source: utils/tools/NESTING/src/agrif_create_bathy.f90 @ 10093

!************************************************************************
! Fortran 95 OPA Nesting tools                  *
!                          *
!     Copyright (C) 2005 Florian Lemarié (Florian.Lemarie@imag.fr)   *
!                        Laurent Debreu (Laurent.Debreu@imag.fr)  *
!************************************************************************
!
PROGRAM create_bathy
  !
  USE NETCDF
  USE bilinear_interp
  USE agrif_readwrite
  USE agrif_partial_steps
  USE agrif_connect_topo
  USE agrif_interpolation
  !
  IMPLICIT NONE
  !
  !************************************************************************
  !                           *
  ! PROGRAM  CREATE_BATHY                 *
  !                           *
  ! program to implement bathymetry interpolation to generate     *
  ! child grid bathymetry file                  *
  !                           *
  ! various options :                     *
  !                           *
  ! 1- Interpolation directly from parent bathymetry file (z-coord)  *
  ! 2- Use new topo file in meters (for example etopo)      *
  !                           *
  ! vertical coordinates permitted : z-coord and partial steps    *
  ! sigma coordinates is not yet implemented          *
  !                           *
  !Interpolation is carried out using bilinear interpolation      *
  !routine from SCRIP package or median average          *     
  !                           *
  !http://climate.lanl.gov/Software/SCRIP/            *
  !************************************************************************
  !
  ! variables declaration
  !      
  CHARACTER(len=80) ::   namelistname
  CHARACTER*100     ::   Childmeter_file,Childlevel_file,Child_coordinates,child_ps, Child_domcfg    
  LOGICAL ::   identical_grids     
  INTEGER ::   nbadd,status,narg,iargc     
  INTEGER ::   jpj,jpi
  LOGICAL,DIMENSION(:,:),POINTER     ::   masksrc => NULL()  
  INTEGER,DIMENSION(:,:),ALLOCATABLE ::   mask_oce,trouble_points
  INTEGER,DIMENSION(:)  ,POINTER     ::   src_add,dst_add => NULL() 
  REAL*8, DIMENSION(:,:),POINTER     ::   matrix,interpdata => NULL()     
  REAL*8, DIMENSION(:,:),POINTER     ::   bathy_fin_constant => NULL()  
  REAL*8, DIMENSION(:,:),ALLOCATABLE ::   bathy_test,vardep
  REAL*8, DIMENSION(:)  ,ALLOCATABLE ::   vardep1d
  REAL*8, DIMENSION(:,:),POINTER     ::   gdepw_ps_interp => NULL() 
  REAL*8  ::   Cell_lonmin,Cell_lonmax,Cell_latmin,Cell_latmax,wghts
  LOGICAL ::   Pacifique = .FALSE.
  INTEGER ::   boundary,iimin,iimax,jjmax,jjmin
  INTEGER ::   nxhr,nyhr,nxyhr,ji,jj,nbiter

