Seasonality in the daytime and night-time intensity of land surface temperature in a tropical city area
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Date
2016-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
International journal of Science of The Total Environment
Abstract
Variations in urban land surface temperature (LST) links to the surrounding rural areas result to urban heat island
(UHI), which is a global problem challenging both cities in develop and developing countries. Satellite data from
the Moderate Resolution Imaging Spectroradiometer (MODIS), covering the period between 2002 and 2013 were
analysed to examine seasonal variability in the daytime and night-time intensity of urban heat island (UHI), using
Lagos metropolitan city of Nigeria as a case study. Contribution index (CI) and landscape index (LI) were used to
estimate the LST contributions from non-urban and urban areas to UHI and assess the relationship between the
Normalized Difference Vegetation Index (NDVI) and LST. The LI showed that both non-urban and urban areas
contribute greatly to strengthen the intensity of LST during the daytime (with LI b1.0) and much more during
the daytime in the dry seasons (LI = 0.13 in the year 2013). The correlation analysis showed seasonal variation in
the relationship (R
2
) between NDVI and the LST for both day and night times. The highest R
2
values were recorded
for daytime, especially during the wet season (R
2
N0.90), while R
2
were very low in the night-time especially during
dry season. The study indicates that reduction in vegetal cover in Lagos urban areas altered the terrestrial thermal
and aerodynamic processes hence resulted in an intensiļ¬cation of UHI in the metropolitan city.
Description
International journal of Science of the Total Environment,issue no:2016, Pg. 415ā424
Keywords
Urban heat island, Seasonality, MODIS, Nigeria, temperatur