[GRASS-dev] Re: grass-dev Digest, Vol 33, Issue 37

Helena Mitasova hmitaso at unity.ncsu.edu
Sat Jan 17 00:28:32 EST 2009


On Jan 17, 2009, at 12:07 AM, Michael Barton wrote:

> Markus,
>
> I compiled last night and was able to try this on my Mac this  
> evening. No problem at all with the North Carolina elev_lid792_1m  
> DEM. Everything ran very fast, of course--even though it runs at  
> 32bit on the Mac.
>
> As expected, the MFD results look much more realistic than the SFD  
> results. Much less linearity and more sinuosity. I can post the  
> displays if anyone wants to see them.
>
> No errors from the command.
>
> No errors in compiling.
>
> Seems to work fine on the Mac.
>
> I'm not sure why this can't be backported to develbranch_6 since  
> 6.4RCx is already out. Does it change any of the r.watershed  
> arguments or behavior using the pre-MFD arguments?

Michael
-  it needs to be thoroughly tested on wide range of data
before replacing it. I am trying to get to it too and Markus M has  
done already quite a bit of testing himself. If you can ask Isaac and/ 
or whoever  has grass7 and is around to test it with different data
(wide range of resolutions, data sources, combinations of parameters,  
integer or float DEMs, latlong, different size and type of  
depressions etc.) that would help.

Has anybody any other issues with the new r.watershed than testing?

Helena

>
> Michael
>
>
> On Jan 15, 2009, at 12:39 PM, Markus Metz wrote:
>
>>
>>
>> Michael Barton wrote:
>>>
>>>
>>> On Jan 15, 2009, at 5:22 AM, <grass-dev-request at lists.osgeo.org>  
>>> wrote:
>>>
>> [...]
>>>> Comment (by mmetz):
>>>>
>>>> I have submitted a new version of r.watershed to trunk with various
>>>> changes
>> [...]
>>>
>>> Markus,
>>>
>>> Can this go into develbranch_6 too?
>> I hope so:-) But I would like to get the new functionality tested  
>> by others before it is backported in case I missed something. You  
>> mentioned that you are testing the new functionality, and you are  
>> using Mac while I use Linux 64bit, so if the new version runs fine  
>> and produces proper results on your system that would be encouraging!
>> Below are test scripts for the North Carolina sample dataset  
>> nc_spm_08 and the Spearfish dataset spearfish60. You can copy the  
>> commands for each dataset into a script and then run the script,  
>> after updating to today's version of r.watershed:-)
>>
>> Markus M
>>
>>
>> Testing commands for the elevation map elev_lid792_1m in the North  
>> Carolina sample dataset nc_spm_08. SFD and MFD output is  
>> strikingly different.
>>
>> g.region rast=elev_lid792_1m
>> # multiply elev_lid792_1m to get millimetres as vertical units
>> r.mapcalc "elev_lid792_1m.1mm = round(elev_lid792_1m * 1000.0)"
>>
>> # SFD (D8) flow distribution
>> r.watershed elev=elev_lid792_1m.1mm threshold=3000 \
>> accum=elev_lid792_1m.1mm.acc.sfd drain=elev_lid792_1m.1mm.drain.sfd \
>> basin=elev_lid792_1m.1mm.basin.sfd stream=elev_lid792_1m. 
>> 1mm.stream.sfd \
>> half_b=elev_lid792_1m.1mm.halfb.sfd vis=elev_lid792_1m.1mm.viz.sfd \
>> length_sl=elev_lid792_1m.1mm.ls.sfd slope_st=elev_lid792_1m. 
>> 1mm.sls.sfd -s
>>
>> # MFD flow distribution
>> r.watershed elev=elev_lid792_1m.1mm threshold=3000 \
>> accum=elev_lid792_1m.1mm.acc.mfd drain=elev_lid792_1m.1mm.drain.mfd \
>> basin=elev_lid792_1m.1mm.basin.mfd stream=elev_lid792_1m. 
>> 1mm.stream.mfd \
>> half_b=elev_lid792_1m.1mm.halfb.mfd vis=elev_lid792_1m.1mm.viz.mfd \
>> length_sl=elev_lid792_1m.1mm.ls.mfd slope_st=elev_lid792_1m. 
>> 1mm.sls.mfd \
>> convergence=5
>>
>>
>> Testing commands for the elevation map elevation.10m in the  
>> Spearfish sample dataset spearfish60. Differences between SFD and  
>> MFD are mainly in the northern half.
>>
>> g.region rast=elevation.10m
>> # multiply elevation.10m to get centimetres as vertical units
>> r.mapcalc "elevation.10m.1cm = round(elevation.10m * 100.0)"
>>
>> # SFD (D8) flow distribution
>> r.watershed elev=elevation.10m.1cm threshold=3000 \
>> accum=elevation.10m.1cm.acc.sfd drain=elevation.10m.1cm.drain.sfd \
>> basin=elevation.10m.1cm.basin.sfd stream=elevation.10m. 
>> 1cm.stream.sfd \
>> half_b=elevation.10m.1cm.halfb.sfd vis=elevation.10m.1cm.viz.sfd \
>> length_sl=elevation.10m.1cm.ls.sfd slope_st=elevation.10m. 
>> 1cm.sls.sfd -s
>>
>> # MFD flow distribution
>> r.watershed elev=elevation.10m.1cm threshold=3000 \
>> accum=elevation.10m.1cm.acc.mfd drain=elevation.10m.1cm.drain.mfd \
>> basin=elevation.10m.1cm.basin.mfd stream=elevation.10m. 
>> 1cm.stream.mfd \
>> half_b=elevation.10m.1cm.halfb.mfd vis=elevation.10m.1cm.viz.mfd \
>> length_sl=elevation.10m.1cm.ls.mfd slope_st=elevation.10m. 
>> 1cm.sls.mfd \
>> convergence=5
>>
>>>
>>> Michael
>>> _______________________________________________
>>> grass-dev mailing list
>>> grass-dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/grass-dev
>>>
>
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