三峡工程蓄水前后城陵矶至武汉河段水沙输移特性分析

根据三峡工程蓄水前后水沙资料，对洞庭湖出流至长江干流武汉河段水沙输移特性进行了分析．结果表明，洞庭湖出流城陵矶站含沙量和输沙量自建站以来呈单向减小趋势，螺山站含沙量和输沙量在荆江裁弯至葛洲坝工程蓄水以前加大，葛洲坝工程蓄水后螺山、汉口两站输沙量减小22％左右．三峡工程蓄水后2003年6月至2005年12月期间，本河段螺山、汉口站流量小于25000m^3／s时，同流量下含沙量略有减小，流量较大时变化不大；悬移质泥沙颗粒变粗，输出比加大，且粗颗粒泥沙输出比增加相对明显．

A Study on Characteristics of Water-sediment Transport in Chenglingji-Wuhan Reach of the Middle Changjiang River before and after the Three Gorges Reservoir Impoundment

According to the hydrologic and sediment observation data before and after the impoundment of Three Georges Project, the analysis of the water-sediment transport of Chenglingji-Wuhan reach show that the sediment concentration and sediment run off at Chenglingji Station has appeared a tendency of one-way decrease, and that of Luoshan Station increased during the cut-off of lower Jingjiang River and the impoundment of Gezhou Dam Project. After the impoundment of the Gezhou Dam Project, the sediment run off of Luoshan and Hankou Station decreased about 22%. In the period from Jun. 2003 to Dec. 2005, the sediment concentration reduced lightly when the flow discharge of Luoshan and Hankou is or less than 25000m^3/s and nearly not changed when the flow discharge is more. The size of suspended load is bigger , the ratio of sediment output to input increased , the ratio of coarse sediment output to input increased distinct relatively.