Will future climate change increase the risk of violating minimum flow and maximum temperature thresholds below dams in the Pacific Northwest

摘要: Abstract Detecting and avoiding environmental thresholds that lead to catastrophic change in ecological communities is an important goal, one especially challenging address over broad geographic extents. Here, we conducted a regional-scale climate vulnerability assessment (RCVA) quantify the risk of violating thermal minimum-flow below reservoirs. Our analysis used hybrid (process-based empirical) models tailwater temperature flow driven by 4-km downscaled CMIP5 projections. Downscaling employed combination process-based models, quantile mapping, non-linear ‘reservoir’ transform function. RCVA can be applied at regional scales without proprietary data-intensive physical reservoir systems or species comprise communities. Using RCVA, produced ensemble projections duration extreme high-temperature low-flow events federal reservoirs Pacific Northwest (PNW), USA. Bayesian modeling simulated results allowed us evaluate differences between under future baseline scenario relative model uncertainties uncertainty modeled risks. Based on assumptions historical patterns dynamics operation will continue, regulatory not change, exceedance was projected increase average 0.27 extend into late-spring fall (average 10.3 d). For flow, 0.07 below-thresholds flows, with 4.6 d. Both raise concerns cold-water salmonids PNW increased scenario.