RANDOM AND SYSTEMATIC LAND-COVER TRANSITIONS IN NORTH-EASTERN WOLLEGA, ETHIOPIA

Alemayehu Adugna,Assefa Abegaz,Asmamaw Legass,Diogenes L Antille

doi:10.19182/bft2017.332.a31329

Abstract

Africa has seen significant changes in land cover at different spatial scales. Changes in Land Use and Land Cover (LULC) include deforestation and subse- quent use of the land for arable cropping, conversion to grassland or urbanization. The work reported in this article was conducted to examine land cover transi- tions in north-eastern Wollega (Ethiopia) between 2005 and 2015. The analysis focused on land cover transitions that occurred systematically or randomly, and identified the main drivers for these changes. Landsat data from 2005 and 2015 were examined to better unders- tand the various dimensions of land cover transitions, namely: swaps, losses, gains, persistency and vulnerability. Results showed that shrubland exhibited the largest gain (22%), with a 63% gain- to-loss ratio, a 47% gain-to-persistence ratio and a positive net change-to-persis- tence ratio of 46%. Cropland showed the largest loss (19%) while grassland was the most stable type of land cover des- pite some fluctuation (»10%) observed during the 10-year period. The land cover transition was dominated by systematic processes, with few random processes of change. Systematic land cover transitions such as agricultural abandonment and vegetation re-growth were attributed to regular or common processes of change. This study suggests that the implementa- tion of practices conducive to sustainable intensification of existing agricultural land, supported by policies that promote increased diversification of Ethiopian agriculture, would mitigate pressure on forests by avoiding their future conver- sion to cropland.

Highlights

Studies using remote sensing technology have shown that land-cover changes are mainly due to deforestation, expansion of cropland areas, including areas used for pastures, urbanization, and increased desertification (Carmona and Nahuelhual, 2012; Belay et al, 2015)
North-eastern Wollega is the source of the Hangar River, which is the main tributary of Nile River
In north-eastern Wollega, land-cover exhibited significant changes during the 10-year period investigated in this study, as shown in table III and figure 2

Summary

Introduction

Studies using remote sensing technology have shown that land-cover changes are mainly due to deforestation, expansion of cropland areas, including areas used for pastures, urbanization, and increased desertification (Carmona and Nahuelhual, 2012; Belay et al, 2015). Such changes in land-cover are more significant in tropical regions compared with areas outside the tropics (Lambin et al, 2003). The area used for cropping in tropical regions exhibited a gain of approximately 6 million hectares per year during the 10-year period indicated above. Underlying factors affecting conversion of forest into cropped land are: population growth, socio-economic changes, active policy intervention or lack of appropriate policy measures aimed at protecting the natural environment, and technology changes (Lambin et al, 2003)

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Discussion

Conclusion