摘要
为了探究北江丁坝群对鱼类栖息地的影响,以北江干流英德段为研究区域,采用非结构化网格有限体积法(FVCOM),计算了不同流量条件下鲫鱼栖息地加权可利用面积(WUA),得到鱼类最适生态流量值。基于鱼类最适生态流量值开展了丁坝群对流速、水深、鱼类栖息地适宜性指数和水力生境多样性变化的影响。结果表明:当上游为最适生态流量350 m 3/s时,丁坝群使得WUA由7.142 km 2降低至5.692 km 2;丁坝群会显著改变河道中心和近岸的流速,导致流速适宜度指数下降,进而降低整个研究区域的栖息地适宜度指数;丁坝群的水位壅高作用有限,最大壅高水深为0.38 m,对水深适宜度指数分布影响较小;在丁坝群作用下,栖息地可接受性高的面积占比由52.151%降至32.271%,降低了鱼类栖息地质量;丁坝群造成水力生境多样性辛普森指数由0.547降至0.529,使得研究区域内的水力生境多样性略微减少。研究成果可为北江鱼类栖息地保护和生态恢复提供参考。
In order to investigate the effects of spur dikes in Beijiang River on fish habitat,we took the Yingde section in the main stream of the Beijiang River as a study area,chose the typical dominant fish,Carassius auratus,as the target species,and used the unstructured-grid finite-volume method computational model(FVCOM) to calculate the weighted useable area(WUA) of Carassius auratus habitat under different flow conditions,and determined the optimal ecological flow value for the fish.Based on the derived fish optimum ecological flow values,the effects of spur dikes on flow velocity,water depth,fish habitat suitability index and hydraulic habitat diversity were studied.The results show that when the upstream flow is at the optimum ecological flow rate of 350 m~3/s,the spur dikes cluster makes the WUA value decrease from 7.142 km~2 to 5.692 km~2.Spur dikes significantly alter flow velocities in the center of the channel and nearshore,resulting in a decrease in the flow suitability index,which in turn decreases the habitat suitability index for the entire study area.The backwater effect of spur dikes is limited,with a maximum backwater depth of 0.38 m,which has a small effect on the distribution of the bathymetry suitability index.The percentage of area with high habitat acceptability decreases from 52.151% to 32.271% under the action of spur dikes,reducing fish habitat quality.Spur dikes reduce the Simpson′s Index of Hydraulic Habitat Diversity from 0.547 to 0.529,resulting in a slight decrease in hydraulic habitat diversity within the study area.The results of this research can provide a reference basis for protection and ecological restoration of fish habitat in the Beijiang River.
作者
程香菊
王龙威
林梓宜
田甜
曾家星
黄东
CHENG Xiangju;WANG Longwei;LIN Ziyi;TIAN Tian;ZENG Jiaxing;HUANG Dong(School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510641,China;Guangdong Research Institute of Water Resources and Hydropower,Guangzhou 510635,China)
出处
《人民长江》
北大核心
2024年第11期10-17,80,共9页
Yangtze River
基金
广东省水利科技创新项目(2023-06)。
