Assessing Local Climate Change by Spatiotemporal Seasonal LST and Six Land Indices, and Their Interrelationships with SUHI and Hot-Spot Dynamics: A Case Study of Prayagraj City, India (1987-2018)

LST has been fluctuating more quickly, resulting in the degradation of the climate and human life on a local-global scale. The main aim of this study is to examine SUHI formation and hotspot identification over Prayagraj city of India using seasonal Landsat imageries of 1987-2018. The interrelationship between six land indices (NDBI, EBBI, NDMI, NDVI, NDWI, and SAVI) and LST (using a mono-window algorithm) was investigated by analyzing correlation coefficients and directional profiling. NDVI dynamics showed that the forested area observed lower LST by 2.25-4.8 degrees C than the rest of the city landscape. NDBI dynamics showed that the built-up area kept higher LST by 1.8-3.9 degrees C than the rest of the city landscape (except sand/bare soils). SUHI was intensified in the city center to rural/suburban sites by 0.398-4.016 degrees C in summer and 0.45-2.24 degrees C in winter. Getis-Ord G(i)* statistics indicated a remarkable loss of areal coverage of very cold, cold, and cool classes in summer and winter. MODIS night-time LST data showed strong SUHI formation at night in summer and winter. This study is expected to assist in unfolding the composition of the landscape for mitigating thermal anomalies and restoring environmental viability.

Automated summary

The aim of this study is to examine SUHI formation and hotspot identification in Prayagraj city, India using seasonal Landsat imageries from 1987 to 2018. By analyzing correlation coefficients and directional profiling, the interrelationship between six land indices and LST was investigated. The results showed that forested areas had lower LST than the rest of the city, while built-up areas had higher LST. SUHI was intensified in the city center during summer and winter, and there was a loss of areal coverage of colder classes. MODIS night-time LST data confirmed strong SUHI formation at night. This study is important for mitigating thermal anomalies and restoring environmental viability.