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Generalizing 1:2500 scale landcover for a 1:25,000 scale map.

September 03 2007 | 0 comments
Categories: ArcGIS Methods, Map Data

I have a land cover feature class that has been interpreted at a scale 1:2500 (using an UTM
System in meters). I would like to make the cartographic output at a scale 1:25000. When I take the data at 1:2500 into a layout of course I get a lot of aggregation in the features and they can not be seen as well. How can I generalize this large scale data and be able to represent it in a smaller scale such as 1:25000 in a layout?

Mapping Center Answer:

I’m going base my response on your having raster land use dataset. In that case there are a couple of tools in the Spatial Analyst extension that should help you. However, I will state that the obvious tool, Aggregate, will not as it is intended for interval and ratio data (versus ordinal or nominal like you have).

The tools I would recommend using are:

Majority Filter, you’ll need to try the combination of parameters to determine which works best for you.

Block Statistics, with the statistics type set to “MAJORITY”, you’ll need to determine the output raster’s cell size via the geoprocessing environment settings.

I think either of these will do what you need, but it’s a matter of your preference in terms of what the best outcome is given your understanding of the local area.

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