Generating hourly local weather data with high spatially resolution and the applications in bioclimatic performance

Abstract

As urbanization expands and diversifies, weather data produced by a single weather station in a suburb are no longer adequate to represent and reflect microclimatic changes of a city. This study selected 34 automatic weather stations in Tainan City, Taiwan, to conduct temperature and humidity measurements over a period of one year. Based on those observed weather data and urban environment parameters obtained from a geographic information system, as well as morphing approach, this study constructed a method of generating hourly local weather data for urban areas while accounting for urban heat island (UHI) effect in summer. Meanwhile, we discussed the relativities of the urban form and its structure against the variations of local hourly temperature and relative humidity under six buffer scenarios. Error analysis results revealed that minimal prediction errors can be obtained using the buffer scenario involving a 1000 × 1000 m2 four-layer buffer with inner and outer layers and upwind and downwind areas. Finally, using the hourly weather data produced for Tainan City, we calculated the long-term cumulative UHI intensity (UHII) and urban bioclimatic indexes (i.e., thermal stress, use of natural ventilation, and cooling degree day) and investigated how urban form and structure are related to UHII, thermal stress, use of natural ventilation, and cooling degree day. The results can inform urban policy making.