Impact of growth of a medium-sized Indian coastal city on urban climate: A case study using data fusion and analytics

Abstract

In India, unlike mega cities, little is known about how the growth of small and medium-sized cities (SMSC) impacts urban climate. Further, such impacts are amplified in coastal settings. We use data fusion and analytics to study how the growth of Thiruvananthapuram, a typical medium-sized coastal city in India, modifies the urban climate. The datasets used are National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) land products, NASA Modern-Era Retrospective analysis for Research and Applications (MERRA-2) and Indian Meteorological Department surface observations contained within the National Oceanic and Atmospheric Administration (NOAA) global compilation of in-situ observations. The study found a ∼ 48% increase in urban and built-up land cover over the last two decades, causing an increase in albedo, surface roughness and a decrease in emissivity and moisture availability. Decreasing moisture availability most affected air temperature, with urban growth adding to large-scale climatic trends of increasing monthly mean daily maximum (+1 °C), minimum (+0.4 °C) and average temperatures (+0.22 °C). Sea-breeze circulation strengthened in response to increasing coastal urbanization and the inland propagation modified with increased convergence and (potentially) rainfall, near the coast.