Environmental changes in the Northern Ethiopian Highlands since the late 19th century

Research outline

The research group on Physical Geography at Ghent University carries out research on medium- and long-term environmental changes in the Northern Ethiopian Highlands, upper Tekezze basin.

The research includes:

• Long-term assessment of land use and cover (LUC) changes, land degradation and resilience
• Understanding gully erosion in the Northern Ethiopian Highlands: networks, rates and controlling factors
• REDD investigations
• Analysis of desertification and resilience in northern Ethiopia since 140 years
• Mountain stream dynamics as impacted by LUC changes and rainfall variability
• Treeline dynamics in Afro-Alpine zones, as affected by climate change and anthropo-zoogenic impacts

Research methodologies

• Quantitative and qualitative geomorphological field techniques
• Recovery of historical terrestrial and aerial photographs
• Repeat photography
• Remote sensing
• Participatory appraisal and other socio-economic research methods
• Field mapping
• Analysis of climatic data and spatio-temporal modelling
• Wood biology
• Modelling of LUC change and treeline dynamics
• Development of land use and management scenarios

Expected scientific outcomes / innovative scientific aspects

The methods developed in this project will open new perspectives for LUC change studies:

• The time span (150 years) gives an exceptional time depth to this geographically explicit LUC change analysis
• The methodology of using terrestrial photographs for LUC mapping has rarely been used, and certainly not in the framework of a region-wide study
• The calibration of ‘historical’ satellite imagery using contemporaneous ground truth is recommended but not done in most other studies
• Gully studies over a time span of 150 years allow for environmental (LUC and climate) explanations that cannot be obtained in short- or medium term studies
• The comprehensive and geographically explicit analysis of land degradation/resilience, LUC change, conservation measures taken, explanatory variables, impacts on geomorphology and hydrology, and future scenarios in a GIS system with high spatial and temporal resolution is innovative
• Mapping treeline dynamics and identifying the driving processes in tropical mountains is almost uninvestigated
• The project will help to expose to what extent geo-ecological paradigms developed from studies outside the tropics are valid for treeline dynamics in tropical mountains
• Protective measures will be suggested that sustain the mountain peoples’ livelihood in the short, medium and long term as well as the afro-alpine ecotone in the North Ethiopian Highlands.

Relevance for development

We investigate the changes in land use and climate, their effects on geomorphology and impacts on livelihood in the north Ethiopian Highlands.

Treelines represent climatic transition zones that respond to climate change and to the anthropo-zoogenic effects.

Vegetation cover is important for the hydrological cycle and subsequently for agriculture in the valleys. Removal of woody vegetation leads to decreased infiltration with as direct results: decreased discharge of downstream springs and increased soil erosion. Both pose a major threat to agricultural productivity in the north Ethiopian Highlands. In Ethiopia eighty percent of the population depends heavily upon labor intensive agriculture for their subsistence. As land resources are pushed to their limits, ruptures in the fragile equilibrium contribute to catastrophes such as the 1984 famine.

However the process acts two-ways, increased woody vegetation will lead to increased spring discharge and decreased soil erosion. This poses the need for sustainable management strategies in the highlands, which enable decreased grazing pressure.

In the valley bottoms, runoff concentration and gully erosion cause river channel erosion, flooding and water pollution by sediment, endangering human life and health. Improved insights into gully and river channel development and their relation to triggering factors can contribute to sustainable development in Northern Ethiopia, where most Ethiopians rely on the land for their livelihood, and live in a subsistence economy where food security is low and regularly threatened by drought.

Our research will provide models for LUC and land management that allow to predict LUC changes, treeline dynamics and subsequent (hydro-)geomorphological processes. Opportunities for ecotourism in the unique mountain scenery of the north Ethiopian highlands will be devised.

