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湘江中下游为典型的分汊河道,现有15个江心洲,江心洲发育与稳定性对河道演变与航道运行具有重要意义。选取衡阳水文站1953-2014年和湘潭水文站1952-2014年实测逐日水沙数据,1987、1995、2002和2015年6个典型江心洲的遥感影像,以及香炉洲和冯家洲分别于1983、1988和2008年的水上水下地形数据,分析了近30年湘江中下游的年际与年内水沙变化,江心洲的面积变化,以及洲头和洲尾的泥沙淤积。湘江下游年径流量变化幅度较小,但1970年代以来输沙量不断减小。湘江来沙集中于汛期,且汛、枯期输沙量有较大差异。1983-1995年江心洲处于发育阶段,洲体的面积与体积持续增加。1995年之后由于上游水库群修建,江心洲出现大幅度的面积萎缩。近20年湘江中下游的江心洲处于不断地冲刷萎缩中,需要采取人工护岸以保护江心洲湿地和维持航道稳定。
The middle and lower reaches of the Xiang River is a typical sub-channel, and the existing development and stability of the river center and river center are of great significance for the evolution of the channel and the operation of the channel. The daily measured data of water and sediment from 1953 to 2014 at Hengyang Hydrological Station and from 1952 to 2014 at Xiangtan Hydrometric Station were selected, and the images of six typical river estuaries from 1987 to 1995, 2002 and 2015 were collected. In 1983, 1988 and 2008 respectively, Year hydrographic and topographic data, the annual and annual variations in water and sediment in the middle and lower reaches of the Xiang River, the area changes in the area and the sediment deposition at Chau Tau and Chau Tau Island were analyzed. Annual runoff changes in the lower reaches of the Xiangjiang River are small, but sediment discharge has been decreasing since the 1970s. Xiangjiang River to sand concentrate in the flood season, and flood, dry season, there is a big difference in sediment load. During 1983-1995, Jiangxin Island was in a developmental stage. The area and volume of the island body continued to increase. After 1995, due to the construction of the upstream reservoirs, the area of Jiangxin Island shrank by a large margin. In the recent 20 years, Jiangxin Island in the middle and lower reaches of the Xiangjiang River has been continuously scouring and shrinking, and artificial revetment needs to be taken to protect the riverbank wetlands and maintain the stability of the waterway.