Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop
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Transcript of Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop
![Page 1: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/1.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Measuring and Modeling Transpiration,or What the Flux is Hydrology?
ChEAS Workshop
Scott Mackay
UW-Madison
![Page 2: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/2.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 3: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/3.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
• Suggested question:– How does landscape fragmentation affect transpiration
and carbon flux rates?
• Your mission:– Develop a 1 (2 max) page micro proposal that
addresses the above question or one of your choosing;
– Your proposal should state questions or hypotheses, objectives, how you would conduct the work, and what the anticipated results would be.
Future Directions?
![Page 4: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/4.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 5: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/5.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Water and Global Vegetation
Precipitation (mm)
500 4500
Deserts
![Page 6: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/6.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 7: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/7.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
a – evaporation, non-vegetation
b – evapotranspiration
c – lateral transport
d – precipitation
e – runoff
f – ground water recharge
Hydrologic Cycle
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Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Streamflow Discharge
![Page 9: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/9.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
tantTtq
Groundwater Flow
![Page 10: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/10.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Sand and Gravel AquiferPrice County
![Page 11: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/11.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 12: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/12.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
First
Stream Orders
Stream
Stream junction
Divide
Watershed Boundary
NestedWatershed
Second
Third
Hillslope
WatershedOutlet
Evapotranspiration as a Residual
P + GIN - (Q + E + GOUT) = 0
E = P - Q
AssumesGIN = GOUT
![Page 13: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/13.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Hillslope Profile (or Catena)
Evapotranspiration
Precipitation
Runoff
Streamflow
Infiltration
Drainage
Throughfalland stemflow
Groundwater flow
Hillslope Hydrology
![Page 14: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/14.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 15: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/15.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
1) leaf level gas exchange
a) direct measurement
b) interrupts ambient environment
c) large number of samples needed to scale up
Direct Transpiration Measurements
Pearcy et al. (1989); Schulze et al. (1982)
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Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
2) tree level xylem sap flow
a) large number of measurements
b) does not interrupt ambient environment
c) requires appropriate scaling in time and space
Direct Transpiration Measurements
Cermak and Kucera (1973);Granier (1987);Schulze and Fichtner (1988)
![Page 17: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/17.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
3) lysimeters
a) most accurate method
b) large disturbance to soil environment
c) difficult to measure large trees
d) difficult to field replicate
Direct Transpiration Measurements
van Bevel and Meyers (1962);Fritschen et al. (1973)
![Page 18: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/18.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Direct Transpiration Measurements
4) micrometeorological techniques
a) direct ecosystem level measurement
b) requires appropriate site conditions
c) can not separate ecosystem components directly
Campbell and Unsworth (1979);Kaimal (1979);Wyngaard (1981)
![Page 19: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/19.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 20: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/20.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Indirect Evapotranspiration Estimation
1. Temperature-Baseda. Cannot resolve time intervals less than monthlyb. Ignore processes
2. Energy Balancea. Simpleb. Relies on differences between uncertain quantitiesc. Unreliable for large vapor pressure gradients
3. Mass Transfera. Uses reliable micrometeorological measurementsb. Data collection difficult for multiple measurement sites
4. Combination Methodsa. Combines benefits of energy balance and mass transferb. Data intensive
![Page 21: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/21.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Thornthwaite (1949)Temperature-Based
a
I
tdE
10
6.1
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Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Indirect Evapotranspiration Estimation
1. Temperature-Baseda. Cannot resolve time intervals less than monthlyb. Ignore processes
2. Energy Balancea. Simpleb. Relies on differences between uncertain quantitiesc. Unreliable for large vapor pressure gradients
