Since natural fracture length is typically unobservable in subsurface data, we derive relationships that relate fracture length to aperture and spacing, both more readily measurable quantities.

• 由于天然裂缝的长度是典型的在地下数据是不可观的，我们得到相关孔穴的裂缝长度和间隙的关系，都更是随时可衡量的数量。