fe 537 catchment modeling · 0.2 0.4 0.6 0.8 1 goodness measu r e a 1 , a 2 s a n d a 3 a 1 a d a 2...
TRANSCRIPT
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CatchmentCatchmentModelingModeling
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This sectionThis section
An experimentalistAn experimentalist’’s view of models and s view of models and their development in their development in catchmentcatchment hydrology hydrology Example of a model that captures Example of a model that captures
dominant runoff processesdominant runoff processesUsing our new process knowledge to build Using our new process knowledge to build
the model and calibrate the modelthe model and calibrate the modelHow to judge the worth of a model with our How to judge the worth of a model with our
process knowledgeprocess knowledgeBringing detailed processes (that we Bringing detailed processes (that we
cannot observe!) into the modelcannot observe!) into the model
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The PrehistoryThe PrehistoryThe need for a design discharge
Examples:• the Rational Method and the Time Area Curve• the Unit Hydrograph, the Effective Rain and Separation of Hydrographs• the Linear Models: the linear channel, the linear reservoir, the Nash cascade• …
only for small and impervious catchmentsvery strong assumptions (e.g. linearity)
Mario Martina
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The Middle AgesThe Middle AgesThe conceptual models
Examples (WMO Intercomparison, 1976):• the STANFORD model IV• the SACRAMENTO model• the continuous API model• the CLS
the parameters are physically meaninglessMario Martina
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The RenaissanceThe RenaissanceThe physically based models
Examples:• the R.A. Freeze Model• the Systeme Hydrologique Europeen• the Institute of Hydrology Model• the SHETRANbreakthrough in hydrological modelling physical processes are now represented
too many parameters, too many information needed for the calibrationMario Martina
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The RomanticismThe RomanticismThe Variable Contributing Area models
Examples:• the Probability Distributed Soil Capacity model• the Xinanjiang Model• the VIC model• …
few parameters, but they are not directly related to measurable quantities
A probabilistic representation of spatially distributed variables
Mario Martina
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The Modern AgeThe Modern AgeThe derived from topography models
Examples:• the Soil Conservation Number model• the Geomorphologic Unit Hydrograph• the TOPMODEL• …
few parameters and they can be related to measurable quantities
but are they really physically based ?
TOPMODELTopographicIndex
Mario Martina
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The Contemporary AgeThe Contemporary AgeNew physically based / process oriented models
Examples:• the Representative Elementary Watershed (REW) model• the Tracer Aided Catchment Distributed (TACD) model• the TIN-based Real-time Integrated Basin Simulator (tRIBS)• the TOPographic KInematic wave APproximation and Integration (TOPKAPI)• …
Physically-based distributed representation of the dominant processes (synthesis)
sometimes a coupled conceptual/physically based approach Mario Martina
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Complexity / PredictabilityComplexity / Predictability
Grayson & Bloschl(Advances in Water Resources, 2002)
More complex does not always mean better !
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Different scalesDifferent scales
Measures Phenomena(and theory)
Models
Mario Martina
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Process assumptions that we have reviewed Process assumptions that we have reviewed (and rejected!)(and rejected!)
Z
T0(a) Topography
(b) Index
(c) Depth to WT
SaturatedArea
ln(a/tanβ)
Depth
T T eZZ= −
0
PreferentialflowBedrock topography
Not steady state
Threshold connections
Bloody Hell!
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Remember this slide from the Introduction?Remember this slide from the Introduction?
0
25
50
75
100
9/30 10/20 11/9 11/29 12/19 1/8
Date
Run
off (
l/s)
0.5
0.7
0.9
100 200 300 400
K (m/d)
Q E
ffici
ency
Vache et al., 2004 GRL
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This is what such uncertainty can mean for This is what such uncertainty can mean for something we (now) know aboutsomething we (now) know about
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If an experimentalist was to build a If an experimentalist was to build a catchmentcatchment modelmodel
““After much whittling down, After much whittling down, this is my most parsimonious this is my most parsimonious
catchmentcatchment model structuremodel structure……..””
