Land Surface Temperature Extracts for Peri-Urban Heat and Rural Cool Troughs in Ghana

Abstract

The objective of this paper is to analyze the land surface temperatures (LST) derived from three satellite images as a proxy for urban heat island potential, through a peri-urban heat troughs (PuHT) to rural cool troughs (RuCT) continuum, concepts largely overlooked in the literature, in the Bosomtwe district of the Ashanti region of Ghana. Four Landsat satellite images from 2002, 2008 Enhanced Thematic Mapper+ (ETM+) and 2014 Landsat 8 Operational Land Imager and Thermal Infrared Sensor (OLI/TIRS) were geo-referenced and processed for classification using the maximum likelihood classifier algorithm in ERDAS Imagine 13. Land Use and Land Cover (LULC) transition analysis was performed in ArcMap for ArcGIS 10.2. Results indicate that, in order of importance, recent fallows and grasslands along with built up/bare land and concrete surfaces have been increasing in terms of coverage. A corresponding surface reflectance translated into LST values ranging between a minimum of 24ºC (297K) to a maximum of 53ºC (326K). Changing LULC types correlated with the land surface temperature fluxes, creating the RuCT and PuHT. This result explains the relatively substantial peri-urban land use dynamics in the district. Future studies should develop threshold values for RuCT and PuHT temperatures.