Preliminary Applications of the HLRDHM within the Colorado Basin River Forecast Center

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Preliminary Applications of the HL-RDHM within
the Colorado Basin River Forecast Center
Ed Clark, Hydrologist Presented July 26th, 2007
as part of the WR Field Hydrology Seminar Series
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Discussion Outline

• Distributed Model background information.
• Parameterization and Setup.
• Applications and Preliminary Results.

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NWS Distributed Model(s)
RDHM Research Distributed Hydrologic
ModelObject oriented with SAC-SMA, Snow17, API,
Frozen Ground, Channel Shape, and Routing Curve
sub-routines
Output Grids -- Any parameters states Time
Series Basin Average (any parameter) and Outlet
Discharge.
DHM NWSRFS OperationRequires RDHM to setup
parameter grids. Limited to SAC-SMA model and
routing via the connectivity file. Delivered to
the RFCs in build 8.2.
Output Discharge time-series for display within
NWSRFS
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Model Structure

• Divides the basin of interest into 4 km2 grids.
  (HRAP)
• Requires gridded Surface Temperature and
  Precipitation (xmrgs from MPE).
• Runs modules the existing models Snow17,
  Sacramento Soil Moisture Accounting Model
  (SAC-SMA) to generate runoff.
• Runoff is routed by solving the Kinematic Wave
  Equations.

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Model Concept
Surface Temperature
Snow Pack
Water content in Soil tanks
Snow17
Rain melt
FRZ (Sac-HT)
SAC-SMA
Precip
Runoff
Water Contents at Depth
RDHM Routing
Discharge Hydrograph
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Channel and Hill-slope routing
Real HRAP Cell
Hillslope model
Cell-to-cell channel routing
From Yu Zhang, OHD
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Control and Calibration

• Input card is passed to the model. Defines
  location of data, simulation period, and
  calibration parameters.
• Parameters grids can be calibrated by multiplying
  the by a scalar.

gt1
Gridded Parameter
lt1
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Model Parameterization

• Snow17 MFMax and MFMin based on DEM analysis,
  provided by OHD.
• SAC-SMA grids provided by OHD and based on
  STATSGO data.
• Routing grids are generated from USGS field
  measurements by defining a relationship between
  channel shape and discharge.
• Other grids written out from the calibrated
  lumped model.

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Evolution to a Fully Distributed Model
Sac_LZTWM

• Lumped Model. Extensively calibrated for the
  CBRFC with a great deal of forecaster skill.
• Lumped parameter values distributed by elevation
  zone. Used to check the mechanics of the model,
  and increase forecast skill with high intensity,
  convective events.
• Fully Distributed. Parameters based on Statsgo
  data, calibrated by applying a scalar multiplier,
  High Spatial Variability

past
Future
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Application/Demonstration Basins

• Comparison w/ RTi SNOWDAS.
• Snow 17 Investigation
• Demonstration of gridded soil moisture norms
  and QPE driven small basin hydrograph. Santa
  Cruz and San Pedro basins.

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Distributed Snow Model

• Theoretically, a distributed model will provide a
  better model to real world relationship of snow
  covered area eliminating some error in
  simulation.
• Preliminary investigation sought to match current
  lumped model skill and check mechanics of the
  model.

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Animas, nr Durango CBRFC Lumped Sac-SMA Grids
Run WY 1975-2000 Scalars set to -1
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Application of Downstream Calibration to Upstream
points of Interest
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Observations and areas of future study

• A-priori MFMAX slightly low resulting in delayed
  of snowmelt.
• ET grids require further analysis - grid values
  from the lumped model.
• More rigorous forcing are required Use
  Auto-Daily-QC (Mountain-Mapper) to generate 30
  years of 6-hr xmrgs from station records.
• Operationally created xmrgs cant be used until
  MPE includes 24 hour data (SNOTEL.)

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Rapid surface-runoff and near surface soil
moisture

• Does spatially distributing convective
  precipitation help improve our ability to
  simulate hydrographs in arid portions of the
  Southwest?
• Can the gridded Sac-SMA model be used to qualify
  the current conditions of near-surface soil
  moisture?

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QPE driven small basin hydrograph flash
flooding quantification.
MPE xmrgs and scaled (calibrated lumped to
a-priori basin mean) OHD a-priori sac-sma grids
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MPE xmrgs and scaled (calibrated lumped to
a-priori basin mean) OHD a-priori sac-sma grids
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Qualified Soil Moisture

• Generate historical daily average states from the
  lumped model calibration.
• Compare the current contents to this days
  average conditions.
• Where are we today compared to where we are
  usually?

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Soil Moisture Percent of Normal
July 1, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
July 25, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
July 26, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
July 27, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
July 28, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
July 29, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
July 30, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
July 31, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
August 01, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
August 02, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
August 03, 2006
Upper Zone
Lower Zone
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Soil Moisture Percent of Normal
July 18, 2007
Upper Zone
Lower Zone
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Contents at Depth

• Utilizes Victor Korens Sacramento Heat Transfer
  (SAC-HT) model.
• Calculates frozen and liquid contents in a set of
  computational layers at specified depths.
• Outputs as outlet time-series or individual
  grids.

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Prototype Plot Lower Santa Cruz
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Continued Study

• Increase the number of calibrated basins.
• Increase the region over which soil moisture
  modeling is computed.
• Work with our customers (WFOs, regional
  scientists and land managers) to better publish
  soil moisture simulations and observations.

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Questions?
Available at http//www.cbrfc.noaa.gov/present/pr
esent2007.cgi