ANALYSIS OF URBAN HEAT ISLAND EFFECT IN THIRUVANANTHAPURAM DISTRICT – A SOUTHERNMOST PENINSULAR REGION OF INDIA

Abstract

Urban areas are the significant contributors of local and regional climatic changes. The Urban Heat Island (UHI) formation can influence the microclimate of urban areas, making them warmer than the surrounding regions. The temporal and spatial variation of UHI effect in a typical southernmost peninsular part of India was studied for around two decades using geospatial techniques. The Land Surface Temperature (LST) was found using ETM+ and OLI/TIRS satellite imageries. The Ecological Evaluation Index (EEI) is a tool that can be used to assess an areas’ ecological quality based on human comfort, from excellent to worst zones. Urban Thermal Field Variance Index (UTFVI) is a term that can be used to scale the intensity of UHI based on EEI. It was observed from the study that the UHS was mostly concentrated in the central business region of the study area. It was also seen that over the years, although there was a reduction in the area of urban hotspots, an increase in the area of worst zones according to UTFVI classification happened. Shifting of zones from ‘excellent’ to ‘worst’ areas was also observed. UHI and Urban Cool Islands (UCI) are identified. The study will be highly helpful in realizing the climatic changes happening in this region and adopting preventive measures in a systematic way based on the baseline data generated.