Impact of urbanization on surface energy balance components over metropolitan cities of India during 2000–2018 winter seasons

Sabiha Sultana,A N V Satyanarayana

doi:10.1007/s00704-022-03937-5

Sabiha Sultana, A N V Satyanarayana

Open Access

https://doi.org/10.1007/s00704-022-03937-5

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Abstract

The present study attempts to evaluate the urban energy balance components concerning increasing urbanization and artificial surfaces over Indian metropolitan cities during the 2000–2018 winter seasons by using Landsat 7 and 8 satellite imageries. The results indicate that the estimated ranges of the energy fluxes are in the typical values reported in the earlier literature over global cities. The sensible heat flux (SHF) increased considerably, and the latent heat flux (LHF) slightly decreased during the study period. The mean SHF over the built-up areas (BA) and the dry lands (DL) of Delhi record a maximum increase of 28.2 Wm−2and 39.7 Wm−2 during the study period. The inland cities have high values of SHF over DL than the coastal cities, and the LHF is high over all the land use classes for the west coast cities. The SHF (LHF) shows a positive (negative) correlation with the land surface temperature. The SHF (LHF) is about 19–33% (1.9–15%) of the net radiation flux, and the residual heat flux is about 60 to 80% of the net radiation flux. The present study advocates that the substantial changes of the surface energy balance parameters have a profound influence on the energy exchange mechanism and could affect regional climatic change.

Highlights

The explosive population rise and fleeting industrialization in the developing countries of tropical and subtropical climate has lead to brisk and abrupt expansion of the artificial surfaces and in turn warmer environment over the cities, the phenomena of urban heat island (UHI) (Oke, 1982; Voogt and Oke, 2003; Sobrino et al, 2012; Roth, 2013)
Estimated surface energy components During the study it is noticed that the net radiation flux and the latent heat flux (LHF) over the built up areas (BA) and the dry lands (DL) are comparatively lower than the vegetated areas and the water bodies have the highest values
As the present study focuses on the high land surface temperature (LST) possessing BA and DL, the analysis is conducted over these land use land cover (LULC) classes only and the Figures 2 – 12 depict the energy balance components only over the DL and the BA and the portions over the vegetated areas and the water bodies are removed

Summary

Introduction

The explosive population rise and fleeting industrialization in the developing countries of tropical and subtropical climate has lead to brisk and abrupt expansion of the artificial surfaces and in turn warmer environment over the cities, the phenomena of urban heat island (UHI) (Oke, 1982; Voogt and Oke, 2003; Sobrino et al, 2012; Roth, 2013). Many remote sensing modeling methodologies are adapted in the recent studies to estimate the influence of urbanization over the surface heat fluxes (Kuang et al, 2014; Eswar et al, 2017) and address the energy-balance-closure problem (Nelli et al, 2019; Mauder et al, 2020) Both earth observation and the ground measurements can be utilized in the estimating the surface energy balance over the urban areas but, the ground observation method requires sufficient number of weather stations, vast amount of data, lots of manpower, huge cost within a small observational area for a productive study (Hanna et al, 2011; Kotthaus and Grimmond, 2014; Templeton et al, 2018) whereas the earth observation data is accessible and covers larger area. The present study attempts to quantify the various surface energy balance components over the different Indian metropolitan cities and investigate the influence of rapid urbanization on variation in the UEB, on sensible and latent heat fluxes, using Landsat-7 and 8 satellite data

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