Ahi = -[^]hi + I )]hi + |(N-l)Ah 



(38) 



where 



h^ = depth in the first cell where angle of initial yield is exceeded 

 N = number of cells where sand is to be redistributed 

 h^ = depth in cell i 



Ah = difference in depth between two neighboring cells as given by the 

 residual angle after shearing 



'T 



T hi 



"id^.L- 



h; 



Figure 56. Definition sketch for describing avalanching 



421. After the depth change in the first cell has been determined 

 according to Equation 38, depth changes Ah^^ in neighboring cells are given 

 by the following expression 



Ahi = hi + Ahi - hi - (i-1) Ah 



(39) 



172 



