瓯江河口入海水沙通量的变化规律

根据瓯江流域圩仁水文站1950-2008年的实测流量资料和1956-1998年的实测输沙量资料,采用水文学和数理统计学方法,分析瓯江河口入海水、沙通量的变化规律及其相关性,并对人类活动的影响进行了探讨。研究结果表明:瓯江多年平均入海流量和悬沙通量分别为442m3/s、61.9kg/s;入海水、沙通量具有明显的年际和季节变化特征,沙通量的变幅要大于水通量;瓯江洪枯季流量、输沙量悬殊,洪峰暴涨暴落,是输水、输沙最集中时期;入海水、沙通量之间具有较好的峰、谷对应关系,但1975年特大洪水导致流域侵蚀模量发生较大变化;紧水滩、石塘水库的建成和运行,对瓯江入海径流起到了明显的调节作用,水沙通量年内分配趋于均匀化。

Variations in water and sediment fluxes from Oujiang River to Estuary

According to the runoff data from 1950 to 2008 and the sediment discharge data from 1956 to 1998 at Yuren station on the Oujiang River,the methods of hydrology and mathematical statistics are adopted to analyze the variation rules and the correlation between the water and sediment fluxes in the Oujiang Estuary,then the impact of human activities is discussed.The results show that the mean annual flow discharge and sediment flux were 442 m3/s and 61.9kg/s respectively;there were significant yearly and seasonal variations of the water and sediment fluxes in the Oujiang Estuary,the variation amplitude of sediment flux was larger than flow discharge;there was great disparity between the flow discharge and sediment flux in flood and dry seasons in the Oujiang River,the flood rose and fell sharply,and the flood season was the most concentrated period of transporting water and sediment.There was good correlations between flow discharge and sediment flux.But the huge flood in 1975 led to the considerable change in the rate of erosion.The commissioning of the Jinshuitan and Shitang reservoirs has played a significant role in the regulation of the runoff in the Oujiang Estuary,leading to the leveling of annual distribution of water and sediment fluxes.