Extended Abstract (120K)9A.4
Modelling the Effect of Landscape Structure on the Dispersal of Biotic Particles
Yves Brunet, Institut National de la Recherche Agronomique, Villenave d'Ornon, France; and H. Foudhil and J. P. Caltagirone
The introduction of genetically modified crops and a growing tendency to limit the use of pesticides have led to a need for methods able to evaluate the dispersal patterns of biotic particles (pollen, spores) across heterogeneous landscapes. For this reason a deterministic flow model with an energy-dissipation closure scheme has been developed to simulate particulate dispersal from the field scale to the landscape scale. The equations of fluid dynamics are solved over a computational domain including the soil surface, the plant canopy and canopy air space, and a layer of atmosphere. Separate transport equations for particles are carried out, along with parameterisations of emission and deposition processes. The model has been extensively validated for wind velocity, turbulence and scalar transfer, using a range of available experimental data sets collected in-situ or in wind tunnels (roughness changes, changes in surface flux, flow in crop canopies, edge flow, flow in clearings). It is currently being validated for the dispersal of pollen and spores, using the outcomes of recent field experiments performed at heterogeneous sites. Further simulations allow the influence of specific landscape features (discontinuities, gaps, barriers, tree lines, forest plots, etc) to be assessed and the effective deposition velocity to be estimated at complex sites. The model provides an efficient tool to investigate the influence of the three-dimensional spatial distribution of landscape elements on particulate dispersal.
Session 9A, Aerobiology: General
Wednesday, 30 October 2002, 1:00 PM-2:30 PM
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