The Effects of Land Indices on Thermal State in Surface Urban Heat Island Formation: A Case Study on Agra City in India Using Remote Sensing Data (1992-2019)

摘要

Growth of populations coupled with industrial and economic development has led to conversion of natural environment to urbanized regions of high built-up areas and infrastructure. The natural space is transforming to built-up set up rigorously which is not only intensifying the thermal state but also changing the climate dynamics. This has resulted in an increase in Land Surface Temperature (LST) leading to critical consequences on the climate and human life. In this study, spatiotemporal imageries of Landsat (1992-2019) are analysed for carrying out the analysis of land indices [Normalised Difference Vegetation Index (NDVI), Normalised Difference Built-up Index (NDBI) and Enhanced Built-up Bareness Index (EBBI)], LST and surface urban heat Island (SUHI) formation for Agra City in India using summer season (April-May) data. The main focus of the present work is the study of spatial pattern of LST and land indices (i.e. NDVI, NDBI and EBBI) and their interrelationship dynamics over the city landscape in directional profiling. The results of SUHI reveal that city center has experienced 0.5-3.5 degrees C of higher LST than urban periphery. The NDVI vs. LST relationship is found negative, whereas both NDBI vs. LST and EBBI vs. LST relationships are found positive in selected four summer time points of 1992, 2000, 2010, and 2019. The NDVI dynamics results indicate that the forest area (viz. 3-4 km and 10-12 km from city center) experienced 3-5 degrees C lower LST than other parts of the city landscape. The NDBI dynamics results indicate that in built-up area (from city center to 7 km in all eight directions) experienced 2-4 degrees C higher LST than other parts of the city landscape (except barren soils area). The EBBI dynamics results indicate that barren soils (viz. 8-10 km of North-East direction, 14-15 km of North-West direction and 7-9 km of South-West direction) have experienced 2-5 degrees C of higher LST than other part of the city landscape. The purpose of is to help in enriching the knowledge base for not only understanding the dynamics of the thermal state but also in knowing the composition of the landscape for enhancing environmental sustainability and carrying capacity for Agra city.