MURPHYS-HSFS-2014 - 7th International Workshop on Multi-Rate Processes & Hysteresis, 2nd International Workshop on Hysteresis and Slow-Fast Systems, April 7-11, 2014 - Abstract

Hinz, Christoph

Self-organized vegetation pattern in arid environments

Arid vegetation displays various degrees of organization. On flat topography regular bands of vegetation alter with bare soil. Other patterns include patches of different size, labyrinths or dendritic patterns following drainage lines. These patterns result from a simple soil vegetation feedback in which the soil's infiltration capacity is higher under vegetation as compared to the bare soil. Water redistribution by surface water runoff from bare soil to soil patches with vegetation causes the feedback to generate self-organized pattern. While water redistribution operates on short time scales of minutes to days, the growth of the vegetation and possibly migration occurs at time scales of years to decades. Current modeling approaches have focused on pattern formation at the vegetation time scale and have not explicitly accounted for the event based nature of surface water redistribution. Moreover, microtopography influencing surface water redistribution has also not be considered in the necessary high spatial resolution as it occurs in nature. We present a cellular automata model, that explicitly describes the diversity of arid vegetation pattern by modeling surface runoff in much greater spatial detail, generating a new set of emergent vegetation pattern. Aspect of the role of temporal scale difference in the modeling is currently under investigation.