Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China; Hunan Key Laboratory of Remote Sensing of Ecological Environment in Dongting Lake Area, China.
Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China; Hunan Key Laboratory of Remote Sensing of Ecological Environment in Dongting Lake Area, China.
J Environ Manage. 2018 Sep 15;222:86-94. doi: 10.1016/j.jenvman.2018.05.024. Epub 2018 May 25.
The spatial, diurnal and seasonal variations of surface urban heat islands (SUHIs) have been investigated in many places, but we still have limited understanding of the interannual variations of SUHIs and associated drivers. In this study, the interannual variations in SUHI intensity (SUHII, derived from MODIS land surface temperature (LST) data (8-day composites of twice-daily observations), urban LST minus rural) and their relationships with climate variability and urbanization were analyzed in 31 cities in China for the period 2001-2015. Significant increasing trends of SUHII were observed in 71.0%, 58.1%, 25.8% and 54.8% the cities in summer days (SDs), summer nights (SNs), winter days (WDs) and winter nights (WNs), respectively. Pearson's correlation analyses were first performed from a temporal perspective, which were different from a spatial perspective as previous studies. The results showed that the SUHII in SDs and WDs was negatively correlated with the background LST and mean air temperature in most of the cities. The nighttime SUHII in most cities was negatively and positively correlated with total precipitation and total sunshine duration, respectively. Average wind speed has little effect on SUHII. Decreasing vegetation and increased population were the main factors that contributed to the increased SUHII in SDs and SNs, while albedo only influenced the SUHII in WDs. In addition, Pearson's correlation analyses across cities showed that cities with higher decreasing rates of vegetation exhibited higher increasing rates of the SUHII in SDs and WDs. Cities with larger population growth rates do not necessarily have higher increasing rates of SUHII.
本研究利用 MODIS 地表温度（LST）数据（每日两次观测的 8 天合成产品）获取的城市热岛强度（SUHII，城市 LST 与农村 LST 之差），分析了 2001-2015 年中国 31 个城市 SUHII 的年际变化及其与气候变率和城市化的关系。结果表明，夏季日（SD）、夏季夜（SN）、冬季日（WD）和冬季夜（WN）SUHII 分别在 71.0%、58.1%、25.8%和 54.8%的城市中呈显著增加趋势。Pearson 相关分析首先从时间角度进行，这与以往研究从空间角度进行不同。结果表明，在大多数城市中，SD 和 WD 中的 SUHII 与背景 LST 和平均气温呈负相关。大多数城市的夜间 SUHII 与总降水量和总日照时间分别呈负相关和正相关。平均风速对 SUHII 影响不大。植被减少和人口增加是导致 SD 和 SN 中 SUHII 增加的主要因素，而反照率仅影响 WD 中的 SUHII。此外，跨城市的 Pearson 相关分析表明，植被减少率较高的城市，SD 和 WD 中的 SUHII 增加率也较高。人口增长率较高的城市不一定具有较高的 SUHII 增长率。
