Methodologies relating river response to basin geomorphology are useful in the estimation of hydrologic behavior in regions with sparse or no data. This study describes research of potential value in traditional hydraulic routing applications. In it the infiltration losses along the streams of a basin are included in the Instantaneous Unit Hydrograph (IUH), which is derived as a function of basin geomorphologic and physiographic characteristics, and the response of the individual channels to upstream and lateral inflows. This response is obtained by solving the linearized continuity and momentum equations, including infiltration losses terms, for the boundary conditions established by the definition of a linear system response to an instantaneous unit input. A methodology is proposed for the estimation of the parameters involved in the channel response. Based on this result, a procedure is suggested to include infiltration losses in the common linear reservoir representation of channel segments. Comparisons indicate that this approximation is adequate. Included are three tables, 50 figures, a 43-item bibliography (1945-82), and an analytical linear solution for the upstream channel IUH and some mathematical properties. (Author abstract, modified).