基于最优粒度的城市热环境与景观特征耦合分析

综合Landsat和国产高分2号遥感影像反演地表温度、划分地表覆被类型,通过划分100m×100m～1000m×1000m等多个网格单元,分析北京市五环内热环境影响因素的粒度效应;并基于最优粒度分析城市景观组分和构型特征与热环境特征的相互关系.结果表明:随粒度增加,网格单元内平均地表温度和不透水地表(IS)、植被水体(...

Coupling analysis of urban thermal environment and landscape characteristics based on optimal granularity

We obtained land surface temperature and landscape components from Landsat and GF-2 within the inner Fifth Ring area in Beijing. The polygon grid approach has been applied for analyzing the relationship between urban landscape components and pattern characteristics and thermal environment characteristics. These various size polygon grids division was from 100m×100m to 1000m×1000m. With the increase of grid size, the correlation between IS/GWS and average LST first decreases and then gradually increases, trending to be flat at 600m. The optimal grid size range of IS and GS affected by LST was 600m×600m within the inner Fifth Ring area of Beijing. Among the 1796grids based on the optimal granularity, the mean temperature (T_m) was significantly correlated with impervious (0.723) and vegetation & water (-0.715), the standard deviation of temperature (T_s) was significantly correlated with impervious (-0.051) and water (0.054); when the proportion of vegetation was more than 55%, T_m decreased rapidly. When the proportion of dominant landscape types in the grid reaches a certain level, an increase or decrease in its proportion will cause rapid changes in the thermal environment. Based on the correlation analysis of vegetation & water, impervious landscape pattern, and thermal environment, T_m and LPI_IS (0.665), COHENSION_GWS (-0.547) were significantly correlated. When the proportion of GWS in the grid is more than 40%, the larger the vegetation water patch area and the higher the spatial connectivity, the more conducive to improving the thermal environment.