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Development and application of the drainage and irrigation module of polders in plain river network region
Zhengqing Lai, Shuo Li, Yang Deng, Guonian [email protected]
7/29/2016
2016 International SWAT Conference
Key Laboratory of Virtual Geographic Environment
Nanjing Normal University
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What We Will Cover…
Introduce the Polder Overview of Existing Techniques Introduce the Polder Module Analysis of Results
─ Drainage and Irrigation─ Watershed Outlet
Conclusion Q & A
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Introduction—What is Polder?
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Bridge
Building
TreeDike
Pond
Pumping Station
River
Paddy
Introduction—What is Polder?
A Polder
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Introduction—What is Polder?
A Polder
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Bridge
Building
TreeDike
Pond
Pumping Station
River
Paddy
Introduction—What is Polder?
Features of the Polder In low-lying areas
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Bridge
Building
TreeDike
Pond
Pumping Station
River
Paddy
Introduction—What is Polder?
Features of the Polder In low-lying areas Enclosed by dikes Surrounded by rivers/lakes
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Bridge
Building
TreeDike
Pond
Pumping Station
River
Paddy
Introduction—What is Polder?
Features of the Polder In low-lying areas Enclosed by dikes Surrounded by rivers/lakes Connect with outside through manually...
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Introduction—Why model Polders?
Dikes cut off the connection Drainage and Irrigation Management Large numbers of Polders
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Introduction—Why model Polders?
Polders in Taihu Lake Basin (Yan and Gao, 2015)
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Introduction—Why model Polders?
River Network in Taihu Lake Basin
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Existing SWAT modeling Methods in Polder Areas
Ignore the dikes of polders Single polder simulation Virtual Reservoir
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Existing SWAT modeling Methods in Polder Areas
Ignore the dikes of polders Single polder simulation Virtual Reservoir
(Xu and Wang, 2010)
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Objective
Modeling the drainage and irrigation processes of polder areas with improved SWAT
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Drainage and Irrigation Modeling
Outside River
Ditch
Pump
Paddy
Culvert
Pond
FenceIrrigation Sluice
Intake Sluice
Outlet Sluice
Intake Culvert
Dike
Irrigation Process
Drainage Process
Inside Outside
Inside River
Outlet Pond
How Polders Work?
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Drainage and Irrigation Modeling
Outside River
Ditch
Pump
Paddy
Culvert
Pond
FenceIrrigation Sluice
Intake Sluice
Outlet Sluice
Intake Culvert
Dike
Irrigation Process
Inside Outside
Inside River
Outlet Pond
How Polders Work?
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Drainage and Irrigation Modeling
Outside River
Ditch
Pump
Paddy
Culvert
Pond
FenceIrrigation Sluice
Intake Sluice
Outlet Sluice
Intake Culvert
Dike
Drainage Process
Inside Outside
Inside River
Outlet Pond
How Polders Work?
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Drainage and Irrigation Modeling Drainage
After DrainageBefore Drainage
Normal Level
Upper Limit Level
Inside River
Inside River
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Drainage and Irrigation Modeling Irrigation
Time(days)
Cro
p co
effic
ient
/ K
c
InitialCrop
development Mid-season Late season
Kc ini
Kc mid
Kc end
Time(Month/Da
y)
Irrigation regime
(water depth)
Crop coefficient(KC)
6/15–6/21 5-30mm 0.942
6/22–7/9 0-30mm 0.942
7/10–7/19 Drain out KC=0.0218t+0.396
7/20–8/30-30mm
(delay 3 days)KC=0.0218t+0.396
8/4–8/80-30mm
(delay 3 days)1.488
8/9–9/70-20mm
(delay 3 days)1.488
9/8–10/170-10mm
KC=-0.0219t+3.68
Irrigation regime
Crop coefficient (FAO)
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Drainage and Irrigation Modeling Drainage and Irrigation Equations
lossirrdrainpcpinstore VVVVV −+−=
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Drainage and Irrigation Modeling Drainage and Irrigation Equations
lossirrdrainpcpinstore VVVVV −+−=
>⋅⋅⋅≤⋅⋅−
=)(360024)(10)(
max
max6
VVqSVVSHH
Vdrainpolder
draininrivernorminriverdrain
310)( −⋅−⋅
+= lossinriver
polderinstoreinriver H
SSQ
HH
310⋅⋅= paddyirrirr SHV
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Module Development Integrated with SWAT
subwatershed
Next subwatershed
ReservoirWater
transferIrrigation
Water use
Point source
Traspertation loss
Water loss or compensation
Remaining water
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Module Development Integrated with SWAT
subwatershed
Next subwatershed
ReservoirWater
transferIrrigation
Water use
Point source
Traspertation loss
Polder regime
Water loss or compensation
Remaining water
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Module Development Polder Input Files
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Module Development—Program
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Module Development—Program
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Case Study—Study Area
Liyang Watershed
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Case Study—Watershed Delineation
Sub-Watershed
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Case Study—Parameters Definition
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Case Study—Results
Drainage and Irrigation Simulation
0
50
100
150
200
250-15
-5
5
15
25
7/17 7/27 8/6 8/16 8/26 9/5 9/15 9/25 10/5 10/15
Prec
ipita
tion(
mm
)
Wat
er v
olum
e(m
3·10
4 )
Month/Day
Precipitation Observed
Drainage
Irrigation
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Case Study—Results
Drainage and Irrigation Simulation
0
50
100
150
200
250-15
-5
5
15
25
7/17 7/27 8/6 8/16 8/26 9/5 9/15 9/25 10/5 10/15
Prec
ipita
tion(
mm
)
Wat
er v
olum
e(m
3·10
4 )
Month/Day
Precipitation Observed SWAT
Drainage
Irrigation
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Case Study—Results
Drainage and Irrigation Simulation
0
50
100
150
200
250-15
-5
5
15
25
7/17 7/27 8/6 8/16 8/26 9/5 9/15 9/25 10/5 10/15
Prec
ipita
tion(
mm
)
Wat
er v
olum
e(m
3·10
4 )
Month/Day
Precipitation Observed SWAT Integrated SWAT
Drainage
Irrigation
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Case Study—Results
Watershed Outlet Simulation
0
200
400
600
800
1000
12000
30
60
90
120
2010-01 2011-01 2012-01 2013-01
Prec
ipita
tion(
mm
)
Stre
am F
low
(m3/
s)
Year-Month
Precipitation Observed SWAT Integrated SWAT
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Case Study—Results
Validation of the Results
Year
SWAT Integrated SWAT
R2 ENS R2 ENS
2010 0.68 0.65 0.83 0.69
2011 0.77 0.22 0.79 0.71
2012 0.67 0.45 0.78 0.74
2013 0.59 0.31 0.86 0.86
2010-2013 0.58 0.43 0.74 0.74
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Conclusion
The new module is able to model the drainage and irrigation processes of polders
The integrated SWAT enhances the simulation accuracy of the streamflow of polder watershed
Benefit the distributed hydrological modeling in plain river network region
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Thank You!
[email protected]
Key Laboratory of Virtual Geographic Environment
Nanjing Normal University