3. Mass Transfera. Uses reliable micrometeorological measurementsb. Data collection difficult for multiple measurement sites
4. Combination Methodsa. Combines benefits of energy balance and mass transferb. Data intensive
![Page 23: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/23.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Energy Balance Method
B = 0.1 (tropical oceans), 0.4 to 0.8 (temperate forests), 10.0 (deserts)
as
asa
ee
TTPc
LE
HB
622.0
EBLEBH w
B
GRE
w
n
1
w
n GHRE
Rn
G
H LE
![Page 24: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/24.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Indirect Evapotranspiration Estimation
1. Temperature-Baseda. Cannot resolve time intervals less than monthlyb. Ignore processes
2. Energy Balancea. Simpleb. Relies on differences between uncertain quantitiesc. Unreliable for large vapor pressure gradients
3. Mass Transfera. Uses reliable micrometeorological measurementsb. Data collection difficult for multiple measurement sites
4. Combination Methodsa. Combines benefits of energy balance and mass transferb. Data intensive
![Page 25: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/25.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
constant2
OHaT
e
aa eT Sate VPD
(Ideal Gas Law)
Mass Transfer
aaSatOH
a eTeP
E 2
622.0
![Page 26: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/26.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Frictional Drag
Eddy Currents
Z
M
M = momentum
HLE
H = sensible heatLE = latent heat of evaporation
HLE
HLE
HLEVapor
PressureGradient
TemperatureGradient
Wind Speed
Mass Transfer: Vertical Transport
![Page 27: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/27.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
EvKE 2
0
2
ln
622.0
2
2
z
zzPD
DK
dOH
a
M
OHE
Mass Transfer: Vertical Transport
![Page 28: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/28.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Indirect Evapotranspiration Estimation
1. Temperature-Baseda. Cannot resolve time intervals less than monthlyb. Ignore processes
2. Energy Balancea. Simpleb. Relies on differences between uncertain quantitiesc. Unreliable for large vapor pressure gradients
3. Mass Transfera. Uses reliable micrometeorological measurementsb. Data collection difficult for multiple measurement sites
4. Combination Methodsa. Combines benefits of energy balance and mass transferb. Data intensive
![Page 29: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/29.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
aaSat eTeE
OH
aaSatOHEn eTevKRE
2
2
Combination Formula (Penman, 1948)
Energy Mass TransferVertical Transport
2
0
2
ln
622.0
2
2
z
zzPD
DK
dOH
a
M
OHE
w
n GHRE
![Page 30: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/30.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
OH
aaSatOHEn eTevKRE
2
2
Penman-Monteith (Monteith,1965)
2
0
2
ln
622.0
2
2
z
zzPD
DK
dOH
a
M
OHE
aaSatE eTevKE
c
aOH
aaSataaanC
g
g
eTegcRE
12
2
0
2
ln
1
z
zz
v
rg
da
a
![Page 31: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/31.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Priestley and Taylor (1972)
OH
nTPTP
RE
2
asoilvw
assatpaS RR
eTecE
])([
Deardorff (1978); Maufouf and Noilhan (1991)
- works best for low VPD;
- crude for low canopy conductance (<20mm/s)
- sensitive to stability; -soil resistance not easyto calculate;
- numerous variants areavailable
![Page 32: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/32.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 33: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/33.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Types of Tree Level Xylem Sap Flow
Xylem flow velocity with heat pulses V=D/T Hard to determine true distances due to wall friction, anastomising
flow paths and other problems
Measurement of xylem sap mass flow (Cermak and Kucera-type sensors)
1) Null balance method maintains a constant pre-selected temperature (4 C) between temperature measurement points
a) power requirements minimal because power is proportional to flowb) little empiricismc) can not determine within tree flow paths
2) Constant heating method (Granier-type sensors)
![Page 34: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/34.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Granier-Type Sap Flux Measurements
![Page 35: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/35.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
231.1M6
S 10119
T
TTJ
Granier-Type Sap Flux Measurements
![Page 36: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/36.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Granier-Type Sap Flux Measurements
1) Appropriate thermal protection (Ewers and Oren 2000)a) minimize thermal gradients b) do not overinsulate
2) Sapwood estimation (Waring, et al. 1982. Whitehead et al. 1984, Ewers et al. 1999, Oren et al. 1999, Schafer et al. 2000)a) use stem cores or cross sectionsb) computer tomography
3) Spatial scaling within trees (Phillips et al. 1996, Ewers and Oren 2000, Oren et al. 1999, Clearwater et al. 1999, Lu et al. 2000, Ewers et al. 2002, James et al. 2002)a) need to measure both circumferential and radial trendsb) appropriate use of tree allometric relations
4) Environmental measurements
5) Time lags (Kostner et al. 1992, Martin et al. 1997, Phillips et al. 1997, Ewers and Oren 2000)
![Page 37: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/37.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
![Page 38: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/38.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Granier-Type Sap Flux Measurements
