Hydrologic output of small forested catchments: implications for management

Summary A study of the hydrology of a small, forested catchment in a foothill environment showed that the major source of streamflow is groundwater seeping from the catchment slopes, and that the streamflow response to rainfall is highly dependent upon the position of measurement, being small at the springhead of the stream. Thus the relative influence of a given land-use treatment on streamflow also strongly depends upon its location within the catchment and the position along the stream at which the influence is measured. Because the main contributing process to the stream was groundwater seepage the rates of discharge with time were relatively low. Thus, factors which lead to the generation of overland flow tended to make marked changes in catchment hydrology. The study showed that such marked changes could be avoided by the diversion of generated overland flow so that it is infiltrated into the catchment slopes before reaching the stream.