Assessments on Plunging Location and Venting Operation of Turbidity Current

Since the completion of a reservoir, sedimentation process decreases reservoir storage and woody debris affects the operation of hydraulic works in many montane areas, especially for the power plant turbines. The flow mechanism of woody debris is usually following with the turbidity current and collection near the plunge point location in a reservoir. Therefore, the collection location of woody debris is valuably to estimate the plunge point location of the turbidity current. If the turbidity current is generated and travelled through a reservoir, successful operation of a sluicing outlet to vent turbidity current depends on the prediction of turbidity current movement. In-situ measured vertical data of sediment concentration and velocity distribution during a flood event can help to estimate turbidity current movement in a reservoir. However, field measurement of the turbidity current in a reservoir is relatively difficult because of large water depth, an unsteady fluid mechanism, and harsh environments during a flood. Therefore, the water elevation, cross-section data and inflow discharge are selected to estimate turbidity current movement. The collection location of woody debris in the field is also adapted to verify plunge point location in this study. A display interface is also developed in this study to display the plunge location, movement velocity, body thickness and sediment concentration of turbidity current. For turbidity current venting, the plunge point location and turbidity current movement estimation can provide useful information to assist the operations of bottom outlets. The study results can also be applied to the related disaster prevention issues on water resources sustainable, reservoir sedimentation and water quality issues.

Keywords: woody debris, turbidity current, plunge point location, display interface