[GRASSLIST:6510] Re: r.water.outlet

[Eric Hillmuth]

I did try r.terraflow initially but in this case r.fill.dir is much 
faster because all I need is flow direction, not flow accumulation, TCI 
or any of the other things r.terraflow provides. Also, I was never able 
to figure out how to get the flow direction r.water.outlet needs from 
the r.terraflow flow direction (I was the guy that started that thread 
you mentioned). Regardless of what I use to get flow direction it would 
be helpful to know what format r.water.outlet  expects, ie what 
direction  is 1 North, East or something else.

Thanks very much, I appreciated the help

Hamish wrote:

>>I'm having trouble coming up with the drainage direction input for 
>>r.water.outlet. The documentation indicates that the input should come
>>from r.watershed but I'm working with large DEMs and r.watershed is
>>too  slow.
>>    
>>
>
>try r.terraflow.
>  
>

>>It seems like I should be able to use flow direction from 
>>r.fill.dir in AGNPS format but it doesn't work out. r.fill.dir
>>produces  flow direction as 1-8 with 1 being North. R.water.outlet
>>takes flow  direction input as 1-8 but I'm unsure of the if 1 is
>>North. I suspect 1  is East but I'd appreciate any ideas.
>>    
>>
>
>
>see this thread as well:
>
>  http://grass.itc.it/pipermail/grassuser/2005-April/028515.html
>
>
>
>
>Hamish
>
>
>  
>