Model tests for waterway regulation of Tuwan shoal of Jialing River

Tuwan shoal is located in the fluctuating backwater area of the Three Gorges Reservoir.The channel appears to be curved,shallow and rapid when water level is low.The period of sediment movement would be delayed and shortened during the Three Gorges Reservoir impoundments.Sediment accumulation causes translocation of river pattern,which will obstruct navigation during the water level falling stage.Through experimental analysis of flow conditions and riverbed evolution after the shoal stores water,the evolution rule of the rapids and the causes of the navigation obstruction are found.Moreover,the model test study puts forward the regulation measures: along the torrent flow dynamic axis of the Tuwan shoal,a new navigation channel is opened up by using capital dredging measures to solve the navigation obstruction problem caused by the translocation of river pattern.Experimental research results show that after the regulation works are finished,the right shoal of the Tuwan keeps developing,and the new navigation channel has no accumulative sediment deposition.The navigation channel can meet the regulation requirements and be up to the standard dimension of channel class III.