Abstract:
Water regulation has contributed to the decline in Pacific salmon in British Columbia (Canada) despite attempts to manage reservoir operations to achieve operational requirements while meeting environmental needs to limit fish thermal stress. The ability of reservoir managers to meet these trade-offs in a changing climate is unknown. Here, we examine the reliability and vulnerability of the Nechako Reservoir to meet hydropower production commitments and fisheries needs under two projected Shared Socioeconomic Pathway scenarios (SSP2-4.5 and SSP5-8.5). While our findings are specific to the operation of the Nechako Reservoir, the issues that emerge are likely common to many reservoirs in areas where reservoir inflow regimes are currently snow-storage dominated. We found that projected changes in the timing of water availability have little to no influence on hydropower generation commitments. However, larger water releases will be required to avoid compromising reservoir safety, possibly endangering downstream fish habitat through scouring. Furthermore, the temperature of water released from the reservoir is projected to more frequently exceed a level, 20°C, that is detrimental to migrating sockeye salmon. Water released is subject to further warming as it travels towards the lower reaches of the Nechako River used by migrating salmon. Hence, there is a need to adapt reservoir operations to ensure reservoir safety and mitigate adverse effects on salmon habitat.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s10584-023-03632-y.
摘要:
尽管试图管理水库的运营以实现运营要求,同时满足环境需求以限制鱼类的热应力,但水调节仍导致不列颠哥伦比亚省(加拿大)太平洋鲑鱼的减少。水库管理者在不断变化的气候中满足这些权衡的能力是未知的。这里,我们研究了Nechako水库的可靠性和脆弱性,以满足两种预计的共享社会经济途径情景(SSP2-4.5和SSP5-8.5)下的水电生产承诺和渔业需求。虽然我们的发现是针对Nechako水库的运作,在目前以水库流入方式为主的地区,许多水库可能会遇到这些问题。我们发现,预计水供应时间的变化对水力发电承诺几乎没有影响。然而,将需要更大的水释放,以避免损害水库安全,可能通过冲刷危及下游鱼类栖息地。此外,从水库释放的水的温度预计会更频繁地超过一个水平,20°C,这不利于红鲑鱼的迁徙。释放的水会进一步变暖,因为它会流向迁徙鲑鱼使用的内查科河下游。因此,有必要调整水库运营,以确保水库安全并减轻对鲑鱼栖息地的不利影响。
■在线版本包含补充材料,可在10.1007/s10584-023-03632-y获得。