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 ??
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.
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 ???
···
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.
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
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