[Qgis-user] Query re: Area measures

[Lene Fischer]

Hi Hugh,
You have to mark the layer>Save As
Choose an UTM projection so you can calculate in m2 and km2.
Close the original layer and zoom to the new UTM layer - This only for visualizing - not for any function..

Click on Attribute table>Fieldcalculator
Either make a new field or update an exsisting field.

I´ve made a small video to show how to. - Sorry I´m using in danish version ;-)
http://screencast.com/t/ZQJyb6zj

Regards
Lene Fischer
________________________________
Fra: qgis-user-bounces at lists.osgeo.org [qgis-user-bounces at lists.osgeo.org] på vegne af Wenban-Smith [wenban at globalnet.co.uk]
Sendt: 13. september 2013 18:13
Til: qgis-user at lists.osgeo.org
Emne: [Qgis-user] Query re: Area measures

My QGIS project uses a .shp file of 179 districts in Tanzania. I wish to know the area of each district in sq km but the Geometry-$area function (in the field calculator of the Attributes table) only reports areas in decimal degrees (whereas the individual area measuring tool from the toolbar reports sq km but is tedious to use and not precise). It appears looking under Settings/Project Properties [General tab] that it is possible to convert to meters only when CRS transformation is disabled but there is no guidance how to do this (nor why this should be necessary). I have tried converting the CRS from Arc 1960 to one the UTM ones but this did not help.

Grateful for any advice more experienced users can offer.

Hugh W-S

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