[Qgis-user] query

[Alex Mandel]

On 04/05/2014 11:38 AM, Anita Graser wrote:
> Am 05.04.2014, 20:30 Uhr, schrieb AntonioLocandro
> <antoniolocandro at hotmail.com>:
> 
>> A source for the z factor values given would be good for reports as
>> usually
>> one has to document things like that, is there a link available or
>> document
>> of why those specific z values would work?
> 
> Sorry, I don't have a literature source at hand. I got these z factor
> valuse from Marco Hugentobler's comments to
> http://anitagraser.com/2012/01/19/a-guide-to-beautiful-reliefs-in-qgis/
> 
> Best wishes,
> Anita
> 

Look like an approximation of the conversion from Decimal Degrees to
meters/feet
http://en.wikipedia.org/wiki/Decimal_degrees

If you need more accurate results convert your DEM to a local projection
1st and do it all in meters.

Thanks,
Alex