Spatio-temporal assessment of mangrove cover in the Gambia using combined mangrove recognition index
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Abstract
This study is an effort to assess mangrove cover in The Gambia utilizing Landsat Data. The gradual land use and land cover variations along the coastal estuarine area of The Gambia provoked this paper to assess variation on the mangrove forest cover. The aim of this research is to do spatiotemporal monitoring and mapping to detect changes in mangrove forest cover of the Gambia from 2000 to 2020. For analyzing change, the technique of supervised classification with CMRI was applied on three multi-temporal Landsat images. Combined Mangrove Recognition Index (CMRI) approach is used in this research which is an index for distinction of mangrove forest from non-mangrove area. In this study, mangrove forest cover decline has been found to be approximately from 1811km2 to 853km2 in the last two decades. The main vegetation being deforested in Greater Banjul Area is mangroves. This impact has significantly increased the vulnerability of residents to flash floods after heavy rainfalls especially in towns like Serrekunda, Tallinding, Bundung, New Jeshwang and even the Capital City, Banjul. These findings can be significant for conservation authorities and research groups. The maps presented in this analysis will be a valuable guide and provide soft grounds for coastline regulatory body to formulate better sustainable development strategies for this region. Alongside, it a matter of global concern because its deforestation has not only threatened the mangrove ecosystem but also increased vulnerability of the nearby communities and fish breeding grounds. The results of the study will help environmental protection agency, agriculture and forest departments to design location specific strategies to reduce mangrove cover degradation.
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