摘要
干支流交汇区是鱼类生存栖息和洄游迁徙的重要场所,交汇区水文条件复杂,水流结构时空演替变化,将对鱼类水力生境指标变化产生直接影响。研究高流量脉冲条件下河道交汇区鱼类水力生境指标的变化特征,对河流生态系统保护具有重要意义。以长江与嘉陵江交汇区为例,采用三维水流数值模拟方法,分析鱼类水力生境指标时空分布与高流量脉冲过程的响应关系。结果表明:涨水过程干支流顶托作用增强,交汇区弯曲河道凹岸及河底深槽处出现最大流速,凸岸分离区回流区宽度减小;栖息地适宜度指数SH大于0.8的区域在深槽和边滩间移动,随涨水过程向河底及凸岸边壁偏移,随落水被压缩至凹岸深槽及边滩;高流量脉冲条件下,交汇区微生境适宜性面积A随涨落水呈先增大后减小的变化趋势,A峰值出现在高流量脉冲峰值附近。
The confluence arterial and tributary is an important place for fish growth,reproduction and migration,and the hydrological condi-tions in the confluence area are exceptionally complex,and the spatial and temporal changes in the flow structure will have a direct impact on the distribution of fish hydraulic habitat indicators.The study of the distribution characteristics of fish hydraulic habitat indicators in the con-fluence zone under high-flow pulse conditions is of great significance to the protection of river ecosystems.Taking the confluence of the Yan-gtze River and the Jialing River as an example,the response relationship between the spatial-temporal distribution of hydraulic habitat indices and the high-flow pulse process was analyzed by using a three-dimensional numerical simulation method.The results show that:during the process of rising water,the interaction between the main stream and its tributaries increases,the maximum velocity appears in the concave bank and the deep channel of the river bottom in the confluence,and the width of the circumfluence structure decreases in the separation area of the convex bank,the change trend of falling water is opposite to that of rising water.The habitat suitability index(SH)greater than 0.8 moved between the deep trough and the bank,and moved to the bottom of the river and the bank wall with the process of rising water,with the falling water is compressed to the concave bank deep trough and the edge beach.Under the condition of high flow pulse,the area of mi-crohabitat A in the confluence area increases first and then decreases with the fluctuation of water,and the A peak appears near the peak of high flow pulse.
作者
汪贤瑶
钟亮
姜利
WANG Xianyao;ZHONG Liang;JIANG Li(National Engineering Research Center for Inland Waterway Regulation,Chongqing Jiaotong University,Chongqing 400074,China;Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《人民黄河》
CAS
北大核心
2024年第6期103-108,112,共7页
Yellow River
基金
重庆市基础科学与前沿技术研究项目(cstc2017jcyjAX0278)。
关键词
高流量脉冲
交汇区
鱼类水力生境指标
时空分布特征
high flow pulse
confluence zone
fish hydraulic habitat indicators
spatial and temporal distribution characteristics
