Evaluation of the urban heat island over Abha-Khamis Mushait tourist resort due to rapid urbanisation in Asir, Saudi Arabia

Increased knowledge of heat island surfaces (HIS) and intense heat island surfaces (IHIS) in urban environments is critical for the mitigation of excess urban heat and the associated burden on power grids. In this study, we propose a robust thermal remote sensing solution for the delineation of HIS and IHIS areas in Abha and Khamis, a tourist resort in southern Saudi Arabia. Land surface temperature (LST) classification images were retrieved by applying the Single Channel Algorithm (SCA) to thermal band 10 of Landsat 08 data. The pixels of the LST images were grouped based on temperature ranges using ENVI 5.5 software, and were then delineated into classification images of HIS and IHIS areas. Analysis of these images revealed that the overall area of HIS dynamics in both Abha and Khamis ranged from 562 to 826 km(2), with temperature variations between 36.0 degrees C and 41.0 degrees C, while IHIS ranged from under 1 to 14 km(2) , with temperature fluctuations ranging between 40 and 46 degrees C. The city of Khamis had larger summer HIS and IHIS areas than the city of Abha. This study has a strong potential to support local stakeholders, including urban planners, in tracking and offsetting the negative urban heat island (UHI) effects that result from population growth and an increase in impervious surfaces.

Automated summary

This study utilized thermal remote sensing to delineate the heat island surfaces in Abha and Khamis, Saudi Arabia, revealing temperature variations and area distributions. Khamis had larger summer heat island and intense heat island areas compared to Abha.