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dc.rights.licenseCC-BY-NC-ND
dc.contributor.advisorHenkens, R.
dc.contributor.advisorLammeren, R. van
dc.contributor.authorHoeven, T. van der
dc.date.accessioned2021-05-25T18:00:14Z
dc.date.available2021-05-25T18:00:14Z
dc.date.issued2020
dc.identifier.urihttps://studenttheses.uu.nl/handle/20.500.12932/39459
dc.description.abstractThe Boé is a unique nature reserve in the southeastern border region of Guinea-Bissau that is home to a relatively large chimpanzee population. However, nowadays there are a number of phenomena threatening this nature. One of these phenomena is the emergence of cashew plantations. One of the focusses of this research is on this problem. However, it is difficult to distinguish cashew plantations from gallery and dry forests with remote sensing data with medium resolution. Furthermore, it is quite difficult to collect representative samples in the study area because there are few resources available and it is a very diverse and fragmented area in terms of landscape. The research aim of this study has been to identify land use trends with an emphasis on deforestation in the last 20 years and specifically in the last 4 years in the Boé area. To achieve this, samples were collected during a fieldwork campaign of four months. During this fieldwork campaign, different land cover types were sampled throughout the Boé area with an emphasis on cashew plantations and forests. After all the samples were collected, several machine learning algorithms (MLA’s) were tested to see which one provided the most representative land cover classification of the Boé area. The accuracy of the classifications turned out to be reasonably well, with an average overall accuracy of about 70% and user's accuracies of around 80 and 90% were achieved, especially for the cashew plantations and gallery forests. A change detection analysis has revealed that 70 ha of gallery forest has been lost in the Boé area between 2016 and 2020 and that the total area of cashew plantations has increased in this same period. In addition, an explorative assessment of two different forest monitoring methods was conducted to see whether deforestation could also be mapped for a longer period of time (between 2001 and 2020). The first assessment of the proven Hansen dataset resulted in some striking results. This is because the dataset showed that until 2013 not much deforestation had occurred but after 2013 but from that year on, the extent of forest loss increased rapidly in the Boé area. However, it has also shown that the extent of forest loss in the Boé area was less than in some other areas in Guinea-Bissau and in the neighboring country of Guinea. The second assessment, the BFAST monitoring method has observed a lot of forest disturbance events in the Boé area. Because all of the conducted analysis have measured forest loss, it can be concluded that the habitat of the Chimpanzees in the Boé area is decreasing, although not as much as in other surrounding areas.
dc.description.sponsorshipUtrecht University
dc.format.extent16561986
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.titleAssessment of Land cover and forest loss in prime Chimpanzee habitat in the Boé of Guinea-Bissau, West-Africa
dc.type.contentMaster Thesis
dc.rights.accessrightsOpen Access
dc.subject.keywordsLand cover change; Forest loss, Chimpanzee; Guinea-Bissau; Remote Sensing; Sentinel-2; Landsat; Machine Learning Algorithms; Random Forest; Support Vector Machine
dc.subject.courseuuGeographical Information Management and Applications (GIMA)


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