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If an experimentalist were to build a model If an experimentalist were to build a model for realfor real
Hillslope box
Riparian box
P E
Runoff
Umax
UUmin
Hollow box
P EP E
Coupled saturated and unsaturated storage
Linear outflow equationsThreshold level in hollow box
Seibert and McDonnell, 2002 WRR
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ExampleExample
hollo
w
Plan
ar
slope
3 ha catchment
Stream and riparian zones
17 ha catchment
Downstream
Hillslope throughflow trench
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The sat and The sat and unsatunsat zone need to be coupled zone need to be coupled from what we have examined todayfrom what we have examined today
nd
n
Saturated zone
Unsaturated zone
Soil
dept
h D
nAWV sat =)()( dunsat nnAWDV −−=
Wat
er ta
ble
dept
h W
Volume:
Saturated zone
Unsaturated zone
ΔW output
Falling water table
Saturated zone
Unsaturated zone
ΔW
Rising water table
intput
)( dsat
sat nnAwVm
m −Δ=Δ
Mass exchange:
)( dunsat
unsat nnAwVm
m −Δ=Δ
Mass exchange:
Initial condition
Weiler and McDonnell, 2003 Weiler and McDonnell, 2003 JoHJoH
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Hillslope
Riparian Zone
Hollow
Why three boxes in this application?
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Na (mol/L)
010
2030405060
7080
90100
K (μ
mol
/L)
StreamRainRiparian ZoneSoil-RidgeSoil-Hollow
0 50 100 150 200 250
Riparian Zone Hollow
Hillslope
Geochemical End Members
Elsenbeer et al., unpub data
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McDonnell et al.,1991 WRR
Hillslope
Hollow
Riparian
Cluster Analysis of Deuterium Concentration in Subsurface Water
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A nonA non--linear reservoir in the linear reservoir in the hollowhollowboxbox
Hillslope box
Riparian box
P E
Runoff
Umax
UUmin
Hollow box
P EP E
Hillslope typediscussed earlier…
Seibert and McDonnell, 2002 WRR
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Effect of drainable porosity decline on Effect of drainable porosity decline on hillslopehillslope response to rainfall (and mixing)response to rainfall (and mixing)
⎟⎠⎞
⎜⎝⎛−=
mznznd exp)( 0 ψψ<0
ψψ<0
δδ1818Ο = Ο = −−55οο//οοοο
Storm Rainfall ΣδΣδ1818Ο = Ο = −−1010οο//οοοο
δδ1818Ο = Ο = −−4.54.5οο//οοοο
⎟⎠⎞
⎜⎝⎛−=
mznznd exp)( 0
McD, 1990 WRR; McD et al 1996 EOS; Freer et al. 2002 WRR
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Model efficiency : 0.93Model efficiency : 0.93
28-Sep 8-Oct 18-Oct 28-Oct 7-Nov 17-Nov 27-Nov
0
2
4
6
Q [m
m/h
]
0
1
2
Gro
undw
ater
leve
l [m
]
Observed QSimulated Q
HillslopeHollowRiparian
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It works, eh?It works, eh?
0
0.2
0.4
0.6
0.8
1
Goo
dnes
s m
easu
re
A1, A2 and A3
A1 and A2
Q and new water
Q and soft GW A1 Q
Runoff efficiencyGW hardGW softParameter valuesNew water
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Model efficiency : 0.93Model efficiency : 0.93
28-Sep 8-Oct 18-Oct 28-Oct 7-Nov 17-Nov 27-Nov
0
2
4
6
Q [m
m/h
]
0
1
2
3
Gro
undw
ater
leve
l [m
]
Observed QSimulated Q
HillslopeHollowRiparian
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Model efficiency : 0.92Model efficiency : 0.92
28-Sep 8-Oct 18-Oct 28-Oct 7-Nov 17-Nov 27-Nov
0
2
4
6
Q [m
m/h
]
0
1
2
3
Gro
undw
ater
leve
l [m
]
Observed QSimulated Q
HillslopeHollowRiparian
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Model efficiency : 0.93Model efficiency : 0.93
28-Sep 8-Oct 18-Oct 28-Oct 7-Nov 17-Nov 27-Nov
0
2
4
6
Q [m
m/h
]
0
1
2
Gro
undw
ater
leve
l [m
]
Observed QSimulated Q
HillslopeHollowRiparian
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The internal tugThe internal tug--ofof--warwar…what about fieldexperience?!
