!$Author: wjr $
!$Date: 2012-03-30 09:46:26 -0500 (Fri, 30 Mar 2012) $
!$Revision: 12162 $
!$HeadURL: https://svn.weru.ksu.edu/weru/weps1/trunk/weps.src/src/inc/erosion/threshold.inc $

!     This common block contains variables used for tracking the conditions
!     that prevented any erosion.

!     + + + VARIABLE DECLARATIONS + + +


module threshold_def

use p1werm_def

    integer :: ne_erosion(maxNumSubRegs)
    integer :: ne_snowdepth(maxNumSubRegs)
    
    real :: ne_wus_anemom(maxNumSubRegs)
    real :: ne_wus_random(maxNumSubRegs)
    real :: ne_wus_ridge(maxNumSubRegs)
    real :: ne_wus_biodrag(maxNumSubRegs)
    real :: ne_wus(maxNumSubRegs)
    
    real :: ne_bare(maxNumSubRegs)
    real :: ne_flat_cov(maxNumSubRegs)
    real :: ne_surf_wet(maxNumSubRegs)
    real :: ne_ag_den(maxNumSubRegs)
    real :: ne_wust(maxNumSubRegs)
    
    real :: ne_sfd84(maxNumSubRegs)
    real :: ne_asvroc(maxNumSubRegs)
    real :: ne_wzzo(maxNumSubRegs)
    real :: ne_sfcv(maxNumSubRegs)


!     + + + VARIABLE DEFINITIONS + + +
!     ne_erosion - flag indicating that erosion was entered
!                  0 - erosion was not entered
!                  1 - erosion was entered
!     ne_snowdepth - snow depth is great enough that no erosion occurs
!                    0 - snow depth too low to prevent erosion
!                    1 - snow depth deeper than threshold, prevents erosion

!     ne_wus_anemom - anemometer located friction velocity for critical no erosion condition
!     ne_wus_random - site surface random roughness adjusted friction velocity for critical no erosion condition
!     ne_wus_ridge - site surface oriented roughness adjusted friction velocity for critical no erosion condition
!     ne_wus_biodrag - site biodrag adjusted friction velocity for critical no erosion condition
!     ne_wus - friction velocity for critical no erosion condition (biodrag added in)

!     ne_bare - bare friction veolocity greater
!     ne_flat_cov - flat cover increases threshold
!     ne_surf_wet - surface wetness increases threshold
!     ne_ag_den - ag density increases threshold
!     ne_wust - resultant threshold friction velocity

!     ne_sfd84 - fraction of the surface material less than 0.84 mm in diameter
!     ne_asvroc - fraction of the surface matherial greater than 2 mm in diameter
!     ne_wzzo - aerodynamic roughness length of the soil surface below canopy (mm)
!     ne_sfcv - fraction of soil surface which is non emitting

end module threshold_def