Urbanization and Its Impacts on Land Surface Temperature in Colombo Metropolitan Area, Sri Lanka, from 1988 to 2016
Urbanization has become one of the most important human activities modifying the Earth’s land surfaces; and its impacts on tropical and subtropical cities (e.g., in South/Southeast Asia) are not fully understood. Colombo; the capital of Sri Lanka; has been urbanized for about 2000 years; d...
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| Format: | Article |
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MDPI AG
2019-04-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/11/8/957 |
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| author | H.P.U. Fonseka Hongsheng Zhang Ying Sun Hua Su Hui Lin Yinyi Lin |
| author_facet | H.P.U. Fonseka Hongsheng Zhang Ying Sun Hua Su Hui Lin Yinyi Lin |
| author_sort | H.P.U. Fonseka |
| collection | DOAJ |
| description | Urbanization has become one of the most important human activities modifying the Earth’s land surfaces; and its impacts on tropical and subtropical cities (e.g., in South/Southeast Asia) are not fully understood. Colombo; the capital of Sri Lanka; has been urbanized for about 2000 years; due to its strategic position on the east–west sea trade routes. This study aims to investigate the characteristics of urban expansion and its impacts on land surface temperature in Colombo from 1988 to 2016; using a time-series of Landsat images. Urban land cover changes (ULCC) were derived from time-series satellite images with the assistance of machine learning methods. Urban density was selected as a measure of urbanization; derived from both the multi-buffer ring method and a gravity model; which were comparatively adopted to evaluate the impacts of ULCC on the changes in land surface temperature (LST) over the study period. The experimental results indicate that: (1) the urban land cover classification during the study period was conducted with satisfactory accuracy; with more than 80% for the overall accuracy and over 0.73 for the Kappa coefficient; (2) the Colombo Metropolitan Area exhibits a diffusion pattern of urban growth; especially along the west coastal line; from both the multi-buffer ring approach and the gravity model; (3) urban density was identified as having a positive relationship with LST through time; (4) there was a noticeable increase in the mean LST; of 5.24 °C for water surfaces; 5.92 °C for vegetation; 8.62 °C for bare land; and 8.94 °C for urban areas. The results provide a scientific reference for policy makers and urban planners working towards a healthy and sustainable Colombo Metropolitan Area. |
| first_indexed | 2024-12-10T17:46:20Z |
| format | Article |
| id | doaj.art-1e5d04f42dfd4f0ebdab861208393e4a |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-12-10T17:46:20Z |
| publishDate | 2019-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-1e5d04f42dfd4f0ebdab861208393e4a2022-12-22T01:39:12ZengMDPI AGRemote Sensing2072-42922019-04-0111895710.3390/rs11080957rs11080957Urbanization and Its Impacts on Land Surface Temperature in Colombo Metropolitan Area, Sri Lanka, from 1988 to 2016H.P.U. Fonseka0Hongsheng Zhang1Ying Sun2Hua Su3Hui Lin4Yinyi Lin5Institute of Space and Earth Information Science, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong KongInstitute of Space and Earth Information Science, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong KongSchool of Geography and Planning, Sun Yat-Sen University, Guangzhou 510275, ChinaKey Laboratory of Spatial Data Mining and Information Sharing of Ministry of Education, National and Local Joint Engineering Research Center of Satellite Geospatial Information Technology, Fuzhou University, Fuzhou 350108, ChinaSchool of Geography and Environment, Jiangxi Normal University, Nanchang 330022, ChinaInstitute of Space and Earth Information Science, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong KongUrbanization has become one of the most important human activities modifying the Earth’s land surfaces; and its impacts on tropical and subtropical cities (e.g., in South/Southeast Asia) are not fully understood. Colombo; the capital of Sri Lanka; has been urbanized for about 2000 years; due to its strategic position on the east–west sea trade routes. This study aims to investigate the characteristics of urban expansion and its impacts on land surface temperature in Colombo from 1988 to 2016; using a time-series of Landsat images. Urban land cover changes (ULCC) were derived from time-series satellite images with the assistance of machine learning methods. Urban density was selected as a measure of urbanization; derived from both the multi-buffer ring method and a gravity model; which were comparatively adopted to evaluate the impacts of ULCC on the changes in land surface temperature (LST) over the study period. The experimental results indicate that: (1) the urban land cover classification during the study period was conducted with satisfactory accuracy; with more than 80% for the overall accuracy and over 0.73 for the Kappa coefficient; (2) the Colombo Metropolitan Area exhibits a diffusion pattern of urban growth; especially along the west coastal line; from both the multi-buffer ring approach and the gravity model; (3) urban density was identified as having a positive relationship with LST through time; (4) there was a noticeable increase in the mean LST; of 5.24 °C for water surfaces; 5.92 °C for vegetation; 8.62 °C for bare land; and 8.94 °C for urban areas. The results provide a scientific reference for policy makers and urban planners working towards a healthy and sustainable Colombo Metropolitan Area.https://www.mdpi.com/2072-4292/11/8/957land use/cover changeland surface temperatureimpervious surfacemulti buffer ring methodgravity model |
| spellingShingle | H.P.U. Fonseka Hongsheng Zhang Ying Sun Hua Su Hui Lin Yinyi Lin Urbanization and Its Impacts on Land Surface Temperature in Colombo Metropolitan Area, Sri Lanka, from 1988 to 2016 Remote Sensing land use/cover change land surface temperature impervious surface multi buffer ring method gravity model |
| title | Urbanization and Its Impacts on Land Surface Temperature in Colombo Metropolitan Area, Sri Lanka, from 1988 to 2016 |
| title_full | Urbanization and Its Impacts on Land Surface Temperature in Colombo Metropolitan Area, Sri Lanka, from 1988 to 2016 |
| title_fullStr | Urbanization and Its Impacts on Land Surface Temperature in Colombo Metropolitan Area, Sri Lanka, from 1988 to 2016 |
| title_full_unstemmed | Urbanization and Its Impacts on Land Surface Temperature in Colombo Metropolitan Area, Sri Lanka, from 1988 to 2016 |
| title_short | Urbanization and Its Impacts on Land Surface Temperature in Colombo Metropolitan Area, Sri Lanka, from 1988 to 2016 |
| title_sort | urbanization and its impacts on land surface temperature in colombo metropolitan area sri lanka from 1988 to 2016 |
| topic | land use/cover change land surface temperature impervious surface multi buffer ring method gravity model |
| url | https://www.mdpi.com/2072-4292/11/8/957 |
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