The spatial, statistical structure of the fluid velocity field in the
case of uniformly recharged heterogeneous aquifers is investigated, an
d the spatial covariances of the velocity field are derived. This info
rmation is necessary for an investigation of flow and macrodispersion
using the Lagrangian formalism proposed by Dagan (1984). The resulting
first two moments of the velocity are nonstationary. They are functio
ns of a parameter beta which characterizes the degree of flow nonunifo
rmity and is related to the recharge. The displacement variances are c
omputed and tested favorably using numerical simulations. Simple relat
ions are developed which relate the transport parameters found for the
case of uniform-in-the-average flows to nonuniform flows using a simp
le, nonlinear transformation of the travel time, based on beta.