Scilab Function
Last update : 23/8/2006

c_ETP - Function to generate potential evapotranspiraton time series

Calling Sequence

[ETP] = c_ETP(NbVal,TimeSteps,Latitude,TM,DateStart)

Parameters

Description

CAUTION : The evapotranspiration values are inter-annual values. The time series is identical every year.

WARNING : This function is written in C language and interfaced with SCILAB (HYDROGR.dll).

The function adjusts a Fourrier transform on the monthly temperature values and apply the formula proposed by Morton (see bibliography) based on temperature and latitude).

Examples

      // Mean monthly temperature
      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];
      
      // Generation of ETP daily time series (2000 days), latitude = 45deg, start = 1/1/1980
      E   = c_ETP(2000,24,%pi/4,T,198001010000);
      
      // Graph
      plot2d(c_CONVDATE(0,198001010000)+(0:1999),E,style=-1);
      
      // Date on the x axis
      a=gca(); a.auto_ticks=['off','on']; [tck tck_txt]=SERIEDATE(198001010000,c_CONVDATE(1,c_CONVDATE(0,198001010000)+2000),'a',1); // Axe des dates (dates ici au format 36893.567)
      XTICKS=tlist(['ticks','locations','labels'],tck,tck_txt);a.x_ticks=XTICKS;xgrid(2);xtitle('PE with the Morton formula','date','PE (mm)')

  

See Also

c_GR4J ,  

Authors

Julien Lerat (transcription of fortran code written by Claude Michel) CEMAGREF Antony, HBAN Unit, julien.lerat@cemagref.fr

Bibliography

Oudin, L., C. Michel, et al. (2005). "Which potential evapotranspiration input for a lumped rainfall-runoff model?: Part 1--Can rainfall-runoff models effectively handle detailed potential evapotranspiration inputs?" Journal of Hydrology 303(1-4): 275-289

Bibliography

Oudin, L., F. Hervieu, et al. (2005). "Which potential evapotranspiration input for a lumped rainfall-runoff model?: Part 2--Towards a simple and efficient potential evapotranspiration model for rainfall-runoff modelling." Journal of Hydrology 303(1-4): 290-306.

Bibliography

Morton, F. I. (1983). "OPERATIONAL ESTIMATES OF AREAL EVAPOTRANSPIRATION AND THEIR SIGNIFICANCE TO THE SCIENCE AND PRACTICE OF HYDROLOGY." Journal of Hydrology 66(1-4): 1-76.