Urban Heat Island Index Change Detection Based on Land Surface Temperature, Normalized Difference Vegetation Index, Normalized Difference Built-Up Index: A Case Study

Climate change is a matter of considerable global importance, as evidenced by the increased urban surface tem-peratures in developed and undeveloped areas. Hence, this study aims to analyze the threshold and index of the urban heat island (UHI) phenomenon within the urban region of Bima City, located in Indonesia. The study was undertaken by utilizing sequential data from 2016, 2019, and 2022 obtained from the Google Earth Engine portal. The analysis focused on the assessment of UHI by examining land surface temperature (LST), normalized differ-ence vegetation index (NDVI), and normalized difference built-up index (NDBI). Algorithms that operate on a single channel are employed to compute the land surface temperature. The findings indicate that the LST peaked in 2016 at 32.54 which rose to 35.08 in 2019 and increased to 39.18 in 2022. This implies a progressive rise in the LST of Bima City as time progresses. Moreover, it was observed that LST exhibited a positive correlation with the NDBI while displaying a negative correlation with the NDVI. The urban heat island phenomenon has been observed to possess the capacity to elevate ambient air temperatures in urban regions by as much as 3 when compared to suburban areas. In addition to considering both developed and undeveloped regions, it is important to acknowledge the observed changes in the UHI threshold in Bima City. Specifically, the UHI threshold has exhib-ited an upward trend, rising from 26.73 in 2016 to 29.57 in 2019 and 31.21 in 2022.