Monitoring and analysis of hot spots of land surface temperature to understand the surface urban heat island effect in Thu Duc City

Abstract Currently, Surface Urban Heat Island (SUHI) is a major problem for many cities around the world, especially those with high population density and rapid economic development. Thu Duc City of Ho Chi Minh City is one of the cities in Vietnam that is also experiencing the SUHI phenomenon, particularly in the hot summer. Therefore, monitoring the spatial distribution of SUHI plays a very important role in urban management. The authors used MODIS Land Surface Temperature and Emissivity (MOD11) data spanning 2000 to 2022, featuring a spatial resolution of 1000 meters. The research applied the spatial zoning analysis method for each object using the hot spot analysis tool. This technique clusters hot spots and cold spots by considering each object (Land Surface Temperature-LST) in relation to its neighbors. The LST analysis results show that the daytime temperature trend from 2000 to 2022 increased by about 0.15°C/year (R 2 = 0.81). In addition, annual mean LST extracted from the MODIS Terra and Aqua images exhibited a strong correlation with air temperature (R 2 = 0.66). The results Indicate that the SUHI area tends to increase. In 2022, strong SUHI areas are concentrated mainly in the Northwest and Southwest of Thu Duc City, accounting for 80.6% of the area.