Parameter Interpretation: "Total Area of Watershed for Direct Surface Runoff (acres)"

[danielninety4]

The definition of this parameter in the use manual is "the entire area of the surrounding upland that contributes direct surface runoff to this Scenario." The site I am attempting to model is immediately bordered by a river with a 292,000 acre watershed. Is that what I should consider the watershed or just the area that would be contributing overland and channelized flow directly into the wetland?

Thanks in advance!

[Stephen Stone]

The 'total area of watershed for direct runoff' is just the portion of the watershed that contributes overland flow and channelized flow to your wetland.  It should be considerably smaller than the 292,000 acre area.

If you have small channels within the 'total area of watershed for direct runoff' that have a base flow component that flows into your wetland, you should estimate the total head added to the wetland each month from the base flow component.  To do this, estimate the volume of water added to the wetland, then divide the volume by the constructed wetland area.  Once you've estimated the head that would be added from base flow, set up a user-in time series to represent the base flow component.  The combination of the user-in base flow component and the curve number method estimate of runoff added to the wetland based on your 'total area of watershed for direct surface runoff' should be representative of the total water added to the wetland from a large adjacent area that has channelized flow.  The curve number method will only estimate runoff fur precipitation events that are greater than the initial abstraction (the initial precipitation after which runoff begins, determined within Wetbud).

You could have Wetbud estimate how much water is added to the wetland when the adjacent river has enough discharge to come out of bank.  With a watershed that large, it would be best to use hourly stage data from a nearby steam gage.

I hope you find this information helpful.

Let me know if you have any other questions.

Stephen

On Mar 17, 2017 5:21 PM, "danielninety4" <daniel...@gmail.com> wrote:

The definition of this parameter in the use manual is "the entire area of the surrounding upland that contributes direct surface runoff to this Scenario." The site I am attempting to model is immediately bordered by a river with a 292,000 acre watershed. Is that what I should consider the watershed or just the area that would be contributing overland and channelized flow directly into the wetland?

Thanks in advance!

--
You received this message because you are subscribed to the Google Groups "Wetbud Plus Technical Support" group.
To unsubscribe from this group and stop receiving emails from it, send an email to wetbudplus+unsubscribe@googlegroups.com.
To post to this group, send email to wetbu...@googlegroups.com.
Visit this group at https://groups.google.com/group/wetbudplus.
To view this discussion on the web visit https://groups.google.com/d/msgid/wetbudplus/b8a1a316-e9fc-4a4a-8188-db32a4d120cd%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.