!*==sbaglos.spg  processed by SPAG 6.70Rc at 15:33 on 10 Dec 2012
!*------------------   SPAG Configuration Options   --------------------
!*--0323,76 000101,-1 000000102011332010100002000000210211210,136 10 --
!*--1100000011112111000000000000,10,10,10,10,10,10,900,100 200000000 --
!*--000000010000000000000,72,72 73,42,38,33 00011112110000100000000  --
!*----------------------------------------------------------------------
!++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
!$Author: joelevin $
!$Date: 2012-03-30 10:14:38 -0500 (Fri, 30 Mar 2012) $
!$Revision: 12163 $
!$HeadURL: https://eweru-dev1.eweru.ksu.edu/svn/code/weps1/branches/WEPS_F90_update/weps.src/src/lib_erosion/sbaglos.for $
!     extensive revision 6-27-06 LH
 
      subroutine sbaglos(wus,wust,wusto,sf84ic,asvroc,&smaglosmx,       &
                       & smaglos,sf84mn,sf84)
      implicit none
!*--SBAGLOS18
!
!*** Start of declarations rewritten by SPAG
!
! Dummy arguments
!
      real :: asvroc,sf84,sf84ic,sf84mn,smaglos,smaglosmx,wus,wust,wusto
      intent (in) asvroc,sf84,sf84ic,wus,wust,wusto
      intent (inout) sf84mn,smaglos,smaglosmx
!
!*** End of declarations rewritten by SPAG
!
 
!     + + + PURPOSE + + +
!     calc. minimum erodible fraction (sf84mn) needed to stop emission
!     on aggregated portion of surface at current threshold friction velocity
!     that occurs when smaglos is removed.
 
!     calc. potential mobile soil reservoir (smaglosmx) for a smooth
!     surface 0.8 m/s friction velocity and sf84ic that armors clod surface.
!
!     calc. available mobile reservoir (smaglos) of sf84 for current surface
!     based on wus-wust ratio for
 
!     + + + ARGUMENT DECLARATIONS + + +
 
!     + + +  ARGUMENT DEFINITIONS + + +
!     wus   - friction velocity (m/s)
!     wust  - friction velocity theshold for en (m/s)
!     wusto - threhold friction velocity = wus minus flat biomass and wetness
!             effects (m/s)
!     sf84ic- surface soil fraction <0.84 mm initial condition
!     asvroc - surface soil volume rock (m^3/m^3)
!     smaglosmx - max mobile soil reservoir of aggregateed sfc.(kg/m^2)
!     smaglos- potential mobile soil reservoir of aggregated sfc.(kg/m^2)
!     sf84mn- surface soil fraction <0.84 mm where wust= wus of ag.sfc.
!     sf84   - soil mass fraction in surface layer < 0.84 mm
 
!     + + + END SPECIFICATIONS + + +
 
      ! edit LH 6-26-06
      ! calc. max mobile soil at wus = 0.75 m/s for bare, smooth surface
      ! sf84 is assumed = 0 after this mass removal.
      smaglosmx = exp(2.708-7.603*((1-sf84ic)*(1-asvroc)+asvroc))
 
      ! reduce max mobile soil for roughness, cover, etc.
      smaglos = smaglosmx*(wus-wust)/(0.75-amin1(wusto,wust))
      smaglos = max(0.0,smaglos)
      !smaglos = min(smaglosmx, smaglos)
 
      ! find sf84 when smaglos has been removed from control volume mass(denominator).
      ! in sbqout emission from cloddy surface goes to zero at sf84mn
      if ((smaglos==0.0).OR.(sf84==0.0)) then
         sf84mn = sf84
      !elseif (smaglosmx .le. smaglos) then
      !    sf84mn = 0.05
      else
         sf84mn = (smaglosmx-smaglos)                                   &
                & /(smaglosmx/(sf84ic*(1.001-asvroc)))
         sf84mn = amax1(0.0,sf84mn)
      end if
 
      end subroutine sbaglos