MOPOD: a model to investigate fracture porosity development.

A model (MOPOD) has been developed to investigate general relationships between simple fracture aperture growth laws and fracture porosity in fractured aquifers. The development of fractures has been studied where growth-rate is proportional to an exponent, e, of the flow rate through each fracture. The approach adopted is similar to that of statistical mechanical studies of simple systems, where evolved structures depend on the initial values. The evolved arrays show a range of diverse structures and geometrical phase changes as a function of the aperture growth-rate law and the initial aperture distribution, i.e. the standard deviation of the initial aperture distribution. Following an initial growth phase, during which dynamically stable aperture configurations develop, arrays undergo simple amplification. The evolved arrays are highly complex and parameterisation and prediction of their evolution in terms of the initial aperture distributions and growth-rate laws is not trivial.