Multi-dimensional histogram-based information capacity analysis of urban heat island effect using Landsat 8 data

The vegetation and impervious surface area (ISA) are the most key indicators for the urban heat islands (UHI). This study used the normalized difference vegetation index (NDVI) as the indicator of vegetation abundance, the modified normalized difference impervious surface index (MNDISI) as the indicator of impervious surface fraction to estimate the land surface temperature (LST)-vegetation relationship and LST-ISA relationship. The land surface cover types were obtained by classification and regression tree (CART). Results demonstrate and verify that LST possessed strong negative correlations with NDVI and positive correlations with MNDISI at various spatial resolutions (30-960 m). Both correlation coefficients reached their strongest points at 30 m resolution, which is believed to be the operational scale of LST, NDVI and MNDISI. Further, information capacity (IC), as a spatial index, is used to characterize the spatial pattern of UHI. Results show that the IC of LST (LSTIC) possessed strong positive correlations with the IC of NDVI (NDVIIC) and the IC of MNDISI (MNDISIIC). It is suggested that the spatial pattern of UHI has a direct correspondence with the vegetation and ISA.