The role of near-stream riparian zones in the hydrology of steep upland catchments

Surface and subsurface waters were monitored and sampled at various topogra phic positions in a 40.5-ha headwater catchment to test several hypotheses of runoff generation and stream chemical and isotopic evolution during snow melt. Transmissivity feedback was observed on the hillslopes during the mel t period. Groundwater levels and stream DOC were highly correlated with str eam discharge. Hysteresis in the groundwater-streamflow relation suggests t hat localized water flux from the riparian areas controlled the rising limb and main peak response of the melt hydrograph, whilst hillslope drainage c ontrolled the timing and volume of the falling limb. Lateral flow from upsl ope positions was detected in the riparian zone.