Analytic Vs Numeric Analytic Vs Numeric Ground Water ModelsGround Water Models
Ray R. Bennett, PERay R. Bennett, PEColorado Division of Water Colorado Division of Water
ResourcesResources
Example Analytic (Glover) Example Analytic (Glover) ApplicationApplication
Analytic (Glover)Analytic (Glover)
Depletion (q) is a function of:Depletion (q) is a function of:–– Pumping (Q)Pumping (Q)–– Transmissitivity (T)Transmissitivity (T)–– Specific Yield (Sy)Specific Yield (Sy)–– Distance from well to river (x)Distance from well to river (x)–– Distance to Aquifer Boundary (w)Distance to Aquifer Boundary (w)
Data is assigned by Aquifer (1 value)Data is assigned by Aquifer (1 value)RELATIVELY SIMPLERELATIVELY SIMPLE
Analytical (Glover) Analytical (Glover) Key AssumptionsKey Assumptions
Conductivity (K) is ConstantConductivity (K) is ConstantUniform Aquifer ThicknessUniform Aquifer Thickness–– Transmissitivity is ConstantTransmissitivity is Constant
Flat Water TableFlat Water TableStream is Fully PenetratingStream is Fully Penetrating
Analytical (Glover) ResultsAnalytical (Glover) ResultsResponse from Pumping in Month 1 OnlyResponse from Pumping in Month 1 Only
URF 6400511
0
2
4
6
8
10
12
14
16
18
20
0 5 10 15 20 25 30 35 40
Month
Volu
me
of D
eple
tion
(%)
Volume of Depletion from AWAS
Adjusted to 100% (URF)
Example Numeric ModelExample Numeric Model
Numerical (Modflow) ModelNumerical (Modflow) ModelDepletion is still a function of:Depletion is still a function of:–– Pumping (Q)Pumping (Q)–– Hydraulic Conductivity (K)Hydraulic Conductivity (K)–– Aquifer Thickness (b)Aquifer Thickness (b)–– Specific Yield (Specific Yield (Sy) or StorageSy) or Storage Coefficient (S)Coefficient (S)–– Distance from well to river (x)Distance from well to river (x)–– Distance to Boundary (w)Distance to Boundary (w)
Data is assigned by Model Cell (1,000Data is assigned by Model Cell (1,000’’s)s)Might include complex geometry, multiple layers, Might include complex geometry, multiple layers, boundary conditions, partially penetrating boundary conditions, partially penetrating streams, ET from GW, subirrigation, impact on streams, ET from GW, subirrigation, impact on canals, canals, ……..LOTS of WORKLOTS of WORK
Numerical (Modflow) ResultsNumerical (Modflow) ResultsStream DepletionStream Depletion–– By stream Reach (not a point)By stream Reach (not a point)
Water LevelsWater LevelsGround Water BalanceGround Water BalanceStream Water BalanceStream Water Balance–– Phreatophyte CUPhreatophyte CU–– SubirrigationSubirrigation–– Complex Geology (faulting)Complex Geology (faulting)–– Complex BoundariesComplex Boundaries–– Multiple, Layered AquifersMultiple, Layered Aquifers
URF 6400511
0
2
4
6
8
10
12
14
16
18
20
0 5 10 15 20 25 30 35 40
Month
Volu
me
of D
eple
tion
(%)
Volume of Depletion from AWAS
Adjusted to 100% (URF)
Comparison SummaryComparison Summary
Item Analytical NumericalStream Depletion Yes Yes
Assumptions High Low-HighWater Levels No Yes
Complex Geology No YesDry Stream No Yes
Multiple Aquifers No YesEffort Low Med-High
South Platte DSS
Republican River
Division 1 except Republican (WD 65) and North Platte (WD 47)North
Platte
South Platte
Colorado Water Conservation Board and Division of Water Resources
SPDSS SPDSS Major ComponentsMajor Components
Data Data -- Tabular and MapsTabular and MapsNew Data New Data -- Irrigated Lands, Irrigated Lands, stream gages, aquifer data, and stream gages, aquifer data, and observation wellsobservation wellsTools Tools –– CU, SW, GWCU, SW, GWUser Involvement User Involvement Documentation & Product Documentation & Product DistributionDistribution
DSS Components
HydroBaseHydroBase Field and Historical Datadmis
dmis
dmis
dmis
d mi s
dmis
dmis
dmis
Surface WaterPlanningModel
TSTools
Water BudgetModel
Water RightsAdminCU Model
Other UserComponents
GroundwaterPlanningModel
= DSS Integration Component
Tabular DataTabular DataStationsStations–– StreamflowStreamflow–– Climate (temp, Climate (temp,
ppt., evap.)ppt., evap.)