  TYPE(Coordinates) :: G0,G1 
  !      
  narg = iargc()      
  IF (narg == 0) THEN
     namelistname = 'namelist.input'
  ELSE
     CALL getarg(1,namelistname)
  ENDIF
  !
  ! read input file (namelist.input)
  CALL read_namelist(namelistname)
  !      
  ! define names of child grid files
  CALL set_child_name(parent_coordinate_file,Child_coordinates) 
  IF( TRIM(parent_bathy_file) .NE. '/NULL' )    CALL set_child_name(parent_bathy_file,Childlevel_file)            
  IF( TRIM(parent_bathy_file) .NE. '/NULL' )    CALL set_child_name(parent_domcfg_output,Child_domcfg) 
  !
  !                                                   ! ------------------------------------------------------------------
  IF( .NOT.new_topo .AND. .NOT.partial_steps ) THEN   ! **** First option : no new topo file & no partial steps
     !                                                !                 ==> interpolate levels directly from parent file
     !                                                ! ------------------------------------------------------------------
     WRITE(*,*) '*** First option: no new topo file & no partial steps'
     !      
     ! read coarse grid bathymetry and coordinates
     status = Read_Coordinates(TRIM(parent_coordinate_file),G0)    
     status = Read_bathy_level(TRIM(parent_bathy_file),G0)
     !           
     ! read fine grid coordinates
     status = Read_Coordinates(TRIM(Child_coordinates),G1,pacifique)
     !
     ! stop if error in size
     IF( imax > SIZE(G0%glamt,1) .OR. jmax > SIZE(G0%glamt,2) .OR. imax <= imin .OR. jmax <= jmin ) THEN                   
        WRITE(*,*) 'ERROR ***** bad child grid definition ...'
        WRITE(*,*) 'please check imin,jmin,imax,jmax,jpizoom,jpjzoom values'       
        STOP
     ENDIF
     IF( SIZE(G1%nav_lon,1) .NE. nxfin .OR. SIZE(G1%nav_lon,2) .NE. nyfin ) THEN
        WRITE(*,*) 'ERROR ***** bad child coordinates file ...'
        WRITE(*,*) 'please check that child coordinates file has been created with the same namelist'
        STOP
     ENDIF
     !
     jpj = SIZE(G0%nav_lat,2)
     jpi = SIZE(G0%nav_lat,1)    
     !           
     ! create logical array masksrc
     ALLOCATE(masksrc(jpi,jpj))
     WHERE(G0%bathy_level.LE.0)   ;   masksrc = .FALSE.   ;
     ELSEWHERE                    ;   masksrc = .TRUE.    ;
     END WHERE

     ! change longitudes (from -180:180 to 0:360)
     IF ( Pacifique ) THEN
        WHERE(G0%nav_lon < 0.001)   G0%nav_lon = G0%nav_lon + 360.
     ENDIF

     ! From levels to meters
     ALLOCATE(G1%bathy_meter(nxfin,nyfin))
     CALL levels_to_meter(G0)
     !             
     ! compute remapping matrix thanks to SCRIP package
     CALL get_remap_matrix(G0%nav_lat,G1%nav_lat,G0%nav_lon,G1%nav_lon,masksrc,matrix,src_add,dst_add)
     CALL make_remap(G0%bathy_meter,G1%bathy_meter,nxfin,nyfin,matrix,src_add,dst_add)  
     DEALLOCATE(masksrc)
     !      
     ! compute constant bathymetry for Parent-Child bathymetry connection
     CALL init_constant_bathy(G0%bathy_meter,bathy_fin_constant)
     !
     ! replace child bathymetry by parent bathymetry at the boundaries
     IF( ln_agrif_domain ) THEN
        boundary = npt_copy*irafx + nbghostcellsfine + 1 
     ELSE
        boundary = npt_copy*irafx
     ENDIF
     G1%bathy_meter(1:boundary,:) = bathy_fin_constant(1:boundary,:)
     G1%bathy_meter(:,1:boundary) = bathy_fin_constant(:,1:boundary)
     G1%bathy_meter(nxfin-boundary+1:nxfin,:) = bathy_fin_constant(nxfin-boundary+1:nxfin,:)
     G1%bathy_meter(:,nyfin-boundary+1:nyfin) = bathy_fin_constant(:,nyfin-boundary+1:nyfin)
     DEALLOCATE(bathy_fin_constant)
     !                  
     ! bathymetry smoothing (everywhere except at the boundaries) 
     IF( smoothing ) THEN
        IF( ln_agrif_domain ) THEN
           CALL smooth_topo(G1%bathy_meter(boundary:nxfin-boundary+1,boundary:nyfin-boundary+1),nbiter)
        ELSE
           CALL smooth_topo(G1%bathy_meter(boundary+1:nxfin-boundary,boundary+1:nyfin-boundary),nbiter)
        ENDIF
     ENDIF
     !
     ! From meters to levels
     CALL meter_to_levels(G1)
     G1%bathy_level=NINT(G1%bathy_level)
     !       
     ! Check errors in bathy
     DO jj=1,nyfin
        DO ji=1,nxfin
           IF (G1%bathy_level(ji,jj).LT.0.) THEN
              PRINT *,'error in ',ji,jj,G1%bathy_level(ji,jj)
              STOP
           ENDIF
        ENDDO
     ENDDO
     WHERE ((G1%bathy_level.LT.3.).AND.(G1%bathy_level.GT.0.))   G1%bathy_level=3
     !
     ! remove closed seas
     IF (removeclosedseas) THEN
        ALLOCATE(bathy_test(nxfin,nyfin))

