Influence of aspect and slope gradient on hydraulic conductivity measured by tension infiltrometer

A tension infiltrometer technique was used to characterize differences in hydraulic conductivity (K) in two rain-fed hillsides (north-facing and south-facing) in central Chile. For the north-facing locations, smaller values of K (at a range of supply water pressure heads psi) compared with south-facing locations were found, with accentuated differences close to saturation (zero pressure head). The differences were attributed to differences in texture and organic matter contents observed for the two sites. Furthermore, K(psi) had a tendency to increase with increasing slope gradient. This tendency was to an extent explained by the deviation from requirements of measurements on level ground. The differences found in K(psi) between different slope gradients were explained by the differences in the vertical and lateral hydraulic conductivity and by the occurrence of surface sealing in low slope plots. Copyright (C) 2000 John Wiley & Sons, Ltd.