Impact of Atmospheric Correction on Spatial Heterogeneity Relations Between Land Surface Temperature and Biophysical Compositions

Investigating the relations between land surface temperature (LST) and biophysical compositions can help the understanding of the surface biophysical process. However, there are still uncertainties in determining the impacts of biophysical compositions on LST due to the atmospheric effects. In this article, four atmospheric correction algorithms were used to correct 12 Landsat 8 images in Xi'an, Beijing, Wuhan, and Guangzhou, China, including the Atmospheric Correction for Flat Terrain (ATCOR2), Quick Atmospheric Correction (QUAC), Fast Line-of-sight Atmospheric Analysis of Spectral Hypercube (FLAASH), and Second Simulation of Satellite Signal in the Solar Spectrum (6S). Then, geodetector was used to investigate the atmospheric correction differences in the spatial heterogeneity relationships between LST and normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI), and bare soil index (BSI). Results indicate that the selected composition factors were greatly improved after atmospheric correction, and the relations between LST and three factors were characterized by obvious atmospheric correction differences in four study areas. On the whole, the 6S algorithm performed the best in improving the factor values and impacting the spatial heterogeneity relations between LST and biophysical compositions, followed by FLAASH, QUAC, and ATCOR2 algorithms. Except for Wuhan, 6S, FLAASH, and QUAC algorithms significantly enhanced the correlation between LST and NDVI. However, all algorithms weakened the correlations between LST, NDVI, and BSI, except Guangzhou. These findings have been verified using the regression analysis. In addition, with geodetector, combinations of any two composition factors all had strongly enhanced impacts on LST, and a combination between NDVI and NDBI performed the strongest in most cases.

I. Introduction

As the global urbanization trend has become increasingly obvious in recent years, the understanding of urbanization sprawl, land use/land cover change (LUCC), and ecological environment transition at the regional scale is becoming increasingly important [1]–[4]. In particular, in some metropolises, the vast majority of heats generated from highly dense urbanized areas, impervious pavements, factories, and motor vehicles gradually changed the exchange of latent and sensible heat between the land surface and the atmosphere as a result of rapid urbanization, leading to the urban heat island (UHI) effect. This phenomenon has attracted a large amount of attention among the public and exerted substantial influences on the ecological environment development, human activities, and the physical health of urban residents [4]–[7].