Convert Polygons to Points in ArcGIS
October 12, 2009 by Timothy
Filed under ArcGIS, Data Management, GIS Tips
During analysis it is important to keep various techniques at hand as the data sometime requires creative thinking to carry out certain tasks in a feasible way. One of these techniques to have handy is the ability to convert polygons to points.
In ArcInfo there is a tool that allows this to be done.
ArcToolBox –>Data Management Tools –>Features –>Feature to Point
However, if you have a lower license, there is a simple workaround. (The headings are links to specific demonstrations of these steps.)
Calculate Lat/Long for Shapefile
1. Add X and Y fields to your polygon attribute table
2. Calculate the X and Y coordinates
3. Export the attribute table to a new *.dbf
Create Point File from XY Data
4. Add new table to map document
5. Add XY event layer
6. Export temporary XY event layer file to permanent file
Buffering Features in ArcGIS
Buffering is a useful technique in GIS. It is referred to as a proximity tool in ArcToolbox. It can be applied to points, polylines, and polygons. Some valuable uses include: Right-of-ways, Tree diameters, Sex Offender Exclusion Zones, Study Areas, Impervious Surfaces from a Centerline, Evacuation Zone of Weather Events, etc.
To perform a single distance buffer:
1. Open the Buffer Tool – ArcToolbox >Proximity >Buffer
2. Fill Inputs
- Input Features (Points, Polylines, Polygons)
- Output Feature Class
- Linear Unit (Distance of Buffer) This can also come from a attribute field value.
The remaining entries are optional.
The new output layer from the buffer will be added to the map (circles around red dots).
To perform a multiple distance buffer:
1. Open the Multiple Ring Buffer Tool – ArcToolbox >Proximity >Multiple Ring Buffer
2. Fill Inputs
- Input Features (Points, Polylines, Polygons)
- Output Feature Class
- Enter each buffer distance.
The remaining entries are optional.
The new output layer from the buffer will be added to the map. Notice that I have used the dissolve option. This causes the buffer rings to dissolve based up distance.
