Experimental study of the formation of linear karren under the effect of rainfall

Linear karrens are exokarst features commonly observed on sloping limestone slabs, characterised by regularly spaced parallel grooves that extend downslope. Assuming that these patterns are formed by rain-induced dissolution processes, we explore their formation using an experimental set-up, where parallelepipedic caramel blocks are exposed to artificial rainfall. The rain flux induces a thin film that flows along the surface of the block. The feedback between the film flow and the topography of the block modifies the solute concentration profile, leading to the formation of these patterns. We identify critical thresholds in rain flux and block tilt with vertical, below which linear karrens emerge. This study contributes to a better understanding of rain-induced dissolution patterns and could inform models of erosion processes in natural landscapes.

Refererences :

Glew, J. R., and D. C. Ford. "A simulation study of the development of rillenkarren." Earth Surface Processes 5.1 (1980): 25-36.

Guérin, Adrien, et al. "Streamwise dissolution patterns created by a flowing water film." Physical Review Letters 125.19 (2020): 194502.

Djambov, Simeon, and François Gallaire. "Boundary-layer approach to the linear karren instability." Journal Of Fluid Mechanics 977 (2023): R3.