MIKE HYDRO River
Rainfall Runoff modelling – overview of RR modelling options
Rainfall Runoff modelling
Content:
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Catchment delineation – Graphical / manual / Import
RR models
Options
Linkage to HD-models
Results
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Rainfall Runoff modelling
Why Rainfall Runoff modelling?
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Calculate catchment runoff from precipitation
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Effects of land use change
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Climate change studies/coupling with atmospheric models
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Forecasting of floods/droughts
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Streamflow extension or gap-filling using Meteorological data
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Surface water/groundwater interaction
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Simulation of spatial patterns within a catchment
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Water availability within river basins
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Rainfall Runoff Model types
MODEL TYPES
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Lumped
Model-type available in MIKE HYDRO
River
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Semi-distributed
Additional model type
characterisation:
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Distributed
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Continuous
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Event-based
MIKE HYDRO River - Rainfall Runoff Models
Available Rainfall runoff models :
‘NAM’ (Numerical Runoff Model)
• Lumped, Continuous model type
‘UHM’ (Unit Hydrograph Method)
• Lumped, Event-based model type
‘Time-area’
• A conceptual model where runoff is controlled by initial and continuous hydrological losses
‘Kinematic wave’
• A non-linear model based on the kinematic wave approach
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Rainfall Runoff model : NAM
THE RAINFALL-RUNOFF PROCESS
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MIKE HYDRO Basin - Rainfall Runoff Modelling (NAM)
PROCESS DESCRIPTION
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Describes the land phase of the hydrological cycle
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NAM is a lumped, conceptual model:
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Lumped
catchment regarded as one unit, parameters are
average values
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Conceptual
based on considerations of the physical processes
The Rainfall Runoff process (NAM)
MIKE HYDRO Basin - Rainfall Runoff Modelling (NAM)
PROCESS DESCRIPTION
QOF
SNOW
SOIL MOISTURE PROFILE
Owp
Root
Zone
Overland Flow
Pn
CK2
RAIN
SNOW
STORAGE
Ofc Osat
Ep
P
U
SURFACE STORAGE
QIF
InterFlow
Ea
DL
Lmax
Lmax
LOVER ZONE STORAGE
L
Sy
G
CAFlux
GWPump
GWL
BFu
GWL
Depth
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OF
IF
Ps
Umax
L
CK1
CKBF
BF
BaseFlow
GROUNDWATER STORAGE
GWLBFo
MIKE HYDRO Basin - Rainfall Runoff Modelling (NAM)
NAM Main parameters
Umax
Maximum contents of surface storage
Evaporation; small peaks
Usual value: 10-25 mm
Lmax
Maximum contents of rootzone storage
Evaporation; water balance
Usual value: 50-250 mm
CQof
Overland flow coefficient
Divides excess rainfall in runoff and infiltration
Usual value: 0.01 - 0.99
TOF
Rootzone threshold value for overland flow
Delays overland flow at the beginning of a wet season
Usual value: 0.0 - 0.7
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MIKE HYDRO Basin - Rainfall Runoff Modelling (NAM)
NAM Main parameters cont’d:
TG
Root zone threshold value for recharge
Delays groundwater recharge at the beginning of a
wet season
Usual value: 0.0 - 0.7
CKBF
Time constant for routing baseflow
Determines shape of baseflow hydrograph
Usual value: 500 - 5000 hours
CK1 ,CK2
Time constant for routing overland flow
Determines shape of peaks
Usual value: 3 - 48 hours
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MIKE HYDRO Basin - Rainfall Runoff Modelling (NAM)
NAM CALIBRATION
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MIKE HYDRO Basin - Rainfall Runoff Modelling (NAM)
NAM Calibration
MAXIMUM:
BUT
15 NAM PARAMETERS
5 PARAMETERS USUALLY FIXED
I.E.
10 PARAMETERS TO BE CALIBRATED
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Most important for the water balance are Lmax, Umax, and CQOF
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Remaining parameters are used for adjustment of peaks and for routing
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MIKE HYDRO River – Rainfall runoff modelling
Activate Rainfall runoff:
RR Catchment definitions:
a)
Delineation (from DEM)
b)
Digitization
c)
Shapefile Import
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MIKE HYDRO River – Rainfall runoff modelling
Combined catchment
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Combine outflow from several individual catchments
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MIKE HYDRO River – Rainfall runoff modelling
NAM calibration plot option
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Compare simulation results to measured timeseries
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Creates automatically a ‘Plot composer file’ with comparison plots during simulation
LIVER, Observed RunOff [m^3/s]
LIVER, Simulated RunOff [m^3/s]
7.0
6.0
5.0
4.0
3.0
2.0
C:\MIKE Zero\AutoCalibT es t\RRc alibration\LIVER.dfs0
C:\MIKEZero\AutoCalibT est\RRc alibration\LIVER.dfs0
LIVER, Accumulated Qobs. Million [m^3]
LIVER, Accumulated Qsim. Million [m^3]
100
80
60
40
20
1.0
0.0
0
00:00
1973-08-20
00:00
1974-03-08
Continuous values comparison
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00:00
09-24
00:00
1975-04-12
00:00
10-29
00:00
1973-08-20
00:00
1974-03-08
Accumulated values comparison
00:00
09-24
00:00
1975-04-12
00:00
10-29
MIKE HYDRO River – Rainfall runoff modelling
Coupling of Hydrodynamic and Rainfall runoff models
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Catchment connections
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Catchments links to one or multiple rivers
River Links
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By fraction or area of catchments
Link types:
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Point
Distritubed
Entire branch
MIKE HYDRO River – Rainfall runoff modelling
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Simulations Results
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All models; Runoff and Rainfall
Additional results depending on RR-model selected:
Example: NAM Additional Result-file content:
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