Page - 344 - in Book of Full Papers - Symposium Hydro Engineering

Fig. 7 Longitudinal Section of Sedimentation over the Years for the Manwan Reservoir According to the calculated results: Affected by the sediment retaining of the Xiaowan HPP, the inflow sediment volume in the Manwan HPP decreased a lot, and it is predicted that the sedimentation volume below the normal water level will be 18.6 million m3 after 20 years, of which the sediment-caused storage loss rate is 6.17% compared with 2014; The sedimentation volume within the dead storage capacity is 11.32 million m3, of which the sediment-caused storage capacity loss rate is 9.63% compared with 2014; and the sedimentation volume of effective storage capacity is 7.29 million m3, of which the sediment-caused storage capacity loss rate is 3.97% compared with 2014. The results of the longitudinal section of the annual sedimentation over the years are shown in Fig.7. Compared with the measured results of the longitudinal section in 2014, the scouring and silting in the Manwan reservoir area changed little, where most sedimentation happened in the section in front of the dam, the scouring and silting in the section in the middle of the dam changed little, while a certain scouring happened in the section at the tail of reservoir due to the clear water discharging of the Xiaowan HPP. 344