Impact of Heat Island on Human Comfort in Lafia Urban Area of Nasarawa State, Nigeria

An urban heat island is the name given to describe the characteristics warmth of both the atmosphere and surface in cities (urban areas) compare to their (non-urbanized) surroundings. The annual mean air temperature of a city with 1million people or more can be 1.8-5.4oF (1-3oC) warmer than its surroundings. The impact of this increase has been a major concern in urban areas where heat could be extremely high. The rising temperature in Lafia town centre than the surrounding environment is derive from urbanization and human activities in Lafia town, the nature of the soil type that belongs to the Benue formation resulting from the deposit of the Benue trough. The land on the region of Lafia is low and sandy, and the climate is hot and humid due to temperature rise in the environment from the hot sun heat reflection on the sand and its subsequent radiation at night has increased heat intensity thereby contributing significantly as one of the reasons of the likely Urban Heat Island (UHI). Therefore, the study was set to analyse the change in Urban Heat Island (UHI) over the last sixteen (16) years and how it impact on human comfort in the town of Lafia. The study used both primary and secondary data. The observed values of urban and suburban sites were represented by the temperature from the urban site Nasarawa State Relevant Technology College (NSRTC station) and the average substation stations of Collage of Agriculture Science and Technology (CAST station) respectively. Simple descriptive and inferential statistical data analysis techniques were adopted. The study reveals increasing temperature duration in Lafia from 1998-2007. Temperature increase of 1-2oC was observed from the data collected in Lafia for the periods under study. The study recommend among others evolving green space planning strategies as a mitigation of the effect of urban heat island in Lafia and also planning measures for the town development to include the need for generous provision of land management and land cover, leisure parks/plazas and spacious building pattern.