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Liberty Lake Watershed Analysis Brian E. Drake The University of Texas at Austin April 24, 2007 CE394K.2 - Hydrology
Liberty Lake Watershed Analysis
Brian E. Drake The University of Texas at Austin
April 24, 2007
CE394K.2 - Hydrology
Outline Geologic Formation and Background
Vegetative Zone of Influence
HEC-HMS
Geologic Formation Creek dammed by ice sheet Lake Missoula flood deposits
http://nwcreation.net/articles/missoulaflood.htm
Lake Missoula Present roughly 12,000 years ago Covered much of western Montana Volume = 530 mi3 Ice Dam = 2500 ft
http://www.pbs.org/wgbh/nova/megaflood/lake.htmlhttp://www.glaciallakemissoula.org/story.html
http://www.uwsp.edu/geo/projects/geoweb/participants/dutch/VTrips/LkPendOr.HTM
The Floods Likely multiple floods Peak flow = 386 x 106 cfs Velocity = 30-50 mph
http://www.uwsp.edu/geo/projects/geoweb/participants/dutch/VTrips/Scablands0.HTMhttp://pirlwww.lpl.arizona.edu/~turtle/photos/PTYS594A_Wash030.html
Liberty Lake Deposits
Lake and Watershed Characteristics Lake = 708 acres Watershed = 14 mi2 15 miles east of Spokane, WA
Outline Geologic Formation and Background
Vegetative Zone of Influence
HEC-HMS
Motivation Coupling hydrological/biological processes Example: Transpiration causing diel
streamflow fluctuations Improve process interactions and water
balance accuracy
(Bond et al. 2002)
Data Collection Stilling well Hourly depth records Calibrated to flow
Vegetative Water UseMay 2003 5-Day Streamflow
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
5/14 5/15 5/16 5/17 5/18 5/19 5/20 5/21
Time
Flow
(cfs
)
Measured Q
Missing Q
Baseflow
June 2003 5-Day Streamflow
0.00
0.50
1.00
1.50
2.00
2.50
3.00
6/15 6/16 6/17 6/18 6/19 6/20 6/21 6/22
Time
Flow
(cfs
)
Measured QMissing QBaseflow
July 2003 5-Day Streamflow
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
7/15 7/16 7/17 7/18 7/19 7/20 7/21
Time
Flow
(cfs
)Measured QMissing QBaseflow
Zone of Influence Transpiration Rates
2.4 – 330 ft3/acre/hr Used 120 ft3/acre/hr for
computations
Month Width of Influence, W (ft)
May 12
June 29
July 24
W
Outline Geologic Formation and Background
Vegetative Zone of Influence
HEC-HMS
Goals Gain exposure to HEC-HMS Define storm capable of causing lake
property damage Adjudicated lake elevation = 2049.51 Flooding at 2054’
Results to Date2 yr – 6 hr Storm Peak Flow = 24.4 cfs Volume = 4.9 acre-ft
100 yr – 24 hr Storm Peak Flow = 6376 cfs Volume = 871 acre-ft
Conclusions Past changes may give insight to future Diel streamflow fluctuations can be used
to quantify vegetative zone of influence Very dependent on transpiration rates MODIS Leaf Area Index (LAI)
HEC-HMS is a powerful tool for rainfall-runoff modeling Still need to determine storage-elevation
relationship
Questions?
