Analysis of urban heat island intensity and its impact on regional precipitation over Tainan city in Taiwan

摘要

Along with urban developing in Tainan, urban heat island (UHI) effect is more pronounced in the downtown areas. The generated convection from increasing UHI intensity may affect the precipitation around urban areas. In order to have better understanding the impact of UHI from urbanization on regional precipitation, the land cover types with supervised classification and the UHI intensity from Landsat data are used in this study. According to the results of land cover type in different time periods, the situation of urbanization and impervious surface area (ISA) in Tainan city can be obtained. Then the impact of UHI effect on the regional precipitation will be analyzed by association with the rainfall data during the summertime (June » July and August from 1993 to 2012 which exclude the data in typhoon periods from Center Weather Bureau in Taiwan). The preliminary results indicate that the expanded ISA will enlarge the intensity of UHI which might change (increase) the precipitation around the urban areas. More case studies and investigations are still ongoing to make the substantial results.