Nineteenth-century sediment yields from the Southern Blue Ridge Mountains

Abstract

Land-use change can dramatically alter soil erosion and sediment yield in watersheds. This paper describes late 19th-century sediment yield reconstructed for two small, low-order catchments in the Southern Blue Ridge Mountains of North Carolina at a time when each catchment had been partially cleared for agricultural activities and/or timber harvest. Historical sediment yield values are compared and contrasted to modern values obtained for the adjoining and better-known Piedmont province, and to modern values recorded in both provinces. The results indicate that had Blue Ridge land clearance equaled that of the Piedmont, historical sediment yield values would have been substantially higher than those recorded for the Piedmont. Secondly, despite differences in geology, physiography, and land-use intensity, sediment yield values trend similarly in both Blue Ridge and Piedmont regions where 19th-century agriculture and logging were replaced by 20th-century reforestation. Although early slope stabilization resulted in lower sediment yield, there was a time lag between slope stabilization and a return to pre-disturbance sediment yield in small catchments in both physiographic provinces. The remobilization of anthropogenic sediment stored in small catchments has been as influential in the Blue Ridge as in the Piedmont in terms of 20th-century fluvial sediment dynamics.