[GIS] Determining direction of longest segment of polygon using ArcGIS Desktop

arcgis-10.2arcgis-desktopdirectionpolygon

I have a shapefile with 9000 agriculture fields and what I like to do is to determine for each field (=each polygon) the direction of the longest segment.
For instance, the selected polygon in the screenshot has its longest segment from west to east so I would like to mark give the polygon the attribute W (for west) or either E (for east).

Is there any solution to solve my problem in a fast but generalized way?

I do not need very detailed results. It's just for the interpretation of a question.

I'm seeking an answer using ArcGIS 10.2 for Desktop.

To be more precise on what I'm looking for I try to explain more practical: I'm doing winderosion analysis for a specific area with 9000 fields. As result I have a potential susceptibility for each field. I like to check, if the fields with high susceptibility are correlated to a certain orientation of the fields, e.g. check if most of the fields with high risk are oriented in the main winddirection or not.

The search for the longest segment is not really important for me. It was just an idea I had to determine the direction. So forget about the longest segment if there is a way to determine the direction with another method 😉

Screenshot

Best Answer

Assuming you just want the general orientation of the polygon, rather than a specific segment... try the Minimum Bounding Geometry (Data Management) ArcGIS tool with the RECTANGLE_BY_WIDTH or RECTANGLE_BY_AREA geometry type and the MBG_FIELDS option. The MBG_FIELDS option will add the following fields to the output attribute table:

  • MBG_Width—The length of the shorter side of the resulting rectangle.
  • MBG_Length—The length of the longer side of the resulting rectangle.
  • MBG_Orientation—The orientation of the longer side of the resulting rectangle.
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