Title |
Mapping deforestation and urban expansion in Freetown, Sierra Leone, from pre- to post-war economic recovery
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Published in |
Environmental Monitoring and Assessment, July 2016
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DOI | 10.1007/s10661-016-5469-y |
Pubmed ID | |
Authors |
Lamin R. Mansaray, Jingfeng Huang, Alimamy A. Kamara |
Abstract |
Freetown, the capital of Sierra Leone has experienced vast land-cover changes over the past three decades. In Sierra Leone, however, availability of updated land-cover data is still a problem even for environmental managers. This study was therefore, conducted to provide up-to-date land-cover data for Freetown. Multi-temporal Landsat data at 1986, 2001, and 2015 were obtained, and a maximum likelihood supervised classification was employed. Eight land-cover classes or categories were recognized as follows: water, wetland, built-up, dense forest, sparse forest, grassland, barren, and mangrove. Land-cover changes were mapped via post-classification change detection. The persistence, gain, and loss of each land-cover class, and selected land conversions were also quantified. An overall classification accuracy of 87.3 % and a Kappa statistic of 0.85 were obtained for the 2015 map. From 1986 to 2015, water, built-up, grassland, and barren had net gains, whereas forests, wetlands, and mangrove had net loses. Conversion analyses among forests, grassland, and built-up show that built-up had targeted grassland and avoided forests. This study also revealed that, the overall land-cover change at 2001-2015 was higher (28.5 %) than that recorded at 1986-2001 (20.9 %). This is attributable to the population increase in Freetown and the high economic growth and infrastructural development recorded countrywide after the civil war. In view of the rapid land-cover change and its associated environmental impacts, this study recommends the enactment of policies that would strike a balance between urbanization and environmental sustainability in Freetown. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Unknown | 103 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Master | 24 | 23% |
Researcher | 13 | 13% |
Student > Ph. D. Student | 10 | 10% |
Student > Bachelor | 6 | 6% |
Student > Postgraduate | 5 | 5% |
Other | 11 | 11% |
Unknown | 34 | 33% |
Readers by discipline | Count | As % |
---|---|---|
Environmental Science | 21 | 20% |
Social Sciences | 14 | 14% |
Earth and Planetary Sciences | 6 | 6% |
Agricultural and Biological Sciences | 5 | 5% |
Arts and Humanities | 4 | 4% |
Other | 13 | 13% |
Unknown | 40 | 39% |