Changes of Channel Conditions of Zhangjiazhou Waterway for the 2020 Hydrological Year and Maintenance Countermeasures

Abstract The 2020 hydrological year is featured with the high-water level and high flow period far exceeding previous years. sediment deposition in flood season shallowed impeded channel. Based on analysis of 2020, impact catastrophic channel conditions upper shallow area Nangang, reasons for deterioration are analyzed. Meanwhile, maintenance countermeasures, necessity emergency dredging, specific dredging scheme proposed accordingly. results show that: Nangang followed law silting scouring dry during a year. depend comparison between after season. In lasted long time, so water-falling was relatively insufficient season, not sufficiently scoured, which resulted navigation obstruction area. Therefore, necessary to be implemented channel, site designed from #10 navigational mark #9 mark, bottom elevation 4.2 m below design water level, width 200 m. Considering hysteresis riverbed deformation, it suggested pay continuous attention variation future, formulate corresponding countermeasures.