r.stream.order and accum map

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

r.stream.order and accum map

Micha Silver
I'm trying to use r.stream.order to get a vector with the full set of stream orders and topological attributes, but it errors with the need for a flow accumulation map as follows:

r.stream.order --o -a streams=str dirs=fdir elev=dtm_full vect=stream_order memory=1500
ERROR: To calculate vector file both accum and elev are required

The stream map and direction map were both created with r.stream.extract. This module does not create a flow accumulation map. Do I need to go back and recreate the streams, flow direction and flow accumulation with r.watershed in order to use r.stream.order ??

(This is with GRASS 7.0, self compiled)

Thanks,
Micha

_______________________________________________
grass-user mailing list
[hidden email]
http://lists.osgeo.org/mailman/listinfo/grass-user
Reply | Threaded
Open this post in threaded view
|

Re: r.stream.order and accum map

jentjr
From a comment on line 74 of main.c it looks like the accumulation map is required when calculating the Strahler stream order.

 in_acc_opt->key = "accum"; /* required if strahler stream order is calculated for existing stream network */
 in_acc_opt->type = TYPE_STRING;
 in_acc_opt->required = NO; /* for now; TO DO: is planned to be optional */
 in_acc_opt->answer = NULL;
 in_acc_opt->gisprompt = "old,cell,raster";
 in_acc_opt->description =
        "(Not recommended) Name of accumulation file (r.watershed or r.stream.extract)";

I believe that you will need to get the accumulation map from r.watershed first.

Hope this helps,

Justin
Reply | Threaded
Open this post in threaded view
|

Re: r.stream.order and accum map

Micha Silver
Thanks,

On 02/22/2013 05:17 PM, jentjr wrote:
From a comment on line 74 of main.c it looks like the accumulation map is
required when calculating the Strahler stream order.

Actually you *can* create a raster stream order map based on strahler without an accum input.
i.e.:
r.stream.order --o -a streams=str dirs=fdir elev=dtm_full strahler=str_strahler memory=1500
works fine
???
 

 in_acc_opt->key = "accum";	/* required if strahler stream order is
calculated for existing stream network */
 in_acc_opt->type = TYPE_STRING;
 in_acc_opt->required = NO;	/* for now; TO DO: is planned to be optional */
 in_acc_opt->answer = NULL;
 in_acc_opt->gisprompt = "old,cell,raster";
 in_acc_opt->description =
	"(Not recommended) Name of accumulation file (r.watershed or
r.stream.extract)";

I believe that you will need to get the accumulation map from r.watershed
first.

Hope this helps,

Justin



--
View this message in context: http://osgeo-org.1560.n6.nabble.com/r-stream-order-and-accum-map-tp5036110p5036173.html
Sent from the Grass - Users mailing list archive at Nabble.com.
_______________________________________________
grass-user mailing list
[hidden email]
http://lists.osgeo.org/mailman/listinfo/grass-user

This mail was received via Mail-SeCure System.




-- 
Micha Silver
GIS Consultant, Arava Development Co.
http://www.surfaces.co.il

_______________________________________________
grass-user mailing list
[hidden email]
http://lists.osgeo.org/mailman/listinfo/grass-user