        bathy_test=0.
        WHERE (G1%bathy_level(1,:)     .GT.0.)   bathy_test(1,:)=1
        WHERE (G1%bathy_level(nxfin,:) .GT.0.)   bathy_test(nxfin,:)=1
        WHERE (G1%bathy_level(:,1)     .GT.0.)   bathy_test(:,1)=1
        WHERE (G1%bathy_level(:,nyfin) .GT.0.)   bathy_test(:,nyfin)=1

        nbadd = 1
        DO WHILE (nbadd.NE.0)
           nbadd = 0
           DO jj=2,nyfin-1
              DO ji=2,nxfin-1
                 IF (G1%bathy_level(ji,jj).GT.0.) THEN
                    IF (MAX(bathy_test(ji,jj+1),bathy_test(ji,jj-1),bathy_test(ji-1,jj),bathy_test(ji+1,jj)).EQ.1) THEN
                       IF (bathy_test(ji,jj).NE.1.) nbadd = nbadd + 1
                       bathy_test(ji,jj)=1.
                    ENDIF
                 ENDIF
              ENDDO
           ENDDO
        ENDDO

        WHERE (bathy_test.EQ.0.)   G1%bathy_level = 0.

        DEALLOCATE(bathy_test)           
     ENDIF
     !
     ! store interpolation result in output file
     CALL levels_to_meter(G1)   ! From levels to meters
     status = Write_Bathy_level(TRIM(Childlevel_file),G1)
     status = write_domcfg(TRIM(Child_domcfg),G1)

     WRITE(*,*) '****** Bathymetry successfully created if no new topo ******'
     STOP
     !
     !                                                ! -----------------------------------------------------
  ELSE                                                ! **** Second option : new topo file or partial steps     
     !                                                ! ----------------------------------------------------- 
     WRITE(*,*) '***Second option : new topo or partial steps'

