1. MAPPING BUILT-UP AREAS USING TWO BAND RATIO ON LANDSAT IMAGERY OF ACCRA IN GHANA FROM 1980 TO 2017.
- Author
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TWUMASI, N. Y. D., SHAO, Z., and ALTAN, O.
- Subjects
URBAN growth ,BODIES of water ,LAND cover ,ECONOMIC policy ,DEVELOPING countries ,VEGETATION classification - Abstract
Lack of historical land cover and urban growth governance structure makes spatial planning within the economic capitals of developing countries difficult. Monitoring urban built-up growth with insitu methods is complicated. In this paper, long-term Landsat archive is utilised to map the built-up areas of Accra, the economic capital of Ghana, in Africa. Simple two band ratio and band combination is coupled with historic Google Earth imagery to monitor built-up dynamics from 1980-2017. A 10-year period was sub-divided into three parts each; early period, mid period and late period - for analysis. Maximum Likelihood classifier was used for the classification within the ENVI environment. The results show 11.90% as the highest and 4.63% as the lowest built-up growth rates between 2001-2005 and 1996- 2000 respectively. Annual loss of non-built-up areas was 1.31%, and 48.57% over the entire study period. Water bodies lost 0.08% annually but 3.1% over the 37-year period. Highest and lowest overall accuracy were 87.18% and 81.31% respectively, with an average kappa coefficient of 0.7618. Gain in the built-up area was 1676.69 km
2 but non-built up areas lost 1576.10 km2 while water bodies lost 100.60 km2 . Results will be of interest to spatial planners, policy makers and land administrators. [ABSTRACT FROM AUTHOR]- Published
- 2019
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