艳洲枢纽下游近坝段航道整治研究

Study on waterway regulation in near-dam reach downstream the Yanzhou hydro-junction

枢纽下游的枯水位下降问题是航道出浅的重要原因,也是影响船闸通航、制约航道等级提升的重要因素。在分析澧水艳洲枢纽下游近坝段碍航特性、枯水位变化及原因的基础上,采用二维平面水流数学模型研究了澧水航道升级整治过程艳洲枢纽下游近坝段的浅滩整治问题,包括工程整治方案、整治效果及对枯水位的影响。结果表明:艳洲枢纽下游近坝段河床比降大、枯水位落差集中,具有明显的"陡坎"及"陡比降"现象,若仅以疏浚方式进行航道整治,则将引起艳洲枢纽船闸下游的枯水位明显下降,在艳洲枢纽船闸改扩建中下游设计最低通航水位的确定应充分考虑枢纽下游高等级航道整治工程的影响。

The descent of low water level downstream hydro-junction is an important cause for shallow chan-nel, also an important unfavorable factor for ship lock safe navigation and waterway grade improvement. In this pa-per, the navigation-obstructing characteristics and the causes of low water level change in near-dam reach down-stream Yanzhou hydro-junction in Lishui River were analyzed, then the 2-D flow mathematical model was employedto study the shoal regulation problem in waterway grade improvement, including regulation scheme, effect and influ-ence on low water level. The results indicate that： the river bed gradient in near-dam downstream the Yanzhou hydro-junction is high, and the height of low water is concentrate, with obvious＂scarp＂and＂steep gradient＂phenome-non, and thus the dredging method is an appropriate way to achieve the design depth; when the channel regulationplan in Lishui River is implemented, the lowest navigation water level downstream the Yanzhou existing ship lockmay largely descend, and need reduce its lowest navigation water level.