Study on the Change of Bankfull Discharge in Three Outfalls of Jingjiang River

As an important area in Yangtze River flood detention, Dongting Lake area plays a pivotal role in Yangtze River flood control. The continuous sedimentation atrophy has happened in the river channel of three outfalls in Jingjiang River in recent years, which leads to a decrease on the water amount into the lake and a severe atrophy on the lake. The trend analysis of the bankfull discharge at three outfalls in Jingjiang River during 1965~2010 through Mann-kendall rank correlation analysis is carried out, the variation period of the bankfull discharge in three outfalls of Jingjiang River through the wavelet analysis method is calculated. The results show that: There is an obvious decreasing trend about the bankfull discharge in the three outfalls of Jingjiang River during 1965~2010, the bankfull discharges are respectively provided with the first primary change period of 6 years, 25 years, 9 years, 21 years, 25 years in Xinjiangkou, Shadaoguan, Mituosi, Guanjiapu, Kangjiagang.