Satellite images reveal a nexus between war, cropland abandonment and food insecurity in South Sudan

Armed conflicts may have a paramount impact on food security and land use. What we know already is that armed conflicts may cause deaths, refugees outflow, and strong requirements for food aid. However, what we do not know is how such conflicts affect land use and food systems.

Satellite images can play a crucial role in surveying armed conflict areas because they are often inaccessible to surveyors. A novel elaboration with multisource satellite imagery allowed the researchers to reveal recent widespread farmland abandonment in South Sudan. Former Master Student, Victor Olsen from the Department of Geosciences and Natural Resource Management, led the project.

“We managed to map subtle land-cover change associated with farmland abandonment from 2016 to 2018, which is difficult to achieve for smallholder agriculture. But it was not clear if these abandoned areas were a product of recent armed conflicts in South Sudan”, Victor Olsen explains.

Cropland abandonment is strongly linked with armed conflict areas

To solve the puzzle and disentangle conflict-driven cropland abandonment from other factors, such as droughts, the researchers employed causative statistical econometric modeling. Once the authors controlled for climatic conditions, distances to settlements and population density, the cropland abandonment was strongly linked with armed conflict areas.

Alexander Prishchepov has been supervisor for Victor Olsen.

“Many studies have looked at farmland abandonment in different parts of the world. What we did in this research, we explored how much food could be produced if cropland abandonment would not occur among smallholder farmers, in the absence of food aid, and cessation of local markets”, says Alexander.

Victor Olsen explains, “We have shown how we can use satellite imagery, econometric techniques and nutrition accounts to evaluate potential implications of armed conflict-driven land change and its implication to food security”.

Farmland abandonment is a widespread global phenomenon

Farmland abandonment is not a rare global phenomenon. Farmland abandonment is widespread in the European Union, across former Soviet Union countries and is becoming common in the Global South too.

“Our results are useful in a number of ways beyond South Sudan. The developed mapping approach with satellite imagery can be applied in other areas where conflicts occur. In that way, organizations such as the UN World Food Programme can monitor cropland abandonment”, Victor Olsen concludes.

The study is published in Nature Food 

The published research was the result of a Master's thesis by Victor Olsen under the supervision of associate professor Alexander Prishchepov and co-supervision of professor Rasmus Fensholt.

Who supported the project

The European Research Council and the Independent Research Fund Denmark partially supported the work. Victor Olsen, a graduate of the MSc geoinformatics program at IGN UCPH, continues his career as a remote sensing specialist working in Amman, Jordan at Impact REACH, an NGO which surveys the countries in need.