Land cover changes as impacted by spatio-temporal rainfall variability along the Ethiopian Rift Valley escarpment
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- 作者：Sofie Annys ; Biadgilgn Demissie ; Amanuel Zenebe Abraha…
- 关键词：Land cover classification ; Landsat ; Rainfall estimates ; Remote sensing ; Woody vegetation ; Northern Ethiopia
- 刊名：Regional Environmental Change
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：17
- 期：2
- 页码：451-463
- 全文大小：
- 刊物类别：Earth and Environmental Science
- 刊物主题：Climate Change; Climate Change/Climate Change Impacts; Oceanography; Geography, general; Regional/Spatial Science; Nature Conservation;
- 出版者：Springer Berlin Heidelberg
- ISSN：1436-378X
- 卷排序：17
文摘
Magnitudes of land cover changes nowadays can be assessed properly, but their driving forces are subject to many discussions. Next to the accepted role of human influence, the impact of natural climate variability is often neglected. In this paper, the impact of rainfall variability on land cover changes (LCC) is investigated for the western escarpment of the Raya Graben along the northern Ethiopian Rift Valley. First, LCC between 2000 and 2014 were analysed at specific time steps using Landsat imagery. Based on the obtained LCC maps, the link was set with rainfall variability, obtained by means of the satellite-derived rainfall estimates (RFEs) from NOAA-CPC. After a correction by the incorporation of local meteorological station data, these estimates prove to be good estimators for the actual amount of precipitation (ρRFE1.0 = 0.85, p = 0.00, n = 126; ρRFE2.0 = 0.76, p = 0.00, n = 934). By performing several linear regression analyses, a significant positive relationship between the precipitation parameter DIFF 5Y (i.e. the at-RFE pixel scale difference in five-year average annual precipitation for the two periods preceding the land cover maps) and the changes in the woody vegetation cover was found (standardised regression coefficient β = 0.23, p = 0.02, n = 108). Despite the dominance of direct human impact, further greening of the study area can be expected for the future concomitantly to a wetter climate, if all other factors remain constant.