StructuresStructures–– DiversionsDiversions–– ReservoirsReservoirs–– Instream Flows Instream Flows
Water RightsWater Rights–– TransactionTransaction–– NetNet
Ground WaterGround Water–– Water LevelsWater Levels–– Pumping TestsPumping Tests
CallsCalls–– TributaryTributary–– MainstemMainstem
OtherOther–– Agricultural Agricultural
StatisticsStatistics–– Crop Growth Crop Growth
CoefficientsCoefficients
Tabular DataTabular DataInternet (WWW)Internet (WWW)
Spatial (Map) DataSpatial (Map) DataBasemapBasemap–– HydrologyHydrology–– RoadsRoads–– Cities and TownsCities and Towns–– Public Land Survey Public Land Survey
(T(T--RR--S)S)
StationsStations–– DiversionsDiversions–– ReservoirsReservoirs–– Instream FlowsInstream Flows–– ClimateClimate
Irrigated AcreageIrrigated Acreage–– Water SourceWater Source–– Crop TypeCrop Type–– Irrigation MethodIrrigation Method
OtherOther–– Average Average
precipitationprecipitation–– Average Average
evaporationevaporation–– CanalsCanals–– DrainsDrains
Spatial DataSpatial DataIrrigated Acreage MappingIrrigated Acreage Mapping
Irrigated Area,
Crop Type,
Irrigation Method,
Water Supply
SoilData
Irrigated Acreage and Crop Type
0
2000
4000
6000
8000
10000
12000
14000
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
Surface Water Supply Data
0
10
20
30
40
50
60
70
80
90
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Climate Data
PARCEL CROP_TYPE IRRIGATION ACREAGE PERIMETER10101 Alfalfa Sprinkler 131.832 2610.94310102 Corn Flood 135.253 2650.78310103 Alfalfa Sprinkler 124.643 3103.06910104 Corn Sprinkler 123.794 2532.17510105 Corn Flood 133.197 2619.83310106 Small Grains Sprinkler 135.335 2649.93310107 Alfalfa Flood 134.877 2637.10510108 Alfalfa Flood 134.181 2637.85210109 Small Grains Flood 125.197 2542.80510110 Alfalfa Sprinkler 122.907 2521.061
Irrigation Method Ditch Efficiencies
Locally Calibrated Blaney-Criddle Crop Coefficients
PCU for Alfalfa at the Fort Collins Climate Station
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Pot
entia
l Con
sum
ptiv
e U
se (f
eet)
ASCE Standardized Modified Blaney-Criddle,TR-21 Coeff.
Bridge on County Road 56 over the Larimer County Canal
Consumptive UseConsumptive UseStateCUStateCU
StateCU Typical ResultsStateCU Typical ResultsCU by Water Supply (SW and GW)CU by Water Supply (SW and GW)
Figure 5Phase 5 CU by Water Supply
0100,000200,000300,000400,000500,000600,000700,000800,000900,000
1,000,000
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
Year
CU
(Ac-
Ft)
Surface Water Ground Water
StateModColorado’s Water Resources Planning Model
Ray Bennett, Colorado Division of Water Resources
StateMod Major Features
•Network System
•Monthly or Daily Time Step
•Prior Appropriation Doctrine
•Structure TypesDiversions, Reservoirs,Instream Flows, Wells &Plans
•Operational Rules•Complex water operations
•Graphical User Interface
StateMod Features (cont.....)
•Creates Base or Natural Flows
•Efficient Solution Method– Direct Solution Algorithm– Modified Direct Solution Algorithm•Variable Efficiency
•Soil Moisture Accounting
•Plan Accounting
•Call Reporting
StateMod Typical ResultsStateMod Typical ResultsCompact Delivery Vs Compact CallCompact Delivery Vs Compact Call
9000
9500
10000
10500
11000
11500
12000
1/1/1850 1/1/1930 1/1/1950 1/1/1960 1/1/1970 1/1/1995
Compact Call Date
Yiel
d (K
af/y
r)
Colorado’s Ground Water Model Modflow (USGS)
Alluvial Aquifer
Modflow FeaturesModflow Features
GeologyGeologyAquifer ParametersAquifer ParametersPumpingPumpingRechargeRechargeBoundary ConditionsBoundary ConditionsStreamflows and DiversionsStreamflows and DiversionsSpringsSpringsDrainsDrainsEvapotranspirationEvapotranspirationSubirrigationSubirrigation
Modflow Typical ResultsModflow Typical ResultsProposed Pumping ImpactProposed Pumping Impact
More about SPDSSMore about SPDSSWeb SiteWeb Site–– http://cdss.state.co.ushttp://cdss.state.co.us
DWRDWR–– Ray Bennett (303) 866 Ray Bennett (303) 866 -- 35853585–– [email protected]@state.co.us
CWCBCWCB–– Ray Alvarado (303) 866 Ray Alvarado (303) 866 -- 3517 3517 –– [email protected]@state.co.us