     ! read fine and coarse grids coordinates file
     status = Read_Coordinates(TRIM(parent_coordinate_file),G0)
     status = Read_Coordinates(TRIM(Child_coordinates),G1,Pacifique)
     !
     ! check error in size
     IF( imax > SIZE(G0%nav_lon,1) .OR. jmax > SIZE(G0%nav_lon,2) .OR. imax <= imin .OR. jmax <= jmin ) THEN                    
        WRITE(*,*) 'ERROR ***** bad child grid definition ...'
        WRITE(*,*) 'please check imin,jmin,imax,jmax,jpizoom,jpjzoom values'       
        STOP
     ENDIF
     IF( SIZE(G1%nav_lon,1) .NE. nxfin .OR. SIZE(G1%nav_lon,2) .NE. nyfin ) THEN
        WRITE(*,*) 'ERROR ***** bad child coordinates file ...'
        WRITE(*,*) 'please check that child coordinates file has been created with the same namelist'
        STOP
     ENDIF
     !
     ! === From here on: G0 is the grid associated with the new topography (like gebco or etopo) ===
     !
     ! read bathymetry data set => G0%bathy_meter
     IF( new_topo ) THEN                                       ! read G0%bathy_meter (on a reduced grid) and G1 coordinates
        DEALLOCATE( G0%nav_lon, G0%nav_lat )
        status = Read_bathy_meter(TRIM(elevation_database),G0,G1,Pacifique)
     ELSE                                                      ! read G0%bathy_meter (on the global grid)
        status = Read_Bathymeter(TRIM(parent_bathy_meter),G0)   
        IF(Pacifique) THEN
           WHERE(G0%nav_lon < 0.0001)   G0%nav_lon = G0%nav_lon + 360.
        ENDIF
     ENDIF
     !               
     ! what type of interpolation for bathymetry
     IF( type_bathy_interp == 0 ) THEN
        WRITE(*,*) 'Interpolation of high resolution bathymetry on child grid: Arithmetic average ...'
     ELSE IF( type_bathy_interp == 1 ) THEN
        WRITE(*,*) 'Interpolation of high resolution bathymetry on child grid: Median average ...'
     ELSE IF( type_bathy_interp == 2 ) THEN     
        WRITE(*,*) 'Interpolation of high resolution bathymetry on child grid: Bilinear interpolation ...'
     ELSE     
        WRITE(*,*) 'bad value for type_bathy_interp variable ( must be 0, 1 or 2 )'
        STOP 
     ENDIF
     !
     ! 1st allocation of child grid bathy
     ALLOCATE(G1%bathy_meter(nxfin,nyfin))
     G1%bathy_meter(:,:)=0.                       
     !
     ! ---------------------------------------------------------------------------------
     ! ===                 Bathymetry of the fine grid (step1)                       ===
     ! ---------------------------------------------------------------------------------
     ! ==> It gives G1%bathy_meter from G0%bathy_meter
     ! ---------------------------------------------------------------------------------
     !                                                               ! ----------------------------- 
     IF( type_bathy_interp == 0 .OR. type_bathy_interp == 1 ) THEN   ! arithmetic or median averages
        !                                                            ! ----------------------------- 
        ALLOCATE(trouble_points(nxfin,nyfin))
        trouble_points(:,:) = 0
        !                       
        DO jj = 2, nyfin
           DO ji = 2, nxfin
              !       
              ! fine grid cell extension               
              Cell_lonmin = MIN(G1%glamf(ji-1,jj-1),G1%glamf(ji,jj-1),G1%glamf(ji,jj),G1%glamf(ji-1,jj))
              Cell_lonmax = MAX(G1%glamf(ji-1,jj-1),G1%glamf(ji,jj-1),G1%glamf(ji,jj),G1%glamf(ji-1,jj))
              Cell_latmin = MIN(G1%gphif(ji-1,jj-1),G1%gphif(ji,jj-1),G1%gphif(ji,jj),G1%gphif(ji-1,jj))
              Cell_latmax = MAX(G1%gphif(ji-1,jj-1),G1%gphif(ji,jj-1),G1%gphif(ji,jj),G1%gphif(ji-1,jj)) 
              !               
              ! look for points in G0 (bathy dataset) contained in the fine grid cells  
              iimin = 1
              DO WHILE( G0%nav_lon(iimin,1) < Cell_lonmin ) 
                 iimin = iimin + 1
              ENDDO
              !               
              jjmin = 1
              DO WHILE( G0%nav_lat(iimin,jjmin) < Cell_latmin ) 
                 jjmin = jjmin + 1
              ENDDO
              !                
              iimax = iimin 
              DO WHILE( G0%nav_lon(iimax,1) <= Cell_lonmax ) 
                 iimax = iimax + 1
                 iimax = MIN( iimax,SIZE(G0%bathy_meter,1))
              ENDDO
              !                               
              jjmax = jjmin 
              DO WHILE( G0%nav_lat(iimax,jjmax) <= Cell_latmax ) 
                 jjmax = jjmax + 1
                 jjmax = MIN( jjmax,SIZE(G0%bathy_meter,2))
              ENDDO
              !
              IF( ln_agrif_domain ) THEN
                 iimax = iimax-1
                 jjmax = jjmax-1
              ELSE
                 iimax = MAX(iimin,iimax-1)
                 jjmax = MAX(jjmin,jjmax-1)
              ENDIF
              !               
              iimin = MAX( iimin,1 )
              jjmin = MAX( jjmin,1 )
              iimax = MIN( iimax,SIZE(G0%bathy_meter,1))
              jjmax = MIN( jjmax,SIZE(G0%bathy_meter,2))

