Author(s): Xiqing Chen
Linked Author(s):
Keywords: Sand-extraction; Yangtze River; Sediment discharge; Human impacts; Fluvial systems
Abstract: Sand-extraction activities in the middle-lower Yangtze river began in the early 1950s. In addition to an extensive impact on riverbank stability, transportation and engineering facilities, the excessive sand-extraction from the main the Yangtze river since the late 1980s also greatly influenced the sediment discharge from the Yangtze river into the sea. The bed-load material annually extracted from the main Yangtze riverbed is estimated from 40 million t a year in the early 1980s to 80 million t a year in the late 1990s. Studies show that the recorded decrease in sediment supply output from the upper Yangtze river since the late 1970s can only accounts for about 50% of the total decrease in sediment discharge into the sea. The rest 50% is attributed to the reduced sediment supply from tributaries as a result of damming and to the increased sand extraction from the middle-lower Yangtzeriver.
Year: 2004