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Using DHSVM to Study Land Cover Change and Temperature Change Effects on Streamflow in Puget Sound Drainage. Lan Cuo and Dennis Lettenmaier July 26 2006. Objectives land cover change effects: ~100 years ago, current and 100 years later Climate change effects (mainly T) Background - PowerPoint PPT Presentation
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Using DHSVM to Study Land Cover Change and Temperature Change Effects on Streamflow in
Puget Sound Drainage
Lan Cuo and Dennis Lettenmaier
July 26 2006
• Objectives1. land cover change effects: ~100 years
ago, current and 100 years later
2. Climate change effects (mainly T)
• Background
• Methodology
• Results
• Problems
• Future Work
Background• Study Area
Puget Sound Drainage• Bounded by the Cascade
and Olympic Mountains• 41,439 sqr.km• 80% land, 20% water• Temperate rainforest ecosystem• Western Hemlock, Douglas fir,
Subalpine forest, and Alpine Medows
• Steep slope: mollisol-ultisol-alfisol
Gentle slope: Inceptisol-mollisol-spodosal
Nearly level: inceptisol-mollisol-histosol
http://wa.water.usgs.gov/projects/pugt/images/studymap.gif
Population in 1900
0
20000
40000
60000
80000
100000
120000
City/T
own
Islan
d Cou
nty
Jeffe
rson
Cou
nty
King C
ounty
Kitsap
Cou
nty
Mas
on C
ounty
Pierce
Cou
nty
San Ju
an C
ount
y
Skagit
Cou
nty
Snoho
mish C
ount
y
Thurs
ton C
ount
y
Wha
tcom C
ount
y
Background
• Population
Population in 2000
0
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
City/T
own
Islan
d Cou
nty
Jeffe
rson
Cou
nty
King C
ounty
Kitsap
Cou
nty
Mas
on C
ounty
Pierce
Cou
nty
San Ju
an C
ounty
Skagit C
ount
y
Snoho
mish
Cou
nty
Thurs
ton
County
Whatc
om C
ounty
King county had almost 18 times more population in 2000 than 1900.
Source: Washington State Office of Financial Management
SkagitStillaguamishSnohomishCedarGreenPuyallupNisquallyDeschutesQuilceneHammahammaDosewallipsDuckabushSkokomish
Dam source: Washington State Department of Ecology
Background• Upland basins
Methodology• Model Structure
DHSVM Components
Interception Evapotranspiration
Energy and radiation balance
Unsaturated soil water movement
Saturation excess and infiltration excess runoff
Ground water recharge and discharge
Snow accumulation & melt
Methodology• Forcing Data 1-16th degree Tmin, Tmax, precipitation and
wind speed grids. Used 33 stations from 1927 to 2003
Mean monthly precipitation comparison between PRISM and 1-16th grid
Accumulated monthly precipitation comparison between stations, 1-8th grid and 1-16th grid over the Cedar Basin
Annual precipitation (mm)
Annual mean Tmax (C)
Annual mean Tmin (C)
• 2002 Land Cover Map in Puget Sound (Marina, 2004)
Fixing problems:Filled no data values and clouds location with reference to CCAP 2000land cover map.
Supplement north and south portion with CCAP 2000 and GAP 1991 land cover map.
Problems:1. Clouds, no data values.2. Incomplete in the north and south portion of Puget Sound
•Modified Land Cover TypesLand Cover Types Percentage
Dense urban (>75% impervious area) 1.20
Light-mediu urban (<75% impervious area) 2.23
Bare ground 0.70
Dry ground 1.03
Native grass 0.02
Grass/crop/shrub 7.36
Mixed/deciduous forest 30.04
Coniferous forest 32.78
Regrowth vegetation 0.48
Clear cuts 0.70
Snow/rock/ice 6.77
Wetlands 0.28
Shoreline 0.09
Water 16.32
Methodology• Pilot Study Areas
• Upland
Cedar Basin
Methodology• Pilot Study Areas• Lowland Urban basins
Mill Creek
Spring Brook Creek
Land cover Springbrookcreek basin
(22 km2)
Mill creek Earthworks Park basin (6.4 km2)
Mill creekbasin (15 km2)
Dense urban 32.59 25.83 46.78
Ligth-medium urban 31.34 32.51 24.98
Bareground 0.83 0.43 0.76
Dry ground 2.24 1.85 1.79
Grass/crop/shrub 7.79 8.86 8.86
Mixed/deciduous forest 22.49 26.23 14.45
Coniferous forest 2.54 4.00 1.72
Water 0.12 0.22 0.33
Land cover types and percentage in urbanized basins.
