Spatial and temporal variation of land surface temperature (LST) in the Kandy District of Sri Lanka

Abstract

In Sri Lanka, there is a considerable increase in the average annual LST in the city of Colombo, and it might have occurred in the city of Kandy as well. Increases in LST can affect to many issues. Research on LST is useful for green city planning and policymaking for development in urban areas. This study examined the spatial and temporal variation of LST in the Kandy District in 1996 and 2017. Geospatial tools such as remote sensing and GIS were used to analyse data. Landsat satellite data has been collected by the United States Geological Survey. The NDVI, NDBI, and NDWI were used to classify the different land uses and to find out the relationships between LST. The mean LST was increased by 2.36°C in 2017 compared to 1996. The LST was higher in the City of Kandy in 2017 than in 1996. The Eastern part of the Kandy was slightly higher in 2017 than in 1996. There is a significant negative correlation (α=0.01) between LST and NDVI. The NDBI increased by 0.11 in 2017, compared to 1996 and spread into suburb areas. The significant strong relationship between NDBI and LST was identified. The lack of satellite images is one of the serious barriers to analysing the LST. Land-use changes, increased build-up areas and decreases in vegetation and water bodies have affected to rise in land surface temperature in the Kandy. The future land use planning should be considered to mitigate the effects of LST in Kandy City.