Name

GR_SIM — Function to simulate discharges with a GR rainfall runoff model

Calling Sequence

[QC,[S,R,ECH,ER,PR,CR,CRrac,CRlog]]=GR_SIM(X,P,E,TS,GRname,[TSini,Q,Icrit])

Parameters

X

Parameters to used by the rainfall-runoff model (matrix [5x1])

P

Rainfall data (matrix [Nx1] where N is the number of time steps)

E

Potential evapotranspiration data (matrix [Nx1])

TS

Time step length in hours (default = 24)

GRname

Name of the GR model to use (possible = GR4J, GR2M)

TSini

Number of time-steps required for model initialisation (default = 365*24/TS)

Q

Discharge data (matrix [Nx1])

Icrit

Indices of the value to use in the Q vector to calculate criteria. Default = find(Q>=0)

QC

Simulated streamflows (matrix [Nx1]).

S

Time-series of soil-moisture reservoir levels (matrix [Nx1])

R

Time-series of routing store levels (matrix [Nx1])

ECH

Time-series of Interbasin Groundwater Flows (matrix [Nx1])

ER

Time-series of real evaporation (matrix [Nx1])

PR

Time-series of effective rainfall (matrix [Nx1])

CR

Numerical quality criteria (matrix [5x1], see CRIT)

CRlog

Numerical quality criteria of log transformed values (matrix [5x1], see CRIT)

CRrac

Numerical quality criteria of squared root transformed values (matrix [5x1], see CRIT)

Description

  • The function performs the following actions:

  • (1) A first simulation is launched with P and E vector and a 50% initial content of the two conceptual reservoirs.

  • (2) Starting one year after the beginning of simulation (1), an averaged content of both reservoirs is calculated out the values given in simulation (1).

  • (3) A second simulation is launched with P, E and the initial content calculated in (2).

Examples

   // Generation of fictious discharge data with the GR4J model (see GR4J help)
   P = max(0,exp(convol(1/3*ones(1,3),rand(4998,1)+0.2).^5)*10-12)'; // Rainfall      
   T   = [0.687;0.498;2.774;6.086;10.565;13.702;16.159;15.585;12.619;8.486;3.300;0.778];
   ETP = c_ETP(5000,24,%pi/4,T,198001010000,1); // Potentiel Evapotranspiration      
   xx   =[665;1.18;90;3.8;0]; // GR4J parameters            
   e=convol(3/50*ones(1,50),rand(size(P,1),1));e=e(50:$)'-1;
   Q=c_GR4J(24,xx,P,ETP,[0.6;0.7])+e; // GR4J simulation + autocorrelated random error

   // GR4J simulation
    X=[870;3;90;3.5;0];
   QC = GR_SIM(X,P,ETP,24,'GR4J',365,Q);

   // Plot of results in validation mode
   plot([Q QC]);
   xtitle('','Days','Discharge (mm/day)');legend(['Obs.' 'Calc.'],%f);

  

See Also

c_GR4J , c_GR2M , lsqrsolve , CRIT , GR_CAL_LM

Authors

Julien Lerat

CEMAGREF Antony, HBAN Unit, julien.lerat@cemagref.fr

Bibliography

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: 113–121.