Hello WEAP users,
I would like to ask something related to meaning of Equation in Soil Moisture Method.

Interflow = (root zone conductivity*preferred flow direction)*z1^2
Baseflow= deep conductivity*z2^2

I just want to know, why we don't use:
Interflow = (root zone conductivity*preferred flow direction)*z1
Baseflow= deep conductivity*z2

What are difference in term of physical meaning between two equation above?
Why we have to multiply by z1^2 or z2^2, if I just multiply by z1, z2, so the how physical meaning of this term change?
Thanks !

Dear Quac Pham,

The squaring of the variables z2 and z1 make the equations non-linear, so baseflow and interflow are more responsive to changes in these variables.

Thank you Stephanie for your kind respond !
Your explanation make me more clear, but I still not totally satisfy. Are there other explanations for this question?
I have a presentation about WEAP model, somebody asked me similar question, I also said that, but I think it's hard to convince audience.