Land use dynamics and demographic change in southern Burkina Faso

Sammanfattning: With the increasing world’s population, coupled with the technology improvement, man has emerged as the major, most powerful and universal instrument of environmental change in the biosphere today. To understand and predict the impacts of this change in the future, long-term reconstruction of land use and cover changes at global, regional and local scales is a prerequisite. The objective of this study was to assess the impacts of population growth on land cover change and generate knowledge that supports sound and informed decision-making on sustainable resource management. The study was done in Sissili Province, southern Burkina Faso, West Africa, where favorable rainfall and availability of arable land have contributed to attract farmers from the arid, crowded and unproductive zones of the north and centre of the country. The methodologies used were a combination of land cover change detection through time-series image processing (1976 – 2006), assessment of population dynamics, measurement of selected landscape metrics, and detection of systematic and random cover transition underlying the processes of change. The results showed that since the 1970s, cultivated areas have been expanded to the detriment of forest, and the expansion of cropland and the decline in forest cover are associated with population growth. Measurements of landscape metrics (Normalized Landscape Shape Index, Interspersion and Juxtaposition Index, and Area Weighted Fractal Dimension Index) highlighted the prevalence of environmental-unfriendly shifting cultivation practices and continual forest degradation. Land cover transition analyses showed that most changes were driven by systematic processes, such as changes induced by population growth, which underpin random changes that bring rapid and abrupt change temporarily with a potential to recover or not, depending on resilience and feedback mechanisms of the land cover type. To sustain the resource base, appropriate land management policy should be issued. The strategies that aim at minimizing the side-effects of the growing population on the environment in southern Burkina Faso might include population control, application of the national land tenure system, promotion of agricultural intensification related policies, promotion of fast-growing trees in plantations, and diversification of sources of income generation for rural people.