variables. The analysis presented is applied on Toulouse urban area (France). Results show first that UCZ differentiate according to air and surface temperature. It has been possible to determine the membership of sample areas to an UCZ using landscape descriptors automatically computed with GIS and remote sensed data. It also emphasizes that climate behavior and magnitude of UCZ may vary from winter to summer. Finally we discuss the influence of climate data and scale of observation on UCZ mapping and climate characterization.

► We proposed a method to map Urban Climate Zones and quantify their climate behaviors.
► UCZ is an expert-based classification and is integrated in the WMO guidelines.
► We classified 26 sample areas and quantified climate behaviors in winter/summer.
► Results enhance urban heat islands and outskirts are surprisingly hottest in summer.
► Influence of scale and climate data on UCZ mapping and climate evaluation is discussed.