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I am currently trying to measure the area of polygons within each square of a fishnet. The aim of what I am doing is to work out the proportion of different agri-environment schemes by 1km squares. I have tried following the instructions in the pdf below but when it comes to the dissolve I get a 'warning empty output'. Any suggestions?

Thanks!

Using the intersect function creates the layer below and cannot be used to calculate area within squares

http://www.cabnr.unr.edu/weisberg/downloads/polygons_within_polygons.pdf

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Have you tried just using Union followed by Summary Statistics? –  PolyGeo Mar 19 '13 at 12:30
    
Thanks, i have just tried that but it gives the sum area of the whole layer rather than by fishnet square. –  user13641 Mar 19 '13 at 13:01
    
Perhaps it is better to wait until i get an Arcinfo license and split it –  user13641 Mar 19 '13 at 13:26
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I think you may want to dissolve your agri-schemes prior to the intersection/union. Then you wouldn't have multiple smaller polygons of the same type within each square and you could easily export/summarize area by class for each. –  JWallace Mar 19 '13 at 15:25
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1 Answer

up vote 5 down vote accepted

if you´re looking for something like this(labels denote area in sqkm): Intersect

You can just intersect the Fishnet with the Polygon Layer.

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Using the intersect function produced the layer i have posted in my question, I can't use this to calculate areas within the fishnet squares...Any ideas? Thanks. –  user13641 Mar 19 '13 at 14:59
    
The areas of the intersecting polygons should be calculated in the "Shape_Area" field of the Intersect Output already. –  rafaelr Mar 19 '13 at 15:11
    
Apologies! Thank you for your help. –  user13641 Mar 19 '13 at 15:54
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