A GIS-based approach for exploring geothermal resources along part of the Kenyan rift

Abstract

Most geothermal prospects have surface manifestations such as hot-springs, mud-pools while others have no obvious features. There are mainly two phases of exploration; reconnaissance and siting of wells when exploiting the geothermal resource. Geothermal exploration efforts are costly and are done using several methods such as geology, geophysics, geochemistry, Remote Sensing and GIS. GIS has the advantage of combining several datasets for analysis therefore achieving better results by narrowing to a target area. Remote sensing data provides a low lost methodology for deriving geothermal indicators. In this study Analytical Hierarchy Process (AHP) was used to determine geothermal potential areas using inputs from Land Surface Temperature (LST), geology, slope, drainage, land use/cover. Geothermal potential map was generated by weighting all the variables using multi criteria analysis. The map was classified into three classes; high potential, moderately potential and less potential areas. The methodology used revealed geothermal potential areas which coincide with ground survey data with over 50% success for areas in Menengai, Eburru and Suswa. Other unexplored areas were also revealed and marked for further detailed filed survey. GIS and Remote sensing methods are powerful tools in geothermal exploration as demonstrated in this study.