HYDROLOGICAL FLOW PATHS AT THE ALLT A-MHARCAIDH CATCHMENT - AN ANALYSIS OF PLOT AND CATCHMENT SCALE OBSERVATIONS

An integrated programme of hydrological monitoring at the 10 km2 Allt a' Mharcaidh catchment in north-east Scotland has been based on observ ations at plot, hillslope and catchment scale. The resonse of the prin cipal soil types has been characterized from a combination of throughf low and three-dimensional tensiometer data at plot scale, and plot seq uences have been used to investigate hillslope scale effects. Seep eme rgence is associated with downslope drainage and local topographic con vergence; in parallel preferential pathways generate a highly dynamic throughflow response. Catchment and subcatchment hydrographs mirror th e twin dynamic observed at hillslope scale, and a unified hypothesis o f response is presented which is consistent with all scales of observa tions.