Driving Mechanisms of Land Use and Land Cover Change in the Sahel: Impacts and Responses

Project period: 2017-2021
Project sources: National Natural Science Foundation of China

The environmental change in semi-arid areas in general, and in the Sahel region in particular, has been a matter of global concern for decades. Particularly, attention is focused on the question of whether a southward encroaching of desert-like conditions was taking place, driven by the trend in climate forcing, or on the contrary, whether changes in land use and land cover (LULC) were driven by growing population and intensification of agricultural practices. The assessment of LULC change and the quantification of its impacts and responses in the Sahel have been both a scientific and political challenge.
The project aimsto study the response of LULC to climate variations and anthropic forces, and the impact of LULC change on water balance in the Sahel. The project builds upon the combination of extended satellite data records and the much-improved capabilities of current observation systems. Data acquired by Chinese satellites will be used wherever possible. The LULC will be mapped at a spatial resolution of 30m based on parallel/distributed computing techniques and machine-learning algorithms over an extended period of 1990–2020 at five-year intervals. Anthropic forcing in the Sahel in the past 30 years will be assessed through analyzing human activities related to land use change. The characterization of anthropic forcing requires detailed ancillary data and will be done for selected North–South transects only. The response of the LULC and of biophysical attributes of land cover to the climate variations and anthropic forcing in the past 30 years in the Sahel will be assessed, and the impact of the evolution of LULC on water balance will be then characterized and investigated.
Based on the above identified driving forces and impacts, it will also explore appropriate and effective ecosystem management paradigms, offer evidence and policy support for ecosystem conservation in the Sahel and for the Pan-Africa Great Green Wall Initiative, and improve conservation and ecosystem management capabilities.
This project will be implemented through a cooperative effort of scientists from China and Africa with the support of UNEP. Led by the Institute of Remote Sensing and Digital Earth, the Chinese Academy of Sciences, and UNEP-IEMP, the project will work with the Regional Centre for Mapping of Resources for Development (RCMRD), Observatory of the Sahara and Sahel, Agrometeorology, Hydrology, Meteorology regional center (AGRHYMET), etc.