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Abstract In this article we present results from transect walks and participatory mapping done in Burkina Faso. Since the Sahelian drought of the 1970s, researchers have continued to depict the Sahelian region of West Africa as an environment experiencing severe degradation; a narrative that persists over time. Recently, however, analyses of satellite imagery have identified remarkable patterns of greening across the Sahel. The causes of this greening are hotly debated. Through this project we aim to inform these debates with on-the-ground perceptions of local farmers and pastoralists. The transect walk method is a community-based process that collects information on the land-use/land-cover (LULC) features across villages. Transects help triangulate data by combining high-resolution satellite imagery, firsthand observations, and local experiences of ecological processes. We describe the methodology behind transects and discuss how they contextualize an otherwise removed process of environmental analysis. We also describe the challenges that arise throughout the fieldwork process. 

Sahelian West Africa is a region that has high population densities and that has frequent severe droughts and enormous pressure on natural resources. Because of these challenges, it is the place where the term desertification was originally coined. Recently, however, experts have identified large zones of greening where the amount of vegetation exceeds what one would expect based on rainfall alone. This pattern is well documented, but its mechanisms remain poorly understood. This research employs participatory mapping linked with high-resolution satellite imagery to better understand the human role behind regional vegetation trends. Through a case study of three communities in northern Burkina Faso, this paper presents a pilot methodology for explicitly mapping perceived areas of both land degradation and rehabilitation. Combining participatory mapping exercises with standard image classification techniques allows areas of land degradation and rehabilitation to be precisely located and their extents measured for individual communities and their surrounding terroirs. Results of the spatial analysis show that the relative proportion of greening and browning varies among communities. In the case of Sakou, nearly 60 percent of its terroir is degraded. While in another, Kouka, this is 48 percent. This method also elicits perspectives of Burkinabè agro-pastoralists on the local land-use practices driving these twin environmental processes. Altogether, this case study demonstrates the analytical power of integrating ethnography and high-resolution satellite imagery to provide a bottom-up perspective on social-ecological dynamics. 

The Re-Greening of the West African Sahel has attracted great interdisciplinary interest since it was originally detected in the mid-2000s. Studies have investigated vegetation patterns at regional scales using a time series of coarse resolution remote sensing analyses. Fewer have attempted to explain the processes behind these patterns at local scales. This research investigates bottom-up processes driving Sahelian greening in the northern Central Plateau of Burkina Faso—a region recognized as a greening hot spot. The objective was to understand the relationship between soil and water conservation (SWC) measures and the presence of trees through a comparative case study of three village terroirs, which have been the site of long-term human ecology fieldwork. Research specifically tests the hypothesis that there is a positive relationship between SWC and tree cover. Methods include remote sensing of high-resolution satellite imagery and aerial photos; GIS procedures; and chi-square statistical tests. Results indicate that, across all sites, there is a significant association between SWC and trees (chi-square = 20.144, p ≤ 0.01). Decomposing this by site, however, points out that this is not uniform. Tree cover is strongly associated with SWC investments in only one village—the one with the most tree cover (chi-square = 39.098, p ≤ 0.01). This pilot study concludes that SWC promotes tree cover but this is heavily modified by local contexts.