RUI: Gully (lavaka) erosion in Madagascar: multi-decadal analysis and intersections with land use

Understanding how gullies develop is essential for managing landscapes affected by soil erosion, yet their evolution remains poorly documented. This project will improve understanding of how landscapes respond to natural processes and human land use by studying Madagascar's distinctive lavaka gullies. It will provide an evidence-based assessment of widely held assumptions about landscape degradation while highlighting how local farming communities adapt to these environments. Because similar gullies occur in many parts of the world, the results will provide a framework for analysing and understanding erosion and landscape change more broadly. By engaging undergraduate researchers and Malagasy collaborators throughout the project and developing educational materials and field activities to teach schoolchildren about soil erosion, the project will strengthen geoscience education and promote broader understanding of land management. The project will re-image and re-measure a unique archive of 244 lavaka previously documented twenty years ago, integrating repeat photography, field measurements, three-dimensional photogrammetry, and radiocarbon dating to quantify gully evolution and reconstruct erosion history. It will document changes in gully size, activity, and agricultural use, test relationships between gully development and anthropogenic landscape change, and determine the age and evolution of the largest gullies through stratigraphic and geochronologic analysis. The resulting dataset will establish a robust framework for understanding long-term gully evolution in Madagascar and analogous gully systems worldwide. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.