Estimating the Effect of Urbanization on Ecological Condition and Urban Thermal Comfort: A Case Study in Colombo, Sri Lanka

Abstract

Urbanization is one of the major factors affecting the ecological condition and urban thermal comfort of cities, particularly in developing countries like Sri Lanka. This study explores the impact of Vegetation cover, Built-up density, and Land surface temperature on urban thermal comfort and ecological condition in Colombo, Sri Lanka using multi-temporal remotely sensed data. Landsat 8 satellite images from 2014 to 2023 was used to assess the spectral indices such as NDVI, NDBI, LST and UTFVI in Colombo. The results show that ecological condition and thermal comfort is fluctuating throughout the study period. Specifically, between 2020 and 2022, covid-19 pandemic is one of the major influencing factors for the good ecological condition since the air quality was controlled by limited human activities due to lockdown. After people adapted to live with Covid-19 and continued their day-to-day activities, industrial activities resumed to normal again in 2023; a pattern leading to ecological condition going back to worst was identified. So, these findings highlight the importance of incorporating green spaces and built-up density in urban planning to mitigate the adverse effects of surface temperature on ecological condition and thermal comfort.