顺直河道低水生态修复工程的数值模拟

目前大多河流存在着平面顺直、断面单一的问题,需要进行生态修复。该文以奥地利某顺直河道段低水生态修复工程为例,利用水流数学模型,研究修复工程的平面布局。研究结果表明:利用错口丁坝,可在低水期形成蜿蜒多样的生态环境,且丁坝间距与错口深度是决定因素;非淹没状态下,丁坝间距为2.28倍河宽、错口深度为0时效果最佳;部分淹没情况下,丁坝间距应保持2.28倍河宽,但错口深度应大于0;相对坝高较小时,错口丁坝壅水较小,对行洪没有影响。

Numerical simulation on low-water ecological restoration project of straight river channel

Due to the problems of most rivers at present such as straight plane and single section,ecological restoration is needed.Based on the example of a low-water ecological restoration project of straight river channel in Austria,the flow mathematical model is established to research the layout for restoration project.Research shows that:by using the alternate groins,the meandering and diversified ecological environment is achievable,and the determining factors to control the form of river are the spacing between spur dikes and the cross-depth of adjacent spur dikes.In the non-submerged condition,the effect of low-water ecological restoration project is the best when the spacing between groins is 2.28 times of the river width and the cross-depth is zero,while in the partly-submerged condition,the spacing should remain 2.28 times of river width and the cross-depth should be adjusted to greater than zero.As the relative dike-height is small,the backwater will be small and the influence of low-water ecological restoration project on draining flood will be insignificant.