drainmod application abe 527 computer models in environmental and natural resources
TRANSCRIPT
DRAINMOD APPLICATION
ABE 527 Computer Models in Environmental and
Natural Resources
Review
drainage design…
soil water characteristic…
hourly rainfall, daily max & min temperature
relative yield input data set
Note: A DRAINMOD hydrology simulation can be run without specifying a relative yield input data set.
Objectives
After this lecture, you should get familiar with DRAINMOD application as for:
• How to input your own data to DRAINMOD required format;• What to consider for calibration purpose; and• How to use the model to predict subsurface drain flow, water table depth, and crop yield.
for different drain spacings.
Soil: Clermont silt loam soil
Slope: <1%; and land-leveled after
drain installation
Area: 6.2 ha
Southeast Purdue Agriculture Center Drainage Field (SEPAC)
Monitoring: Subsurface drain flow
Water quality samples
- Hourly rainfall
- Daily maximum and minimum temperatures
(measured on site or from nearby stations)
Model Inputs
- Hourly rainfall
- Daily maximum and minimum temperatures
Model Inputs
- Drainage design parameters
Model Inputs
Drain spacing, L 5 m 10 m 20 m 40 mDrain depth, b 75 cm 75 cm 75 cm 75 cm
Effective radius, re1.1 cm 1.1 cm 1.1 cm 1.1 cm
Distance from surface to restricting layer, h 120 cm 120 cm 120
cm120 cm
Maximum surface storage, Sm1.0 cm 1.0 cm 1.0 cm 1.0 cm
Note: parameter to be calibrated—Surface micro storage S1
- Soil properties: soil water characteristic, saturated hydraulic conductivity
Model Inputs cont.
Note: parameters to be calibrated— lateral Ksat; volumetric moisture at 0 cm tension; and the vertical hydraulic conductivity of the restrictive layer
- Crop parameters
Model Inputs cont.
Month Day Root depth (cm)1 1 3.04 25 3.05 14 9.05 27 18.06 1 19.56 20 24.07 24 30.08 20 30.09 2 30.09 24 18.09 25 3.0
12 31 3.0
Time distributions of effective rooting depths
Calibration Procedure1. Choose most uncertain parameters to be
calibrated
Range of parameter needed to be calibrated
Volumetric soil moisture
at 0 m tension (cm3/cm3)
Layer RangeLayer 1 (0-25 cm) 0.389-0.46
Layer 2 (25-30 cm) 0.382-0.46
Layer 3 (30-120 cm) 0.405-0.46
Horizontal Ksat (cm/hr)Layer 1 (0-25 cm) 0.03-2
Layer 2 (25-30 cm) 0.03-0.65Layer 3 (30-120 cm) 0.05-0.67
Vertical Ksat of restrictive layer (cm/hr) 0.0005-0.003
Surface Micro storage S1 (cm) 0.3-1
m
Drain
Calibration Procedure cont.
2. Choose plot and year to be calibrated
Year Drain flow ratioW20/E20 W10/E10 W5/E5
1985 1.3 2.5 1.11986 2 2.3 1.71987 2 2 1.51988 1.8 2 1.11989 1.7 2.3 1.41990 2.1 2.3 1.21991 2.2 2.4 1.41992 3.1 2.4 1.91993 1.5 2.3 1.31994 1.6 1.9 1.61995 1.5 1.5 1.21996 1.5 1.9 1.31997 1.8 2.1 1.31998 1.5 2 1.41999 1.7 1.6 1.1
--West block and east block need to be calibrated separately. --W20 and E20 in 1988-1989 were chosen.
Range of parameter needed to be calibrated
Volumetric soil moisture
at 0 m tension (cm3/cm3)
Layer Range
Layer 1 (0-25 cm) 0.389-0.46
Layer 2 (25-30 cm) 0.382-0.46
Layer 3 (30-120 cm) 0.405-0.46
Horizontal Ksat (cm/hr)
Layer 1 (0-25 cm) 0.03-2
Layer 2 (25-30 cm) 0.03-0.65
Layer 3 (30-120 cm) 0.05-0.67
Vertical Ksat of restrictive layer (cm/hr) 0.0005-0.003
Surface Micro storage (cm) 0.3-1
n
ii
n
iii
n
ii
OO
OPOOEF
1
2
1
2
1
2
%100
1
11
n
ii
n
ii
n
ii
O
OP
APE
Calibration Objective Functions(1) Nash-Sutcliffe efficiency:
(2) Absolute percent error:
22 )5.0()1( APEEFFagg
Aggregated function, combining (1) and (2):
Automatic CalibrationParameter values against model Nash-Sutcliffe efficiencies
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.05 0.15 0.25 0.35 0.45 0.55 0.65KsatH3
Nas
h-S
utc
liffe
Eff
icie
nc
y
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.03 0.13 0.23 0.33 0.43 0.53 0.63
KsatH2
Nas
h-S
utc
liffe
Eff
icie
nc
y
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.03 0.33 0.63 0.93 1.23 1.53 1.83KsatH1
Nas
h-S
utc
liffe
Eff
icie
nc
y
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.0005 0.001 0.0015 0.002 0.0025 0.003KsatV
Nas
h-S
utc
liffe
Eff
icie
nc
y
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0S1
Nas
h-S
utc
liffe
Eff
icie
nc
y
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.389 0.409 0.429 0.449W1
Nas
h-S
utc
liffe
Eff
icie
nc
y
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.382 0.402 0.422 0.442W2
Nas
h-S
utc
liffe
Eff
icie
nc
y
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.405 0.415 0.425 0.435 0.445 0.455W3
Nas
h-S
utc
liffe
Eff
icie
nc
y
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
Relative absolute percent error
Nash
-su
tcliff
e e
ffic
ien
cy
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 2 4 6 8 10 12 14 16 18 20
Sumulation ranked by EF values
Ab
so
lute
percen
t erro
r
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Nash
-Su
tcliff
e e
ffic
ien
cy
0.11
0.008 0.018 0.004
0.796 0.780 0.778 0.773
0.554 0.563 0.552
EF
Fagg
APE
0.643
Identify Optimum Parameter Set 22 )5.0()1( APEEFFagg
0.0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
Julian Date
Drai
nflo
w (c
m/d
ay)
Observed
Predicted
Representative observed and predicted drain flow graph
Observed and predicted water table graph
Predicted and observed relative yields
30
40
50
60
70
80
90
100
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999Year
Rel
ativ
e Y
ield
(%
)
Obs_5 m Obs_10 m Obs_20 m Obs_40 mPre_5 m Pre_10 m Pre_20 m Pre_ 40 m
SUMMARY
Nash-Sutcliffe efficiency (EF) for daily drain flow ranging from -0.66 to 0.81;
EF for water table depth from -0.66 to 0.9;
Statistical tests of EF indicating insignificant difference among the three drain spacings;
Both observed and predicted relative yields indicating yields decreasing with the increase of drain spacing;
Average percent errors ranging from 1.3 to 9.7% for corn yield and from -0.8 to 10.3% for soybean yield.