As a direct contribution to rural development in the study area, our researchers participate in the following development projects:

• May Zeg-zeg Integrated Watershed Development Project
• Ma'ar Honey in Tigray, Ethiopia
• Trees For Farmers
• ASBL Tesfay

Research team at UGent

• Prof. Dr. Jan Nyssen
• M.Sc. Amaury Frankl
• M.Sc. Tesfaalem Gebreyohannes
• M.Sc. Miró Jacob

Master thesis students involved in the research

• Ellen Meire (UGent Department of Geography, 2008-2009) - Mapping of land use and cover changes in the Ethiopian highlands since 1868 using historical photographs.
• Stephanie de Mûelenaere (UGent Department of Geography, 2008-2009) - Land use and cover changes in the Ethiopian highlands; Landsat data analysis using contemporaneous ground photographs for calibration.
• Miró Jacob (UGent Department of Geography, 2009-2010) - The changes in rainfall regime in the north Ethiopian highlands and impacts on the cropping system.
• Nelles Scholiers (UGent Department of Geography, 2009-2010) - Development of gully networks and volumes since 1965 in the May Mekdan catchment (northern Ethiopian highlands).
• Simon Stock (UGent Department of Geography, 2010-2011) - Land use/land cover and population dynamics in North Ethiopia, as derived from aerial photographs.
• Martin Schumacher (T.U. Dresden, Institute of Geography, 2011) - Recent trends in gully erosion as evidenced by repeat photography around Hagere Selam (Northern Ethiopia). (preliminary title)
• Lys Moulaert (UGent Department of Geography, 2011-2012) - The use of subsurface plastic dams to stabilize and rehabilitate gullies in Vertisol areas (Northern Ethiopia). (preliminary title)

Projects

The different topics of this research are addressed through specific projects:

• Institutional funding of PhD research by Amaury Frankl by Ghent University
• Long-term assessment of land use and cover changes, land degradation and resilience in Tigray (Ethiopia) – BOF UGent Startkrediet
• Repeat photography for analysis of desertification and resilience in northern Ethiopia since 140 years – FWO
• Mountain Stream Dynamics in the Northern Ethiopian Highlands as Impacted by Land Cover/Use Changes and Rainfall Variability – BOF – PhD project Tesfaalem Gebreyohannes
• Treeline dynamics in Afro-Alpine Ethiopia, as affected by climate change and anthropo-zoogenic impacts – BOF - PhD project Miro Jacob

This research is complementary to the following projects:

• "Land Management" and "More Crop per Drop" projects of VLIR-Mekelle University Institutional University Cooperation
• Be-REDD-I (Belgian REDD Investigations)
• The adjacent Lake Tana basin (to the West) is studied in the WASE-TANA project

Associated partners

Promoters of PhD research

• Prof. Dr. Jan Nyssen, Ghent University
• Prof. Dr. Mitiku Haile, Mekelle University
• Prof. Dr. Morgan De Dapper, Ghent University
• Prof. Dr. Jean Poesen, K.U.Leuven
• Dr. Hans Beeckman, Africamuseum

Correspondents

• Prof. Dr. Paolo Billi, University of Ferrara
• Neil Munro, Old Abbey Associates
• Prof. Dr. Jozef Deckers, K.U.Leuven
• Dr. Jan Moeyersons, Africamuseum
• Prof. Dr. Hans Hurni, Universität Bern
• Prof. Dr. Donald Crummey, Illinois
• Prof. Dr. Richard Pankhurst, Addis Ababa
• Dr. Katrien Descheemaeker, CSIRO, Australia
• Girmay Kassa, EMA
• Prof. Dr. Eric Lambin, UCL

Activities

• Regional conference of the International Association of Geomorphologists, Addis Ababa, February 2011
• Participation and lead in the IAG excursion to the Northern Ethiopian Highlands, February-March 2011

In the media

• Desertification reversed in northern Ethiopia - SciDev.Net
• Bodemerosie niet onomkeerbaar – Universiteit Gent Magazine

Scientific output

• Publications in international journals
• Others

Reference material for downloading

• Topographic maps 1:200 000 of Upper Tekezze basin 1978-1982 (52MB, password protected)
• Topographic maps 1:250 000 of Upper Tekezze basin (post 2000) (71MB, password protected)
• Topographic maps 1:50 000 of Upper Tekezze basin (376MB, password protected)