… we need real datafor model calibration!
reviewers
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What is What is ““soft datasoft data””??
Qualitative knowledge from the geoscientist that cannot be used directly for model calibration (or validation)
(e.g. new water contribution [%] to peak flow, maximum
groundwater level, mean soil depth, reservoir volume, etc))
Bypass flowand mixing
Pipeflow of oldwater
z
StorageRainfall
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Dialog between the experimentalist and Dialog between the experimentalist and modelermodeler
Hillslope box
Riparian box
P E
Runoff
Umax
UUmin
Hollow box
P EP E
Experimentalist ModelerEvaluation rules
Values for evaluation rules
Seibert and McDonnell, 2002 AGU Monograph
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Dialog between experimentalist and Dialog between experimentalist and modelermodeler
Experimentalist ModelerEvaluation rules
Values for evaluation rules (ai)
a1
a2 a3
a4
0.03
0.06 0.12
0.15
(30/9/87 event, McDonnell et al. 1991 WRR)
0
1
New water contribution to peak flow [-]
“Degree of acceptability”
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Soft data and degree of acceptabilitySoft data and degree of acceptability
⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
>
<≤−−
<≤
<≤−−
≤
=
4
4334
4
32
2112
1
1
0
1
0
)(
axif
axaifaaxa
axaif
axaifaaax
axif
xμ
a1
a2 a3
a4
Fuzzy Rules- new water at peak- reservoir volumes, Ksat etc- range of gw levels- hollow threshold level
0
1“Degree of acceptability”
Seibert and McDonnell, 2002 AGU Monograph
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Different ways of evaluating model acceptability based on Different ways of evaluating model acceptability based on hard (A1) and soft (A2 and A3) datahard (A1) and soft (A2 and A3) data
Acceptability according to: Example MeasureA1 Fit between simulated and Runoff Efficiency
observed dataA2 Agreement with perceptual New water Percentage of
(qualitative) knowledge contribution peak flowA3 Reasonability of parameter Spatial extension Fraction of
values of riparian zone catchment area
321321321 nnnnwithAAAA n nnn ++==
Combined objective function:
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Model performanceModel performance
0
0.2
0.4
0.6
0.8
1
Goo
dnes
s m
easu
re
A1, A2 and A3
A1 and A2
Q and new water
Q and soft GW A1 Q
Runoff efficiencyGW hardGW softParameter valuesNew water
Increasing amount of soft data
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Best overall performanceBest overall performance——a little a little ““less less rightright”” but for the correct process reasons but for the correct process reasons
28-Sep 8-Oct 18-Oct 28-Oct 7-Nov 17-Nov 27-Nov
0
2
4
6
Q [m
m/h
]
0
1
2
Gro
undw
ater
leve
l [m
]
Observed QSimulated Q
HillslopeHollowRiparian
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Other reservoir assemblages Other reservoir assemblages (it(it’’s a soft model approach that you can use in your area)s a soft model approach that you can use in your area)
It is physically-based
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Other modeling Other modeling examples at the examples at the hillslopehillslope scale (where scale (where we can use our new we can use our new process knowledge)process knowledge)
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PipeflowPipeflow
Pipeflow is mostly pre-event water but, applied line sources of tracer often show rapid lateral breakthrough through the pipe/hillslope system.
