Urban Landscape Dynamics and the Implication on Surface Urban Heat Island: The Case of Hawassa Town and Surrounding Area, Ethiopia
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Date
2018-11
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Addis Ababa University
Abstract
The Hawassa Town was experienced a rapid urban expansion over the past two decades because
of accelerated economic growth and increase in population which resulted in unplanned
urbanization. Due to this, land use land cover change has been formed and will result
environmental problems and challenges. To notice the above-mentioned problems, exploring the
land use land cover dynamics which will finally resulted in the emergency of Urban Heat Island
(UHI) will be assessed that will value` both the communities and local government in the cities.
This research work was conducted on the relationship between land use transformation and its
implication on land surface temperature change at the heart of rift valley, Hawassa Town,
Ethiopia. Remote sensing, GIS techniques and statistical methods were mainly employed for data
analysis. A series of Landsat data was used to assess and analyze urban landscape dynamics and
land surface temperature. It does so by generating land use land cover maps derived from
Landsat 5 TM for 1986, 1998 and 2010, and Landsat 8 OLI for 2017, using supervise
classification techniques. Spatial pattern analysis of LST was performed using thermal band of
landsat images. Cross tabulation methods, regression analysis and hotspot analysis was
employed to study to urban landscape dynamics and land surface temperature. Based on the
analysis done, it was obtained that the areal extant of urban (built-up) area has increased
considerably by 121.68%.The increasing difference of Surface Heat Intensity (SHIn) between
urban area and non-urban area was distinguished. For instance, non-urban area was cooler than
the urban area except the agriculture sector. As per calculation performed, the difference of the
mean of hotspot and mean of cold spot areas ranged from 8.8 °C to 14.37 °C. Therefore,
increasing surface heat intensity was observed between 1986 and 2017. The surface temperature
was found to be greater for agriculture and urban (built-up) land use land cover types. Finally, it
has been concluded that, with rapid urbanization, surface thermal intensity increased but
relationships with vegetation, water bodies and swampy area suggest that optional for mitigating
urban warming in tropical climate may be available. The use of hotspot analysis and the
investigations of the Urban Heat Island (UHI) will fill the research gaps for the rest of Ethiopian
city for studies of urban thermal variations.
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Keywords
Land use land cover, Land surface temperature, Urban Heat Intensity, Regression analysis, Cross Tabulation, Urban Heat Island