carrie vuyovich and steven daly erdc-crrel
DESCRIPTION
Omaha inflow forecasts based on snow regressions Second Annual Missouri Basin River Forecaster’s Meeting 15-17 November 2010. Carrie Vuyovich and Steven Daly ERDC-CRREL Cold Regions Res. and Engr. Lab. (CRREL) U.S. Army Corps of Engineers November 2010. Project overview. - PowerPoint PPT PresentationTRANSCRIPT
US Army Corps of EngineersBUILDING STRONG®
Omaha inflow forecasts based on snow regressionsSecond Annual Missouri Basin River Forecaster’s Meeting15-17 November 2010
Carrie Vuyovich and Steven DalyERDC-CRRELCold Regions Res. and Engr. Lab. (CRREL)U.S. Army Corps of Engineers
November 2010
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Project overview
Improve spring forecasts for reservoir inflow at 6 major basins
Current method: Monthly forecasts for 1 July inflow volume
► 1JAN, 1FEB, 1MAR, 1APR Developed in late 1980s Multiple linear regression, based on:
► Basin average SWE► Average spring (Apr – Jun) precipitation (5.73)► Antecedent flow (Oct – Nov)► Holdouts
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Project overview
To improve forecasts: Improve estimate of SWE Update regression
equations with recent data Look for climate change
trends in earlier snowmelt, rising temperatures, changes in precipitation
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Canyon Ferry
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Additional SWE regression parameters• Elevation• Latitude• Aspect• Regional Slope
Improve basin SWE estimate
Methods to calculate basin SWE volume• Station Average• IDW• IDW adjusted for elevation trend in SWE
BUILDING STRONG®Average Max annual SWE
0
n
ii
BasinArea SWEn
n = number of reporting stationsSWEi = SWE depth reported at SNOTEL station
Station Average
Total Basin SWE =
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20 ,
20 ,
1
ni
i i jj n
i i j
SWEd
SWE
d
SWEj = Average SWE depth in 1 km grid celldi,j = distance between station, i and grid cell, j
Interpolation using Inverse Distance Weighting
Total Basin SWE =
k = number of grid cells in basin
0
k
cell jj
Area SWE
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20 ,
20 ,
( )
1
ni SWE i
i i jj SWE jn
i i j
SWE L Elevd
SWE L Elev
d
LSWE = estimated rate of change of SWE with elevationElevi = Elevation of SNOTEL stationElevj = Elevation of1 km grid cell
Interpolation using IDW, adjusting for elevation
Total Basin SWE =0
k
cell jj
Area SWE
k = number of grid cells in basin
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Average 1 Apr SWE by Elevation
April 1 - Average
ALBRO LAKE
BARKER LAKES
BASIN CREEKBEAGLE SPRINGS
BEAVER CREEK
BLACK BEAR
BLOODY DICK
BOULDER MOUNTAINBRACKETT CREEK
CALVERT CREEK
CARROT BASIN
CLOVER MEADOW
DARKHORSE LAKE
DIVIDE
FROHNER MEADOW
LAKEVIEW RIDGE LEMHI RIDGE
LONE MOUNTAINLOWER TWIN
MADISON PLATEAU
MULE CREEK
PETERSON MEADOWSPICKFOOT CREEK
PORCUPINE
ROCKER PEAK
S FORK SHIELDS
SACAJAWEA
SADDLE MTN
SHORT CREEK
SHOWER FALLS
TEPEE CREEK
TIZER BASIN
WARM SPRINGS
WEST YELLOWSTONE
WHISKEY CREEK
y = 0.4565x - 669.09R2 = 0.2955
0
200
400
600
800
1000
1200
1900 2000 2100 2200 2300 2400 2500 2600 2700 2800
Elev (m)
SWE
(cub
ic m
eter
s)
Other attributes showed little or no correlation with SWE, including:• Latitude• Aspect • Regional Slope
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Canyon Ferry Total Basin SWE estimates
0.E+00
5.E+09
1.E+10
2.E+10
2.E+10
3.E+10
3.E+10
4.E+10
7/10/1987 4/5/1990 12/30/1992 9/26/1995 6/22/1998 3/18/2001 12/13/2003
date
Tota
l bas
in S
WE
(m3)
SWE IDW SWE Average SWE IDW-elev SSM/I
Calculated total basin SWE using SSM/I passive microwave data. SWE was significantly underestimated, most likely due to the saturation level of the satellite instrument.
