THE IMPACTS OF HUMAN CONFLICT ON SOIL EROSION, THE ENVIRONMENT AND LAND USE CHANGE ASSOCIATED WITH THE EARLY MODERN PERIOD

Human-induced soil erosion occurs on a global scale, reshaping landforms, sediment budgets, and reducing soil quality. Our knowledge of soil erosion from human activity is vast. Yet, significant gaps remain, such as the effects of human conflict on soil erosion, which underscores the environmental, agronomic, and climate consequences of war. Prior work has focused on individual conflicts. However, a baseline understanding for how conflict affects soil erosion is lacking, this study will develop such a baseline by establishing the soil erosion effects of conflict during the early modern period in Europe. Field data and samples derive from sedimentary archives of eroded soil in high order watersheds. Floodplain strata in catchments overlapping with conflict regions in the Upper Rhine Graben were chosen for analysis. Excavation of strata reveals pedogenically modified alluvial deposits interspersed with colluvial material. A landscape equilibrium index is used to assess landscape age versus mean residence time of soils. Results of this analysis indicate that modern soils are closer to equilibrium relative to buried soils, indicating the buried soils were more susceptible to erosion. A new model for Soil Erosion, Discharge, and Slope (SEDS) is developed to reconstruct these parameters. The SEDS model indicates that slope has decreased from the past to the modern, with the greatest change in the highest order streams. These streams have reconstructed stream power in excess of the stream erosion threshold, indicating bank erosion had a significant role. Streams with lower discharge display more erosion sensitivity to rainfall intensity, indicating spatial variability in the processes controlling soil erosion. Ongoing work on stratigraphic age and colluvium provenance will establish the temporal connection of these results to human conflict, and the connection between bank erosion and slope movements of soil material, respectively.