Mangrovedynamiek door teledetectie van temporeel sequentiële luchtfoto's: een studie in Gazi Bay, Kenya = Mangrove dynamics by teledetection from temporal sequential aerial photographs: a study of Gazi Bay
Van Pottelbergh, I. (1999). Mangrovedynamiek door teledetectie van temporeel sequentiële luchtfoto's: een studie in Gazi Bay, Kenya = Mangrove dynamics by teledetection from temporal sequential aerial photographs: a study of Gazi Bay. MSc Thesis. VUB: Brussel. 122 pp. |
Available in | Author | | Document type: Dissertation
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Keywords | Mangroves Remote sensing ISW, Kenya, Gazi Bay [Marine Regions] Marine/Coastal; Brackish water |
Abstract | This study is situated in the research for the dynamics o f a mangrove area in Gazi Bay (Kenya) during the period between 1972 and 1992 and the present condition. Based on the aerial photographs of 1972 and 1992, which function as the only source of information available about the condition of the mangrove forest in the past, a visual analysis can take place which results in the construction of an interpretation key. This interpretation key is a means of help for the collection of data on the spatial distribution of the species. All the data collected can then be converted into vegetation maps in a G1S environment, which serve for the further analysis. After the visual qualitative comparison of the two obtained vegetation maps based on the aerial photographs of 1972 and 1992, an evolution can be observed in our area of study along the coast from mainly a mixed mangrove zone to a certain zonation in the mangroves. Further local research provides data about the changes in the mangrove forest and the causes that may have led to the present mangrove condition. It is also possible to carefully project a prediction of the future. The production of propagules on a very large scale assures the future of this mangrove forest if establishment is possible and if no major natural destruction’s occur. The results obtained through analysis of the data by means of ordination, display an almost parallel distribution between the adult trees and the young trees of all the different mangrove species. This is totally contrary to the distribution of the juveniles, which points out the good distribution capacity of propagules and the impossibility to establish, but near the parent tree. The measured environmental variables do not account for the distribution of the mangrove species. Thus, establishment of mangroves depends on a combination of factors which have not all been studied here. A combination of remote sensing, GIS, field work and data analysis, can visualize the dynamics in time o f a certain mangrove area. |
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