Spatio-Temporal Analysis of Urban Heat Island Using Remote Sensing and GIS in Lucknow City, Lucknow District, U.P. (2002-2020)

Author Uma Singh
Co-Author Sarika Shukla
DOI https://ww

Country : India
Subject : Geography

Keywords : urban heat island, land surface temperature, normalised difference vegetation index, normalised difference build-up Index.

Abstract

An Urban Heat Island (UHI) is a metropolitan phenomenon. The morphological character of a dynamic city creates pockets in an urban area that are significantly warmer than its surrounding urban and peripheral rural areas. The causes for the creation of UHI vary globally but the core sources are due to industrialisation, urbanisation and varied anthropogenic activities.
The urban area of the city of Lucknow has been expanding rapidly in the past decades. In this study ARC GIS 10.5 and QGIS 3.18 softwares were used to obtain the effect of UHI which is analysed using Landsat 4-5 TM, Landsat 7 ETM+ and Landsat 8 OLI/TIRS data in the period of 2002–2020 in Lucknow City. A mono window algorithm was applied to retrieve the Land Surface Temperature (LST) distribution from the Landsat 4-5 TM, Landsat 7 ETM+ and Landsat 8 OLI/TIRS data and UHI Intensity was calculated between the LST of urban and rural points. Google Earth Pro was used identify the 5 areas classified in the LULC classification.
Land Use/Land Cover (LULC) was calculated on the same data using supervised classification with the help of Maximum Likelihood classifier (MLC) statistical tool, reclassify tool and raster to polygon tool. Linear regression analysis was used and scatter plots were developed to calculate the correlation between Land Surface Temperature (LST) and the Normalised Difference Vegetation Index (NDVI) which was calculated to check the impacts of the green areas on the urban heat island and the correlation between LST and the Normalised Difference Build-up Index (NDBI) was also calculated which was analysed to explore the impact of the built-up area on the urban heat island.
The results indicate that the effects of the Urban Heat Island (UHI) in Lucknow City are felt in many urban pockets. The UHI intensity shows that there is a wide difference in temperature between 8 urban location and 8 rural locations in the study area. UHI intensities from remotely sensed data show that the study area reflects a maximum temperature of 34.1°C and a minimum temperature of 29.54°C which is 4.56°C warmer than rural areas over an 18-year period from 2002 to 2020. The negative correlation between LST and NDVI indicates that the green area can reduce the effect of the urban heat island such as found in Kukrail forest, dense forest on western side, Badi Jugauli Forest, Lohia Park, Janeshwar Mishra Park etc. while the positive correlation between LST and NDBI means that the built-up land use can increase the effect of the urban heat island in a given urban region.
The future sprawling of the study area should be more holistic where human welfare should be first prioritised. Various relevant mitigation strategies are proposed for the study area in order to combat increasing urban heat at the local level in order to achieve Lucknow as a smart and sustainable city.

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