Shoreline development index

Lakes in Saskatchewan with varying shoreline development indices (islands included): Peter Pond - 1.5, Churchill - 4.1, Ile a la Crosse - 8.2

The shoreline development index of a lake is the ratio of the length of the lake's shoreline to the circumference of a circle with the same area as the lake. It is given in equation form as ${\textstyle D_{L}={\frac {L}{2{\sqrt {\pi A}}}}}$, where ${\textstyle D_{L}}$ is shoreline development, $L$ is the length of the lake's shoreline, and $A$ is the lake's area. The index can also include the length of island shoreline, modifying the formula to ${\textstyle D_{L+L_{i}}={\frac {L+L_{i}}{2{\sqrt {\pi A}}}}}$, where $L_{i}$ is the combined length of the lake's islands' shoreline. Shoreline development correlates strongly with lake area.