A system dynamics approach to land use changes in agro-pastoral systems on the desert margins of Sahel

Land use changes in the Sahel are influenced by multiple socio-economic and bio-physical driving forces that result in a complex and dynamic land use system. This paper outlines to what extent a system dynamics approach may serve to nuance the understanding of Sahelian agro-pastoral systems. Firstly, by using the Sahelian part of Northern Burkina Faso as a case study, we build a simple model that includes the most influential drivers of land use changes and their impacts in the land use system. As the developed model is proven to successfully simulate the main directions of change in the land use system, we employ the model to explore the impacts of important and realistic alterations in those factors driving land use change. This is done by generating 'what if' scenarios. The results show that 'what if scenarios based on sudden events, such as a drop in millet prices or a total stop in circular migration, have a more pronounced impact on the system than other more long term alterations such as increased rainfall variability. As the developed model allows testing simple hypotheses about the dynamics of land use systems, the approach serves as a useful complementary tool to more established approaches in advancing land change science. (C) 2011 Elsevier Ltd. All rights reserved.