Environmental Engineering
A. Suharyanto; A. Maulana; D. Suprayogo; Y.P. Devia; S. Kurniawan
Abstract
BACKGROUND AND OBJECTIVES: This study aims to determine the relationships between land cover presented by vegetation index and land surface temperature, between vegetation index and the built-up index, between built-up index and land surface temperature, and between land surface temperature and rainfall ...
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BACKGROUND AND OBJECTIVES: This study aims to determine the relationships between land cover presented by vegetation index and land surface temperature, between vegetation index and the built-up index, between built-up index and land surface temperature, and between land surface temperature and rainfall characteristics in East Java Province, Indonesia.METHODS: Three cities and four regencies were used as examples. Landsat imagery scanned in 1995, 2001, 2015, and 2020 were used. Daily rainfall data recorded in the same years with Landsat data are used. The pixel values along the urban heat island line were used to analyze the interrelationships between vegetation index, built-up index, and land surface temperature. The land surface temperature and daily rainfall data from each Thiessen polygon were used to analyze the relationship between land surface temperature and rainfall characteristics. Image processing analysis was used to analyze the vegetation index, built-up index, and land surface temperature. The mathematical interrelationship between vegetation index, built-up index, land surface temperature, and rainfall intensity was analyzed using linear regression.FINDINGS: The results of the analysis show that the relationship between vegetation index and built-up index is inversely proportional and with land surface temperature is nearly inversely proportional to a coefficient of determination greater than 0.5. For the relationship between the built-up index and land surface temperature, the results of the analysis show that both have a directly proportional relationship, with a significant coefficient of determination (R2>0.5). For the relationship between land surface temperature and rainfall characteristics, the results of the analysis show that land surface temperature has a directly proportional but weak relationship with rainfall intensity and an inversely proportional but weak relationship with the number of rainfall days. Decreasing environmental conditions indicated by decreasing vegetation index will influence increasing land surface temperature and its effect on increasing rainfall intensity and decreasing rainfall days.CONCLUSION: Changes in land use/land cover are characterized by a change in vegetation cover to built-up land. These changes affect the land surface temperature. Changes in land surface temperature affect the occurrences of rainfall intensity. When the vegetation index decreases, the built-up index increases, and the land surface temperature increases as well. The increase in land surface temperature will increase the rainfall intensity. Satellite remote sensing imagery is effective and efficient for analyzing vegetation index, built-up index, and land surface temperature.
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 ...
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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 ...
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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.