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Our simple modelOur simple model
⎟⎠⎞
⎜⎝⎛−=
bznznd exp)( 0
1
1)(−
⎟⎠⎞
⎜⎝⎛ −=
m
o DzKzK
wtTtqSSF β)()( =
Lateral subsurface flowLateral subsurface flowDupuitDupuit--ForchheimerForchheimerassumptionassumption (slope of (slope of water table)water table)22--D explicit grid by grid D explicit grid by grid cell approach cell approach (Wigmosta, 1994 WRR)(Wigmosta, 1994 WRR)
Water and mass balance Water and mass balance within the saturated and within the saturated and unsaturated zone unsaturated zone in each in each grid cellgrid cellSimple infiltration (soil Simple infiltration (soil water content, power law) water content, power law) and evapotranspirationand evapotranspiration
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Combining this with the process Combining this with the process understandingunderstanding
Experimental commonality**:Experimental commonality**:PPipeipe diameter within a narrow range. diameter within a narrow range.
Uchida et al. 2002 WRRUchida et al. 2002 WRRPPipeipe length and connectivity mapping length and connectivity mapping shows discontinuous pipe sectionsshows discontinuous pipe sections ((mamax.x.length length << somesome mmeters)eters)
KitiharaKitihara 1994 Bull. FFPRI1994 Bull. FFPRIPipe Pipe location within the soil profiles is location within the soil profiles is mostly within a narrow band above the mostly within a narrow band above the soilsoil--bedrock interfacebedrock interface..
Uchida et al. 2002 HP; Uchida et al. 2002 HP; WWaterater flow in the pipe flow in the pipe
Sidle et al. 1995 Sidle et al. 1995 JoHJoH::
( ) 4.0hkq p =**from review by Uchida et al 2001 HP
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Pipe height within starting cell
z
How to model the unknown pipe How to model the unknown pipe system?system?
slop
e
Spatial pipe geometry
Despite the limited length of preferential flow structures (e.g.Despite the limited length of preferential flow structures (e.g. pipes), pipes), they can connect by water flow from microthey can connect by water flow from micro--mesomeso--macro porosity.macro porosity.
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Visualizations Visualizations -- MaimaiMaimai
RunoffRunoff
ConcentrationConcentration
00 maxmax
Relative concentration in soil columnRelative concentration in soil column
Pipe FlowPipe Flow
Matrix FlowMatrix Flow
00 maxmax
Relative flow in soil pipesRelative flow in soil pipes
Pipe Flow Line tracer movement
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MaimaiMaimai
0.0
1.0
2.0
3.0
0.0
0.5
1.0
1.5
2.0
20 30 40 50 600.0
0.5
1.0
1.5
2.0
Run
off (
mm
/h)
Average with Pipes Ensembles with Pipes W ithout Pipes Measurements
Run
off (
mm
/h)
Total Pre-event runoff Average with Pipes Ensembles with Pipes W ithout Pipes
Trac
er R
ecov
ery
(%)
T ime (h)
Average with Pipes Ensembles with Pipes W ithout Pipes
Evaluation Criteria*
Flow
Event TracerWater % Recovery
*Consistency more important than optimality
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More QuestionsMore Questions………………
HHowow does soil depth does soil depth variation affect flow?variation affect flow?How can placeHow can place--based based experimental knowledge experimental knowledge be coupled with the model be coupled with the model approach? approach?
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Remember this site from beforeRemember this site from before……..
