Topological properties of random crack networks

The junctions of cracks in mudcrack, patterned ground, and columnar joint patterns can be categorized into "Y," "T,"and "X"types. The mean number of sides, $$\tilde g$$ ,to the polygonal areas in such nets is $$\tilde \bar g$$ = 2(2J_T + 3J_Y + 4J_X)/(J_T + J_Y + 2J_X)where J_T, J_Y,and J_Xare the proportions of T, Y,and Xjunctions, respectively.