Spatial and temporal variations of temperature and rainfall, and land use/land cover changes in the Bengaluru urban district

Abstract

Sustainable Development Goal (SDG) 11 focuses on ‘Sustainable Cities and Communities.’ This paper presents the spatial and temporal changes in rainfall and temperature from 1980 to 2022 and Land Use and Land Cover (LULC) in the Bengaluru urban district between 1992 and 2022. This study employs linear regression and non-parametric Modified Mann-Kendall techniques to evaluate the importance of weather data patterns at yearly, monthly, and seasonal levels. The findings reveal a decrease in mean maximum temperature and an increase in minimum temperature, indicating cooler days and warmer nights. Seasonal rainfall also exhibits an increasing trend in the study area over the observation period of 40 years. To quantify some of the key reasons for these microclimate changes, LULC analysis was conducted over 30 years (1992-2022). This analysis indicates a substantial transformation in Bengaluru's landscape, with built-up areas growing at the expense of water bodies, vegetation, and fallow landdue to the rapid urbanization around Bengaluru and the consequent land-use alterations without adequate planning and assessing their environmental and climate impacts. While this study is based in Bengaluru, the method used in this study can be expanded to other megacities to contribute to the achievement of SDG 11.