Problems with 2 Met Stations

[russell...@gmail.com]

Hi Steve,

I'm attempting to run a simulation with Observed PET using a CSV file to input the values on a daily timestep. The second column has modified data to increase the PET during the summer due to having a willow plantation.

When I test the model by setting the default MET station code to 2 everywhere, I am getting some very strange results indeed. I've attached the MB file for a week of simulation and you'll see that there's a small amount of evaporation from bare soil (very surprising as I've run this simulation with a uniform vegetation type having a  PLAI of 1!), and no ET from the canopy or transpiration.

I printed out the input data into the PRI file, and surprisingly this looks okay in terms of having two different PET values (in mm/hr). There's only 1 raingauge, so rainfall for station 2 is zero.

MET DATA -  TIME :   91.00
 STATION           RAINFALL      POT. EVAP.(MM/HR)
     1              2.100              0.059
     2              0.000              0.088

I've also attached the PET data file for you to have a look at if you get the time, although this doesn't seem to be the issue here?

Thanks,
Russell

[Steve Birkinshaw]

Hi Russell,

You are right, there is something odd going on. I guess the bare ground evaporation is from river channels. But there should be canopy evaporation and transpiration is the potential evaporation is above zero. So it would seem there somehow where the met station is set to 2 the potential evaporation is zero, although it is read in correctly.

How are you running the model? Are you using the library (xml) file together with the map files or are you using the input files?

Maybe send me the files you are using and I will have a look.

Just as a thought if you are using the input files as well as changing ":FR43 - MET STATIONS" have you changed the following lines when you added the 2nd met station:

:FR28 - NO. OF MET./RAINFALL STATIONS - the first value should be 2

:ET5 - MEASPE (0 NOT MEASURED, 1 MEASURED)    - there should now be 2 values as there are two measured met stations.

Cheers,

Steve