Raven Tutorial #3 (HBV-EC configuration)

[mranjram]

Hi Rob and James (and/or other member of the RAVEN team),

In the HBV-EC configuration of RAVEN provided in Tutorial #3, I'm having trouble locating the "frac" parameter which appears in the HBV-EC applications of Zegre et al.(2010) and Jost et al. (2012). The paper by Hamilton et al. (2000), which I'm taking to be the governing HBV-EC paper, I believe has the parameter listed as "f".

Taking the Zegre et al. (2010) and Jost et al. (2012) definitions, "frac" represents "the fraction of runoff directed to fast reservoir." Now, following the process diagram in Tutorial #3, is it correct to interpret the following of the RAVEN HBV-EC configuration:

(1) Unintercepted rainfall and melted snow enter the "PONDED WATER” store
(2a) The "PONDED WATER" store infiltrates into the "TOPSOIL" store
(2b) The water that does not infiltrate becomes "SURFACE STORAGE"
(3) 100% of the water in "SURFACE STORAGE" is assigned to the "FAST RESERVOIR" store via the FLUSH process.

And so, if the above is correct, then, in the parlance of the "frac" parameter, "100% of runoff is directed to the fast reservoir"?

And thus, the "frac" parameter is not a tunable parameter in the RAVEN configuration? (This question comes specifically out of CIVE781 Assignment 3, Question 3, where we're being asked to calibrate the model with frac as an uncertain parameter, so I wouldn't be surprised if I am wrong somehow -- I'm at my wits end though! Any help would be super appreciated).

Thanks,

Mark

Hamilton, A.S., Hutchinson, D. G., & Moore, R. D. (2000). Estimating winter streamflow using conceptual streamflow model. Journal of Cold Regions Engineering, 14(4).

Jost, G., Moore, R. D., Menounos, B., & Wheate, R. (2012). Quantifying the contribution of glacier runoff to streamflow in the upper columbia river basin, canada. Hydrol.Earth Syst.Sci., 16(3), 849-860.

Zégre, N., Skaugset, A. E., Som, N. A., McDonnell, J. J., & Ganio, L. M. (2010). In lieu of the paired catchment approach: Hydrologic model change detection at the catchment scale. Water Resources Research, 46(11).

[jrcraig]

Your interpretation is correct. The frac parameter is not easily tune-able in Raven with that configuration. However, if you wished to you could use the following in the .rvi file (replacing the flush command from surface water to the fast reservoir ):

:Split RAVEN_DEFAULT SURFACE_WATER FAST_RESERVOIR SLOW_RESERVOIR 0.9

This sends 90% of the surface water to the fast reservoir and 10% is moved to the slow reservoir, i.e., the 0.9 parameter is your F. Note that for calibration this would require creating an extra Ostrich template file (corresponding to the .rvi) to adjust this parameter.

[mranjram]

Great, thanks James.

A minor follow-up regarding a potential typo in the RAVEN manual:

In the manual, Adiabatic Lapse Rate is listed in units of [◦C/m] -- however, in Tutorial #3 Adiabatic Lapse Rate is set to 4.0. Surely then, the manual units are incorrect and should be corrected to [◦C/km]?

Thanks,

Mark

[rchlumsk]

Hi Mark

Yes, the units should be in ◦C/km, this is a typo in the manual. I have noted it for future revisions. Thanks for the catch!
Rob