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Total Basin SWE, using Station Average
1 Apr R2 = 0.6278
1 Mar R2 = 0.4665
1 Feb R2 = 0.5035
1 Jan R2 = 0.403
0.E+00
5.E+09
1.E+10
2.E+10
2.E+10
3.E+10
3.E+10
0 200000 400000 600000 800000 1000000 1200000 1400000 1600000 1800000 2000000
Total Inflow, Apr - Jul
Tota
l bas
in S
WE
(in)
1-Jan1-Feb1-Mar1-Apr
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Total Basin SWE, using IDW
1 Apr R2 = 0.6434
1 Mar R2 = 0.4768
1 Feb R2 = 0.5099
1 Jan R2 = 0.4038
0.E+00
5.E+09
1.E+10
2.E+10
2.E+10
3.E+10
3.E+10
0 200000 400000 600000 800000 1000000 1200000 1400000 1600000 1800000 2000000
Total Inflow, Apr - Jul
Tota
l bas
in S
WE
(in)
1-Jan1-Feb1-Mar1-Apr
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Total Basin SWE, using IDW and Elevation adjustment
1 Apr R2 = 0.5153
1 Mar R2 = 0.3663
1 Feb R2 = 0.4091
1 Jan R2 = 0.3086
0.E+00
5.E+09
1.E+10
2.E+10
2.E+10
3.E+10
3.E+10
0 200000 400000 600000 800000 1000000 1200000 1400000 1600000 1800000 2000000
Total Inflow, Apr - Jul
Tota
l bas
in S
WE
(in)
1-Jan1-Feb1-Mar1-Apr
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SWE Calculation statistics
SWEav g R2 Slope Intercept RMSE MAE SWEav g R2 Slope Intercept RMSE MAE SWEav g R2 Slope Intercept RMSE MAE1-Jan 7370171708 0.404 51.56 4117462666 32330293 23882627 7143015605 0.404 48.47 4085147441 32277334 23825255 4180025638 0.293 26.47 2509928145 41288265 321486111-Feb 10448603482 0.504 72.18 5894924548 26394548 20538793 10076529272 0.510 67.93 5790933920 26060605 20439512 5967310818 0.399 36.03 3694471940 32673387 260833371-Mar 13232835283 0.467 80.94 8126905472 28430845 23534274 12730554684 0.477 75.93 7940660792 27849600 22997622 7662684574 0.345 39.90 5145315005 36659807 302379631-Apr 16251083023 0.627 99.05 10002437017 20490651 16807358 15685011908 0.643 93.24 9802920386 19817254 16272976 9259351130 0.515 52.48 5948645938 25801221 20689287
SWE Average of Stations SWE IDW SWE IDW - Elev
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1ST April SWE / Inflow Volume correlations
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Max annual accumulated precip
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Average annual temperature
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Multiple Linear Regression
Variables:• 1 Apr SWE• Antecedent Flow (Oct-Nov)• Previous years Max SWE• Apr – Jun Total Precipitation• Average Apr-Jun Total Precipitation (5.79 in)• Previous years total annual precipitation• Thiessen-weighted precipitation
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Average Annual Inflow volume 63085409R2 Std Error
Station Average SWE 1 Apr SWE 0.62751Apr SWE + Antec Flow 0.6869 0.247
1 Apr SWE + Last year Max SWE + Spring Precip 0.8228 0.1891 Apr SWE + Antec Flow + Spring Precip 0.8853 0.152
1 Apr SWE + Antec Flow + Prev yrs total Precip 0.7149 0.240
IDW SWE 1 Apr SWE 0.64301Apr SWE + Antec Flow 0.7028 0.241
1 Apr SWE + Last year Max SWE + Spring Precip 0.8322 0.1841 Apr SWE + Antec Flow + Spring Precip 0.8970 0.144
1 Apr SWE + Antec Flow + Prev yrs total Precip 0.7311 0.233
IDW-Elev SWE 1 Apr SWE 0.51511Apr SWE + Antec Flow 0.5890 0.283
1 Apr SWE + Last year Max SWE + Spring Precip 0.7468 0.2262 Apr SWE + Antec Flow + Spring Precip 0.824 0.188
1 Apr SWE + Antec Flow + Prev yrs total Precip 0.6353 0.271
Linear Regression with Total Reservoir inflow
Canyon Ferry Multiple Linear Regression
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R2 = 0.6275
0
5000000000
10000000000
15000000000
20000000000
25000000000
30000000000
0 20000000 40000000 60000000 80000000 100000000 120000000 140000000
Inflow volume
1Apr
SW
E
R2 = 0.7149
0.0E+00
2.0E+07
4.0E+07
6.0E+07
8.0E+07
1.0E+08
1.2E+08
1.4E+08
0.0E+00 2.0E+07 4.0E+07 6.0E+07 8.0E+07 1.0E+08 1.2E+08 1.4E+08
Observed Flow Volume
Est F
low
vol
ume
R2 = 0.6869
0.0E+00
2.0E+07
4.0E+07
6.0E+07
8.0E+07
1.0E+08
1.2E+08
1.4E+08
0.0E+00 2.0E+07 4.0E+07 6.0E+07 8.0E+07 1.0E+08 1.2E+08 1.4E+08
Observed Flow Volume
Est F
low
vol
ume
R2 = 0.8853
0.0E+00
2.0E+07
4.0E+07
6.0E+07
8.0E+07
1.0E+08
1.2E+08
1.4E+08
0.0E+00 2.0E+07 4.0E+07 6.0E+07 8.0E+07 1.0E+08 1.2E+08 1.4E+08
Observed Flow Volume
Est F
low
vol
ume
1 Apr SWE 1 Apr SWE + antec inflow
1 Apr SWE + antec inflow + Prev yrs total precip
1 Apr SWE + antec inflow + AMJ precip
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Current work
Estimation of SWE Further analysis using SCA Station weightingMultiple linear regression Climate indices/NWS long-term forecast for additional information on spring
precipitation Holdouts Calculate significance of parametersClimate Trends Timing of precipitation Regularly incorporate additional data to regression analysisOther basins Similar SWE analysis Update regressionsNew forecast techniques ready to test by 1 Jan 2011.