Study on the Runoff Trends in Huaihe River Basin during 1956 ∼ 2000

Based on the measured runoff data during 1956 similar to 2000 of 11 key stations on 9 rivers in Huaihe River Basin, the changing trends of annual runoff as well as flood season runoff and non - flood season runoff are analyzed with Mann - Kendall statistics testing method. The result indicates that the annual runoff is generally shown as a decreasing trend in Huaihe River Basin. There are no significant changing trends of annual runoff in Bantai station and Wangjiaba station in the upper reaches; Bengbu station and Zhongdu station on the main stream as well as Jiangjiaji station in tributary show the decreasing trends but insignificant; other stations show significantly decreasing trends ever since 1979. The changing trend of flood season runoff is similar to annual runoff; whereas the decreasing amplitude of changing trend of non - flood season runoff is larger than annual runoff. The decreasing trend of the station in lower reaches is more significant than that in the upper reaches. The decreasing trend of runoff would have impact on the sustainable utilization of water resources in Huaihe River Basin.