Chapter 3 - Sediment Dynamics at Global and Drainage-Basin Scales

Summary

This chapter focuses on the factors that influence the erosion, transport, and storage of sediment at global and drainage-basin scales. It examines global variations in sediment fluxes by rivers and the factors that influence these variations, including human effects. It introduces the concepts of the sediment delivery ratio and the sediment budget, and demonstrates how estimation of sediment budgets provides insight into spatial patterns of sediment production, storage, and transport within drainage basins. It also shows how sediment budgets have been used to understand human impacts on sediment dynamics at drainage-basin scales and discusses the value of sediment budgets for watershed management. It reviews approaches that have been used to try to examine sediment movement at watershed scales, such as various fine-sediment tracing technologies, and addresses challenges to estimating sediment dynamics at large scales, including the sediment-budget closure problem.