[GRASSLIST:7848] Re: visualize DEM error

[orkun]

Dylan Beaudette wrote:

> Couple ways that are outlined in this book [1] suggest making 
> histograms of elevation and aspect data. if you see spikes at regular 
> intervals in either graph then you have some artifacts - possibly due 
> to the use of contours as your input data. You can do this with the 
> GRASS-R interface in a couple of minutes.
>
> Another quick check, does your DEM support realistic flow patterns, 
> when modeled with something like r.terraflow? i.e. do numerous sinks 
> and dams cause water to move with no outlet, when expert knowledge of 
> the area suggests otherwise? Comparison with an alternate source of 
> stream data may also shed some light on the quality of the DEM.
>
> How did you create the DEM, and from what type of source ?
>
> [1]    J. P. Wilson and J. C. Gallant, editors. Terrain Analysis. John 
> Wiley and Sons Inc., New York, 2000.
>
>
> -- 
> Dylan Beaudette
> Soils and Biogeochemistry Graduate Group
> University of California at Davis
> 530.754.7341
>
>
> On Aug 10, 2005, at 12:46 AM, orkun wrote:
>
>> hello
>>
>> how  can  I visualize DEM error ?
>> how can I interpret whether DEM which I have created is correct ?
>>
>>
>> could you give me hints ?
>>
>> regards
>>
>> Ahmet Temiz
>>
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>
>
>
thank you Dylan

I used v.surf.rst to create DEM.
I have a topographic contour map as source.

regards


______________________________________
XamimeLT - installed on mailserver for domain @deprem.gov.tr
Queries to: postmaster at deprem.gov.tr
______________________________________
The views and opinions expressed in this e-mail message are the sender's own
and do not necessarily represent the views and the opinions of Earthquake Research Dept.
of General Directorate of Disaster Affairs.

Bu e-postadaki fikir ve gorusler gonderenin sahsina ait olup, yasal olarak T.C.
B.I.B. Afet Isleri Gn.Mud. Deprem Arastirma Dairesi'ni baglayici nitelikte degildir.