[GRASS-dev] r.watershed flow option
Hamish
hamish_b at yahoo.com
Sun May 23 01:28:58 EDT 2010
Helena wrote:
> Maybe I am overlooking it but the man
> page for r.watershed does not say what units
> the option "flow" should be in - I am guessing it is
> fraction of 1 (or percent given as decimal - e.g. 50% will
> be 0.5)
>
> so should flow amount read as fraction or something
> like that, so that if all rainfall turns to runoff = 1
> only 50% rainfall turns to runoff (rest is captured by
> vegetation or infiltrates) = 0.5
I don't think so, it seems to be reading the map as CELL, so
giving it input data in the range of 0.0-1.0 would be binary.
ram/init_vars.c
/* read flow accumulation from input map flow: amount of overland flow per cell */
opened with
G_open_cell_old(run_name, "")
read with
G_get_c_raster_row()
into
G_allocate_cell_buf()
value set as
wat[SEG_INDEX(wat_seg, r, c)] = buf[c];
after that I lose track of what it does.. maybe it is setting up
initial conditions??
> should some explanation go into manual?
once we know the answer, sure :)
Hamish
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