Ecosystem Modeling for Evaluation of Adaptive Management Policies in the Grand Canyon

Facilitating Adaptive Management in California’s Sacramento-San Joaquin Delta

“…A large, complex system such as the Delta might seem to require large, complex models, but their development can make unreasonable demands for expertise, time, and costs. For example, the initial, complex Grand Canyon Ecosystem Model (Walters et al 2000) often failed to predict the effects of altered river flows, while later submodels could deal with specific management needs (Melis et al 2015).…”

Surprise and Opportunity for Learning in Grand Canyon: the Glen Canyon Dam Adaptive Management Program

“…Ecosystem modeling workshops were coordinated by the Grand Canyon Monitoring and Research Center in collaboration with Adaptive Management Program stakeholders and cooperating scientists, and resulted in the Grand Canyon Ecosystem Model (Walters et al 2000). The Grand Canyon Ecosystem Model is a large and complex spatial model representing key ecosystem indicators within unique geomorphic segments of the 470 km-long Colorado River ecosystem.…”

“…The Grand Canyon Ecosystem Model built on historical flow, sediment, and temperature monitoring data from http://www.ecologyandsociety.org/vol20/iss3/art22/ the Colorado River ecosystem, and on an existing hydrologic operations model used by the Bureau of Reclamation, to schedule water deliveries throughout the Colorado River basin. However, as with the Environmental Impact Statement, most Grand Canyon Ecosystem Model biotic response predictions are considered to be highly uncertain (Table 2 in Walters et al 2000), and some are now known to be wrong on the basis of new monitoring information provided to the Adaptive Management Program by its science provider, the Grand Canyon Monitoring and Research Center. From the perspective of resource managers, it may seem reasonable to hope that models like the Grand Canyon Ecosystem Model will eventually be improved enough to correctly predict efficacy of various treatments.…”

“…This was the case with the Grand Canyon Ecosystem Model, and earlier predictions regarding operation of selective withdrawal structures (formerly proposed for the Glen Canyon Dam powerplant, but never built) to warm dam releases as an engineering technique for increasing native fish recruitment in Grand Canyon National Park. Moderate downstream warming achieved through use of selective withdrawal structures at the dam is generally predicted to increase both native and non-native fishes, and their interactions (see Table 2 of Walters et al 2000 and Table 4 of Schmidt et al 1998). Also, some ecosystem modeling predictions in the Environmental Impact Statement were prone to fail owing to incorrect assumptions about physical processes, such as sediment transport in river settings such as the Colorado River ecosystem, as shown by Rubin et al (2002), and uncertain changes in future basin hydrology and streamflow under continued warming of the southwestern United States (Jain et al 2005, Milly et al 2008, Vano et al 2014.…”

Adaptive Management Planning Projects as Conflict Resolution Processes

“…The explicit workshop tasks cover three major systems analysis phases: (1) Scoping the problem area; (2) Exploring the structure, or patterns of cause and effect that shape outcomes in the problem area; and (3) Exploring views of the dynamics of the system's behavior, usually using a simulation model designed by the workshop participants, as they explore scope, structure, and dynamics (Holling 1978, Walters 1986, Gilmour et al 1999, Walters et al 2000.…”