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Figuring shape areas of more than one polygon in a shapefile?

March 19 2008 | 0 comments
Categories: ArcGIS Methods

I am trying to layer a bunch of polygons by size, but when I originally made the polygons, I selected counties- then changed the boundaries of the counties. Now, when I layer the polygons by shape area, it layers it based on the original shape area of the county. Is there a way to calculate a new area of each polygon, without it using the area of the county that I originally edited? Thank you for your help.

Mapping Center Answer:

At version 9.2 we added a feature for calculating measures of geometry (X,Y,Z, length, perimeter, area). The help topic on calculating fields was enhanced to cover this topic.

Not only can you calculate the area in the units of your feature class's coordinate system, but you can choose a custom set of units, this way you can create and maintain new fields for several different units. Typically the field type for these measurements will be DOUBLE (or FLOAT).

Thus, at any given state of editing your geometry you can calculate a new field with the areas, and that calculation will be preserved independently of the geodatabase field for the feature's current area (in the SHAPE_AREA) field).

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