DISTRIBUTED RAINFALL RUNOFF MODELS APPLIED TO THE DARGLE Prof. Eng. Ezio TODINI e-mail :...
Transcript of DISTRIBUTED RAINFALL RUNOFF MODELS APPLIED TO THE DARGLE Prof. Eng. Ezio TODINI e-mail :...
DISTRIBUTED RAINFALL RUNOFF MODELS APPLIED TO
THE DARGLEProf. Eng. Ezio TODINI
e-mail : [email protected]
PROtezione e GEstione Ambientale Sede Operativa: Via Don Bedetti 20 - 40129 Bologna Tel. 051-6389099 Fax 051-6389100 E-mail: [email protected]
DISTRIBUTED RAINFALL-RUNOFF MODELLING
Advantages of Distributed Models
- Physical meaning of model parameters
- Distributed representation of phenomena
Limited calibration requirements
Possibility of internal analysis
Rainfall Runoff Models
Black Box M. Semi Distributed M. Distributed M.
Model 1: AFFDEF
Main model characteristics:
- Modified CN for estimating infiltration
- Radiation method for evapotranspiration
- Muskingum-Cunge for ovrland and channel flow
EPSH
P
HtF
dt
tdF
S
1
)()(
Pl[t,(i,j)]
I[t,(i,j)]
Pn[t,(i,j)]
E[t,(i,j)]
P[t,(i,j)]
Cint . S(i,j)
Ep[t,(i,j)]
F[t,(i,j)] H.S(i,j)
W[t,(i,j)]=F[t,(i,j)]/Hs
Mass Balance in each cell
Model 2: TOPKAPI
Main model characteristics
- Vertical lumping of hydraulic conductivity
- Dunne infiltration
- Soil horizontal flow, overland and channel flows represented using a kinematic equation
- Horizontal lumping of kinematic equations
dzzkTL
0
~ ~~
LkT s
Model for the single cell
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~
Lkq
rx
q
tL
s
rs
TOPKAPI Distributed approachThe model for the single cell
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Lkq
rx
q
tL
s
rs mass conservation
moment conservation
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t
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is
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x
Cxr
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dy ODE
SOIL COMPONENT
TOPKAPI Distributed approachThe model for the single cell
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mass conservation
moment conservation
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SURFACE COMPONENT
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TOPKAPI Distributed approachThe model for the single cell
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mass conservation
moment conservation
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CHANNEL COMPONENT
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TOPKAPI Distributed approachParameters
Model 3: MIKE SHE
Main model characteristics:
- 1D Richards equations for unsaturated zone
- 3D Boussinesq equation for greoundwater
- Parabolic approximation for overland flow
)()(
))(( zSz
K
zK
zt
t
hSQ
z
hK
zy
hK
yx
hK
x zzyyxx
)()()(
Case study
The Dargle
County of Wicklow
Republic of Eireland
Case study
- Surface Area circa 122 km2
- Elevation from 20 m to 713 m a.s.l.
- Sandy and sandy loam for about
1.5 m
Saturation mechanism
Horton Dunne
The “unrealistic” profile used in MIKE
SHE
to meet the observations
Results: AFFDEF
Variance of obs. = 17.85 Variance of errors= 6.97Nash Sutcliffe= 0.59Explained Variance= 0.61 Coefficient of correlation =0.91 Volume Control = 0.74 Willmott= 0.93
Efficiency Coefficients
Risults: AFFDEF
Uniform value for curve number: 20
0.01 [ms-1]
5 [Km2 ]Areal threshold
Saturated Hydraulic Conductivity
Infiltration Res. Const 4320000[s]
Infiltration constant 0.7
Infiltration Capacity 0.1
Average computer time = 5 min
Variance of obs. = 17.85 Variance of errors= 6.97Nash Sutcliffe= 0.59Explained Variance= 0.61 Coefficient of correlation =0.91 Volume Control = 0.74 Willmott= 0.93
Efficiency Coefficients
Results: TOPKAPI
Variance of obs. = 17.85 Variance of errors= 4.01Nash Sutcliffe= 0.77Explained Variance= 0.77 Coefficient of correlation =0.91 Volume Control = 0.90 Willmott= 0.95
Efficiency Coefficients
Results: TOPKAPI
Permeability[m3s-1]
θS θR α L[m]
Soil Type
9.1E-04 0.453 0.041 2.5 0.9 Sandy Loam
9.1E-04 0.453 0.041 2.5 0.7 Sandy Loam
3.1E-05 0.453 0.041 2.5 1.5 Sandy Loam
9.1E-04 0.463 0.020 2.5 1.0 Loam
4.1E-05 0.453 0.041 2.5 1.5 Sandy Loam
9.1E-04 0.463 0.020 2.5 0.7 Loam
Variance of obs. = 17.85 Variance of errors= 4.01Nash Sutcliffe= 0.77Explained Variance= 0.77 Coefficient of correlation =0.91 Volume Control = 0.90 Willmott= 0.95
Efficiency Coefficients
Average comp. time = 5 min
Results: MIKE SHE
Variance of obs. = 17.85 Variance of errors= 8.32Nash Sutcliffe= 0.52Explained Variance= 0.54Coefficient of correlation =0.85 Volume Control = 0.80 Willmott= 0.90
Efficiency Coefficients
Results: MIKE SHE
Thickness of soil layer -1.3 [m]
Horizontal hydraulic conductivity 5*10-4 [m s-1]
Vertical hydraulic conductivity 1*10-5 [m s-1]
Storativity coefficient 0.2 [m-1]
Variance of obs. = 17.85 Variance of errors= 8.32Nash Sutcliffe= 0.52Explained Variance= 0.54Coefficient of correlation =0.85 Volume Control = 0.80 Willmott= 0.90
Efficiency Coefficients
Average computer time = 2.5 h
Distributed soil moisture
Saturation percentage
TOPKAPI CALIBRATION TOOL
Example of link ECMWF -TOPKAPI on the Po Basin
The basin closed at Ponte Spessa (Surface area 36,900 km2 )
Ponte Spessa
The DEM The Soil Types
The Land Uses
Reproduction of the 1994 event in the Po river
ECMWF: deterministic run
ECMWF: deterministic run
ECMWF: deterministic run
ECMWF: deterministic run
ECMWF: deterministic run