              nxhr = iimax - iimin + 1
              nyhr = jjmax - jjmin + 1                    

              IF( nxhr == 0 .OR. nyhr == 0 ) THEN
                 !
                 trouble_points(ji,jj) = 1
                 !
              ELSE
                 !
                 ALLOCATE( vardep(nxhr,nyhr), mask_oce(nxhr,nyhr) )
                 vardep(:,:) = G0%bathy_meter(iimin:iimax,jjmin:jjmax)
                 !
                 WHERE( vardep(:,:) .GT. 0. )   ;   mask_oce = 1 ;
                 ELSEWHERE                      ;   mask_oce = 0 ;
                 ENDWHERE
                 !
                 nxyhr = nxhr*nyhr
                 IF( SUM(mask_oce) < 0.5*(nxyhr) ) THEN ! if more than half of the points are on land then bathy fine = 0
                    G1%bathy_meter(ji,jj) = 0.
                 ELSE
                    IF( type_bathy_interp == 0 ) THEN     ! Arithmetic average
                       G1%bathy_meter(ji,jj) = SUM( vardep(:,:) * mask_oce(:,:) ) / SUM( mask_oce(:,:) )
                    ELSE                                  ! Median average
                       ALLOCATE(vardep1d(nxyhr))
                       vardep1d = RESHAPE(vardep,(/ nxyhr /) )
                       !!CALL ssort(vardep1d,nxyhr)
                       CALL quicksort(vardep1d,1,nxyhr)
                       !
                       ! Calculate median
                       IF (MOD(nxyhr,2) .NE. 0) THEN
                          G1%bathy_meter(ji,jj) = vardep1d( nxyhr/2 + 1 )
                       ELSE
                          G1%bathy_meter(ji,jj) = 0.5 * ( vardep1d(nxyhr/2) + vardep1d(nxyhr/2+1) )
                       END IF
                       DEALLOCATE(vardep1d)   
                    ENDIF
                 ENDIF
                 DEALLOCATE (mask_oce,vardep)
                 !
              ENDIF
           ENDDO
        ENDDO

        IF( SUM( trouble_points ) > 0 ) THEN
           PRINT*,'too much empty cells, proceed to bilinear interpolation'
           type_bathy_interp = 2
        ENDIF
           
     ENDIF
     !                                                       ! ----------------------------- 
     IF( type_bathy_interp == 2) THEN                        ! Bilinear interpolation
        !                                                    ! ----------------------------- 
        identical_grids = .FALSE.

        IF( SIZE(G0%nav_lat,1) == SIZE(G1%nav_lat,1) .AND. SIZE(G0%nav_lat,2) == SIZE(G1%nav_lat,2)  .AND.   &
            SIZE(G0%nav_lon,1) == SIZE(G1%nav_lon,1) .AND. SIZE(G0%nav_lon,2) == SIZE(G1%nav_lon,2) ) THEN
           IF( MAXVAL( ABS(G0%nav_lat(:,:)- G1%nav_lat(:,:)) ) < 0.0001 .AND.   &
               MAXVAL( ABS(G0%nav_lon(:,:)- G1%nav_lon(:,:)) ) < 0.0001 ) THEN
              PRINT*,'same grid between ',elevation_database,' and child domain'    
              G1%bathy_meter = G0%bathy_meter 
              identical_grids = .TRUE.                          
           ENDIF
        ENDIF

        IF( .NOT. identical_grids ) THEN 

           ALLOCATE(masksrc(SIZE(G0%bathy_meter,1),SIZE(G0%bathy_meter,2)))
           ALLOCATE(bathy_test(nxfin,nyfin))
           !
           !Where(G0%bathy_meter.le.0.00001) 
           !  masksrc = .false.
           !ElseWhere
              masksrc = .TRUE.
           !End where                       
           !            
           ! compute remapping matrix thanks to SCRIP package            
           CALL get_remap_matrix(G0%nav_lat,G1%nav_lat,G0%nav_lon,G1%nav_lon,masksrc,matrix,src_add,dst_add)
           CALL make_remap(G0%bathy_meter,bathy_test,nxfin,nyfin,matrix,src_add,dst_add)  
           !                                  
           G1%bathy_meter = bathy_test               
           !            
           DEALLOCATE(masksrc)
           DEALLOCATE(bathy_test) 

