Building Local Climate Zones by using socio-economic and topographic vectorial databases

Christine Plumejeaud-Perreau (1) , Cyril Poitevin (1) , Cécilia Pignon-Mussaud (1) , Nathalie Long (1)

1 LIENSs - LIttoral ENvironnement et Sociétés

During the past few decades, the urban development’s impact on urban climatic condition has been reported throughout the world. It is well recognized that site morphology and geometry can modify the local climatic condition and form its unique climatic characteristics. Thus, describing physical site properties in a scientific and precise way is important and necessary for urban climatic analysis and application into urban planning. Tim Oke initiated a scheme of urban climate zone (UCZ) in 2004 (Oke, 2004 & 2006) and later in 2009 Iain Stewart and him further developed a refined comprehensive approach of “local climate zone (LCZ)” classification by using a standardized and quantitative way to present physical surface properties of sites and their local climate features(Stewart & Oke,2009 & 2012). LCZ classification has 17 standard types including two subsets: 10 built types and 7 land cover types. Each LCZ can be defined quantitatively by using a standard set of parameters. Some case studies have been conducted in cities of Sweden, Japan and Canada, which are located low density city. Unfortunately, there has been no study testing LCZ classification in high-dense cities. The study wishes to fill this knowledge gap by focusing on high density built-up types and land cover types of Hong Kong. Using field measurement, computational numerical simulations, information regarding the metadata and meteorological data could be collated. First, this study will collect site metadata through the field visit study and up to 20 sites would be surveyed. The survey sample sites will take into account all parameters of LCZ including sky view factor, canyon aspect ratio, building surface fraction, impervious surface fraction, pervious surface fraction, surface admittance, surface albedo and anthropogenic heat flux. Secondly, an experimental study of defining the thermal source area by using thermal sensor and infrared cameras will be also conducted. Thirdly, the study will use both local and micro scale models to do the numerical simulations to capture the thermodynamic features and surface energetics of each survey site. Then, the collected data and simulation result will be analyzed and classified into ‘LCZ’ of Hong Kong. It would allow not only climatologists, but also planners and governors to gain insight into the “how much, where and what” questions of local climatic condition. The information would allow the formulation of urban planning guidelines and climatic spatial design strategies based on a set of threshold value of urban morphology and its climatic impact.

Mots clés: urban database; local climate zone; urban indicators

Domaines: Environnement et Société

Christine Plumejeaud-Perreau, Cyril Poitevin, Cécilia Pignon-Mussaud, Nathalie Long. Building Local Climate Zones by using socio-economic and topographic vectorial databases. 9th International Conference on Urban Climate, CNRM - Météo France, Jul 2015, Toulouse, France. ⟨hal-01252819⟩