1) Appropriate thermal protection (Ewers and Oren 2000)a) minimize thermal gradients b) do not overinsulate
2) Sapwood estimation (Waring, et al. 1982. Whitehead et al. 1984, Ewers et al. 1999, Oren et al. 1999, Schafer et al. 2000)a) use stem cores or cross sectionsb) computer tomography
3) Spatial scaling within trees (Phillips et al. 1996, Ewers and Oren 2000, Oren et al. 1999, Clearwater et al. 1999, Lu et al. 2000, Ewers et al. 2002, James et al. 2002)a) need to measure both circumferential and radial trendsb) appropriate use of tree allometric relations
4) Environmental measurements
5) Time lags (Kostner et al. 1992, Martin et al. 1997, Phillips et al. 1997, Ewers and Oren 2000)
![Page 39: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/39.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Inner extent of sapwood
Sapwood Estimation
![Page 40: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/40.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Granier-Type Sap Flux Measurements
1) Appropriate thermal protection (Ewers and Oren 2000)a) minimize thermal gradients b) do not overinsulate
2) Sapwood estimation (Waring, et al. 1982. Whitehead et al. 1984, Ewers et al. 1999, Oren et al. 1999, Schafer et al. 2000)a) use stem cores or cross sectionsb) computer tomography
3) Spatial scaling within trees (Phillips et al. 1996, Ewers and Oren 2000, Oren et al. 1999, Clearwater et al. 1999, Lu et al. 2000, Ewers et al. 2002, James et al. 2002)a) need to measure both circumferential and radial trendsb) appropriate use of tree allometric relations
4) Environmental measurements
5) Time lags (Kostner et al. 1992, Martin et al. 1997, Phillips et al. 1997, Ewers and Oren 2000)
![Page 41: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/41.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
3
1
3
1
ii
iSii
S
W
JW
J
Circumferential Trends
![Page 42: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/42.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
G
SSC AA
JE
Allometric Relations
![Page 43: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/43.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Granier-Type Sap Flux Measurements
1) Appropriate thermal protection (Ewers and Oren 2000)a) minimize thermal gradients b) do not overinsulate
2) Sapwood estimation (Waring, et al. 1982. Whitehead et al. 1984, Ewers et al. 1999, Oren et al. 1999, Schafer et al. 2000)a) use stem cores or cross sectionsb) computer tomography
3) Spatial scaling within trees (Phillips et al. 1996, Ewers and Oren 2000, Oren et al. 1999, Clearwater et al. 1999, Lu et al. 2000, Ewers et al. 2002, James et al. 2002)a) need to measure both circumferential and radial trendsb) appropriate use of tree allometric relations
4) Environmental measurements
5) Time lags (Kostner et al. 1992, Martin et al. 1997, Phillips et al. 1997, Ewers and Oren 2000)
![Page 44: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/44.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Canopy Environmental Measurements
Environmental measurements (VPD)
![Page 45: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/45.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Granier-Type Sap Flux Measurements
1) Appropriate thermal protection (Ewers and Oren 2000)a) minimize thermal gradients b) do not overinsulate
2) Sapwood estimation (Waring, et al. 1982. Whitehead et al. 1984, Ewers et al. 1999, Oren et al. 1999, Schafer et al. 2000)a) use stem cores or cross sectionsb) computer tomography
3) Spatial scaling within trees (Phillips et al. 1996, Ewers and Oren 2000, Oren et al. 1999, Clearwater et al. 1999, Lu et al. 2000, Ewers et al. 2002, James et al. 2002)a) need to measure both circumferential and radial trendsb) appropriate use of tree allometric relations
4) Environmental measurements
5) Time lags (Kostner et al. 1992, Martin et al. 1997, Phillips et al. 1997, Ewers and Oren 2000)
![Page 46: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/46.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Diurnal Time Lags and Daily Fluxes
![Page 47: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/47.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
![Page 48: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/48.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Canopy Transpiration – N. Wisconsin
Notes: All species show exponential EC
rise to a maximum with respect to vapor pressure deficit;
Stomatal control exhibits similar function across species;
Maximum stomatal conductance varies 2-3 fold among species
![Page 49: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/49.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 50: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/50.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
tantTtq
Recall: Groundwater Flow
![Page 51: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/51.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
fazz /))tan/ln(( area
a )tan/ln(
Topography-Based Groundwater-Surface Water Interactions
![Page 52: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/52.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Groundwater Flow
Samanta and Mackay, 2002, WRR in press
![Page 53: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/53.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 54: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/54.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Effect of reduced stomatal regulation of leaf water potential is to lower Bowen ratios, increase pre-dawn water potentials and reduce water use efficiency
Soil or VPD ControlledTranspiration?
