presented by: diane cooper arkansas-red basin river forecast center hydrologist

Arkansas Red Basin River Forecast Center

An Operational Forecast Office Perspective An Operational Forecast Office Perspective of the of the

National Weather Service National Weather Service Hydrologic Distributed Modeling System Hydrologic Distributed Modeling System

(HDMS)(HDMS)

Presented by:

Diane CooperArkansas-Red Basin River Forecast Center Hydrologist

2Arkansas-Red Basin River Forecast Center October 18, 2006

ObjectivesObjectives

Overview of HDMS

Preliminary Statistical Analysis


HDMS, HDMS, What is it?What is it?

A Hydrologic Model that takes into account: Spatial distribution of hydrologic characteristics across a

drainage basin including soils, vegetation, land use, slope

Temporal and spatial distribution of rainfall…4X4 km HRAP grids

Many 4x4 km grid cells embedded in the main basin.

Maintains spatial Precipitation footprint which impacts hydrologic response.


Features Of HDMSFeatures Of HDMS

Performs routing simulations using the kinematic wave technique

– flow velocity in each element is dependent on flow level

Separates the runoff components– Surface flow: includes impervious, surface and

direct runoff

– Subsurface flow: includes interflow and baseflow


Advantages of HDMSAdvantages of HDMS

Potential for improved simulations for:– Basins with non-uniform rainfall.– Basins with relatively impervious areas (surface runoff

occurs quickly…i.e. highly populated regions). Prediction of hydrologic variables at interior

points. Output of Gridded soil moisture states. Potential to improve flash flood forecasting. Can account for Land-use change (i.e. burn

areas).


Statistical AnalysisStatistical Analysis

Comparisons of HDMS and NWSRFS SQIN to the observed flow data was performed for 14 of the 21 test basins from Early 2002 through August 2005.

For a more “consistent” comparison, the Lumped Model SQIN crest time and peak discharge were compared to the hourly observed time series. This is referred to as the Adj. NWSRFS SQIN.

Note: Seven Basins were not included in the analysis due to:

• 4 HDMS test basins are not identified in the NWSRFS Lumped model

• 2 basins had a very short NWSRFS SQIN timeseries.

• 1 Basin the SQIN has not yet been generated.

How well is HDMS performing compared to How well is HDMS performing compared to the NWSRFS the NWSRFS lumpedlumped model? model?



For 7 of the 14 test basins, the overall flow percent bias is lower with the HDMS simulations

For 8 of the 14 basins, the overall Correlation Coefficient ”R” is closer to 1 with most of them at 0.85 and higher.

Note: Due to limitations with the statistical analysis software, the Overall simulations do not use the same observed timeseries dataset. HDMS is compared to the 1-hour observed discharge while NWSRFS is compared to a 6-hour timeseries. Hence, flow is “lost” in the 6- hour timeseries.

Multi-Year Overall FlowMulti-Year Overall Flow



For only 3 of the 14 test basins, the HDMS model performed better than the Adj. NWSRFS on the Timing of the Crest. However when taking the standard deviation into account, HDMS had a lower deviation on half of the basins.

Time to Peak ErrorTime to Peak Error

HDMS Time to Peak Error

-60

-50

-40

-30

-20

-10

0

10

20

30

40

50

60

0 5000 10000 15000 20000 25000 30000 35000

Peak Discharge(cfs)

Tim

e t

o P

ea

k E

rro

r(h

ou

rs)

ELDO2

ELMA4

SVYA4

KNSO2

TALO2

BSGM7*

INCM7*

WTTO2

BLKO2

BLUO2

CBNK1

CVSA4*

ELTT2

MLBA4

SLSA4*

SPRA4

TIFM7

WSCO2*



For 8 of the 14 basins, the normalized Mean Peak Discharge Error is better with HDMS.

When evaluating the Standard Deviation and the normalized Peak Discharge “Adj” error, 9 of the 14 basins performed better with HDMS.

Peak DischargePeak Discharge

Plots of normalized HDMS peak discharge errors for Events identified

between 4/02 through 8/05.

HDMS Peak Discharge Error

-2.50

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

0 10000 20000 30000 40000 50000 60000

Peak Discharge (cfs)

No

rmal

ized

Cre

st E

rro

r (2

-yea

r fl

oo

d f

req

uen

cy p

eak

dis

char

ge)

ELDO2

ELMA4

SVYA4

KNSO2

TALO2

BSGM7*

INCM7*

WTTO2

BLKO2

BLUO2

CBNK1

CVSA4*

ELTT2

MLBA4

SLSA4*

SPRA4

TIFM7

WSCO2*


A Closer Look at a A Closer Look at a Calibrated BasinCalibrated Basin

Minor improvement from 0.84 (Lumped) to 0.86 (HDMS) in the correlation coefficient “R”.

Improved simulation of the higher flow events, typically these are under simulated.

