典型地表对长沙主城区地表温度的影响分析

城市热岛是一种城市地区温度比郊区温度高的现象,它可改变城市的自然和社会过程,引发一系列环境问题.利用Landsat 8 TIRS10波段的单通道算法(TIRS10_SC算法)反演了长沙主城区2013年7月、2016年3月、7月和11月4景Landsat 8影像的地表温度,并进一步分析了地表温度的时空分布特征,建设用地、...

Typical Land Cover Impacts on Land Surface Temperature of Changsha Metropolitan Area

Urban heat island is a phenomenon that the temperature of urban area is higher than suburb， which can change the natural and social process of city and causes a series of environmental problems. In this paper， Single-channel algorithm for Landsat 8 TIRS10 band （TIRS10_SC algorithm） is used to retrieval the land surface temperature of four landscape Landsat 8 images in Changsha metropolitan area in July 2013， March 2016， July 2016 and November 2016. This paper further analyzes the influence of typical land surfaces such as construction land， green land， rivers and roofs of different materials on the land surface temperature， the results indicate that： （1） The areas with high LST were located in Changsha Railway Station， the Gaoqiao Market and some factories at all times. Compared with July 2013， the heat island effect in the surrounding area of Liuyang River was alleviated in July 2016， which was mainly caused by the different weather conditions and the change of land cover nature by demolition. The largest ratio of construction land in March was moderate LST zone. The highest ratio of construction land in July was sub-high LST zone. In March and July， the highest ratio among green areas is sub-low LST zone， the largest ratio in water is low LST zone. In November， the highest ratio of construction land and green space was medium LST zone， and the sub-highest LST zone in water was the highest； （2） Within 120 m around the river， for every 30 m decrease from land to river， the average temperature of construction land decreased by 0.93~1.26 ℃ and the average temperature of green land decreased by 0.57~0.99 ℃ in July. The average temperature of construction land decreased by 0.51~0.78 ℃ and the average temperature of green land decreased by 0.3~0.57 ℃ in March. The cooling intensity of the river is related to the difference between the river temperature and LST more than 120 m away from the river； （3） Negative MNDWI is positively correlated with land surface temperature and positive MNDWI is negatively correlated with land surface temperature in March and July. However， MNDWI is positively correlated with land surface temperature in November； （4） Emissivity has a significant effect on the results of land surface temperature inversion. It is difficult to distinguish the high reflectivity roofs and other types of construction land by using NDVI to estimate emissivity. Therefore， the influence of high-reflectivity roofs on emissivity needs to be further studied to improve the inversion accuracy of land surface temperature and provide a reference for mitigating the urban heat island effect.