Mackay, 2001
![Page 55: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/55.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 56: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/56.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Physiology of Water FluxLeaf Water Potential
Pre-Dawn: Stomata Closed Midday: Stomata Open
![Page 57: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/57.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
ghΨΨDKG wLSLS
DmGG lnSrefS SrefS 6.0lndd GDGm
Monteith, 1995; Sperry et al., 1998; Oren et al., 1999; Ewers et al., 2000
Hydraulic Limits to Transpiration
0
20
40
60
80
100
120
140
160
180
0 1 2
lnD [ln(kPa)]
GS
(mm
ol
m-2
s-1) bDmGs ln
0
20
40
60
80
100
120
140
160
180
0 1 2
lnD [ln(kPa)]
GS
(mm
ol
m-2
s-1) bDmGs ln
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200
GSref (mmol m-2 s-1)
-dGS
/ dl nDS
[mm
ol
m-2
s-1l n
(kP
a)-1
]
SrefGb
DG
m S
lndd
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200
GSref (mmol m-2 s-1)
-dGS
/ dl nDS
[mm
ol
m-2
s-1l n
(kP
a)-1
]
SrefGb
DG
m S
lndd
![Page 58: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/58.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
f f f min321SmaxS Q g = g
DgG 1SmaxSref
D
Dgm
lnd
ddˆ Smax
DmQGG lnˆ, minSrefS
Replacing Boundary Line Analysis with Modeling
Model gSmax, , Qmin with automated parameter evaluation
Qmin
Jarvis (1976)
Mackay et al (2002)Advances in Water Resources
![Page 59: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/59.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Universal Relationship
0
0.4
0.8
1.2
0 0.5 1 1.5 2
G Sref (mm s-1)
-dGS
/dlnD
[m
m s
-1 ln
(kP
a)-1
]
red pine
aspen
sugar maple
alder
cedar
m ~ -0.6 GSref y = 0.601x - 0.022
R2 = 0.96
0
0.4
0.8
1.2
0 0.5 1 1.5 2
G Sref (mm s-1)
-dGS/d
lnD
[m
ms
-1 ln
(kP
a)-1
]
Stomata are regulatingleaf water potential
Mackay et al (2002) - Advances in Water Resources
![Page 60: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/60.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
![Page 61: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/61.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 62: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/62.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Mackay et al., 2002 GCB
![Page 63: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/63.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Effect of Spatial Aggregation
![Page 64: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/64.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Effect of Taxonomic Aggregation
![Page 65: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/65.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
![Page 66: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/66.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
Outline
(A) Basic Hydrologic ConceptsA.1 Water Resources and Global Terrestrial EcosystemsA.2 Hydrologic budgets and conservationA.3 Evapotranspiration as a residual: the traditional hydrologic
approach
(B) TranspirationB.1 Direct measurements of transpirationB.2 Indirect measurements of transpirationB.3 Sapflux instrumentation and flux measurements in N. Wisconsin
(C) Water Flux ModelingC.4 Groundwater / surface water interactionsC.2 Incorporating spatial variation in water fluxesC.3 Incorporating physiologyC.4 Results from N. Wisconsin
(D) Future Directions?
![Page 67: Measuring and Modeling Transpiration, or What the Flux is Hydrology? ChEAS Workshop](https://reader031.fdocuments.us/reader031/viewer/2022013101/56814ff8550346895dbdc159/html5/thumbnails/67.jpg)
Ecosystem Hydrology Modeling Group email: [email protected]://ra.forest.wisc.edu/ehmg
ChEAS WorkshopKemp StationAugust 20, 2002
• Suggested question:– How does landscape fragmentation affect transpiration
and carbon flux rates?
• Your mission:– Develop a 1 (2 max) page micro proposal that
addresses the above question or one of your choosing;
– Your proposal should state questions or hypotheses, objectives, how you would conduct the work, and what the anticipated results would be.
Future Directions?