用于航道整治的丁坝在发挥束水攻沙整治作用的同时,因其改变了河流流场、流速、水深、底质分布而造成水生生物栖息地变化。为探讨该种丁坝能否对栖息地有改善作用,基于河道内流量增量法(IFIM),以岷江支流锦江穿过成都华阳镇河段为研究对象,采用River 2D进行了鱼类栖息地的模拟。结果表明:不同丁坝及其组合方案下,鱼类栖息地加权可利用面积(WUA)均大于天然状况,即修建丁坝对改善城市河流水生生物栖息环境有利;同时从模拟成果中进一步分析得到在保证通航条件下WUA最大时所需要的生态流量及最佳丁坝布置方案。
Spur dikes shrink water and scour sand to play as an important waterway regulation structure,a change of aquatic habitats by transforming the flow field,flow velocity,water depth and riverbed substrate were leaded to.Whether spur dike can rehabilitate aquatic habitats in small to middle scale municipal rivers? Hence,a case study was conducted in the river reach of Jin-jiang river,a tributary of Ming-jiang river,passing through Huayang town of Chengdu city.On the basis of Instream Flow Incremental Methodology(IFIM),a 2D hydrodynamic model of River 2D was applied to simulate the variation of fish habitats.Results of this study indicate that weighted usable area(WUA) of fish habitats with the acts of different spur dikes is much bigger than that of the natural river condition,which means aquatic habitats can be benefits from the construction of spur dikes.In addition,in-stream environmental and ecological flow and the optimal layout of spur dikes to guarantee the safety of navigation can also be obtained from the simulated results of maximum WUA.