Range Graded Proportional Circle Map

Range graded proportional circle maps are proportional circle map that us the circles based on ranges of data. The information is classified as equal quantiles, breaks, natural breaks, and minimum variance. The image above is based on river characteristics. The area of the circle is proportional to the channel width. The color of the large circle represents the color of the water. Descriptions of the bed material are determined by the position of the solid black circle inside of the black triangle. The example in the upper right is equal to a width of 500 yards.

Source:http://pubs.usgs.gov/fs/fs-004-03/