Effect of Urbanization on surface urban heat island（SUHI）in North District of Hong Kong, using remote sensing techniques

Abstract

There is direct relationship between urbanization and Land use and cover (LULC) change, there is also relationship between the land surface temperature (LST) and Albedo, Albedo and LST can be influenced by urbanization at the same time. In this study, i try to explore the impact of urbanization on surface urban heat island (SUHI). There are no researches studied by remote sensing method in North District of Hong Kong. In this study, i have classified the LULC in North District of Hong Kong, then, LST has been analyzed by using Landsat (TM/OLI) images. The inversion LST was obtained in this study's usage of the maximum likelihood classifier approach (supervised classification) to categorize pictures. There are so many methods to define urban area and non-urban area, simplified urban extend (SUE) method is used to distinguish urban area and non-urban area and then calculate the surface urban heat island (SUHI) in North District of Hong Kong, the correlation between urban heat island effect and urban green space and building land can provide important information for our urban development and environmental protection. To study the influence of urban green space and building land on urban heat island effect, I also analyzed the correlation between land surface temperature and Albedo, and the relationship between LST and NDVI, NDBI shows the influence of vegetation area on UHI is negative. Then the positive correlation between urban building land and surface temperature distribution is that urban building land has positive influence on UHI, it also shows building area can enhance urban heat island effect. The results of LULC revealed that According to the classification results, from 1987 to 2004, 71.157% of forest area remained unchanged, 26.903% of forest were changed into urban area, 9.529% of barren area were changed into urban area.From 2004 to 2021, 71.157% of forest area remained unchanged, 26.903% of forest area were changed into urban area, 9.529% of barren area were changed into urban area. From 1987 to 2021, 42.654% of forest area changed into other land area, urban area continued to increase from 1987 to 2021