关中平原城市群夏季城市热岛特征及驱动力

以2001～2017年夏季长时间序列的MODIS地温产品及相关数据为基础,使用Mann-Kendall非参数检验与Sen's斜率分析法揭示了关中平原城市群地表热环境的时空变化趋势,利用主成分分析法构建城市热环境指数(UTEI)来表征地区热环境的优劣,借助地理探测器对影响地表温度(LST)的主要因子进行驱动力分析.结果 ...

The characteristics and driving forces of summer urban heat island in Guanzhong Plain urban agglomeration

Based on the MODIS land surface temperature (LST) products and related data of the long time series of summer 2001~2017, the spatial and temporal variation trend of surface thermal environment in Guanzhong plain urban agglomeration was revealed using Mann-Kendall non-parametric test and Sen's slope analysis. The pros and cons of the regional thermal environment was characterized by using Principal component analysis to construct the urban thermal environment index (UTEI), and the driving forces affecting LST were analyzed with the help of Geodetector. From 2001 to 2017, the average LST of Guanzhong plain urban agglomeration in summer was 29.3℃ during the daytime and 18.3℃ at night. The change rates of LST in the daytime and at night were −0.053℃/a and 0.026℃/a respectively, and the cooling rate of daytime was slightly higher than the heating rate of nighttime. Surface urban heat island intensity (SUHII) showed an upward trend during 17years. The growth rate in the daytime was higher than that at night, and SUHII in the old urban area is larger than that in the new urban area. There was a significant negative correlation between UTEI and LST, which is quadratic during the day(P<0.05, R²=0.850) and at night(P<0.05, R²=0.624). The factor detection analysis showed that normalized difference built-up and soil index(NDBSI), DEM and enhanced vegetation index (EVI) were the main controlling factors of the spatial differentiation of LST during the day (q>0.6), and LST at night was more affected by night light, aerosol optical depth (AOD) and DEM (q>0.4). The results of interactive detection showed that interaction between DEM and NDBSI was the best in the daytime, and the interaction between DEM and night light was the largest at night. The interaction between any two factors is better than that of a single factor. This study has important guiding significance for strengthening the monitoring and evaluation of the surface thermal environment in Guanzhong plain urban agglomeration.