期刊名称:Research Journal of Environmental and Earth Sciences
印刷版ISSN:2041-0484
电子版ISSN:2041-0492
出版年度:2012
卷号:4
期号:1
页码:68-75
出版社:Maxwell Science Publications
摘要:Urban Heat Island (UHI) effect controls internal climates of buildings and affects energy use and comfort of urban dwellers. The objective of this study was to detect UHI from Land Surface Temperature (LST) and to investigate whether land cover has any influence on UHI in Tarkwa, South West Ghana using satellite remote sensing techniques. A Landsat 7 ETM+ image, DEM and meteorological data were used to generate a land cover map with the maximum likelihood classification algorithm whiles LST was modeled with the Landsat Plank's curve. Validation of the LST map was achieved by comparing it with air temperature measured at the UMaT meteorological station. The mean modeled LST of 298.60 Kelvin compared well with the mean observed air temperature of 298.30 Kelvin. Furthermore, LST ranged between 289 and 305 Kelvin while urban areas and bare soils had higher LSTs than vegetated areas implying that higher NDVI areas are associated with lower temperatures. Hence, LST maps produced indicated the existence of UHI effect in the Tarkwa area. From the study it is evident that impervious and non-evaporative surfaces have high LSTs due to absence of vegetation. Therefore, uncontrolled land cover changes may intensify the UHI effect. The study has proven that remote sensing can be used in operational mapping of LST for climate studies, vegetation monitoring and detecting UHIs in the humid regions of Ghana. This confirms the important role Earth observation and geoinformation technology can play in environmental monitoring and management as global climate and land cover changes.
关键词:Geo-information; land cover; landsat; LST; remote sensing; urban heat island;