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The next step will be to add a new future use to all four models (the original monthly model as well as <br /> the three daily models). For the monthly model, results will be distributed to daily following the <br /> historical distribution of daily flow across the month, as currently done by USFWS. Daily gage flows <br /> from the four models will be compared to determine which are credible and whether differences among <br /> the results are significant. <br /> 1. Download the current databases for Division 6. Download the most recent version of Statemod and <br /> all DMI's. This subtask is budgeted to allow for software and/or system difficulties, to the extent that <br /> it would require approximately three days' effort:by an associate engineer with direction and <br /> oversight by the project manager. <br /> 2. Create a monthly model of the Elk River from the existing Yampa IIIb model from the headwaters to <br /> the Clark gage. This river reach was selected because it contains two reservoirs,two instream flow <br /> rights, and several diversion structures. The study period will be 1975-1991, a span within the model <br /> calibration period during which the gage record i.s complete. <br /> 3. Create a daily model by having Statemod disaggregate monthly baseflows, diversion demand, <br /> instream flow demand, and reservoir targets,by setting them to an average daily value(station <br /> c...idy variables set to 0). Monthly return flow fractions will be converted to daily values that effect <br /> the same total return over the month, as described in Task 1. Execute the Calculated data set for <br /> 1975-1991 and compare gage flows at Clark with historical daily gage records for 1975-1991. <br /> 4. Create a daily model by having Statemod disaggregate monthly baseflows at the Clark gage by using <br /> the pattern provided by the historical stream gage. Allow Statemod to disaggregate diversion <br /> demand, instream flow demand, and reservoir targets by setting them to an average daily value, as in <br /> subtask 3 (station c...idy variables set to 0). Monthly return flow fractions will be converted to daily <br /> values that effect the same total return over the month, as described in the previous task. Execute the <br /> Calculated data set for 1975-1991 and compare gage flows at Clark with historical daily gage <br /> records for 1975-1991. <br /> 5. Create a daily model by generating daily baseflows from daily gage records and historical diversion <br /> records as available from the database. Daily reservoir content will be created by straight-line <br /> interpolation between end-of-month content data. Monthly return flow fractions will be converted to <br /> daily values as in the other two daily pilot models. Execute the Calculated data set for 1975-1991 <br /> and compare gage flows at Clark with historical gage records for 1975-1991. <br /> Note that Statemod will need to be modified to conduct baseflow calculations on a daily basis for <br /> this model. <br /> 6. Add a future demand to the Calculated data set for all four models (the monthly model and three <br /> types of daily models). The monthly model will be executed and the resulting monthly gage flow at <br /> Clark will be disaggregated to daily using the Clark historic daily pattern to distribute simulated <br /> gaged flows. Compare these disaggregated Clark gage streamflows with daily streamflows from the <br /> three daily models for 1975-1991. <br /> 7. Summarize the results of the calibration runs, focusing on the relative accuracy of the three <br /> approaches to a daily model. Summarize the results of the future scenario runs, focusing on a <br /> comparison between the current approach of disaggregating monthly results to daily, and each of the <br /> three daily model approaches. <br />