Abstract:
Based on a series of engineering field data, the characteristics of dredging maintenance and sedimentation of the Yangtze River estuary 12.5 m deepwater navigation channel (DNC) in 2015 are primarily analyzed, meanwhile the sedimentation trend of the DNC in the future is also discussed. The analysis results show that the DNC operation was under a good condition in 2015 and the total dredging volume was in a controllable and reasonable range. Thus, the DNC has stepped into a steady operation stage, which has achieved a desired social and economic effect. The temporal and spatial distribution of the dredging intensity in the south waterway's north passage of the DNC was still relatively concentrated in 2015. Comparing with 2011-2014, the dredging intensity of the south waterway and Yuanyuansha channel was reduced by 15% in 2015, and the dredging intensity in all the months during the year was also generally decreased, which is mainly related to the improvement of the bed bathymetry condition of the south waterway and the surrounding river regime as well as optimization the dredging management. In the future, under the stable conditions of the river regime and water-sediment dynamic environment in the Yangtze River estuary, the maintenance situation of the DNC will be overall controllable and positive. Because the space-time characteristics of the sedimentation are not variable substantially, the maintenance highlight of the DNC is still in the summer and autumn (June to November) and the location is in the middle-stream of the north passage.