Stream laws in tectonic landscape analogue models

Abstract. The interplay between tectonics and surface processes defines the evolution of mountain belts. However, correlating these processes through the evolution of natural orogens represents a scientific challenge. Analogue models can be used for analyzing and interpreting the effect of such interaction. We use nine analog models characterized by different combinations of imposed regional slope and rainfall rates to investigate how a small scale orogen evolves in response to tectonics and surface processes. We show how the combination of these parameters control the development of drainage networks and erosional processes. We quantify the different morphological expression of analogue landscapes in terms of a proposed Ae number that accounts for both observables and boundary conditions. We find few differences between analogue models and natural prototypes, in terms of parametrization of the detachment-limited stream power law. We observe a threshold in the development of channelization, modulated by a tradeoff between applied boundary conditions.