Temporal variability of subsurface stormflow formation

P. M. Kienzler (1) , F. Naef (1)

1 Institute of Environmental Engineering

Subsurface storm flow (SSF) can play a key role for the runoff generation at hillslopes. Quantifications of SSF suffer from the limited understanding of how SSF is formed and how it varies in time and space. This study concentrates on the temporal variability of SSF formation. Controlled sprinkling experiments at three experimental slopes were replicated with varying precipitation intensity and varying antecedent precipitation. SSF characteristics were observed with hydrometric measurements and tracer experiments. SSF response was affected in different ways and to varying degree by changes of precipitation intensity and antecedent precipitation. The study showed that the influence of antecedent soil moisture on SSF response depends on the type of SSF formation. Formation of subsurface stormflow was hardly influenced by the increase of precipitation intensity. As a consequence, subsurface flow rates were not increased by higher precipitation intensity. Different soil structures determined runoff formation at different precipitation intensities. Saturation and flow formation occurred at the base of the soil, but also within the topsoil during high precipitation intensity. This implies that timing and magnitude of flow response can change substantially at different precipitation intensities.

Domaines: Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

P. M. Kienzler, F. Naef. Temporal variability of subsurface stormflow formation. Hydrology and Earth System Sciences Discussions, 2007, 4 (4), pp.2143-2167. ⟨hal-00298857⟩