Understanding the multifaceted influence of urbanization, spectral indices, and air pollutants on land surface temperature variability in Hyderabad, India

Abstract

Hyderabad, similar to many cities worldwide, has experienced accelerated urbanization, leading to increased surface temperature and air pollution. The present study investigated the relationship between land surface temperature (LST) and various air pollutants, urbanization, surface indices, and meteorological parameters, which are associated with Sustainable Development Goals (SDGs), especially Goal 13 (Climate Action) and Goal 11 (Sustainable Cities and Communities). The effect of air pollution on LST across seasons was also examined for five years (2018–2022). LST images collected from MODIS satellite. Data on air pollutants and meteorological parameters were collected from air quality monitoring stations. The results showed that PM2.5 exceeded the WHO guidelines. A weak or moderate relationship was observed between LST and individual air pollutants. However, the association significantly improved when all air pollutants were considered simultaneously. The relationship improved even further when additional parameters such as Normalized Difference Built-up Index (NDBI), Normalized Difference Vegetation Index (NDVI), Digital Elevation Model (DEM), road line density (RLD), and global population density (GPD), were also included. The resulting relationship was very strong (R2 > 0.80) during the summer and winter seasons. The study identified that NH3 had a prominent influence on LST during winter, while PM2.5 and NH3 exhibited a higher influence during summer. The research findings emphasized that LST variations were influenced by both air pollutants and meteorological conditions, along with urbanization factors represented by various parameters and indices. The research underscores the importance of considering these findings in future studies. It suggests the need to explore efficient approaches to address the combined problem of rising LST and concentration of air pollutants in urban areas.