General Questions in Raven

[anonymous34]

How are properties such as hydraulic conductivity, soil porosity, etc., automatically generated from soil classes?

[rchlumsk]

These properties are generated based on regression results from soil types that are found in literature.

[anonymous34]

What is a warm start? I have come across this term but not sure what it means.

[rchlumsk]

What is a warm start? I have come across this term but not sure what it means.

A warm start is when the model is initialized from a previous run’s solution file, such that Raven basically picks up where the last run left off. This can be useful for breaking up long run times, or in case of a run failure partway through a long run, or to remove the need for a warm-up period in the model. A warm start can be done by using the .rvc file of your model run (as a model output) as the input .rvc file for your next run.

[anonymous34]

How does the MULTIPLE get handled in the rvi file for specifying the TO and FROM in processes?

[rchlumsk]

How does the MULTIPLE get handled in the rvi file for specifying the TO and FROM in processes?

In general the TO and FROM is largely determined automatically by the model, although supplying it can dictate which option is used in the case where a process can use multiple targets. In the case of MULTIPLE the model will know where the water is moved to based on the process used, so it is process dependent and dictated by the model and MULTIPLE is used.

As an aside, it is possible to have a nonsensical TO/FROM specified in the RVI file that does not result in an error. This can occur if a faulty TO/FROM is specified in a spot where the process only has one option. As an example, if the process baseflow is specified as FROM SOIL[1] TO ATMOS_PRECIP, the model will not throw an error since the TO is automatically dictated by the model as SURFACE_WATER with no other options, even if the user has specified something different.

[ephilip]

Hi Rob,

The run1_WatershedStorage.csv file has Cum_loss, Cum.Input and Cum.Outflow columns. Would you please explain the variables? Should the difference of Cum_Inflow-Cum-loss be equal to Cum_Outflow?

Thank you
Elizabeth

[jrcraig]

The cumulative input is the total cumulative amount of incoming precipitation across the watershed plus specified inflows (e.g., that from the :BasinInflowHydrograph commands), in mm.

The cumulative outflow includes the total amount of water leaving the watershed outlets (from all basins with no downstream subbasin) plus all evaporative and pumped losses from reservoirs, if present, in mm.

The cumulative loss term you speak of is likely the cumulative losses to atmosphere, which is a storage variable in raven.

the cumulative outflow should be equal to the cumulative input minus the change in total system storage (which - perhaps non-intuitively - includes the cumulative losses) over the duration of simulation, calculated as the current Total minus the total at t=0.

If you want to calculate the total amount of water stored *on the landscape* at any point in time, you would subtract the Cum Losses to Atmosphere [mm] from the Total [mm].

[ephilip]

Hi Rob,

I am using GR4J model. I would like to get the base flow using :Transport GWTracer . I am getting the following error

ERROR : ParseMainInputFile: cannot currently perform transport with convolution processes.

Is it because of GR4J implementation?

Thank you
Elizabeth

[jrcraig]

Yes, Elizabeth - the general transport scheme of Raven cannot support the convolution process used in GR4J.