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Hello Abbas:<br>
<br>
On 19/01/2010 06:51, badaveil wrote:
<blockquote
cite="mid:e0cf077f1001182051p2f0adb78o65c2c5a1153ad2b4@mail.gmail.com"
type="cite">Hi everyone. I'm trying to promote QGIS in Malaysia
particularly among govt.agencies. <br>
<br>
</blockquote>
Good to hear.<br>
<blockquote
cite="mid:e0cf077f1001182051p2f0adb78o65c2c5a1153ad2b4@mail.gmail.com"
type="cite">I want to create a slope analysis showing 4 class levels
of slope gradient so that it can help in processing planning
applications by local planning authorities. How does one go about using
QGIS to create it? Where can I get reading material on this for QGIS.
However, QGIS User Guide 1.3 has not been helpful in the above area.<br>
</blockquote>
I think your best option is using the GRASS tool (from within QGIS)
called r.slope.aspect. You first need, of course, an elevation raster,
or DEM. The preferred source today is the ASTER Global DEM data (30 m.
resolution all over the globe). This data is available from:
<a class="moz-txt-link-freetext" href="https://wist.echo.nasa.gov/">https://wist.echo.nasa.gov/</a><br>
You need to register on the site, choose the ASTER data category, and
the region you're interested in, then you can get the raster tiles.
They are georeferenced in LatLon WGS84 datum, Geotiff format.<br>
Then use the GRASS toolbox to create a slope raster using the
r.slope.aspect module.<br>
<br>
Regards,<br>
Micha<br>
<blockquote
cite="mid:e0cf077f1001182051p2f0adb78o65c2c5a1153ad2b4@mail.gmail.com"
type="cite"><br>
Thanks<br>
<br>
Abbas Abdul Wahab<br>
<br>
<br>
<br>
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</blockquote>
<br>
<br>
<pre class="moz-signature" cols="62">--
Micha Silver
<a class="moz-txt-link-freetext" href="http://www.surfaces.co.il/">http://www.surfaces.co.il/</a>
Arava Development Co. +972-52-3665918
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