[Qgis-user] query

[Anita Graser]

Hi Nishant,

Am 05.04.2014, 10:20 Uhr, schrieb Nishant Alag <alagnishant at gmail.com>:
> i used srtm_52_06 to obtain aspect and slope. Aspect in one sense seems
> fine but slope is not undestandable in terms of figures, i chose slope in
> percent but it gives me figures ranging from 0 to 1.15778e+07. How to
> convert it into percentage or what would be the stepwise process i.e.  
> using srtm as a input file.

The SRTM data is in WGS84 EPSG:4326, right? That means that x,y are in  
degrees and z is in meters. Calculating slope will give strange results if  
you don't use the correct z factor settings:

If everything is in meters, use z factor 1.0 (default).
If x/y is in degree and z in meters, use z factor 111120.
If x/y degree and z is feet, use z factor 370400.

Best wishes,
Anita


-- 
anitagraser.com