The Shoreline Development Factor (SDF) compares the shorelength of a lake to the circumference of a circle with the same area as the lake.
shoreline development factor =
= (length of the shoreline around the lake in miles) / (circumference of a circle in miles with the same area as the lake)
area of circle in square miles =
= PI() * ((radius of circle in miles)^2)
circumference of circle in miles =
= PI() * 2 * (radius) = 2 * SQRT(PI() * (area of lake in square miles))
where:
• 640 acres equals 1 square mile.
Interpretation:
• A lake that is a perfect circle will have an SDF of 1.
• The higher the SDF the more irregular the shoreline. An irregular shoreline may pose greater safety risks and limit the use of certain watercraft.
