Presenter : Pavithra Jayasinghe
With the concentration of development activities Colombo City is growing faster and it is experiencing considerable changes in its vegetation cover and built-up areas. As past records indicate, the city was experiencing around 270C surface temperature which is recording significant increase in recent years. The attempt of this study is to identify the change of vegetation cover and built-up area using NDVI and NDBI indices and to compare the results with land surface temperature differences along past 20 years by analyzing Landsat images in three respective years, 1995, 2005 and 2015. The analysis was performed for LANDSAT 4-5TM and LANDSAT 8 OLI/TIRS images in each year. Detected results from two indices were compared with the calculated Land Surface Temperature (LST) using thermal band of all three images. The result shows a strong relationship between the reduction of vegetation cover and increased land surface temperature. Results of two indices over three years will be further discussed in relation with the elevated temperature within the city.