11 Overview of capabilities for Rainfall Runoff modelling - Mô hình mưa dòng chảy

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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…

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…

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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

© DHI

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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
© DHI

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
© DHI

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:

© DHI