Morfología Fluvial.- Ephemeral Channel Modelling at Historic timescales in Semi-arid Environments

Abstract

ABSTRACT There is an increasing need to understand how ephemeral channels mediate the movement of water through catchment systems, both to identify the quantity of groundwater and reservoir recharge and to inform flash flood prediction. At historic timescales (101-102 years) it is recognised that this requires an understanding of the interactions between flow, sediment and vegetation which feedback to control morphological change and future flood wave propagation. Reduced-complexity models provide a means to develop such understanding. This paper presents a coupled 1D-2D numerical model that can be applied at the catchment scale to account for transmission losses and floodwave propagation (1D model), but which also simulates local-scale flow patterns that may be applied to simulate geomorphic response to flood inundation (2D model). The initial model evaluation, conducted at the Walnut Gulch Experimental Watershed, Arizona is presented.