Fenomena Urban Heat Island dan Kontribusi Fungsi Ruang Terbuka Hijau pada Periode 2013-2023 di Kota Bogor

Abstract

The Urban Heat Island (UHI) phenomenon is an effect of urbanization and land use changes that cause an increase in surface temperature, reduced thermal comfort, and lower environmental quality. Bogor, a city experiencing rapid population growth, has seen a significant conversion of vegetation areas into built- up areas over the past decade, contributing to increased temperatures and urban heat island (UHI) effects. Green Open Spaces (GOS) play a crucial role in mitigating the Urban Heat Island (UHI) effect by enhancing evapotranspiration and reducing heat absorption by built-up surfaces. This study aims to (1) analyze the UHI phenomenon in the city of Bogor from 2013 to 2023, (2) analyze the influence of GOS on thermal comfort, and (3) analyze public perceptions of environmental conditions related to UHI and GOS. This study employs remote sensing and spatial analysis approaches using Landsat 8 OLI/TIRS satellite imagery data from 2013, 2015, 2017, 2019, 2021, and 2023 to calculate Land Surface Temperature (LST) and analyze UHI distribution. The Normalized Difference Vegetation Index (NDVI) was used to measure vegetation cover, while the Normalized Difference Built-Up Index (NDBI) was used to identify built-up areas. UHI was determined based on the statistical distribution of LST, and a correlation analysis was conducted between LST, NDVI, and NDBI to understand the relationship between land use changes and surface temperature. The Temperature Humidity Index (THI) was calculated based on air temperature and humidity data from field measurements in three subdistricts. Public perception was assessed using a likert scale-based questionnaire, with Spearman's rank correlation analysis employed to examine the relationship between the presence of green open space and environmental comfort. Based on UHI classification data, the UHI area increased by 0.25% (27.50 ha) in Tanah Sareal District, while Bogor Tengah District experienced a decrease of 0.17% (18.30 ha) in the UHI area. NDVI analysis revealed that Bogor Selatan had the highest vegetation index, indicating a greater green cover. In contrast, Tanah Sareal had the highest NDBI index, indicating a dominance of built-up areas. The presence of green open spaces plays a crucial role in mitigating the Urban Heat Island (UHI) effect and enhancing thermal comfort. The negative correlation between NDVI and LST suggests that areas with higher vegetation cover have lower temperatures. THI values indicate that most of Bogor City experiences uncomfortable conditions (THI > 27°C), especially in subdistricts with limited green open spaces. In contrast, South Bogor has some areas with more comfortable conditions due to broader vegetation coverage. Public perception confirms the results of the spatial analysis, where the majority of respondents feel that air temperature has increased and environmental comfort has decreased, especially in areas with limited GOS and high UHI effects. Respondents recognize the importance of GOS in reducing temperature but assess that its extent is still insufficient to balance the impacts of urban heating. The correlation between public perception of GOS availability and environmental comfort shows that the lower the availability of GOS, the higher the complaints regarding rising temperatures and declining environmental quality. This study emphasizes the importance of ecology-based mitigation strategies to mitigate UHI impacts, including enhancing GOS quality, implementing green building technologies, and utilizing materials that reduce heat absorption. The Bogor City Government needs to integrate spatial planning policies focused on ecosystem balance by tightening regulations related to green open spaces. Public participation in environmental conservation and the optimization of urban green spaces are also key factors in creating a more comfortable and sustainable environment.