Mapping the local climate zones of urban areas by GIS-based and WUDAPT methods: A case study of Hong Kong

Local Climate Zone (LCZ) developed by Stewart and Oke has become an international standard to analyse urban morphology and the corresponding urban heat island phenomenon. Primary methods for LCZ mapping include in-situ measurements, geographic information system (GIS)-based and remote-sensing-image-based calculations. However, there are few studies discussing their accuracy and suitability. This study focuses on examining and discussing the GIS-based method and the World Urban Database and Access Portal Tools (WUDAPT) Level 0 method. Hong Kong is selected as the study area due to its complex urban morphology and high-density context. The results show, at a city level, both methods can detect LCZ classifications that match with the actual spatial distribution of land use in Hong Kong. Thus WUDAPT level 0 data can be used as input data for mesoscale weather and climate modelling, when lacking precise urban morphology data. Meanwhile, at a district level, the GIS-based method detects more details than the WUDAPT method. However, WUDAPT method classifies land cover types more accurately. These findings provide an in-depth understanding of different LCZ mapping methods and their advantages and limitations. It can also help climatologists, modellers and planners select an appropriate LCZ mapping method for their studies of urban climatic applications.