Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Climate change and ecohydrological dynamics of Upper Nile basin in Ethiopia : the Tekeze River basin case

Auteur : Baye, Samuale Tesfaye

Université de soutenance : Wageningen University

Grade : Doctor 2020

Résumé partiel
Climate change is affecting society and environment across every continent, particularly water limited regions which are sensitive to disturbances due to limited available water resources. Recent accelerated climate variation has aggravated existing environmental problems in the Nile River Basin, particularly regions in the East Africa that are caused by the combination of land degradation processes and recurrent droughts. East Africa including Ethiopia is one of the most vulnerable region to climate variability and change given the region has experienced some of the worst drought events in the past several decades. In Ethiopia, particularly in the northern Ethiopia, the relations between climate, land degradation, hydrological processes and ecosystem production are quite complex. The variability in climate, topography, lithology, vegetation cover and land management may imply a considerable variation in the hydrological and ecological processes at both basin and regional scales. These variabilities together with frequent occurrence of droughts pose major challenges for water and ecosystems management in the area.

Although dealing with challenges that climate variability and change poses and crafting appropriate adaptation and mitigation mechanisms are crucial in the region, hydro-climatic variability and change is not yet well understood and the resulting climate, hydrology and ecology interactions and feedbacks are highly uncertain in this region. Thus, a better understanding of hydrological and ecological responses to climate variability and change is essential for water and land managers and decision makers to develop appropriate mitigation and adaptation strategies to sustain the broad variety of ecosystem services. This study aims at better understanding dynamics of ecohydrological processes under past to future climate variabilities and change and their effects on the resilience of ecosystems at different spatiotemporal scales in Tekeze River basin of the upstream parts of the Nile basin, northern Ethiopia. An integrated approach with combination of multiple statistical analysis of hydro-climatic data, remote sensing data, field observation, laboratory analysis and hydrological and ecological modelling have been developed and conducted at various spatial and temporal scales in the basin.

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