Tải bản đầy đủ (.pptx) (17 trang)

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

Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (973.92 KB, 17 trang )

MIKE HYDRO River
Rainfall Runoff modelling – overview of RR modelling options


Rainfall Runoff modelling

Content:







Catchment delineation – Graphical / manual / Import
RR models
Options
Linkage to HD-models
Results

© DHI


Rainfall Runoff modelling

Why Rainfall Runoff modelling?



Calculate catchment runoff from precipitation




Effects of land use change



Climate change studies/coupling with atmospheric models



Forecasting of floods/droughts



Streamflow extension or gap-filling using Meteorological data



Surface water/groundwater interaction



Simulation of spatial patterns within a catchment



Water availability within river basins










© DHI


Rainfall Runoff Model types
MODEL TYPES



Lumped

Model-type available in MIKE HYDRO
River



Semi-distributed

Additional model type
characterisation:



Distributed


© DHI

-

Continuous

-

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

© DHI


Rainfall Runoff model : NAM

THE RAINFALL-RUNOFF PROCESS


© DHI


MIKE HYDRO Basin - Rainfall Runoff Modelling (NAM)

PROCESS DESCRIPTION



Describes the land phase of the hydrological cycle



NAM is a lumped, conceptual model:



Lumped

catchment regarded as one unit, parameters are
average values



© DHI

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

© DHI


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

© DHI


MIKE HYDRO Basin - Rainfall Runoff Modelling (NAM)

NAM CALIBRATION

© DHI


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

 
 
 



Most important for the water balance are Lmax, Umax, and CQOF



 Remaining parameters are used for adjustment of peaks and for routing

© DHI


MIKE HYDRO River – Rainfall runoff modelling

Activate Rainfall runoff:


RR Catchment definitions:

a)

Delineation (from DEM)

b)

Digitization

c)

Shapefile Import

© DHI


MIKE HYDRO River – Rainfall runoff modelling

Combined catchment



Combine outflow from several individual catchments

© DHI


MIKE HYDRO River – Rainfall runoff modelling


NAM calibration plot option



Compare simulation results to measured timeseries



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



Catchment connections





Catchments links to one or multiple rivers

River Links





By fraction or area of catchments
Link types:





© DHI

Point
Distritubed
Entire branch


MIKE HYDRO River – Rainfall runoff modelling



Simulations Results




All models; Runoff and Rainfall

Additional results depending on RR-model selected:

Example: NAM Additional Result-file content:

© DHI



×