FREQUENCY RESPONSE OF THE STREAM AND SOIL TO RAIN INPUT AT MINK BROOK, ETNA, NH
We compare two time periods, both having similar soil moisture contents in the upper unsaturated zone but differing in the stream baseflow. The period with the lower baseflow shows higher frequency signals transmitted to the stream but no difference in the soil response. This response to higher frequency input under dry conditions may be due to only the shortest flowpaths connecting to the stream when baseflow is low. One significant pathway is direct precipitation on the stream (Renshaw et al., 2003). Under wetter conditions, activation of additional transport pathways will result in a wider distribution of travel times to the stream and a further loss of high frequency temporal variations in stream discharge. The activation of longer flow paths will also push out old water that has been in the watershed, damping the chemical signal of new input water. These long flowpaths can be activated during light rains when baseflow is high or alternatively during times of heavy rain. This leads to a somewhat counterintuitive conclusion that heavier rains will likely result in more dilution of the new water signal in the stream as has been observed by Renshaw et al. (2003).