Adding a Buffer When Creating, Copying, or Uploading a Shape

Steps to Create a Buffer

When uploading a shapefile with the Upload Shapes widget, or creating or copying a shape with Create Edit Shapes, you can create a buffer by selecting the "Create a buffer around this shape" option before clicking create. This produces two shapes, one is the uploaded or copied shape, and a second is the buffer.

Once the option to "Create a buffer around this shape" is selected, the widget will expand to show buffering options:

1. Specify the buffer distance and units. Options include feet, meters, yards, kilometers, and miles.

2. Specify a buffer shape and whether to make the buffer hollow. For example, selecting "Around shape" and checking the "Hollow" option creates a ring-shaped buffer around the shape. See the buffer options section below for full detail.

   Note: For points and lines, buffer output selections differ from those for polygons. Line buffers also have a "Flat ends" option to end the buffer at the edges of the line.

3. Click Create.

   

4. After you click Create, two shapes will be displayed, the original and the buffer.

5. By default, the buffer is stored in the folder as the shape it is created from.

   

Available Buffer Outputs

This section describes buffer options for:

• Polygons

• Lines

• Points

Polygons

Several buffer outputs are available for polygons that will cover the area outside, inside, or including the original shape. These include:

• Around shape, "Hollow (cut out the middle)" is selected - Creates a hollow ring around the outside of the shape, following shape contours.

• Around shape - Creates an area covering the inside of the shape and extending outward a specified distance.

• Box, " Hollow (cut out the middle)" is selected - Creates a rectangular area around the outside of the shape.

• Box - Creates a rectangular area covering the inside of the shape and extending outward a specified distance.

• Inside Shape, "Hollow (cut out the middle)" is selected - Creates a hollow ring around the inside of the shape, following shape contours.

• Inside Shape - Creates an area inside the shape that ceases at a specified distance from the outer shape contours.

Examples of each of these, with the resulting buffer displayed as a hashed area, are shown in the diagram below.

Lines

Buffer outputs available for lines include:

• Around shape - Creates a polygon around the entire line following the line contours, including the ends of the line.

• Around shape and "Flat ends" option selected - Creates a polygon following the line contours, the polygon ends flush with the end of the line.

• Box (rectangle around shape) - Creates a rectangular polygon around the entire line, including the ends of the line.

• Box (rectangle around shape) and "Flat ends" option selected - Creates a rectangular polygon around the entire line, the polygon ends flush with the end of the line.

Points

Buffer outputs available for points include:

• Around shape - Creates a circular polygon around the point.

• Box (rectangle around shape) - Creates a rectangular polygon around the point.