Application of Landsat 8 images to map surface heat loss on Olkaria East and Southeast Geothermal Field, Naivasha, Kenya

Abstract

Olkaria East and Southeast fields are part of the Olkaria geothermal complex, located in the eastern arm of the East African Rift System (EARS) and approximately 120 km from Nairobi, Kenya. It is the first geothermal field in the country to start power production in 1981 with Unit I (15 MWe). Geoscientific exploration confirms that the Olkaria complex is a highly faulted and fractured system dotted with geological features such as volcanic centres, Olkaria hill, and steam vents (fumaroles and steaming ground). The objective of this study was to investigate the temporal heat discharge (or loss) using surface temperature classification features of Landsat 8 images obtained from the U.S Geological Survey website on 11^th July 2015. This involved mapping the localities of temperature anomalies where active geothermal land surface temperature recorded a maximum of 15.2862°C, where 3.943°C matched existing fumaroles. The radiated heat loss of about 0.4459 MW over 0.1494 km² was observed along fault structures. Non-geothermal related anomalies were masked that included radiated heat from power plants and constructions to improve the accuracy of the research output.