Spatial Distribution of Urban Heat Island based on Local Climate Zone of Automatic Weather Station in Seoul Metropolitan Area

Abstract

Urban Heat Island (UHI) intensity is one of vital parameters in studying urban boundary layer meteorology as well as urban planning. Because the UHI intensity is defined as air temperature difference between urban and rural sites, an objective sites selection criterion is necessary for proper quantification of the spatial variations of the UHI intensity. This study quantified the UHI intensity and its spatial pattern, and then analyzed their connections with urban structure and metabolism in Seoul metropolitan area where many kinds of land use and land cover types coexist. In this study, screen-level temperature data in non-precipitation day conditions observed from 29 automatic weather stations (AWS) in Seoul were analyzed to delineate the characteristics of UHI. For quality control of the data, gap test, limit test, and step test based on guideline of World Meteorological Organization were conducted. After classifying all stations by their own local climatological properties, UHI intensity and diurnal temperature range (DTR) are calculated, and then their seasonal patterns are discussed. Maximum UHI intensity was 4.3 o C in autumn and minimum was 3.6 o C in spring. Maximum DTR appeared in autumn as 3.8 o C, but minimum was 2.3 o C in summer. UHI intensity and DTR showed large variations with different local climate zones. Despite limited information on accuracy and exposure errors of the automatic weather stations, the observed data from AWS network represented theoretical UHI intensities with difference local climate zone in Seoul. 1. 서 론 도시화에 따른 기후 변화 현상은 산업혁명 초기 때 부터 관심을 받은 주제로, 이미 19세기 초 Luke Howard 의 저서 'Climate of London'을 통해서 소개된바 있 다(Luke Howard, 1833). 이 책에서 "런던에 가득한 인 공 배출 열기는 도시의 구조와 높은 인구밀도를 비롯 해 많은 양의 화석 연료 연소를 통해서 증폭되고 있 다"는 표현은 현재의 도시에 적용하기에도 충분한 표 현이라고 할 수 있다. 1877년, 영국의 왕립 기상학회 장인 Henry Storks Eaton의 연설문에 따르면, 화석 연 료의 소비와 증가하는 인구에 의해서 런던의 기후가 변화했음은 의심의 여지가 없다고 밝히고 있다(Henry Storks Eaton, 1877). 이보다 반세기가 흐른 1921년 미 국 Phoenix, Salt River Valley 지역에서 관측된 겨울 철 최저 온도의 그림에는, Phoenix 도심의 도시 열섬