The use of environmental flow (e-flow) regimes has been widely implemented to improve fish habitat quality in river restoration efforts. However, e-flow designs focusing only on one key life stage (e.g., spawning) without considering potential bottlenecks in other stages (e.g., hatching) can result in little to no improvement, especially when targeting the restoration of fish with drifting eggs. Few e-flow assessments are available that closely link the spatial–temporal dependence of the hydrodynamic effect of drifting eggs on hatching habitats. Moreover, an understanding of how to allocate e-flows to achieve the best possible outcomes for biological diversity conservation is still lacking. In this study, a new framework was developed to assess e-flows, aiming to satisfy the requirements of multiple fish species with different spawning patterns concerning streamflow requirements during spawning and hatching periods. In this framework, the final weighted usable area (FWUA) was proposed by linking the spawning demand to the hydrodynamic effect of drifting eggs to assess habitat quality for fish that produce drifting eggs, and water temperature was used to guide when and how to shift from fixed to moving protection targets in allocating e-flows. Here, we used the Xiangjiaba Reservoir, located in the lower Jinsha River, as a case study to design e-flows for the conservation of multiple fish species with different spawning patterns, which was beneficial for increasing the probability of restoration success. By testing scenarios with an absence of drifting passage, the ecological base flow considering only spawning habitat appears to be lower than that considering both quality of spawning habitat and hatching passage. The ecological benefits (FWUA) generated from the ecological base flow identified by traditional models represent only 64.91% of our framework and are thus anticipated to have cascading deviant effects on ecological patterns and processes in riverine ecosystems. This underlying difference in FWUA generated due to different ecological base flows determined from traditional models and our framework, however, has been overshadowed in previous research. We highlight that the highest fish population density recovery potential will be reached at only certain ratios for both sets of habitat benefits. This work provides a tool that can help managers evaluate e-flows and compare different river restoration scenarios to protect degraded rivers or develop strategies to build resilience to climate change.

环境流量（e-flow）机制的使用已被广泛实施，以改善河流恢复工作中的鱼类栖息地质量。然而，仅关注一个关键生命阶段（例如，产卵）而不考虑其他阶段（例如，孵化）的潜在瓶颈的电子流设计可能几乎没有改善，尤其是在以漂流卵恢复鱼类为目标时。很少有电子流评估可以将漂流卵的水动力效应对孵化栖息地的时空依赖性紧密联系起来。此外，仍然缺乏对如何分配电子流量以实现生物多样性保护的最佳结果的理解。在这项研究中，开发了一个新的框架来评估电子流，旨在满足多种不同产卵方式的鱼类在产卵和孵化期间对水流的需求。在这个框架中，通过将产卵需求与漂流卵的水动力效应联系起来，以评估产生漂流卵的鱼类的栖息地质量，提出了最终加权可用区域（FWUA），并使用水温来指导何时以及如何从在分配电子流时固定在移动的保护目标上。在这里，我们以位于金沙江下游的向家坝水库为例，设计了保护具有不同产卵模式的多种鱼类的电子流，这有利于提高恢复成功的概率。通过测试没有漂移通道的场景，仅考虑产卵栖息地的生态基流似乎低于同时考虑产卵栖息地质量和孵化通道的生态基流。传统模型确定的生态基流产生的生态效益（FWUA）仅占我们框架的 64.91%，因此预计会对河流生态系统的生态模式和过程产生级联的异常影响。然而，由于传统模型和我们的框架确定的不同生态基础流量而产生的 FWUA 的潜在差异在之前的研究中被掩盖了。我们强调，对于两组生境效益，只有特定的比率才能达到最高的鱼类种群密度恢复潜力。