7245

• UCREFRP Catalog Number: 7245
• Author: Rose, K. L. and D. R. Hann.
• Title: Consolidated Instream Flow Report, Habitat Modeling on the Green River Using the Physical Habitat Simulation System.
• USFW Year: 1989.
• USFW - Doc Type: Grand Junction, Colorado.
• Copyright Material: NO

2. Hydraulic Simulation

The output from the WSEI4S program gives an estimated WSE and discharge for
each transect at measured flows (Tables 8 and 9). The accuracy of the model
predictions is evaluated by the ratio between the measured and predicted
discharge. In this analysis, ratios range from 0.94 to 1.01 for all transects
and measured discharges except one (Table 9). At transect 1, the ratio
between the predicted (6330 cfs) and measured discharge (5553 cfs) is 0.88.
This discrepancy is the result of pooled water at transect 1 which
artificially raises the WSE. Thus, to facilitate calibration, a lower WSE of
88.66 (the calibrated WSE; Table 8) versus 88.99 was entered in the WSEI4S
program. This elevation increased the ratio at transect 1 from 0.88 to 0.96
resulting in a predicted discharge of 5789 cfs (Table 1~).

Similar to the WSEI4S program, the precision of the model outputs in the IFG4
program are determined by the ratio between measured and predicted discharges.
Fortunately, all the ratios from the IFG4 simulation range from 1.02 to 1.06
(Table 11).

Table 8. Measured versus predicted Water Surface Elevations (WSE)
for the measured flows at Ruple Ranch study site.

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1194 cfs
Meas. Pred.
Transect WSE

2589 cfs
Meas. Pred.
WSE

87.09 87.11
87.18 87.21
87.33 87.42
87.49 87.58
87.63 87.60
87.90 87.90

1
2
3
4
5
6

85.82 85.83
85.87 85.87
86.12 86.09
86.23 86.20
86.26 86.29
86.58 86.58

5553 cfs
Meas. Pred.
WSE

88.99 88.66
89.14 89.08
89.27 89.25
89.55 89.45
89.66 89.51
89.91 89.77

9586 cfs
Meas. Pred.
WSE

89.76 90.04
90.87 90.96
91. 04 91. 04
91.25 91.30
91.29 91.50
91.62 91.67

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