Fig. 5. The GCM modeling interface allows users to vary policy actions (e.g., flow and water temperature) and model parameters. Temporal and spatial trends in output can be viewed in a variety of ways (time series at particular locations, maps, longitudinal trends) and results can be compared to historical data (circles in the time series graphs). Red indicates predicted values and blue indicates observed values. Units for suspended sediment are mg/L, units for tributary suspended load are 1000 tons per month, and units for algal biomass are g/ft²,measured over years (top and bottom rows) and over river miles from Glen Canyon Dam (middle row).