Landscape and Urban Planning 130 (2014) 36–49 Contents lists available at ScienceDirect Landscape and Urban Planning j o ur na l ho me pag e: www.elsevier.com/locate/landurbplan Research Paper Quantifying spatiotemporal patterns of urban impervious surfaces in China: An improved assessment using nighttime light data Qun Ma a,b , Chunyang He a,∗ , Jianguo Wu a,c , Zhifeng Liu a,b , Qiaofeng Zhang d , Zexiang Sun a,b a Center for Human-Environment System Sustainability (CHESS), State Key Laboratory of Earth Surface Processes and Resource Ecology (ESPRE), Beijing Normal University, Beijing 100875, China b College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China c School of Life Sciences and School of Sustainability, Arizona State University, Tempe, AZ 85287, USA d Department of Geosciences, Murray State University, Murray, KY 42071, USA h i g h l i g h t s • VANUI improved accuracy of estimating impervious surface areas with NTL data. • China’s impervious surface areas increased by 6.54% per year between 1992 and 2009. • Expansion of China’s urban impervious surfaces exhibited pronounced regional differences. • Three coastal regions accounted for 54.64% of China’s impervious surfaces in 2009. • Five of the six large expansion hotspots of impervious surfaces were in eastern China. a r t i c l e i n f o Article history: Received 6 September 2013 Received in revised form 14 June 2014 Accepted 16 June 2014 Keywords: Urban impervious surfaces Nighttime light (NTL) Vegetation Adjusted NTL Urban Index (VANUI) NDVI China a b s t r a c t Quantifying the spatiotemporal patterns of impervious surfaces (ISs) is crucial for assessing the envi- ronmental impacts of urbanization. Nighttime light (NTL) data provide a new way of mapping urban IS on broad scales. However, the accuracy of this approach is currently low and thus further improve- ments are much needed. Here we have estimated the urban IS dynamics of China from 1992 to 2009 using the Vegetation Adjusted NTL Urban Index (VANUI), which combines NTL and Normalized Differ- ence Vegetation Index (NDVI) data. With VANUI, we were able to quantify the spatiotemporal patterns of IS in China with a much higher accuracy than previous methods. Key to this improvement was VANUI’s ability to alleviate the problem of saturation inherently associated with NTL data. Our study shows that the total urban IS area of China increased substantially from 10,614.23 km 2 in 1992 to 31,147.63 km 2 in 2009, at an annual increase rate of 6.54%. China’s urban IS expansion exhibited pronounced regional differences, with six large “hotspot” areas where urban IS expanded most substantially. These hotspot regions accounted for 0.87% of China’s total land area, but 37.66% of the total area of urban IS expansion during 1992–2009. Measures of urban IS are not only important for characterizing urbanization patterns and processes, but also essential for assessing ecological and environmental impacts of urbanization. Our results provide a valuable dataset and new insights for better understanding the speed and scope of China’s recent urbanization, as well as for designing and developing sustainable cities in China and beyond. © 2014 Elsevier B.V. All rights reserved. ∗ Corresponding author. Tel.: +86 10 58804498; fax: +86 10 58808460. E-mail addresses: mq-0127@163.com (Q. Ma), hcy@bnu.edu.cn (C. He), Jingle.Wu@asu.edu (J. Wu), hanboms@126.com (Z. Liu), robin.zhang@murraystate.edu (Q. Zhang), kindsnake@126.com (Z. Sun). 1. Introduction Impervious surfaces (ISs) in urban areas refer to human-made land covers through which water cannot penetrate, including rooftops, roads, driveways, sidewalks, and parking lots (Arnold & Gibbons, 1996; Weng, 2012). With rapid urbanization, increasing proportions of landscapes have been converted into IS (Sutton, Elvidge, Tuttle, & Ziskin, 2010). The proliferation of urban IS has http://dx.doi.org/10.1016/j.landurbplan.2014.06.009 0169-2046/© 2014 Elsevier B.V. All rights reserved.