(jane rossing) lr10 at
Thu Mar 11 18:21:23 EST 1993

In Message Thu, 11 Mar 1993 11:02:22 -0500,
  riker at (Dan Riker) writes:

>Hello, I hope all is well
>I am presently working on TOPMODEL, a rainfall-runoff model, for my thesis.
> What I need GRASS for is a topographic index ln(a/tanB), but I'm not certain
> how to calculate it.  I would also like to know  how to get the mean, std
> deviation and skewness of that index. Finally I need to put it in an I*2 form
> to be used by the model.
>If anyone has any information on any aspect of this I would certainly appreciate
> it.
>Dan Riker
>Duke University

I am delighted to learn that others are using TOPMODEL and GRASS.

I simply used the "accumulation" map calculated in r.watershed for the
parameter "a", and the slope map from r.slope.aspect for "tan B"
(remembering that the slope is given in degrees).  Could this be
too simplistic?  It certainly was simple!

Jane Rossing
Department of Agricultural and Biological Engineering
Cornell University
Ithaca NY 14853
jr20 at

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