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      SUBROUTINE UPDATE_CBC
CNG04272010 UPDATE CBC BASED ON INSTANTANEOUS DEPTH DT(I,J)
      INCLUDE 'comdeck'
      SAVE

      Do 6030 J = 1, JM
        Do 6020 I = 1, IM
          If (FSM(I,J).NE.0.0) Then
C
C  VARIABLE BOTTOM FRICTION FOR SEDIMENT TRANSPORT
C
            IF (SEDTRAN.EQ.'INCLUDE') THEN
C
C  COHESIVE ELEMENTS
C
              IF (IBMSK(I,J).EQ.0) THEN
                Z0 = Z0BCOH
                CBCMIN = BFCOH
                IF (TOR.EQ.'BAROTROPIC') THEN
                  CBC(I,J)=BFCOH*FSM(I,J)
                ELSE
                  CBC(I,J)=AMAX1(CBCMIN,.16/ALOG((DZ(KBM1)*0.5)*
     +             AMAX1(DT(I,J),Z0+5.E-1,WETMIN)/Z0)**2)*FSM(I,J)
                ENDIF
C
C  NON-COHESIVE ELEMENTS
C
              ELSE
CRM                Z0 = Z0B
                Z0=Z0B(I,J) !RMarsooli_May2015, VARIABLE Z0B
                CBCMIN = BFRIC
                IF (TOR.EQ.'BAROTROPIC') THEN
                  CBC(I,J)=BFRIC*FSM(I,J)
                ELSE
                  CBC(I,J)=AMAX1(CBCMIN,.16/ALOG((DZ(KBM1)*0.5)*
     +             AMAX1(DT(I,J),Z0+5.E-1,WETMIN)/Z0)**2)*FSM(I,J)
                 ENDIF
              ENDIF
            ELSE
CRM              Z0 = Z0B
              Z0=Z0B(I,J) !RMarsooli_May2015, VARIABLE Z0B
              CBCMIN = BFRIC
              IF (TOR.EQ.'BAROTROPIC') THEN
                CBC(I,J)=BFRIC*FSM(I,J)
              ELSE
                CBC(I,J)=AMAX1(CBCMIN,.16/ALOG((DZ(KBM1)*0.5)*
     +             AMAX1(DT(I,J),Z0+5.E-1,WETMIN)/Z0)**2)*FSM(I,J)
              ENDIF
            ENDIF
          Else
           CBC(I,J)=BFRIC !Initialize CBC even at FSM=0 cells 05302012
          END IF
          CBC(I,J) = AMIN1(CBC(I,J)*VARBF(I,J),0.5) ! FACTOR IN 2D VARIABLE BFRIC, AND DO NOT ALLOW CBC TO EXCEED 0.5 !UNITY.
 6020   CONTINUE
 6030 CONTINUE

      RETURN
      END