牡丹江对松花江依兰航电枢纽工程的影响

依兰航电枢纽工程位于松花江"三姓"浅滩下段牡丹江入汇口上游约700 m处,松花江具有典型的平原冲积性河流的特征,牡丹江具有典型的山区河流的水文特征。牡丹江入汇松花江涨水期汇流比为0.235,牡丹江对"三姓"浅滩河段产生顶托壅水影响,落水期汇流比为0.096,"三姓"浅滩河段将产生落水冲刷,两江相异的水流、泥沙、洪峰遭遇特性是影响拟建坝址河段具有涨冲落淤的主要因素。枢纽兴建后改变了该河段水流运动规律,同频率松花江来水条件下,随牡丹江入汇水量的加大,电站尾水位不断升高,枢纽上下游水位差减小,枢纽泄流能力减小,枢纽上游引航道口门区及连接段通航水流条件逐渐改善,下游引航道口门区及连接段通航水流条件逐渐恶化。

Influence of Mudanjiang river on Yilan Navigation Hydro-junction project

The Yilan Navigation Hydro-junction project is located in the lower section of Sanxing Bank of Songhuajiang river,700 m upstream of the confluence of Mudanjiang river.Songhuajiang river has the typical characteristics of alluviation river while Mudanjiang river has the typical characteristics of mountain stream.The discharge ratio is 0.235 when Mudanjiang river is in conjunction with the Songhuajiang river during rising stage,and Mudanjiang river brings great influence to Sanxing Bank.The discharge ratio is 0.096 during falling flood stage when the Sanxing Bank will be eroded.The main causes of erosion in flooding up and deposition in flooding down are the flow,sediment and the flood peak characteristic of the two rivers.Regularity of water flow is changed by the hydro-junction construction.With the increasing of water flow in Songhuajiang river,the power plant tail water level elevates unceasingly,water level difference of the hydro-junction reduces,the discharge capacity decreases.The navigation flow condition of upstream approach channel and the connection section is improved while the condition of the downstream approach channel and the connection section becomes even worse.