HR: 15:25h
AN: NG43A-08    [Abstracts]
TI: Cellular Automaton Simulation of Vegetated Dune Field Dynamics
AU: * Nield, J M
EM: joanna.nield@kcl.ac.uk
AF: Department of Geography, King's College London, Strand, London, WC2R2LS, United Kingdom
AU: Baas, A C
EM: andreas.baas@kcl.ac.uk
AF: Department of Geography, King's College London, Strand, London, WC2R2LS, United Kingdom
AB: Vegetated aeolian dune fields develop through non-linear interactions between physical geomorphic processes and ecological vegetation growth and response into complex ecogeomorphic systems that are sensitive to both climatic and environmental variations. We present a Discrete Ecogeomorphic Aeolian Landscape (DECAL) cellular automaton model that replicates the self-organisation of vegetated dune systems and enables the investigation of conditions necessary for long-walled (hairpin) parabolic dune and nebkha formation in coastal and semi-arid environments over various temporal and spatial scales. The algorithm utilises simple transport rules and mutual feedback between geomorphic and ecological components to investigate vegetation pattern formation and how and why this influences dune dynamics. We examine ecogeomorphic interactions both by exploring system mechanics via dune mobility and by more descriptive numerical state variables, facilitating the investigation of trajectories and potential attractors as a function of environmental parameters and system perturbations and leading to the identification of possible system sensitivities and thresholds. The model simulations elucidate possible dune field responses to anthropogenic impacts and palaeo and future climate variations and highlight the ability of vegetation to impart a characteristic length-scale on a landscape. This simple vegetated dune model illustrates the power and versatility of a cellular automaton approach for exploring ecological and geomorphic interactions in complex earth surface systems.
DE: 0515 Cellular automata
DE: 1622 Earth system modeling (1225)
DE: 4430 Complex systems
DE: 4485 Self-organization
SC: Nonlinear Geophysics [NG]
MN: 2007 Fall Meeting