        ENDIF
        !            
     ENDIF
     ! ---
     ! At this stage bathymetry in meters has already been interpolated on fine grid
     !                    => G1%bathy_meter(nxfin,nyfin)
     !
     ! Also G0 was the grid from the new bathymetry data set (etopo, gebco...) and not the coarse grid
     ! ---
     !
     ! ---------------------------------------------------------------------------------
     ! ===                 Bathymetry of the fine grid (step2)                       ===
     ! ---------------------------------------------------------------------------------
     ! ==> It gives an update of G1%bathy_meter and G1%bathy_level
     ! ---------------------------------------------------------------------------------
     ! From here on: G0 is the coarse grid
     !
     ! Coarse grid bathymetry : G0%bathy_meter (on the global grid)
     IF( partial_steps ) THEN                     
        status = Read_Bathymeter(TRIM(parent_bathy_meter),G0)
     ELSE
        status = Read_Bathymeter(TRIM(parent_bathy_file),G0)
     ENDIF
     
     ! Coarse grid coordinatees : G0 coordinates
     DEALLOCATE(G0%nav_lat,G0%nav_lon)
     status = Read_coordinates(TRIM(parent_coordinate_file),G0)

     ! allocate temporary arrays                  
     IF (.NOT.ASSOCIATED(G0%gdepw_ps))       ALLOCATE(G0%gdepw_ps    (SIZE(G0%bathy_meter,1),SIZE(G0%bathy_meter,2)))
     IF (.NOT.ASSOCIATED(G1%gdepw_ps))       ALLOCATE(G1%gdepw_ps    (SIZE(G1%bathy_meter,1),SIZE(G1%bathy_meter,2)))                  
     IF (.NOT.ASSOCIATED(gdepw_ps_interp))   ALLOCATE(gdepw_ps_interp(SIZE(G1%bathy_meter,1),SIZE(G1%bathy_meter,2)))
     !                       
     IF( ln_agrif_domain ) THEN
        boundary = npt_copy*irafx + nbghostcellsfine + 1
     ELSE
        boundary = npt_copy*irafx
     ENDIF
     !
     ! compute G0%gdepw_ps and G1%gdepw_ps
     CALL get_partial_steps(G0) 
     CALL get_partial_steps(G1)
     CALL bathymetry_control(G0%Bathy_level)

     ! ---------------------------------------
     ! Bathymetry at the boundaries (npt_copy)                      
     ! ---------------------------------------
     ! 1st step: interpolate coarse bathy on the fine grid (using partial steps or not)
     IF( partial_steps .AND. ln_agrif_domain ) THEN                   
        CALL Check_interp(G0,gdepw_ps_interp)
     ELSE
        gdepw_ps_interp = 0. * G1%gdepw_ps
        !!CALL agrif_interp(G0%gdepw_ps,gdepw_ps_interp,'T')
        CALL init_constant_bathy(G0%gdepw_ps,gdepw_ps_interp)
     ENDIF

