西江长洲枢纽库尾段采砂工程对航道通航水流条件的影响

西江航道桂平航运枢纽—长洲水利枢纽之间存在约34 km的水位未衔接段,而大藤峡水利枢纽建设选取的江口料场位于长洲枢纽库区回水末端和上游附近滩段。为研究库尾段采砂工程对上游通航水流条件的影响,须同步考虑上游来水和下游库区回水的变化,建立桂平三江口上游黔江河段16 km和桂平枢纽—长洲枢纽约156 km的长河段二维水流数学模型,分析采砂工程对航道通航水流条件的影响。结果表明,采砂工程实施后上游桂平航运枢纽引航道水位降落0.09 m,布岭沙弯道凸岸侧边滩挖除引起主流一定左偏。整体上,除设计流量外,库尾段采砂工程对航道水流条件影响较小。

Impact on waterway hydraulic condition induced by sand mining project in reservoir end of Changzhou hydro-junction in Xijiang River

There is about 34 km non-connection channel between Guiping navigation junction and Changzhou hydro-junction in Xijiang channel.Jiangkou building stone ground supplying material for the construction of Datengxia hydro-junction is as the reservoir end of Changzhou junction and near the upstream reach.To study the impact on the upstream hydraulic navigation environment induced by the sand mining project,we simultaneously consider the upstream flow and downstream reservoir water level variations,establish the 156 km two-dimension numerical model from three river mouths of Guping to Changzhou junction including the upstream 16 km Qianjiang river and Guiping junction,and analyze the impact on waterway hydraulic condition by sand mining project.The results show that since the sand mining project,the upstream water level of entrance area at approach channel decreases 0.09 m,mainstream in the reach of Bulingsha is altered left because of the beach mined.Generally,except the designed discharge,the impact on the waterway hydraulic environment induced by sand mining in reservoir end is relatively small.