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Abstract: Extensive research into the changing sediment load throughout the Yangtze River (Changjiang) basin has been completed over recent years, and it provides an ongoing example of how to evaluate the consequences of natural and anthropogenic impacts on sediment processing in a very large fluvial system. This paper reviews these recent studies and critically assesses their findings regarding changes in sediment yield, load (both spatial and temporal variations), grain size, and rating curves, as well as the morphodynamic response of the channel and delta. We also discuss the factors driving these changes, including climate change, soil and water conservation measures, dam construction, and sand extraction, and consider the likely future trends in sediment load. Based on a consideration of the major outcomes of, and discrepancies between, recent studies, we conclude that sediment supply, transport, mobilization, and deposition in this large river system are complicated by the heterogeneous nature of its morphology and climate, as well as the progressive intensification of human activities. Therefore, the identification and interpretation of hydrological and sedimentological changes in the Yangtze basin can be difficult, and an in-depth study of the causal mechanisms of variations in sediment load and the impacts on the Yangtze River system is urgently required. [Copyright &y& Elsevier]

Abstract: This paper examines the spatial variation of sediment yield in the Yangtze basin in China, a large basin with complex geology, climate, land-use history, and extensive sediment monitoring. 287 stations with drainage area less than 10,000km2 were used to study the scale effects of sediment yield. In order to develop scale relations for regional sediment yield, the whole study area was divided into eight sub-basins. Relation between specific sediment yield and drainage basin area was built for each sub-basin. Regional scaling relation was analyzed based on landforms, geology, lithology and land-use of each sub-basin. Three regional trends were identified in relation to the drainage area: (1) a declining trend, due to soil erosion on heavily cultivated steep land and the storage of sediment in floodplains; (2) a flat trend, due to mass movement on the upper reach and heavy agricultural disturbance on the middle and lower reaches; and (3) an increasing trend, due to downstream recruitment of sediment from land downstream where slope farming and deforestation occurred. Using these developed relations, areally adjusted sediment yield maps were created over the entire Yangtze basin. [Copyright &y& Elsevier]