Study of Urban Heat Island Phenomena for Baghdad City using Landsat- 7 ETM+ Data

Abstract

Urban areas have well documented effects on climate, such as the urban heat island effect, reduction of wind speeds, enhanced turbulence and boundary layer heights, and changes in cloud cover and precipitation. The objective of the present work is to study the Urban Heat Island in Baghdad city, by finding out the spatial variation of four indicators, Normalized Difference Vegetation Index (NDVI), soil adjusted vegetation index (SAVI), Leaf Area Index (LAI) and Land Surface Temperature (LST) using Landsat-7 ETM+ imagery. Land use/ Land cover map for the study area were retrieved using supervised classification by ERDAS(9.1) software. This paper classifies Baghdad city area as five type of land built up area with trees, built up area without trees, water area, low vegetation and high vegetation. The results shows that the maximum difference of land surface temperature between the built-up and the surrounding area reach to 11.97 oC. The maximum value of the land surface temperature appeared in the built-up area without trees in the downtown of the city (29.96 oC ),while the water and high vegetation area show 17.93 oC of minimum land surface temperature values. The result of the spatial analysis of the NDVI, LAI and SAVI indicated that there is a negative correlation with the built-up area and positive correlation with vegetation area.