Soil depth mapped Soil depth mapped at 2 m gridat 2 m gridAverage: 0.63 mAverage: 0.63 mStd: 0.3 mStd: 0.3 mCorrelation length: Correlation length: 12 m12 m
Subsurface flow Subsurface flow measured at 10 2measured at 10 2--m m wide trench sectionswide trench sections
-2.0
-1.6
-1.2
-0.8
-0.4
0.0
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Time2/1/02 2/15/02 3/1/02 3/15/02 3/29/02 4/12/02
Sub
surfa
ce fl
ow (m
m/h
r)
0.00.10.20.30.40.50.60.7
ObservedModel: mapped soil depthModel: uniform soil depth
Pre
cipi
tatio
n (m
m/h
r)0
25
50
75
100
Model results: total subsurface flowModel results: total subsurface flow
Time2/6/02 2/7/02 2/8/02 2/9/02 2/10/02 2/11/02 2/12/02
Sub
surfa
ce fl
ow (m
m/h
r)
0.0
0.1
0.2
0.3
0.4
ObservedModel: mapped soil depthModel: uniform soil depth
Pre
cipi
tatio
n (m
m/h
r)0
5
10
Soil depth variability has a very large influence on modeled subsurface storm flow volume
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Model results: statistical representationModel results: statistical representation
Time2/6/02 2/7/02 2/8/02 2/9/02 2/10/02 2/11/02
Sub
surfa
ce fl
ow (m
m/h
r)
0.0
0.1
0.2
0.3
0.4Model: statistical representationsObservedModel: mapped soil depth - 20 m long trenchModel: mapped soil depth - 28 m long trenchModel: uniform soil depth
Pre
cipi
tatio
n (m
m/h
r)0
5
10
Multiple realizations of a model with statistical representations of soil depth represent observed subsurface storm flow better than a model with average soil depth
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Time2/6/02 2/7/02 2/8/02 2/9/02 2/10/02 2/11/02
Sub
surfa
ce fl
ow (m
m/h
r)
0.0
0.1
0.2
0.3Model: statistical representationsAverage of statistical representationsModel: uniform soil depth
Pre
cipi
tatio
n (m
m/h
r)0
5
10
Moving to larger segments of the landscapeMoving to larger segments of the landscape
70 x 100 m wide hillslopeFor larger hillslopes the effect of soil depth variability on total subsurface flow is less than for the smaller hillslope but the effect on timing of subsurface flow is large
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Other modeling Other modeling examples where we examples where we can use our new can use our new process knowledgeprocess knowledge
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m n
Init. Sat. Keff
Use this Use this expert knowledgeexpert knowledge to constrain to constrain our models alsoour models also
Vache et al GRL 2005
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Red dotsRed dots = % new = % new water < 50water < 50Black dots = % new Black dots = % new water > 50water > 50
Identifies parameter Identifies parameter sets that produce sets that produce the the ““efficientefficient””results for the wrong results for the wrong reasonsreasons
m n
Init. Sat. Keff
Rejecting nonsense dotsRejecting nonsense dots
Vache et al GRL 2005
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Other modeling Other modeling examples where we can examples where we can use our new process use our new process knowledge to determine knowledge to determine how much complexity is how much complexity is warranted in the modelwarranted in the model
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Discharge
Soil Water MRT
Stream Water MRT
Discharge
Soil Water MRT
Stream Water MRT
A Multi-Criteria Evaluative Strategy
Towards more orthogonal measures for model structural improvement and uncertainty
reduction
Gordon Grant’s Blob
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Captures flow path Captures flow path heterogeneityheterogeneity
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MaimaiMaimai: The simplest of our various : The simplest of our various experimental watershedsexperimental watersheds
hollo
w
Plan
ar
slope
3 ha catchment
Stream and riparian zones
17 ha catchment
Downstream
Hillslope throughflow trench
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Grid-based, highly simplified with 3 tunable parameters
The simplest of models to start
Vache et al., 2004 GRL inoutout SSSOFSSETPdtdV
+−−−=
The volume of water within each reservoir is accounted for using the familiar continuity equation:
Precipitation
Evapotranspiration
