| Abstract: | The two-component hydrograph separation method has been used to investigate the sources of storm runoff at Allt a Mharcaidh during storms in October 1987, September 1988, and June 1989. Results show that for the September and October storms, more than 88 per cent of storm runoff was contributed by pre-event water and 54 per cent of the June storm runoff. Instantaneous contributions of pre-event water at the hydrograph peak vary from 91 per cent in September 1988 to 41 per cent in June 1989. Detailed examination of soil and borehole water, however, shows that these subcomponents of pre-event water do not always have similar chemistry and isotope concentrations. Therefore, information from the two-component separation method alone should not be used to infer processes or pathways, although some broad indications can be obtained through the additional use of soil water and groundwater chemistry. |
