Abstract

Examining the spatial relationship of surface temperature and Normalized Difference Vegetation Index (NDVI) in the urban center helps to balance heat island effect and creates sustainable urban environment. This study identifies the relationship between vegetation condition and surface temperature of Addis Ababa over various land use/cover (LU/LC) types. For this purpose, Landsat 8 OLI and TIR sensor data which were obtained in a dry season are used. The Land Surface Temperature (LST) of the area was retrieved by having surface emissivity that was derived from NDVI threshold method. The LST result of the city shows that the surface temperature of the city varied from 291.61 to 313.06 Kelvin (K). Within the city a significant change in surface temperature was observed over various LU/LC types, which is inversely proportional to their respective vegetation condition. The highest surface temperature and the lowest NDVI were registered on paved surfaces, bare land and settlement areas have lower NDVI value respectively. Whereas, forest and vegetative areas have low surface temperature and high NDVI as compared to the other land use and land cover types. Following the poor distribution of healthy vegetation in the city, the surface temperature varied from the center of the city where it has low NDVI in settlement areas to the peripheral zones. Therefore, to create a livable urban environment, we need sufficient land development regulation which should be friendly to the urban climate such as adding to the numbers of green places in parcels and city level that can attribute to the betterment of the climatic condition in the settlement area.

Key words:  Addis Ababa, Ethiopia, Landsat 8, Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI).