Question regarding Canopy

[kims3411]

Hello,
I have a question regarding PrecipIceptFract & WatershedStorage.csv

I have the following lines coded for canopy intercept in the model

:PrecipIceptFract PRECIP_ICEPT_LAI
:CanopyEvaporation CANEVP_MAXIMUM CANOPY ATMOSPHERE
:CanopySnowEvap CANEVP_MAXIMUM CANOPY_SNOW ATMOSPHERE

When I execute the code, everything runs fine however when I check WatershedStorage.csv, CANOPY and CANOPY_SNOW timeseries values are always equal to zero. I thought it might be just my model error but when I check Raven tutorial models, even for those, CANOPY and CANOPY_SNOW timeseries values are always equal to zero.

I don't know if it's just csv file that is coming out wrong or if PrecipIceptFract is actually not working.

Thank you

SJ

[sgrass]

Did you define the RAIN_ICEPT_FACT and SNOW_ICEPT_FACT in the .rvp in :VegetationParameterList? Or is it being auto-generated? What values did you use?

-Sarah

[kims3411]

Hello, sorry for the late reply - didn't see a reply being posted.

I do have fractions specified - I chose PRECIP_ICEPT_USER so it asks for RAIN_ICEPT_PCT and SNOW_ICEPT_PCT instead. (I tried RAIN_ICEPT_FACT too, it looks for PCT and autogenerates values which still comes out blank).
I tried different values between 0-1 but none of them gave any values in the canopy and canopy_snow in watershedstorage.csv.

Thank you

[jrcraig]

Hi SJ,

When you choose :CanopyEvaporation CANEVP_MAXIMUM, all of the water stored in the canopy is evaporated at the maximum rate (PET), which can often lead to it being emptied as fast as it is filled, i.e., canopy storage would often be zero in the reporting at the end of the timestep unless PET is fairly small or the maximum canopy storage (determined by the RAIN_ICEPT_PCT/SNOW_ICEPT_PCT and the vegetation LAI) is relatively large.

[kims3411]

Hello,

I see - I didn't think of that. I kept checking other output csv files and saw that evaporation functions were working fine and was wondering why only WatershedStorage.csv came out blank.
Thank you.

SJ