Predicting the impacts of urban development on seasonal urban thermal environment in Guwahati city, northeast India

Abstract

The formation and intensification of the urban heat island (UHI) phenomenon over an urban area largely depend on its land surface properties, which alters the urban thermal environment. So, assessing and predicting the effect of land use land cover (LULC) change on thermal environment of urban area is crucial. In this context, the present study aims to analyze the LULC change and its effect on land surface temperature (LST) and the UHI phenomenon over Guwahati city, northeast India, from 1995 to 2020 using Landsat data. A significant increase in built-up land of about 147.5% is seen during 1995–2020, while vegetation and cropland show decreasing trend of about 47% and 27%, respectively. Moreover, the future simulation of LULC using the Artificial Neural Network (ANN) based Cellular Automata (CA) model suggests a continuous increase in urban built-up land to about 10.18% during 2020–2030. The future prediction result of seasonal LST using XGB (Extreme Gradient Boosting) regression suggests that around 86.73% in 2025 and 94.53% in 2030 will have to face higher LST of 15 °C-<20 °C in the summer season and 82.58% in 2025 and 97.16% in 2030 of 25 °C-<30 °C zone in the winter season. The distribution of urban thermal field variance index (UTFVI) maps suggest the occurrence of the strongest UTFVI zones over the built-up land while none UTFVI over the surrounding rural region, suggesting a positive UHI phenomenon. Over the predicted years, a notable increase in the strongest UTFVI zone in the built-up region is seen, more significantly in summer than in winter.