Identification of runoff processes in a small undisturbed catchment in the Chilean Andes - Experimental study and modelling

Hydrology of the Tres Arroyos in Malalcahuello, Chile

Modelling

The physically based model CATFLOW (potential based Richards equation, ...) will be used in the modelling part of this study. Orthogonal curvilinear coordinates describe hillslope geometry. CATFLOW uses the vanGenuchten-Mualem Model for soil properties (Zehe et al. 2001, Zehe & Bloeschl 2004).
In this study, so far only the hillslope module has been used in order to test first hypotheses. There is a lot more work to do: While times of peak are only off by 20-30 minutes, neither continuously layered soils over the whole hillslope nor included areas of preferential flow could reproduce flow dynamics.

• the recession is too slow in all scenarios
• specific discharges are underestimated
• the layered soil system produces less lateral flow than expected
• the incorporation of vertical preferential flow needs to be improved