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 Printable version |
Vegetation cover change in the Laf-Madjam forest reserve of northern Cameroon: Quantification using remote sensing |
Science et changements planétaires / Sécheresse. Volume 21, Number 3, 169-78, juillet-août-septembre 2010, Article de recherche
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 Résumé
Article gratuit
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Author(s) : Gervais Wafo Tabopda, Jean-Marie Fotsing |
Summary : Forest reserves, in spite of the regulatory role they could play in dry regions, are the subject of a double demographic and climatic constraint. We proposed to highlight the successive states of land occupation in the Laf-Madjam forest reserve and to evaluate their dynamics from 1976 to 2003. With this intention, we adopted a method of analysis based on the exploitation of the satellite images Landsat MSS (1976), Landsat TM (1986) and Landsat ETM (2001). Through directed pseudo hierarchical classification, coupled to statements of land, we characterized the various types of land occupation by identifying the components of vegetable cover. On the basis of these treatment operations, it appears that the vegetation covered 4,700 hectares in 1976, 6,200 hectares in 1986 and 5,300 hectares into 2001. The annual rate of increase in vegetable cover between 1976 and 1986 was 1.30 %, whereas between 1986 and 2001 it regressed by 0.51%. The results obtained reveal that the dryness of the 1970s contributed to the major transformation of the land in the forest reserve by causing changes in behaviour of the bordering populations. The vegetable recurrence at the end of 1980 is due to the reforestation campaigns initiated by the State to mitigate the effects of the dryness. However, these overall positive points are far from being satisfactory. The directives of the UICN require that only one third of the surface of a protected area from category VI be exploited. The growth of the population and the pressures which it generates can in the middle term cause the degradation of vegetable cover in the forest reserve, in the absence of a real management policy. The methodology which is developed in this work made it possible to set up a cartographic base which can constitute an invaluable management tool of the units of conservation and follow-up of their vegetation. it is simple to use and could be adapted to other protected surfaces of Cameroon. |
Keywords : Cameroons, diachronic study, protected areas, remote sensing, vegetal cover |
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