%0 Journal Article
%T Changes and driving forces of the transport characteristics of the pebble bed load in the upper reaches of Yangtze River<br>长江上游卵石推移特性变化及驱动力分析
%A WANG Miao-lin
%A XIA Jun
%A LIU De-chun
%A <br>王渺林
%A 夏军
%A 刘德春
%J 地理研究
%D 2004
%I 
%X Analysis on the changes of the characteristics of runoff and sediment in the upper reaches of the Yangtze River is necessary to the operation and management of the Three Gorges Project. Zhutuo and Cuntan hydro-stations are the major water and sediment reference points for the Yangtze River and the Three Gorges Reservoir. Through analyzing the field data of the annual runoff and the pebble bed load (the PBL) across Zhutuo hydro-station from 1975 to 2001 and Cuntan hydro-station from 1966 to 2001,we concluded that the characteristics of the PBL of the upper reaches of Yangtze River change markedly. First of all, the mean annual transportation amount decreased distinctly: the transportation amount at Zhutuo station from 1992 to 2001 decreased by 46.9% compared with that from 1975 to 1991;and the transportation amount at Cuntan station from 1982 to 2001 decreased by 40.6% compared with that from 1966 to 1981. Secondly, the grading sizes of the PBL became smaller: the median granule diameter decreases 11 mm. Thirdly, the relationship between bed load rate and hydraulic factors changed obviously: the parameters B decreased by 47.5% at Zhutuo hydro-station and 41.1% at Cuntan hydro-station. Finally, the sediment discharge imbalance increased: the calculated abrasion parameter between Zhutuo and Cuntan hydro-stations increased by about 70%. Based on the fore study, the driving causes for the changes of the characteristics of the PBL in the upper reaches of the Yangtze River were analyzed. Firstly, the measures adopted such as soil and water conservation are the direct reason. Next, because the runoff keeps the same during different periods, the runoff has nothing to do with the above changes. Thirdly, it was concluded that the main causes are that more sediments which are being used as timbering are excavated from the watercourse and soil and water conservation prevent sediments from entering the main channel of the Yangtze River. Based on the above analysis,it is pointed out that soil and water conservation should be strengthened.And it is important for us to investigate the current conditions and the patterns of siltation and silt movement in tributaries of the upper reaches of the Yangtze River. Finally, it is suggested that the sands excavation should be confined strictly according to the capacity of sand that can be excavated.
%K pebble bed load
%K driving forces
%K the upper reaches of Yangtze River
%K Three Gorges Project<br>卵石推移质
%K 三峡工程
%K 长江上游
%K 驱动力
%K 泥沙
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=869B153A4C6B5B85&jid=C0C75E88BA2EE501C8298896F64A711F&aid=FF895ABEDD80B4D0&yid=D0E58B75BFD8E51C&vid=EA389574707BDED3&iid=94C357A881DFC066&sid=E934BC2766053B28&eid=1C3BB0F444F5E427&journal_id=1000-0585&journal_name=地理研究&referenced_num=1&reference_num=30