1. A method of representing fractures and computing a petrophysical parameter for a simulation model of a subterranean reservoir, said method comprising: providing, to a processor, measurements that characterize the subterranean reservoir to derive a statistical description of a full fracture network of the subterranean reservoir; partitioning the statistical description of the full fracture network based at least in part on a criterion; based on the partitioning of the statistical description of the full fracture network, creating, and storing to a storage device, a discrete fracture network for a portion of the full fracture network; computing the petrophysical parameter using the stored discrete fracture network and at least a portion of the statistical description of the full fracture network or separately computing the petrophysical parameter using the stored discrete fracture network and using at least a portion of the statistical description of the full fracture network wherein the computing and separately computing using the at least a portion of the statistical description of the full fracture network comprise calculation of stochastic realizations of one or more random variables representing the petrophysical parameter, in part, by deriving a spatial correlation parameter with respect to a separation distance using, from at least a portion of the statistical description of the full fracture network, fracture density and probability density functions of fracture length and of fracture orientation.