Using Landsat ETM+ and ASTER DEM in mapping geothermal Potential area around Olkaria

Abstract

Olkaria field is licensed by the Kenyan Government to harvest geothermal energy since 1950s where wells have been drilled in various fields and power generated. GIS and Remote Sensing technology was explored as a tool for mapping geothermal potential area using freely available datasets to minimise cost of exploration and provide prior guided information to geoscientist. A model was developed using four main datasets; suitability map which was processed from ASTER DEM, land use/cover suitability map which was derived from Landsat imagery for the year 2003, Land Surface Temperature derived from the thermal band of Landsat imagery, NDVI, emissivity and vegetation fraction and last Terrestrial Emittance derived from Landsat imagery by computation of emissivity, broad bans surface emittance and downwelling atmospheric transmittance. The results showed satisfactory estimations of geothermal potential map with limitations due to effects of albedo and solar radiation. Landsat data and DEM provide valuable information in mapping geothermal potential areas. The method described in this research could be improved by correcting albedo and solar radiation effects