Retrieving Soil Moisture States Using Streamflow Data Assimilation C. Rüdiger a Supervisors:...
-
Upload
taniya-digby -
Category
Documents
-
view
217 -
download
0
Transcript of Retrieving Soil Moisture States Using Streamflow Data Assimilation C. Rüdiger a Supervisors:...
Retrieving Soil Moisture States Using Streamflow Data
Assimilation C. Rüdigera
Supervisors:Jeffrey P. Walkera, Jetse D. Kalmab,
Garry R. Willgoosec
a Dept. of Civil & Env. Eng., University of Melbourne, Australia
b School of Engineering, University of Newcastle, Australia
c School of Geography, University of Leeds, United Kingdom
Christoph Rüdiger
Postgrad Seminar 2004
Koster et al., JHM, 2000
Christoph Rüdiger
Postgrad Seminar 2004
Christoph Rüdiger
Postgrad Seminar 2004
Goulburn Catchment
Melbourne
NewcastleSydney
1000km0km
Christoph Rüdiger
Postgrad Seminar 2004
Goulburn Catchment
Streamgauge
Soil Moisture
Climate
www.civenv.unimelb.edu.au/~jwalker/data/oznet/
Christoph Rüdiger
Postgrad Seminar 2004
Catchment Land Surface Model
Koster et al., JGR, 2000Saturation
Depth
Water Table
Eq. profile
Moisture Deficit
D = 0
D = smallD = large
Prognostic variables:
•Catchment Deficit
•Surface Moisture Excess
•Root Zone Excess
Christoph Rüdiger
Postgrad Seminar 2004
Internal routing
Travel time TpiVelocity weight v-1
Unit Hydrograph for Catchment
0
0.05
0.1
0.15
0.2
0.25
0.3
1 2 3 4 5 6 7 8
Hours
Co
ntr
ibu
tin
g F
rac.
of
To
tal
Are
a [1
/h]
Christoph Rüdiger
Postgrad Seminar 2004
Synthetic ExperimentVariational Data Assimilation
model outp
ut
time
ob
j. f
un
ctio
n
assimilation step
NLFIT (Kuczera, WRR, 1982)
• “Truth”:– 10yr spin up– 1yr full run
• “Experiment 1”:– One month only– Degraded soil moisture values (low catchment deficit)
• “Experiment 2”:– “Openloop 1” and changed forcing (33% lower radiation and
20% higher precipitation)
Christoph Rüdiger
Postgrad Seminar 2004
Results from assimilation with "true" forcing (runoff)
0
50
100
150
200
250
300
350
400
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
Date
Dis
char
ge [
m^3
/s]
true
Results from assimilation with "true" forcing (profile mc)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
DateV
WC
[-]
true
Results from assimilation with "true" forcing (runoff)
0
50
100
150
200
250
300
350
400
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
Date
Dis
char
ge [
m^3
/s]
truedeg
Results from assimilation with "true" forcing (profile mc)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
DateV
WC
[-]
truedeg
Results from assimilation with "true" forcing (runoff)
0
50
100
150
200
250
300
350
400
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
Date
Dis
char
ge [
m^3
/s]
truedegDA
Results from assimilation with "true" forcing (profile mc)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
DateV
WC
[-] true
degDA
Results “Experiment 1”
Discharge Soil Moisture
Christoph Rüdiger
Postgrad Seminar 2004
Results “Experiment 1”Results from assimilation with "true" forcing (runoff)
0
50
100
150
200
250
300
350
400
01/08/2003 02/08/2003 03/08/2003
Date
Dis
char
ge [m
^3/s
]
truedegDA
Christoph Rüdiger
Postgrad Seminar 2004
Results form assimilation with "wrong" forcing data (runoff)
0
100
200
300
400
500
600
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
Date
Dis
char
ge [
m^3
/s]
true
Results form assimilation with "wrong" forcing data (profile mc)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
DateV
olu
met
ric M
ois
ture
Co
nte
nt [-
]
true
Results form assimilation with "wrong" forcing data (runoff)
0
100
200
300
400
500
600
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
Date
Dis
char
ge [
m^3
/s]
truedeg
Results form assimilation with "wrong" forcing data (profile mc)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
DateV
olu
met
ric M
ois
ture
Co
nte
nt [-
]
truedeg
Results form assimilation with "wrong" forcing data (runoff)
0
100
200
300
400
500
600
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
Date
Dis
char
ge [
m^3
/s]
truedegDA
Results form assimilation with "wrong" forcing data (profile mc)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
01-Aug 08-Aug 15-Aug 22-Aug 29-Aug
DateV
olu
met
ric M
ois
ture
Co
nte
nt [-
]
truedegDA
Results “Experiment 2”
Discharge Soil Moisture
Christoph Rüdiger
Postgrad Seminar 2004
Results “Experiment 2”Results form assimilation with "wrong" forcing data (runoff)
0
100
200
300
400
500
600
23-Aug 24-Aug 25-Aug
Date
Dis
char
ge [
m^3
/s]
truedegDA
Christoph Rüdiger
Postgrad Seminar 2004
Conclusion from Results
• Results show that runoff has useful information about soil moisture states
• Problems in semi-arid regions, when overestimation of water input due to degraded forcing data (potentially for too dry, as well!?)
• Monthly assimilation windows have positive impact, reduction of assimilation window should improve results further
Christoph Rüdiger
Postgrad Seminar 2004
Future Work
• Including inter-catchment routing• Comparison of different climates
(real data)• Assimilation of surface soil moisture
Christoph Rüdiger
Postgrad Seminar 2004
Acknowledgments• Australian Research Council (ARC-DP grant
0209724)• Hydrological Sciences Branch, National
Aeronautics and Space Administration (NASA), USA
• University of Melbourne – Melbourne International Fee Remission
Scholarship (MIFRS)– Postgraduate Overseas Research Experience
Scholarship (PORES)