Lateral Subsurface Stormflow
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StreamwaterStreamwater residence time (120 days)residence time (120 days)but also soil water residence timebut also soil water residence time
2410550 2410600 2410650 2410700 2410750 2410800
5901850
5901900
5901950
5902000
5902050
5902100
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
Near Stream
Pit 5
Pit A
Tensiometer Network
ln(a/tanβ)
Raingauge
Annual DataP 2250 mmQ 1350 mmE 850 mm
Average DataSlope 34o
Relief 100-150mKsat 5 m/hr
Soils DataDepth 1 mStrong catenary sequence
Soil water Residence
Time
-4
-8
-12
δ18O
‰
-4
-8
-12
δ18O
‰
Soil WaterPrecipitation
Average 9 4‰ ‰
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MRT and distance from the divideMRT and distance from the divide2410550 2410600 2410650 2410700 2410750 2410800
5901850
5901900
5901950
5902000
5902050
5902100
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
Near Stream
Pit 5
Pit A
Tensiometer Network
ln(a/tanβ)
Raingauge
0
40
80
120
160
0 10 20 30 40 50 60 70 80
Distance from divide (m)
Mea
n R
esid
ence
tim
e (d
ays
MRT = 1.9(Distance) + 19.0r 2̂ = 0.88
Based on data from Stewart and McDonnell, 1991 WRR
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Regionalized MRT to the entire basin based on a 2 meter elevation grid using a single direction D8 algorithm
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Model outputModel output
0.1
1
10
100
9/30 10/20 11/9 11/29 12/19 1/8
Date
Run
off (
l/s)
Measured Run1426 Run1836
0
25
50
75
100
9/30 10/20 11/9 11/29 12/19 1/8
Date
Run
off (
l/s)
Measured Run1426 Run1836
1750 runs, cutoff NS > 0.75
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Tracer in the modelTracer in the model
outinpt qCqCpC
dtdM
−+=
∫
∫∞
∞
=
0
0
Cdt
tCdtMRT
Then defined as a mass balance of some arbitrary conserved tracer:
The mean residence time is derived by the concentration breakthrough:
i.e. time averaged C normalized by total mass of the tracer
Precipitation
Evapotranspiration
Lateral Subsurface Stormflow
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Simulated tracer breakthroughSimulated tracer breakthrough
0
5
10
15
20
9/2 10/12 11/21 12/31 2/9 3/20 4/29
Time
Bre
akth
roug
h (m
g/l)
Directly simulated MRT over the prior parameter range varied from 30 to 95 days.
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0.1
0.3
0.5
0.7
0.9
30 50 70 90 110Mean Residence Time (days)
Q E
ffici
ency
…the slide you saw earlier
Vache and McDonnell, 2005 WRR
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Model output from before
0
25
50
75
100
9/30 10/20 11/9 11/29 12/19 1/8
Date
Run
off (
l/s)
Measured Run1426 Run1836
…we would rejectthis model…recall that ourmeasured rangewas 0-120 days
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Precipitation
Evapotranspiration
Lateral Subsurface Stormflow
Residence time as a process-based model rejection tool
Model 1
Model 4
Model 3
Model 2
Precipitation
Evapotranspiration
Lateral Subsurface Stormflow
Precipitation
Evapotranspiration
Lateral Subsurface Stormflow
Precipitation
Evapotranspiration
Lateral Subsurface Stormflow
66YesYesYesYesYesYesModel 4Model 4
55YesYesNoNoYesYesModel 3Model 3
44NoNoYesYesYesYesModel 2Model 2
33NoNoNoNoYesYesModel 1Model 1
# Tuned # Tuned ParametersParameters
Explicit Explicit Unsaturated Unsaturated
ZoneZone
Effective Effective PorosityPorosity
Saturated Saturated ZoneZone
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Runs with NS > 0.7Runs with NS > 0.7
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BreakthroughsBreakthroughs
Note early time and late time differences between Models 1-4
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How much detail is warranted?How much detail is warranted?Complementary measures for evaluationComplementary measures for evaluation
Vache and McDonnell, 2005 WRR
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Take a virtual field trip that deals Take a virtual field trip that deals with with catchmentcatchment scale hydrology atscale hydrology at
http://www.cof.orst.edu/cof/fe/watershd/fe537/FE605http://www.cof.orst.edu/cof/fe/watershd/fe537/FE605--VFT_oak.htmVFT_oak.htm