AET & Percolation
Posted: Fri Apr 29, 2022 8:27 am
Hey there,
i am currently using raven to model some hydrological parameters for a small forested catchment in southwest germany for a time period of 2005 until 2015.
Right now the model already runs, but i am having some problems regarding the output.
Evapotranspiration:
Since i am comparing raven to another hydrological model, i already know what output values i should get regarding the evapotranspiration. Unfortunately with raven, the output values for soil evaporation (and percolation) are too small.
I tried to attach my input and output files here, but unfortunately it does not work. Is there any other way to send the files to you so you also get an idea of what i am doing?
Anyways, I added some soil evaporation to my model the following way:
In the RVI file, under SoilModel I added:
:Evaporation PET_PENMAN_MONTEITH
:OroPETCorrect OROCORR_HBV
And under hydrological processes I added:
:SoilEvaporation SOILEVAP_GR4J SOIL[0] ATMOSPHERE
Unfortunately, as already mentioned, the values are too low ( yearly SUMS of about 400 to 500 mm). With the second model i am using i receive annual MEAN values ranging from 600 to 700 mm. These values are already validated.
Within raven i tried to use different evaporation algorithms, but unfortunately the outputs did not change.
The same holds for the percolation values. Here, the output values are also too low. Percolation was added to my model the following way:
:Percolation PERC_GR4J SOIL[0] SOIL[1]
In case it helps, here is the complete code for the RVI file:
:StartDate 2005-01-01 00:00:00
:EndDate 2015-12-31 00:00:00
:TimeStep 1.0
:Method ORDERED_SERIES
#
:SoilModel SOIL_MULTILAYER 3
:Interpolation INTERP_INVERSE_DISTANCE
:Evaporation PET_PENMAN_MONTEITH
:Routing ROUTE_NONE
:CatchmentRoute ROUTE_DUMP
:OroTempCorrect OROCORR_SIMPLELAPSE
:OroPrecipCorrect OROCORR_SIMPLELAPSE
:OroPETCorrect OROCORR_HBV
#
:HydrologicProcesses
:Precipitation PRECIP_RAVEN ATMOS_PRECIP MULTIPLE
:Percolation PERC_GR4J SOIL[0] SOIL[1]
:Infiltration INF_GR4J PONDED_WATER MULTIPLE
:Baseflow BASE_POWER_LAW SOIL[1] SURFACE_WATER
:Baseflow BASE_LINEAR SOIL[1] SURFACE_WATER
:SoilEvaporation SOILEVAP_GR4J SOIL[0] ATMOSPHERE
:EndHydrologicProcesses
I am a bit lost. My question now is: What could i try to change in order for the AET and percolation values to be what they should be? Do i need to add anything to my input files?
Also, i stumbled upon another problem. Within the WatershedMassEnergyBalance output excel table i realised the following.
For e.g. percolation, infiltration and soilevaporation, it seems that per timestep/day the daily amount is added to the previous day resulting in a cumulative sum increasing day after day. Is there any way to change that into separate daily values being posted into that table so that I can also calculate annual mean values?
I am happy to answer any upcoming questions and I am looking forward to discussing my problems with any of you!
Best
Leonard
i am currently using raven to model some hydrological parameters for a small forested catchment in southwest germany for a time period of 2005 until 2015.
Right now the model already runs, but i am having some problems regarding the output.
Evapotranspiration:
Since i am comparing raven to another hydrological model, i already know what output values i should get regarding the evapotranspiration. Unfortunately with raven, the output values for soil evaporation (and percolation) are too small.
I tried to attach my input and output files here, but unfortunately it does not work. Is there any other way to send the files to you so you also get an idea of what i am doing?
Anyways, I added some soil evaporation to my model the following way:
In the RVI file, under SoilModel I added:
:Evaporation PET_PENMAN_MONTEITH
:OroPETCorrect OROCORR_HBV
And under hydrological processes I added:
:SoilEvaporation SOILEVAP_GR4J SOIL[0] ATMOSPHERE
Unfortunately, as already mentioned, the values are too low ( yearly SUMS of about 400 to 500 mm). With the second model i am using i receive annual MEAN values ranging from 600 to 700 mm. These values are already validated.
Within raven i tried to use different evaporation algorithms, but unfortunately the outputs did not change.
The same holds for the percolation values. Here, the output values are also too low. Percolation was added to my model the following way:
:Percolation PERC_GR4J SOIL[0] SOIL[1]
In case it helps, here is the complete code for the RVI file:
:StartDate 2005-01-01 00:00:00
:EndDate 2015-12-31 00:00:00
:TimeStep 1.0
:Method ORDERED_SERIES
#
:SoilModel SOIL_MULTILAYER 3
:Interpolation INTERP_INVERSE_DISTANCE
:Evaporation PET_PENMAN_MONTEITH
:Routing ROUTE_NONE
:CatchmentRoute ROUTE_DUMP
:OroTempCorrect OROCORR_SIMPLELAPSE
:OroPrecipCorrect OROCORR_SIMPLELAPSE
:OroPETCorrect OROCORR_HBV
#
:HydrologicProcesses
:Precipitation PRECIP_RAVEN ATMOS_PRECIP MULTIPLE
:Percolation PERC_GR4J SOIL[0] SOIL[1]
:Infiltration INF_GR4J PONDED_WATER MULTIPLE
:Baseflow BASE_POWER_LAW SOIL[1] SURFACE_WATER
:Baseflow BASE_LINEAR SOIL[1] SURFACE_WATER
:SoilEvaporation SOILEVAP_GR4J SOIL[0] ATMOSPHERE
:EndHydrologicProcesses
I am a bit lost. My question now is: What could i try to change in order for the AET and percolation values to be what they should be? Do i need to add anything to my input files?
Also, i stumbled upon another problem. Within the WatershedMassEnergyBalance output excel table i realised the following.
For e.g. percolation, infiltration and soilevaporation, it seems that per timestep/day the daily amount is added to the previous day resulting in a cumulative sum increasing day after day. Is there any way to change that into separate daily values being posted into that table so that I can also calculate annual mean values?
I am happy to answer any upcoming questions and I am looking forward to discussing my problems with any of you!
Best
Leonard