This supplement contains the following files:

yardangmodel.c - source code for the numerical model. this code runs the model for just one time step, hence it must
 be used in conjunction with a batch script that runs a boundary layer flow model. at each time step the code accepts, 
 as input, the topography at the previous time step in a file called "topo.txt", a random field that represents spatial
 variations in bedrock erodibiluty (used only if mapKbedded is called), and the 3D wind field corresponding to the flow
 over the topography at the previous time step in a file called "velocity.txt". the model outputs the
 topography at the end of the time step in both "topo.txt" (read in during the next time step) and "topo#.xyz" 
 (where # is the number of the time step) which can be used to make a model animation in paraview or another graphics 
 program.  
topo0.txt to topo40.txt - text files of the initial topography and the topography output by the model
 every 50 years from time to 2000 yr for the case with initially small periodic hills (fig. 8). the files
 starts with the upper left grid point and proceeds with columns first and then rows to the last (lower right) 
 grid point.  
velocity0.txt to velocity39.txt - text files of the 3D mean wind velocity. each line has two columns (u and then v). 
 the order of the data has columns, rows, then layers and can be read with a for loop of the form
  for (n=1;n<=30;n++)
   for (j=1;j<=128;j++)
    for (i=1;j<=256;i++)
 the 30 vertical layers have heights above the topography equal to 
 10*zr+(maxheight-10*zr)*pow(1.0*n/lattice_size_z,3)
 where zr is the aerodynamic roughness length, maxheight is the uppermost height (30 m is used here), and n varies 
 from 1 to 30.  
 
The source code is written in C. It is run in conjunction with a boundary layer flow model (PHOENICS is used
in this study but another model could be used) that computes, at each time step, the mean flow velocity in 
terrain-following coordinates given the topography at that time step and a value of the aerodynamic roughness length.

Questions? Email jdpellet@email.arizona.edu