海湾型城市地表温度景观格局时空演变特征

Spatial-temporal change of land surface temperature landscape patterns in bay city

以厦门市为研究区,以1994—2015年间4景Landsat TM/OLI影像为数据源,对厦门市地表温度景观格局时空演变特征及其与不透水面分布的关系进行研究.结果表明:厦门市城市地表温度空间分异越来越大,次高温和高温区景观类型的面积增大;地表温度景观总体上破碎化程度降低,斑块类型的多样性和均匀分布程度降低,次高温和高温斑块的面积及最大斑块指数增大,斑块数量降低,斑块形状越趋复杂,各类型斑块在空间上趋于聚集成片分布;研究时段内中低等级斑块类型(1、2、3级)向高等级斑块类型(4、5级)转化的面积呈持续增大趋势,等级升高的面积明显大于同期等级降低的面积.统计分析表明,随着城市化的发展,不透水面的增温效应显著增大.

The multi-temporal Landsat TM/OLI images collected from 1994,2004,2010 and 2015 for Xiamen City of China were used to investigate the spatial-temporal change of landscape pattern in LST,employing landscape index and transfer matrix. The impervious surface percentage （ISP） in Xiamen City was obtained using the linear spectral mixture model. The relationships between LST and ISP were investigated to determine the effects of the different underlying surfaces on LST. The results show a large spatial variation in LST landscape pattern with the rapid urbanization during the period of 1994 to 2015. The area for low-grad LST landscape is decreasing,however,it is increasing for high-grad landscape. The thermal landscape is more and more dominated by high-grade LST landscape patches. The fragmentation of the whole landscape had been reduced. The diversion and evenness of patches have been obviously decreased. The patch area and the largest patch index for 4 and 5 grades are both increased,but the number of patches is decreased,thus,shape for the both grades becomes more complex. The spatial distribution patterns for all the patches tend to aggregated. The area of thermal patches which converted form low-grade to high-grade is bigger than that converted form high-grade to low-grade. ISP exhibits a strong linear correlation with LST,and a higher ISP generally correlates to higher LST.