A stochastic model for the formation of channel networks in 2 tidal marshes

8 [1] Salt marshes are often dissected by a network of 9 channels formed by tidal oscillations and related water 10 fluxes. In this note we present a stochastic model able to 11 simulate the formation and evolution of tidal networks in 12 salt marshes. The model is based on a simplification of the 13 shallow water equations that enables the determination of 14 the water surface gradients on the marsh platform and 15 related bottom shear stresses. The governing equations are 16 then solved with a random walk algorithm in an enclosed 17 domain representing the marsh platform and its physical 18 boundaries. Model results show how the development of the 19 network depends on the tidal forcing, the critical shear stress 20 for erosion, as well as the local heterogeneities in vegetation 21 and sediment substrate.