Time to crest error showed a decrease with a smaller variability:

– HDMS error was 1.9 hrs - most crests late – NWSRFS error was 3.3 hrs – most crests early

Statistical analysis for Corbin, KS (CBNK1) – period 1/2002 though 8/2005.


Focusing on the EventsFocusing on the Events

CBNK1 Crest Time Error

-20

-15

-10

-5

0

5

10

15

20

0 2000 4000 6000 8000 10000

Peak Discharge (cfs))

Cre

st

Tim

e E

rro

r (H

ou

rs)

HDMS

NWSRFS

AdjNWSRFS

CBNK1 Peak Discharge Error

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0 3000 6000 9000 12000 15000 18000

Peak Discharge (cfs))

Nor

mal

ized

Pea

k Er

ror

(2-y

ear f

lood

freq

uenc

y p

eak

disc

harg

e)

HDMS

NWSRFS

AdjNWSRFS

Plot of the Crest Time Error for the 26 events identified at CBNK1. HDMS

tended to be late in its timing of the crest while NWSRFS tended to be early.

Plot of the Peak Discharge Error for the 26 events identified at CBNK1. The Normalizing Factor is the 2-year flood frequency which is 8990 cfs. Both models give a mix of over and under simulations for events that are 6000 cfs and less. However for the larger events, both models dramatically undersimulate the crest.


SummarySummary

HDMS appears to perform as well or better than lumped model for most of test basins…especially in the simulation of peak discharge.

HDMS shows promise as a more advanced Hydrologic Model for NWS operations.


ContactsContacts

OHD– Lee Cajina [email protected]– Seann Reed [email protected]

ABRFC – Diane Cooper [email protected]

WGRFC– Paul McKee [email protected]


Appendix AAppendix AHDMS Statistical Analysis DataHDMS Statistical Analysis Data

Basin 2 year Flood Frequency(Normalizing Factor)

CorrelationCoefficient

"R"

Overall PercentBias

Mean Time toPeak Error

(hr)

Mean Time to peak ST Dev

Mean Normalized Peak Discharge

Error

Mean NormalizedPeak St Dev

CVSA4 1980 0.75 -23.6 8.8 3.7 -0.41 0.36

ELMA4 5480 0.81 7.84 7.2 4.0 -0.29 0.35

MLBA4 21100 0.92 17.74 5.6 5.6 0.01 0.18

SLSA4 27900 0.79 58.51 11.6 10.3 -0.07 0.27

SPRA4 794 0.69 16.09 3.2 2.9 -0.07 0.56

SVYA4 10700 0.88 -0.02 5.7 6.7 -0.23 0.44

TIFM7 23400 0.95 5.07 4.9 7.4 -0.03 0.14

CBNK1 8990 0.87 -23.09 1.9 7.1 -0.18 0.31

BLKO2 22400 0.86 -29.71 13.1 18.3 -0.24 0.26

BLUO2 8770 0.82 14.78 8.8 17.0 -0.03 0.19

ELDO2 16200 0.92 0.26 -1.4 13.0 -0.18 0.34

KNSO2 3580 0.89 7.98 1.5 5.3 0.02 0.22

TALO2 20300 0.94 38.82 -2 11.5 0.08 0.17

WSCO2 1280 0.83 -21.46 3.5 2.6 0.19 0.34

WTTO2 20700 0.88 60.69 9.3 11.1 0.01 0.21

ELTT2 2610 0.59 41.7 -1.7 39.3 0.07 0.21

ELTT2a 7.2 15.0 0.01 0.15

BSGM7 5020 0.9 0.34 2.3 4.7 -0.05 0.20

INCM7 3980 0.94 20.03 -0.7 11.1 0.09 0.41


Appendix BAppendix BNWSRFS Statistical Analysis DataNWSRFS Statistical Analysis Data

Basin Correlation Coefficient “R”

Overall Percent Bias

Mean Time to Peak Error (hr)

Mean Time to peak ST Dev

Mean Normalized Peak Discharge Error

Mean Normalized Peak St Dev

CVSA4 N/A N/A N/A N/A N/A N/A

ELMA4 0.63 -22.43 -2.8 3.8 -0.13 0.4

MLBA4 0.79 -3.83 -2.7 5.8 -0.02 0.15

SLSA4 0.82* -32.99* -2.6* 4.5* –0.14* 0.23

SPRA4 N/A N/A N/A N/A N/A N/A

SVYA4 0.79 0.51 2.0 7.0 -0.08 0.12

TIFM7 0.87 -20.28 1.6 8.5 -0.06 0.17

CBNK1 0.84 0.83 -3 8.2 -0.12 0.34

BLKO2 0.9 -15.3 -1.2 14.1 -0.12 0.18

BLUO2 0.85 -47.29 -6.2 17.9 -0.07 0.15

ELDO2 0.78 -28.22 -3.6 9.0 -0.24 0.38

KNSO2 0.86 -4.46 -4 8.3 0.02 0.26

TALO2 0.95* -27.96* -2.0* 14.1* –0.12* 0.12*

WSCO2 0.52* -41.34* -5.2* 5.0* –0.14* 0.18*

WTTO2 0.96* -22.49* -1.4* 7.8* –0.08* 0.10*

ELTT2 0.68 56.5 -6 39.1 0.02 0.15

ELTT2a 2.7 16.9 0.07 0.21

BSGM7 0.65† -70.42† -6† 0.7† 0.15† 0.05†

INCM7 0.70† -68.97† 0† 0† –0.29† 0.24†


Appendix CAppendix CAdj. NWSRFS Statistical Analysis DataAdj. NWSRFS Statistical Analysis Data

