Environmental Management
E. Igun; M. Williams
Abstract
The rapid growth in urban population is seen to create a need for the development of more urban infrastructures. In order to meet this need, natural surfaces such as vegetation are been replaced with non-vegetated surfaces such as asphalt and bricks which has the ability to absorb heat and release it ...
Read More
The rapid growth in urban population is seen to create a need for the development of more urban infrastructures. In order to meet this need, natural surfaces such as vegetation are been replaced with non-vegetated surfaces such as asphalt and bricks which has the ability to absorb heat and release it later. This change in land cover is seen to increase the land surface temperature. Previous studies have tried to explain the impact of land cover changes on the land surface temperature. However, there is a growing need to spatially quantify the extent to which temperature has increased so as to identify areas where immediate mitigation measures can be introduced. In view of this, this study has incorporated remotely sensed Landsat data with remote sensing techniques in order to effectively quantify the spatial extent of urban growth and its impact on the land surface temperature in Lagos, Nigeria. The result shows that there have been changes in the land cover which has increased the land surface temperature between 2002 and 2013. Overall, there was an increase in the highly dense areas, moderately dense areas and less dense areas by 3.35% (2200.77 ha), 27.87% (13681.35 ha), 6.20% (3284.01 ha) and a corresponding increase in the mean land surface temperature of these urban areas by 3.8 oC, 4.2 oC and 2.2 oC. Hence, it was recommended that in order to reduce the land surface temperature of urban areas, sustainable urban planning strategies that include increasing the vegetated areas and embracing other green initiatives such as urban forestry should be adopted.
Environmental Management
S. Ali; S. Patnaik; O. Madguni
Abstract
Urbanization brings biophysical changes in the composition of the landscape. Such change has an impact on the thermal environment locally. The urban mosaic of land use and land cover is thus characteristically composed of local climate zones. The spatial variation in the land surface temperature across ...
Read More
Urbanization brings biophysical changes in the composition of the landscape. Such change has an impact on the thermal environment locally. The urban mosaic of land use and land cover is thus characteristically composed of local climate zones. The spatial variation in the land surface temperature across specific zone is studied for Bhopal city. The objective of the study was to understand how the surface temperature varies with the spatial characteristics of the landscape. The green spaces had the lowest surface temperature that reaches to about 30.5 °C in parks with dense tree cover and highest mean normalized difference vegetation index value of about 0.5. The surface temperature was 36.1 °C for built up/barren areas. The study documents the correlation that exists between surface vegetation and surface temperature across the landscape of Bhopal city. The extent of tree cover and land surface temperature exhibited a strong negative correlation. A decrease in vegetation cover and successive increase in urban built up area were found to be related with high surface temperature. This implies that land surface temperature is an effective tool and may help city planners to make appropriate strategies for improving the tree resources of the urban landscape.
EndNote