12113346 Gage (Spring brook creek)
12113347 Gage (mill creek at Earthworks Park)
12113349 Gage Location and Surround (Mill creek at mouth)
Results - Streamflow Calibration in Cedar Basin
A. Cedar River (1945-1985 )
Daily statistics:Observation Mean = 7.50 cmsSimulation Mean = 7.50 cmsCorrelation Coefficient = 0.86RMSE = 3.92 cmsModel Efficiency = 0.67
B. Rex River (1945-1985)
Daily statistics:Observation Mean = 2.93 cmsSimulation Mean = 2.48 cmsCorrelation Coefficient = 0.81RMSE = 2.15 cmsModel Efficiency = 0.23
C. Taylor Creek (1956-1985)
Daily Statistics:Observation Mean = 2.80 cmsSimulation Mean = 2.78 cmsCorrelation Coefficient = 0.87RMSE = 1.18 cmsModel Efficiency = 0.73
Results – Streamflow Validation period : 1985-2003
A. Cedar River
Daily statistics:Observation Mean = 6.87 cmsSimulation Mean = 6.97 cmsCorrelation Coefficient = 0.84RMSE = 4.54 cmsModel Efficiency = 0.60
B. Rex River
Daily Statistics:Observation Mean = 2.69 cmsSimulation Mean = 2.29 cmsCorrelation Coefficient = 0.78RMSE = 2.42 cmsModel Efficiency = 0.15
C. Taylor Creek
Daily Statistics:Observation Mean = 2.63 cmsSimulation Mean = 2.65 cmsCorrelation Coefficient = 0.85RMSE = 1.40 cmsModel Efficiency = 0.65
Urban Basin Streamflow Simulation
Simulation Period: 1995-10-1 to 2003-9-30. Time step: 1 hourMill Creek at Earthworks Park, area 2.49 sq.mile (6.4 sq.km)
Urban Basin Streamflow Simulation
Mill Creek Basin area 5.63 sq.mile (14.6 sq.km)
Urban Basin Streamflow Simulation
Spring brook creek basin 8.44 sq.mile (21.9 sq.km)
Green River Basin Simulation
Daily Statistics:Observation Mean = 10.85 cmsSimulation Mean = 10.39 cmsCorrelation Coefficient = 0.84RMSE = 7.69 cmsModel Efficiency = 0.56
Map ID Creator Published Year
Uw001* USGS 1902
Uw017* USGS 1898
Uw029* USDA 1910
Topo063* USGS 1900
Topo064* USGS 1900
Uw083 USGS 1898
Uw102 Department of Interior 1883
Uw073 USGS 1898
Uw072 USGS 1898
Uw054 USGS 1899
Reconstruction of Historical Land Cover Map
Map of Washington Showing Classification of Lands 1902 (USGS)
Re-construction Strategy• Geo-reference land cover maps.• Digitize land cover types ( 5 maps)• Make a composite historical map of land cover types for timber
industry• Transform historical timber industry land cover types to Alberti
Marina’s land cover types by using census data, DEM. Crittenden 1997; Harlow et al. 1979: Maple tree grows up to 1000 ft in
B.C Canada.
• Timber industry land cover types Transformed land cover types• Cut areas/ Timberless /Burned areas Light-medium urban (?)
Grass/crop/shrub (?)Bareground (?)Dry ground (?)Clear-cuts (?)
• 0-100,000 feet B.M. per acre Coniferous forest (?) Mixed/deciduous forest (?)
Problems
• Good calibration in one basin does not guarantee good simulations in the other basins.
• Critical issue for urban basin is to get correct basin area. Stream channels on topo map are need to get the outline of basin.
Future Work
• Write a urban basin study report.• Search or make lowland urban basins.• Simulate streamflow in Puget Sound
basins• Generate historical land cover map for
DHSVM• Study current and historical land cover
change effects• Study climate change (mainly Ta) effects
Special thanks to:Matt WileyChunmei
BerntAlan
Questions?