title: Data concurrency is required for estimating urban heat island intensity.
abstract: Urban heat island (UHI) can generate profound impacts on socioeconomics, human life, and the environment. Most previous studies have estimated UHI intensity using outdated urban extent maps to define urban and its surrounding areas, and the impacts of urban boundary expansion have never been quantified. Here, we assess the possible biases in UHI intensity estimates induced by outdated urban boundary maps using MODIS Land surface temperature (LST) data from 2009 to 2011 for China's 32 major cities, in combination with the urban boundaries generated from urban extent maps of the years 2000, 2005 and 2010. Our results suggest that it is critical to use concurrent urban extent and LST maps to estimate UHI at the city and national levels. Specific definition of UHI matters for the direction and magnitude of potential biases in estimating UHI intensity using outdated urban extent maps.
authors.affiliation: College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China. Electronic address: sqzhao@urban.pku.edu.cn.
authors.forename: Shuqing
authors.initials: S
authors.lastname: Zhao
authors.affiliation: College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China.
authors.forename: Decheng
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Geospatial Science Center of Excellence (GSCE), South Dakota State University, Brookings SD 57007, USA.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Liu
mesh_terms: D002681:China; D002947:Cities; D004777:Environment; D004784:Environmental Monitoring / Q000379:methods; D005843:Geography; D006358:Hot Temperature
keywords: Concurrency of data; Definition of UHI; Mapping urban extent; Urban expansion; Urban heat island (UHI)