Scilab Function
Last update : 16/9/2006
GR4J_CAL_LM - Function to calibrate GR4J model with a split sample test using lsqrsolve
Calling Sequence
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[X,CALC,CR,[S,R]]=GR4J_CAL_LM(Q,P,E,TS,[ICAL,TSini,FOBJ,Xini,RSini])
Parameters
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Q
: Discharge data (matrix [Nx1] where N is the number of time steps)
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P
: Rainfall data (matrix [Nx1] where N is the number of time steps)
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E
: Potential evapotranspiration data (matrix [Nx1] where N is the number of time steps)
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TS
: Time step length in hours (default = 24)
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ICAL
: Indices of the value to use in the Q vector during the calibration process
-
TSini
: Number of time-steps required for model initialisation (default = 365)
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FOBJ
: Transformation applied to calculate the objective function (default = 'Q', possible = 'logQ' - logarithm transform - or 'racQ' -square root transform -)
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RSini
: Initial value of reservoirs level (matrix [2x1])
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X
: Optimised parameters for the 3 subperiods (matrix [4x3])
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CALC
: Discharge values calculated with optimisation on the 3 sub-periods and a cross-validation (matrix [Nx4])
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CR
: Numerical quality criteria on each sub-period in calibration mode and on a cross-validation mode (matrix [5x4], see CRIT)
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S
: Time-series of soil-moisture reservoir levels (matrix [Nx1])
-
R
: Time-series of routing store levels (matrix [Nx1])
Description
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The function performs the following actions:
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(1) The dataset is split into 2 equal parts, P1 and P2. P3 represents the whole dataset.
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(2) On each sub-period, GR4J is calibrated with the lsqrsolve function (see lsqrsolve function and c_GR4J).
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(3) The calibration quality on P1 and P2 is assessed by calculating quality criteria (see CRIT function).
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(4) The model quality in validation mode is assessed by calculating quality criteria on a simulation made on P1 with parameters from P2 and vice-versa.
See Also
c_GR4J
,
lsqrsolve
,
CRIT
,
Authors
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Julien Lerat
CEMAGREF Antony, HBAN Unit, julien.lerat@cemagref.fr
Bibliography
Klemes, V. (1986). "Operational testing of hydrological simulation models." Hydrological Sciences Journal/Journal des Sciences Hydrologiques 31(1): 13-24.
Perrin, C., C. Michel, et al. (2003). "Improvement of a parsimonious model for streamflow simulation." Journal of Hydrology 279(1-4): 275-289.
Edijatno and C. Michel (1989). "Un modèle pluie-débit journalier à trois paramètres." La Houille Blanche 2: 113121.