Analysis on influencing factors and simulation of sediment release by density current: the case of Xiaolangdi Reservoir

¹ Yellow River Institute of Hydraulic Research, Zhengzhou 450003, China ;
² Key Laboratory of Yellow River Sediment Research, MWR, Zhengzhou 450003, China )

^* Corresponding author: wangyuanjian@hky.yrcc.gov.cn
Author introduction: Wang Ting (1980-), born in Xixian, Henan, Master’s degree, senior engineer, mainly engaged in the research and application pertaining to reservoir sediment and river dynamics.

Abstract

Density current venting by bottom outlets is the main form of sediment release from large reservoirs during sediment retention periods. Taking Xiaolangdi Reservoir as a case study, this study analyzed influencing factors of sediment release by density currents and proposed a semi-empirical formula to simulate the density current release process. The results show that the amount of incoming water and sediment, length of backwater, and sedimentation volume upstream of backwater zones are the main factors influencing sediment discharge. However, the importance of influencing factors varies slightly for different sediment supply areas. The semi-empirical formula provides a good simulation of the actual sediment release process under a relatively stable water level, and thus, it can extend scientific and technical support necessary for reservoir operation.