Toward more detailed field monitoring of variable source areas

Variable source area storm flow generation is now a well‐accepted process in natural catchments. Although the concept of variable source areas, together with more theoretical modeling, has received much recent attention, detailed field delineation, both seasonally and for short storms, has not. The work reported here uses an automatic tensiometer system to obtain continuous data on soil water potential status in a hillslope hollow. The results discussed demonstrate that source areas can be accurately delineated by such equipment and that hollows are significant source areas at all stages of drainage. Moreover, the convergence shown by the soil water flow nets in such source areas remains almost constant throughout the year.