Urban Heat Island and Its Relation to Green Spaces and Built-up Areas: A Study in Delhi, the Capital City of India

Abstract

Urbanization has brought along with it changes in land use and land cover (LULC), which are not only causing changes in the spatial characteristics of the landscape but also in land surface temperatures, leading to the formation of surface urban heat islands (UHI). This study thus tries to understand the effect of LULC change on land surface temperature (LST) in Delhi between 2013 and 2020 and also tries to see if Delhi has a presence of surface UHI in the year 2020 by comparing the surface temperatures of built-up and green spaces. For collecting data, three geospatial tools were used, namely remote sensing, Google Earth Pro, and the QGIS application. For extracting LST, LULC, and the Normalised Difference Vegetation Index (NDVI), Landsat 8 satellite images were used. The results obtained revealed that change in LULC leads to a change in LST, as all locations which underwent LULC change from non-built-up to built-up and from vegetated to non-vegetated experienced an increase in surface temperatures. Secondly, the results confirmed the presence of a surface UHI in Delhi in the year 2020, as built-up areas recorded more LST than the green spaces. In addition, the low surface temperatures at green spaces highlight the importance of vegetation in mitigating the impact of the urban heat island and recommend city planning with more green spaces.