Basin Adj Mean Time to Peak Error (hr)

Adj. Mean Time to peak ST Dev

Adj. Mean Normalized Peak Discharge Error

Adj. Mean Normalized Peak St Dev

CVSA4 N/A N/A N/A N/A

ELMA4 -2.2 2.7 -0.27 0.51

MLBA4 -1.5 5.7 -0.04 0.16

SLSA4 -3.9* 7.3* –0.16* 0.24*

SPRA4 N/A N/A N/A N/A

SVYA4 2.7 6.6 -0.15 0.26

TIFM7 -0.6 8.5 -0.07 0.18

CBNK1 -3.3 7.6 0.14 0.35

BLKO2 -0.9 13.6 0.12 0.18

BLUO2 -5.7 18.1 0.08 0.16

ELDO2 -3.7 8.2 0.32 0.42

KNSO2 -3.6 8.2 0.03 0.3

TALO2 -1.9* 15.0* –0.12* 0.12*

WSCO2 -3.1* 5.6* –0.27* 0.30*

WTTO2 -1.4* 8.0* –.12* 0.11*

ELTT2 -4.9 39.0 0.01 0.15

ELTT2a 3.9 16.3 0.03 0.13

BSGM7 -5.5† 0.7† –0.16† 0.06†

INCM7 1.5† 3.5† –0.33† 0.28†


Reference Information for Reference Information for Appendices A, B and C.Appendices A, B and C.

Appendix A, B and C are summaries of selected statistical parameters. The Correlation Coefficient “R” and Percent Bias were derived from the multi-year time series analysis. The HDMS simulation was compared to the one hour observed and the NWSRFS simulation was compared to the six hour observed discharge. The NWSRFS “Adj.” information is a comparison of the six hour NWSRFS simulations to the one-hour instantaneous discharge time series. The ELTT2a Peak Error averages, excludes 2 events which both models performed very poorly.

Note: “†” indicates the NWSRFS multi-year analysis began in March 2005, and “*” indicated the analysis began in the summer of 2003.) Elsewhere, the multi-year period was from April 2002 through August 2005.

The basins shaded in Pink, the Annual Peak Discharge’s period of record is less than 10 years. So the accuracy of the 2-year frequency peak discharge normalization factor is suspect.


Appendix DAppendix DTable of the HDMS Test BasinsTable of the HDMS Test Basins

NWS Handbook 5 ID USGS Site Number Gauge Location Basin Size mi2 (km2)

CVSA4 07194880 Osage Creek at Cave Springs, AR 35 (90)

DMLA4 07196900 Barron Fork Creek at Dutch Mills, AR 40 (105)

ELMA4 07195000 Osage Creek at Elm Springs, AR 130 (337)

MLBA4 07252000 Mulberry River near Mulberry. AR 373 (966)

SLSA4 07195430 Illinois River at Siloam Springs, AR 575 (1489)

SVYA4 07914800 Illinois River at Savoy, AR 167 (433)

SPRA4 07195800 Flint Creek at Springtown, AR 14 (37)

CBNK1 07151500 Chikaskia River at Corbin, KS 794 (2056)

BSGM7 07188653 Big Sugar Creek at Pineville, MO 141 (365)

INCM7 07188885 Indian Creek at Anderson, MO 239 (619)

TIFM7 07189000 Elk River at Tiff City, MO 872 (2258)

BLKO2 07152000 Chikaskia River at Blackwell, OK 1859 (4815)

BLUO2 07332500 Blue River near Blue, OK 476 (1233)

CPCO2 07196973 Peacheater Creek at Christie, OK 25 (65)

ELDO2 07197000 Barron Fork River at Eldon, OK 307 (795)

KNSO2 07196000 Flint Creek at Kansas, OK 110 (285)

TALO2 07196500 Illinois River at Tahlequah, OK 959 (2484)

WSCO2 07195865 Sager Creek at West Siloam Springs, OK 19 (49)

WTTO2 07195500 Illinois River at Watts, OK 635 (1645)

AMAT2 07227500 Canadian River at Amarillo, TX 19445 (50363)

ELTT2 07312200 Beaver Creek near Electra, TX 10298 (26672)

presented by: diane cooper arkansas-red basin river forecast center hydrologist

Documents

hdms test basins

hdms model

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nwsrfs lumped model

short nwsrfs sqin timeseries

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