| This study identified changes in habitat suitability in the spawning grounds of the fluctuating backwater area of Three Gorges Reservoir (TGR), and general methods for measuring ecological flow thresholds that protect spawning grounds. The aim of the research was to provide a reference for protecting spawning ground habitat in the fluctuating backwater area of reservoirs and ecological scheduling of reservoirs. The Guangyang-Shituo River section of the fluctuating backwater area in the Three Gorges Reservoir was selected for research, and is highly impacted by the operation of Three Gorges Dam. Eight typical fish species with drifting eggs were the research subjects, including the?four?major?Chinese?carps, Coreius heterodon, Rhinogobio ventralis, Rhinogobio cylindricu, and Jinshaia sinensis. Firstly, we calculated the ecological flow thresholds by simulating the habitats of fish spawning grounds and coupling the ecological needs of the eight fish species for spawning, and then regulation strategies were formulated. Results show that the minimum ecological flow at impoundment levels of 145, 150, 155, 160 and 165 m and natural condition were 6 543, 7 130, 9 943, 13 713, 17 603 and 6 106 m3/s, and the maximum ecological flow were 17 028, 17 526, 23 110, 28 291, 29 858 and 15 753 m3/s, respectively. The most suitable ecological flows for the four?major?Chinese?carps, C. heterodon, R. ventralis, R. cylindricu, and J. sinensis at impoundment levels of 145, 150, 155, 160 and 165 m and natural condition were 10 002, 10 916, 14 479, 18 810, 23 226 and 9 365 m3/s, respectively, with the upper thresholds of the most suitable ecological flows of 13 515, 14 221, 18 794, 23 550, 26 542, 12 559 m3/s and lower thresholds of the most suitable ecological flows of 8 272, 9 023, 12 211, 16 262, 20 414, 7 736 m3/s. Furthermore, when the flow is small and within a certain flow range, lowering the water level is beneficial for increasing the weighted usable area (WUA); When the flow is high, increasing the water level is beneficial for increasing WUA after the flow reaches a certain value; When the flow is between the two flows, the water level and ecological flow threshold in this study can be referred for regulatory decision-making. |
| 易 燃,陈小娟,杨 志,陶江平,戴凌全,郜星晨,刘宏高,朱其广,徐 薇,曹 俊.2024.基于栖息地法的水库变动回水区鱼类产卵场生态流量及调控策略研究[J].水生态学杂志,45(5):85-96. |
