GEOSPATIAL ANALYSIS OF URBANIZATION IMPACT ON LAND SURFACE TEMPERATURE IN CALABAR AND ITS ENVIRONS, CROSS RIVER STATE, NIGERIA

Abstract

Urbanization is one of the most significant phenomena of the anthropogenic influence on the Earth’s environment. Urbanization has driven massive land use and land cover changes, and generated urban heat island (UHI) phenomenon around the world. One of the principal results of urbanization is its impact on the local climate and high impact on the surrounding area. The main purpose of this study is to examine the impact of urbanization on land surface temperature in Calabar and its environs over a period of 30 years. The study utilized both primary and secondary data. The primary data include: GPS points of areas with high human activities, Questionnaire to assess the impact of temperature rise on the locals. The secondary data include: Landsat TM /ETM+, OLI, EMCWF and STRM data. Landsat satellite data were used to extract land use/land cover information and their changes for 30 years. Land surface temperature was retrieved from Landsat thermal images. The relationship between land surface temperature and land use/land cover classes, as well as the normalized difference vegetation index (NDVI) and normalized difference built up index (NDBI) was analyzed. Using correlation and linear regression this interrelationship was then quantified. The mean temperature of the area was 17.27°C in 1989 which became 18.91°C in 1999, then 22.30°C in 2009 and 24.59 °C in 2019. The relationship between NDBI and LST initiate strong positive correlation with a R value of 0.818 in 1989, 0.902 in 1999, 0.913 in 2009 and 0.928 in 2019; while the relationship between NDVI and LST is positively related and the R value derived as 0.847, 0.848, 0.747 and 0.796 in years 1989, 1999, 2009 and 2019 respectively. The results also show that Calabar has the highest LST value when compared to its neighboring rural area (Akpabuyo) LST. One of the implications of this heat is that increase in temperature makes the locals uncomfortable and expose them to heat- related symptoms and illnesses. The result of this research will be helpful for urban planners and environmental scientists. The study recommended regular monitoring of urban sprawl and development by the state Government in the study area especially with the aid of geospatial techniques for better decision making and further research into the subject matter.