Abstract:To optimize the matching of threshold water depth between the expansion project of Shanxiu Ship Lock in Zuojiang River and threshold water depth of downstream cascade,this study proposes a threshold water depth design method based on continuous cascade water level analysis.By analyzing the multi-year hydrological measurement data of the main line of the Xijiang River,a multi-dimensional analytical model including water level duration and response relationships of threshold water depth is constructed.The research shows that :1) The water depth improvement in the Laokou reservoir area exhibits significant nonlinear characteristics,and the channel can be improved to the 5,000-ton class at a relatively low cost.2) There is a dynamic difference of 0.98 m between the threshold water depth of 7.29 m during the wet season of the Xijiang trunk line and the originally designed threshold water depth of 6.31 m during the wet season of Shanxiu,forming a “navigation bottleneck effect during the wet season”.Therefore,it is recommended to increase the threshold water depth from 5.8 to 6.5 m to match the downstream hub threshold water depth and avoid navigation bottlenecks.The research results can provide a quantifiable technical path for collaborative design of threshold water depth in similar hub groups.
