c     -----------------------------------------------------------------
c     file 'e3grid.inc'

c     This block common is contains variables used for a simulation run
c     for  EROSION.

c     + + + VARIABLE DECLARATIONS + + +

      integer          kbr
      integer          i1, i2, i3, i4, i5, i6
      real             awa, sin_awa, cos_awa, tan_awa

      common /e3grid/
     i                 kbr,
     i                 i1, i2, i3, i4, i5, i6,
     r                 awa, sin_awa, cos_awa, tan_awa

c     + + + VARIABLE DEFINITIONS + + +

c     kbr    - wind quadrant key relative to simulation region
c
c              for barrier effect

c              range values      min       max
c              ------------   ---------  ---------
c              fixed              1         8
c              typical            1         8
c              ------------   ---------  ---------

c


c     i1..i6 - do loop parameters defining grid update sequence
c              i3..i6 defines first update direction
c              i1..i3 defines second update directions

c              range values       min        max
c              ------------   ---------  ---------
c              fixed            -1          imax - 1
c              typical          -1          imax - 1
c              ------------   -----------  ---------

c

c              update direction always moves downwind

c     awa    - wind angle across simulation region relative to Y-axis

c              range values      min       max
c              ------------   ---------  ---------
c              fixed              0        360
c              typical            0        360
c              ------------   ---------  ---------

c

c     sin_awa - precomputed sin of awa angle
c     cos_awa - precomputed cos of awa angle
c     tan_awa - precomputed tan of awa angle