This paper describes an investigation of flow and transport phenomena in heterogeneous, nonstationary formations, where the log conductivity is the superposition of a linear trend and a stationary fluctuation. The problem of flow and transport in a steady, two-dimensional flow without recharge is investigated analytically for an infinite flow domain. General results are obtained for any space dimensionality, but applications were limited to the case of two-dimensional flow in the horizontal plane. The log conductivity field is assumed to have a linear trend. We limited the scope of this study to the cases where the trend is either parallel or normal to the lead gradient and to small variance in the log conductivity. This paper presents results for the moments of the velocity and the hydraulic head, the effective conductivity, macrodispersion coefficients, solute mass breakthrough curves, and travel time distributions, all in terms of the parameters of the log conductivity field and the boundary conditions. The effects of the trend in the conductivity on these results are analyzed and compared with those obtained when the apparent trend is neglected. The results may be used for predicting transport phenomena extending over distances of many integral scales, as well as for interpretation of field data where the presence of a trend is suspected. ¿ American Geophysical Union 1994