A model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/erosion law. Different delta types are reproduced by using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data pattern...

The amounts of Zn and Mg eluted from the zinc polycarboxylate cement into acetic, lactic and citric acids increased with an increase in the formation constant of the acid-Zn or -Mg complexes. The erosion process consisted of two processes, namely, dissolution of the unreacted cement powder and decomposition of the matrix. The matrix was remarkably eroded by 0.01M citric acid which formed stable...

Flow through a saturated, granular, porous medium can lead to internal erosion, preferential flow enhancement, and the formation of channels within the bulk of the medium. We examine this phenomenon using a combination of experimental observations, continuum theory and numerical simulations in a minimal setting. Our experiments are carried out by forcing water through a Hele-Shaw cell packed wi...

Horqin Sandy Land is located in northeast China (4241’-4515’N, 11835’-12330’E). The wind-sand topography in Horqin Sandy Land can be described as two series--sand deposition and wind erosion. Wind is the natural force for the formation of wind-sandy environment, under windsandy environment, the wind erosion processes such as sand drifting, dust-storm, etc. occurred frequently because of the fre...

Using real-time x-ray scattering to measure the surface morphology of Au(111) during sputter erosion with 500 eV Ar ions, we observe three distinct regimes: three-dimensional rough erosion at 20–60 ±C, quasi-layer-by-layer removal at 120–220 ±C, and step retraction above 270 ±C. Sputtering at 20–60 ±C leads to pattern formation with a characteristic spacing between features. The average separat...