丁坝群对疏浚整治河道生物栖息地修复效果研究  

Biological Habitat Restoration of Rivers by Spur Dikes After Channel Dredging and Remediation

作　　者：南军虎[1] 陈垚 刘一安 NAN Junhu;CHEN Yao;LIU Yian(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,P.R.China)

机构地区：[1]兰州理工大学能源与动力工程学院,甘肃兰州730050

出　　处：《水生态学杂志》2025年第2期33-43,共11页Journal of Hydroecology

基　　金：国家自然科学基金(52069011)。

摘　　要：为评估丁坝群对河道内水生生物栖息地的修复效果,以江西省金沙溪弯曲河段为研究对象,进行疏浚整治后,选择鲢为目标物种,采用河道内流量增量法(IFIM),耦合二维水动力模型和栖息地模型计算栖息地加权可用面积,探讨了不同缩窄率的3种单丁坝和最优缩窄率组合的单丁坝群对整治河道内鲢栖息地的修复效果,并分析其影响机理。结果表明:河道整治后有效降低了汛期洪水位,水流平均流速增大,鲢栖息地遭到了破坏,可用面积百分率PUA由原来的17.99%锐减到5.03%;各单丁坝鲢栖息地面积随着缩窄率增大呈现不同的变化规律,其栖息地变化过程中均出现明显的拐点;丁坝1和丁坝2最优缩窄率为0.4,丁坝3最优缩窄率为0.35,丁坝3改善效果优于其他丁坝;丁坝3下游大部分区域流速都集中在0.2 m/s左右,与鲢适宜的最佳流速较为接近,其下游流速适宜度Su分布比较均匀,主要集中在0.6~0.9;丁坝群对鲢栖息地修复效果较显著,其PUA增长至18.72%,较整治河道增长272.09%,增加的高等级栖息地占比达到了60%以上,同时河道内栖息地质量较原河道也有所提升;丁坝群对沿程行洪水位和流速影响较小,与原河道相比,丁坝群河道有效缓解了防洪压力。丁坝群下游弗劳德数Fr和剪切速度值减小到0.1以内,水流流速下降到0.5 m/s以下并且形成一定范围的回流区,可在洪水期为鱼类提供有利的庇护场所。Spur dikes are widely used in hydraulic projects designed for habitat restoration and remediation of meandering river sections.In this study,the meandering section of the Jinsha Creek in Jiangxi Province was selected for a case study,and we evaluated the effects of spur dikes on the restoration of aquatic habitat in river channels after dredging.Dredging was carried out for flood control and we analyzed the impact of spur dikes on habitat restoration.Silver carp was selected as the target species,and a two-dimensional hydrodynamic model was coupled with a habitat model to calculate the Percent Usable Area(PUA)of habitat based on the Instream Flow Incremental Method(IFIM).The habitat PUA of silver carp in the river channel was simulated using a group of three spur dikes with 7 different narrowing ratios and then with the spur dikes at the optimal narrowing ratio.Results show that river dredging effectively decreased the water level during flood season and increased the average flow velocity.However,the habitat of silver carp was damaged,and the PUA decreased sharply from 17.99%to 5.03%.We found that the habitat area of silver carp could be improved at each spur dike by increasing the narrowing rate,and there were obvious inflection points.Based on maximizing habitat area,the optimal narrowing rate for spur dike 1 and 2 was 0.4,and the optimal narrowing rate for spur dike 3 was 0.35.The improvement of spur dike 3 was better than that of the other two.The flow velocity downstream of spur dike 3 was generally about 0.2 m/s,close to the optimal flow velocity for silver carp.The suitability(Su)distribution of habitat downstream spur dike 3 was relatively uniform,with most regional values between 0.6 and 0.9.The spur dikes significantly increased the area of silver carp habitat restored,with the PUA increasing by 18.72%,272.09%higher than the river channel after dredging.The proportion of habitat with a high suitability level increased more than 60%,and the habitat quality of the river channel improved compared to the r

关 键 词：河道 栖息地 鲢 丁坝 修复效果 金沙溪 

分 类 号：Q178.1[生物学—水生生物学]