     IF (.NOT.ASSOCIATED(G1%wgt))   ALLOCATE(G1%wgt(SIZE(G1%bathy_meter,1),SIZE(G1%bathy_meter,2)))
     G1%wgt(:,:) = 0.
     IF ((.NOT.ASSOCIATED(G0%wgt)).AND.bathy_update) THEN 
        ALLOCATE(G0%wgt(SIZE(G0%nav_lat,1),SIZE(G0%nav_lat,2)))
        G0%wgt(:,:) = 0.
     ENDIF
     !
     ! 2nd step: copy parent bathymetry at the boundaries
     DO jj=1,nyfin   ! West and East
        IF ( gdepw_ps_interp(nbghostcellsfine+1,jj) > 0. ) THEN
           G1%gdepw_ps(1:boundary,jj) = gdepw_ps_interp(1:boundary,jj) 
           G1%wgt(1:boundary,jj) = 1.
        ELSE
           G1%gdepw_ps(1:nbghostcellsfine+1,jj)=0. 
        ENDIF
        !
        IF ( gdepw_ps_interp(nxfin-nbghostcellsfine,jj) > 0.) THEN
           G1%gdepw_ps(nxfin-boundary+1:nxfin,jj)=gdepw_ps_interp(nxfin-boundary+1:nxfin,jj)
           G1%wgt(nxfin-boundary+1:nxfin,jj) = 1.
        ELSE
           G1%gdepw_ps(nxfin-nbghostcellsfine:nxfin,jj) = 0.
        ENDIF
     END DO
     !
     DO ji=1,nxfin    ! South and North
        IF (gdepw_ps_interp(ji,nbghostcellsfine+1)>0.) THEN
           G1%gdepw_ps(ji,1:boundary) = gdepw_ps_interp(ji,1:boundary)
           G1%wgt(ji,1:boundary) = 1.
        ELSE
           G1%gdepw_ps(ji,1:nbghostcellsfine+1)=0. 
        ENDIF
        !
        IF (gdepw_ps_interp(ji,nyfin-nbghostcellsfine)>0.) THEN
           G1%gdepw_ps(ji,nyfin-boundary+1:nyfin)=gdepw_ps_interp(ji,nyfin-boundary+1:nyfin)
           G1%wgt(ji,nyfin-boundary+1:nyfin) = 1.
        ELSE
           G1%gdepw_ps(ji,nyfin-nbghostcellsfine:nyfin) = 0.
        ENDIF
     END DO
     !
     !clem: recalculate interpolation everywhere before linear connection (useless to me)
     IF( partial_steps .AND. ln_agrif_domain ) THEN                
        gdepw_ps_interp = 0.
        CALL Check_interp(G0,gdepw_ps_interp)
     ENDIF
     !
     ! -------------------------------------------------------
     ! Bathymetry between boundaries and interior (npt_connect)                 
     ! --------------------------------------------------------
     ! Make linear connection (on npt_connect*irafx points) between the boundaries and the interior
     IF( ln_agrif_domain ) THEN
        boundary = (npt_copy + npt_connect)*irafx + nbghostcellsfine + 1
     ELSE
        boundary = (npt_copy + npt_connect)*irafx
     ENDIF

     IF( npt_connect > 0 ) THEN
        WRITE(*,*) ' linear connection on ',npt_connect,'coarse grid points'

        wghts = 1.
        DO ji = boundary - npt_connect*irafx + 1 , boundary
           wghts = wghts - (1. / (npt_connect*irafx + 1. ) )
           DO jj=1,nyfin
              IF (G1%gdepw_ps(nbghostcellsfine+1,jj) > 0.)       G1%wgt(ji,jj) = MAX(wghts, G1%wgt(ji,jj))  
           END DO
        END DO

        wghts = 1.
        DO ji = nxfin - (boundary - npt_connect*irafx), nxfin - boundary +1 , -1
           wghts = wghts - (1. / (npt_connect*irafx + 1. ) )
           DO jj=1,nyfin
              IF (G1%gdepw_ps(nxfin-nbghostcellsfine,jj) > 0.)   G1%wgt(ji,jj) = MAX(wghts, G1%wgt(ji,jj))
           END DO
        END DO

        wghts = 1.
        DO jj = boundary - npt_connect*irafy + 1 , boundary
           wghts = wghts - (1. / (npt_connect*irafy + 1. ) )
           DO ji=1,nxfin
              IF (G1%gdepw_ps(ji,nbghostcellsfine+1) > 0.)       G1%wgt(ji,jj) = MAX(wghts, G1%wgt(ji,jj))
           END DO
        END DO

        wghts = 1.
        DO jj = nyfin - (boundary - npt_connect*irafy) , nyfin - boundary +1, -1
           wghts = wghts - (1. / (npt_connect*irafy + 1. ) )
           DO ji=1,nxfin
              IF (G1%gdepw_ps(ji,nyfin-nbghostcellsfine) > 0.)   G1%wgt(ji,jj) = MAX(wghts, G1%wgt(ji,jj))
           END DO
        END DO
        IF (.NOT.identical_grids) THEN
           G1%gdepw_ps(:,:) = (1.-G1%wgt(:,:)) * G1%gdepw_ps(:,:) + gdepw_ps_interp(:,:)*G1%wgt(:,:)
        ENDIF

