Jan Nyssen

Nyssen's research showed that high levels of soil loss in the Ethiopian highlands are caused by a combination of erosive rainfall, steep slopes (as a consequence of rapid tectonic uplift during Pliocene and Pleistocene), and impacts of deforestation, overgrazing, an agricultural system where the open-field system dominates, and the aftermath of povery induced by the feudalism. He further studied in the Ethiopian highlands how the high density of soil and water conservation structures led to land resilience.[3] Through the use of rephotography, Prof. Nyssen could link up changes in Ethiopian landscapes with land degradation.[4]

In all this, he strongly values indigenous knowledge, as he observed that Ethiopian farmers plough the same lands and hills since thousands of years with their oxen plough. They know their soils and know when rains will come or what they have to plant if rains are late.[5][6][7]

Through the years, he lived the many changes that occurred; since his first stay in 1994, he observed that the amount of food available to rural households, as well as the overall living standard has strongly improved.[3][8]

When war erupted in Tigray in 2020, he involved strongly for ceasefire and humanitarian aid to the people of Tigray.[9][10]

Nyssen's research in Belgium is also related to the consequences of human activities on geomorphic processes: the reintroduction of beavers, spoil tips of the derelict coal mining industry, and the age-old agriculture in the Pays de Herve (the region where he was born), which led to the occurrence of lynchets or cultivation terraces, by analogy to a common practice in current Ethiopia;[11] The beaver dams have drawn his attention because they contribute to conserving water in the rivers’ headwaters. He studied their effect on discharges of the Chevral creek, that is part of the Ourthe basin. The research confirmed that such dams have a buffering effect on discharges: downstream the peak discharges are much lower that what was observed before beaver reintroduction.[12]

Invitation for local Siwa (beer) by a farmer in Tigray

• (2019) Geo-trekking in Ethiopia's Tropical Mountains – The Dogu’a Tembien district[15]
• (2016) In Tigrinya: ካብ ሓረስቶት ደጉዓ ተምቤን እንታይ ንስምዕ? (What do we hear from the farmers in Dogu'a Tembien)[7]

2020

• The Zeyi Cave Geosite in Northern Ethiopia[16]

Red-black soil catena near Hagere Selam

2019

• Understanding spatial patterns of soils for sustainable agriculture in northern Ethiopia’s tropical mountains[17]

2018

• Persistence and changes in the peripheral Beles basin of Ethiopia[18]

2017

• Boulder-Faced Log Dams as an Alternative for Gabion Check Dams in First-Order Ephemeral Streams with Coarse Bed Load in Ethiopia[19]
• Geographical determinants of inorganic fertiliser sales and of resale prices in north Ethiopia[20]

2016

• Recovery of the aerial photographs of Ethiopia in the 1930s[21]
• Grèzes litées and their genesis: the site of Enscherange in the Rhenish-Ardennes Massif as a case study[22]

2015

• Environmental Conservation for Food Production and Sustainable Livelihood in Tropical Africa[23]
• Land Management in the Northern Ethiopian Highlands: Local and Global Perspectives; Past, Present and Future[3]

2014

• Environmental conditions and human drivers for changes to north Ethiopian mountain landscapes over 145 years[24]
• Twentieth century land resilience in Montenegro and consequent hydrological response[25]
• Lynchets in eastern Belgium — a geomorphic feature resulting from non-mechanised crop farming[11]

2012

• Belgium's burning coal tips – coupling thermographic ASTER imagery with topography to map debris slide susceptibility[26]

2011

• The use of the marasha ard plough for conservation agriculture in Northern Ethiopia[27]
• Effect of beaver dams on the hydrology of small mountain streams: Example from the Chevral in the Ourthe Orientale basin, Ardennes, Belgium[12]

Beaver dam

2010

• Digital Photographic Archives for Environmental and Historical Studies: An Example from Ethiopia[28]
• Slope aspect affects geomorphic dynamics of coal mining spoil heaps in Belgium[29]

Petite Bacnure spoil heap in Herstal, Belgium

• Impact of soil and water conservation measures on catchment hydrological response—a case in north Ethiopia[30]

2009

• Desertification? Northern Ethiopia re-photographed after 140 years[31]
• Transhumance in the Tigray Highlands (Ethiopia) [32]
• How soil conservation affects the catchment sediment budget – a comprehensive study in the north Ethiopian highlands[33]
• Effects of land use and land cover on sheet and rill erosion rates in the Tigray highlands, Ethiopia[34]
• An upland farming system under transformation: Proximate causes of land use change in Bela-Welleh catchment (Wag, Northern Ethiopian Highlands)[35]
• Land degradation and soil and water conservation in tropical highlands[36]

2008

• Spatial and temporal variation of soil organic carbon stocks in a lake retreat area of the Ethiopian Rift Valley[37]

Lake Abijata (right), Ethiopia

• Effects of region-wide soil and water conservation in semi-arid areas: the case of northern Ethiopia[38]
• Environmental change, geomorphic processes and land degradation in tropical highlands[39]
• Dynamics of soil erosion rates and controlling factors in the Northern Ethiopian Highlands – towards a sediment budget[40]
• Soils and land use in the Tigray highlands (Northern Ethiopia)[6]

2007

• Interdisciplinary on-site evaluation of stone bunds to control soil erosion on cropland in Northern Ethiopia[41]

2006

• Processes and rates of rock fragment displacement on cliffs and scree slopes in an amba landscape, Ethiopia[42]
• Comment on “Modelling the effect of soil and water conservation practices in Tigray, Ethiopia” [43]
• Assessment of gully erosion rates through interviews and measurements: a case study from northern Ethiopia[44]

2005

• Rainfall erosivity and variability in the Northern Ethiopian Highlands[45]

2004

• Human impact on the environment in the Ethiopian and Eritrean highlands—a state of the art[46]
• Environmental policy in Ethiopia: a rejoinder to Keeley and Scoones[47]
• The effectiveness of loose rock check dams for gully control in Tigray, northern Ethiopia[48]

2002

• Spatial distribution of rock fragments in cultivated soils in northern Ethiopia as affected by lateral and vertical displacement processes[49]
• Impact of road building on gully erosion risk: a case study from the Northern Ethiopian Highlands[50]
• The environmental significance of the remobilisation of ancient mass movements in the Atbara–Tekeze headwaters, Northern Ethiopia[51]

2001

• Removal of rock fragments and its effect on soil loss and crop yield, Tigray, Ethiopia[52]

2000

• Soil and water conservation in Tigray (Northern Ethiopia): the traditional daget technique and its integration with introduced techniques[53]
• Vertic movements and the developments of stone covers and gullies, Tigray Highlands, Ethiopia[54]
• Tillage erosion on slopes with soil conservation structures in the Ethiopian highlands[55]

Ploughing in Tigray, Ethiopia

Nyssen also contributed to many other publications as co-author – see UGent's academic bibliography[56]