topic Zonal Statistics using polygons (no raster file) in ArcGIS Spatial Analyst Questions

Zonal Statistics using polygons (no raster file)

Hasin_ShahadMunna — Wed, 10 Apr 2013 21:13:49 GMT

Hello,

This is my first post and I am trying to illustrate my question as simply as I can 🙂

Shapefile 1: Contains sub-basin boundaries of a basin (100+ polygons showing the boundary of each subbasin)
Shapefile 2: Contains numerous (2000+) smaller polygons having their areas calculated within the attribute table.

Goal: Calculate the total area of polygons (Shapefile 2) within the boundary of each sub-basin polygon (Shapefile 1).

Any help is much appreciated.

Thanks a lot.

Re: Zonal Statistics using polygons (no raster file)

MarkBoucher — Thu, 11 Apr 2013 13:04:20 GMT

Use the Intersect Tool with Shapefile 1 and Shapefile 2. You will get a new shapefile that includes shapes only where they intersect and the fields of both in the table. Then find the field that represents Shapefile 1 and use the Dissolve tool (Data Management Tools.tbx\Generalization\Dissolve) with that field. This will result in polygons that are dissolved to represent the Shapefile 1 areas only where they overlapped Shapefile 2. If these are outside of a geodatabase, you will have to recalculate the Shape_Area field or create an Area field and calculate the area.

You might get the same results using the Analysis Tools.tbx\Extract\Clip tool.

Re: Zonal Statistics using polygons (no raster file)

Hasin_ShahadMunna — Thu, 11 Apr 2013 15:01:04 GMT

Use the Intersect Tool with Shapefile 1 and Shapefile 2. You will get a new shapefile that includes shapes only where they intersect and the fields of both in the table. Then find the field that represents Shapefile 1 and use the Dissolve tool (Data Management Tools.tbx\Generalization\Dissolve) with that field. This will result in polygons that are dissolved to represent the Shapefile 1 areas only where they overlapped Shapefile 2. If these are outside of a geodatabase, you will have to recalculate the Shape_Area field or create an Area field and calculate the area.

You might get the same results using the Analysis Tools.tbx\Extract\Clip tool.

Worked Perfectly!

Thanks a lot... 😄