     ENDIF

     ! replace G1%bathy_meter by G1%gdepw_ps
     G1%bathy_meter = G1%gdepw_ps
     !                     
     ! --------------------
     ! Bathymetry smoothing                 
     ! --------------------
     IF( smoothing .AND. (.NOT.identical_grids) ) THEN
        ! Chanut: smoothing everywhere then discard result in connection zone
        CALL smooth_topo(G1%gdepw_ps(:,:),nbiter)
        WHERE (G1%wgt(:,:)==0.) G1%bathy_meter(:,:) = G1%gdepw_ps(:,:)
     ELSE
        WRITE(*,*) 'No smoothing process only connection is carried out'
     ENDIF
     !
     ! ------------------
     ! Remove closed seas
     ! ------------------
     IF (removeclosedseas) THEN
        ALLOCATE(bathy_test(nxfin,nyfin))
        bathy_test=0.
        WHERE (G1%bathy_meter(1,:)    .GT.0.)   bathy_test(1,:)=1
        WHERE (G1%bathy_meter(nxfin,:).GT.0.)   bathy_test(nxfin,:)=1
        WHERE (G1%bathy_meter(:,1)    .GT.0.)   bathy_test(:,1)=1
        WHERE (G1%bathy_meter(:,nyfin).GT.0.)   bathy_test(:,nyfin)=1

        nbadd = 1
        DO WHILE (nbadd.NE.0)
           nbadd = 0
           DO jj=2,nyfin-1
              DO ji=2,nxfin-1
                 IF (G1%bathy_meter(ji,jj).GT.0.) THEN
                    IF (MAX(bathy_test(ji,jj+1),bathy_test(ji,jj-1),bathy_test(ji-1,jj),bathy_test(ji+1,jj)).EQ.1) THEN
                       IF (bathy_test(ji,jj).NE.1.) nbadd = nbadd + 1
                       bathy_test(ji,jj)=1.
                    ENDIF

                 ENDIF
              ENDDO
           ENDDO
        ENDDO
        WHERE (bathy_test.EQ.0.)   G1%bathy_meter = 0.
        DEALLOCATE(bathy_test)
     ENDIF
     !
     !                              ! ----------------
     IF( partial_steps ) THEN       ! If partial steps
        !                           ! ----------------
        !
        CALL get_partial_steps(G1)  ! recompute gdepw_ps for G1

        IF(bathy_update)   CALL Update_Parent_Bathy( G0,G1 ) 
        CALL set_child_name(parent_bathy_meter,child_ps)
        
                           status = Write_Bathy_meter(TRIM(child_ps),G1)
        IF(bathy_update)   status = Write_Bathy_meter(TRIM(updated_parent_file),G0)
        IF(bathy_update)   status = write_domcfg(TRIM(updated_parent_domcfg),G0)

        CALL get_partial_steps(G1)
        !
        G1%bathy_level=NINT(G1%bathy_level)
        !
        ! store interpolation result in output file
        CALL levels_to_meter(G1)   ! From levels to meters
        IF( TRIM(parent_bathy_file) .NE. '/NULL' )    status = Write_Bathy_level(TRIM(Childlevel_file),G1)
        IF( TRIM(parent_bathy_file) .NE. '/NULL' )    status = write_domcfg(TRIM(Child_domcfg),G1)
        !
        WRITE(*,*) '****** Bathymetry successfully created for partial cells ******'
        STOP
        !
        !                           ! ----------------
     ELSE                           ! No partial steps
        !                           ! ----------------
        !
        ! convert bathymetry from meters to levels
        CALL meter_to_levels(G1) 

        IF(bathy_update)   CALL Update_Parent_Bathy( G0,G1 ) 
        CALL set_child_name(parent_bathy_meter,child_ps)
        
                           status = Write_Bathy_meter(TRIM(child_ps),G1)        
        IF(bathy_update)   status = Write_Bathy_meter(TRIM(updated_parent_file),G0)
        IF(bathy_update)   status = write_domcfg(TRIM(updated_parent_domcfg),G0)
        !
        ! store interpolation result in output file
        CALL levels_to_meter(G1)   ! From levels to meters
        status = Write_Bathy_level(TRIM(Childlevel_file),G1)
        status = write_domcfg(TRIM(Child_domcfg),G1)
        !
        WRITE(*,*) '****** Bathymetry successfully created for full cells ******'
        STOP
        ! 
     ENDIF
  ENDIF
  !
END PROGRAM create_bathy