近年来东荆河下游出现洪水位持续偏高的问题,分析其原因在于:20世纪70年代东荆河治理中仅围挽了联合大垸而并未扩挖深水河槽,后经洲滩民垸持续围垦及淤积,造成杨林尾洪水位偏高。为解决该问题,在深入研究丹江口水库大坝加高后汉江防洪形势以及三峡水库蓄水后长江防洪形势变化情况的基础上,确定了新形势下东荆河下游河道治理标准采用东荆河来流4 250 m³/s,相应汉口水位28.28 m,杨林尾控制水位31.0 m为宜;通过河槽疏挖等工程,有效扩大东荆河下游河道泄洪能力。在拟定的3种治理方案中,采用了二维水流数学模型进行比较,计算成果表明,保持现有堤距,扩挖深水槽的方案1具有投资少、施工易、降低洪水位效果明显的优点,因此将方案1确定为治理推荐方案。

In recent years, high flood level lasts in the downstream of Dongjing river during flood period. Analysis shows that the United Dyke was surrounded in 1970s during the regulation project of Dongjing River, but deep groove dredging was inadequate. Moreover, reclamation and siltation of dyke in the bottomland are continued, which lead to high flood water level at Yanglinwei station in Dongjing river. In view of this, we analyze the flood control situation of Hanjiang river after the Danjiangkou dam’s heightening and the situation of Yangtze river after Three Gorges Reservoir’s impoundment. Furthermore, we determine suitable standard of flood control in the downstream of Dongjing river(4 250 m³/s as the import flow from Dongjing river, 28.28 m as the export water level of Hankou station, 31.0 m as the control water level of Yanglinwei station). Through channel dredging project, the discharge capacity in the downstream of Dongjing river is amplified effectively. We design three schemes for flood control . In scheme 1, current spacing of levee is unchanged and deep groove dredging is needed. Calculated results of two-dimensional mathematical model show that scheme 1 has advantages such as low investment, easy construction, and obvious reduction of flood water level, so we choose it as recommended scheme.