Assessing remotely sensed temperature humidity index as human comfort indicator relative to landuse landcover change in Abuja, Nigeria

Abstract

Abuja, Nigeria’s capital city has witnessed remarkable expansion, growth and developmental activities since its inception in 1976. This mass inrush and settlement of people often leads to the replacement of the natural land cover with urban infrastructural facilities resulting in micro-climate change and worsening thermal environmental conditions. It is therefore pertinent to study the thermal environment of the city if Abuja will avoid the associated problems of growing and expanding city like many others in the world. Thus this study examines the use of remote sensing and geographic information system in mapping the temperature humidity index (THI) as human comfort indicator relative to land use land cover change in Abuja using Landsat Thematic Mapper, Enhanced Thematic Mapper + and Landsat 8 Operational Land Imager/Thermal Infrared Sensor data of 1987, 1999, 2009 and 2014. This is to assess the changes that have taken place between these periods. Subsequently, an attempt was made at comparing differences in the THI between five different land cover classes: water body, built-up area, closed canopy vegetation, open vegetation and waste land. The results show that the declining trend of vegetation cover between 1987–1999, and 2009–2014 saw a rise in the region with THI > 26 (discomfort) while the periods between 1999 and 2009 where there was a remarkable improvement in the vegetation cover saw an increase in region where comfortable condition is achieved. The discomfort index class category is the most dominant across most of the land cover classes except in the water body and closed canopy class categories. This order of dominance is the highest in wasteland and built-up areas land use/land cover categories.