topic Extract raster area summary for a number of polygons in Data Management Questions

Extract raster area summary for a number of polygons

JamieGairns — Tue, 24 Apr 2012 21:24:36 GMT

Hi All,

This seems like an incredibly basic function, yet I have not found anything yet. Could be the search terms I am using.

I have a polygon layer with a number of shapes (land ownership polygons; each polygon maps to a specific owner).
I have a thematic raster layer (land cover classification, actually). This layer exists as a polygon layer too, just in case.

I want to query the land cover (raster or polygon) and calculate the area (or even % of the polygon) of each land cover class that occurs in each polygon. The output should be something like:
OwnerPoly1 = 45.3ha wheat; 12ha barley
OwnerPoly2 = 61.2ha wheat; 1.4ha barlet
... and so on

I tried Spatial Analyst -> Zonal -> Tabulate Area is what I want, but it doesn't seem to work.
I tried GME, but it doesn't seem to work.

Any suggestions? I feel very noobish in asking this, but nothing seems to work.

Many Thanks (in advance)

Jamie

Re: Extract raster area summary for a number of polygons

MarcinGasior — Wed, 25 Apr 2012 10:15:14 GMT

The tool you've chosen is correct. Why it doesn't seem to work?
I made a test in similar scenario - regions and global land cover, and the tools returns a table with area (in LC raster measurement units) of each LC class in each region.
Here are possible settings:
[ATTACH=CONFIG]13800[/ATTACH]

Re: Extract raster area summary for a number of polygons

JeffreySwain — Wed, 25 Apr 2012 18:38:55 GMT

I would consider the Zonal Statistics as a Table tool. Specify the Zone Layer as the polygon file with the field of the land cover and then specify the value raster as the one you would like to survey. The output will be in a table,which you should be able to join back to your original feature class. Area is one of the statistics generated.