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Universidade Nova (2011)

Land cover dynamics in Savanna Ecosystem of Borena Ethiopia

Beza, Teshome Abate

Titre : Land cover dynamics in Savanna Ecosystem of Borena Ethiopia.

Auteur : Beza, Teshome Abate

Université de soutenance : Universidade Nova

Grade : Master of Science 2011

Résumé
A study was conducted to examine land use and land cover change dynamic and spatial pattern of landscape structure in arid and semi-arid rangeland of Borena, Ethiopia. Three multi-temporal satellite (TM, and ETM+) images of 1987, 1995 and 2003 were used. Supervised maximum likelihood classification at pixel level and post-classification comparison of images was used. The landscape structures were calculated using Fragstats3.3 soft ware. Over the past 16 years, the arid and semi-arid savanna ecosystem of the Borena experienced land use and land cover change. Result indicated that about 39.04% of the total landscape remains unchanged and about 51.8% of total landscape was covered by bush land and woodland together. During 1987 to 2003 bush land, cultivation and urbanization had increased by 17%, 72.49% and 79.75% whereas woodland (11.68%) grassland (7.73%) and shrubby grassland (86.14%) were reduced. Spatial metrics analysis showed that during 1987 to 2003 the Borena landscape went through important change. The resulting landscape has become more fragmented and indicated by the proliferation of large number of patch, increasing of patch density, decreasing of largest patch index ; more diversity and heterogeneity with tend to more unevenly distribution of patch and irregular shape patch within landscape. In overall, the present tendency of bush and woodland cover in the landscape may lead to more bush encroachment and grassland shrinkage if no proper measurement has taken. The continued land use cover change, coupled with a drier and climatic variability and considering human induced factor in the area, it is likely that the landscape change tendency will be continued which greatly affects people’s livelihood and put the pastoral production system under increasing threat.

Mots clés : Land use change ; Landscape structure ; Spatial metrics ; Vegetation cover ; Borena pastoralist ; Ethiopia

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Page publiée le 20 juin 2013, mise à jour le 22 août 2018