Multiple hydrological stable states and the probability of climate variability causing a threshold crossing

Abstract

Many physically based models of surface and groundwater hydrology are constructed without the possibility of multiple stable states for the same parameter set because they do not include positive feedbacks. For such a conceptualisation, at the cessation of a transient hydrological disturbance of any magnitude the model will return to the initial stable state, and thus show an infinite resilience. To highlight and challenge this assumption a numerical distributed eco-hydrological model (coupled hillslope Boussinesq-vertically lumped vadose zone) was developed in which qualitatively different steady state water table elevation and stream flow exist for the same parameter set. It is used herein..