Start at implemention realistic LSM

src/modlsm.f90

@@ -0,0 +1,157 @@
+!
+! Copyright (c) 2020-2020 Wageningen University and Research (WUR)
+!
+! This file is part of DALES
+!
+! DALES is free software: you can redistribute it and/or modify
+! it under the terms of the GNU General Public License as published by
+! the Free Software Foundation, either version 3 of the License, or
+! (at your option) any later version.
+!
+! DALES is distributed in the hope that it will be useful,
+! but WITHOUT ANY WARRANTY; without even the implied warranty of
+! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+! GNU General Public License for more details.
+!
+! You should have received a copy of the GNU General Public License
+! along with DALES.  If not, see <http://www.gnu.org/licenses/>.
+!
+
+module modlsm
+    use netcdf
+    implicit none
+    public :: initlsm, lsm, exitlsm
+
+    ! Land-surface / van Genuchten parameters from NetCDF input table.
+    real, allocatable :: &
+        theta_res(:), theta_wp(:), theta_fc(:), theta_sat(:), gamma_sat(:), vg_a(:), vg_l(:), vg_n(:)
+contains
+
+!
+! Initialise the land-surface model
+!
+subroutine initlsm
+    implicit none
+
+    ! Read the soil parameter table
+    call read_soil_table
+end subroutine initlsm
+
+subroutine lsm
+    implicit none
+end subroutine lsm
+
+!
+! Cleanup (deallocate) the land-surface model
+!
+subroutine exitlsm
+    implicit none
+
+    deallocate( theta_res, theta_wp, theta_fc, theta_sat, gamma_sat, vg_a, vg_l, vg_n )
+end subroutine exitlsm
+
+!
+! Read the input table with the (van Genuchten) soil parameters
+!
+subroutine read_soil_table
+    implicit none
+    integer :: n, ncid, dimid, varid
+
+    ! Open the NetCDF file and read the table size
+    print*,'Reading "van_genuchten_parameters.nc"'
+    call check( nf90_open('van_genuchten_parameters.nc', nf90_nowrite, ncid) )
+    call check( nf90_inq_dimid(ncid, 'index', dimid) )
+    call check( nf90_inquire_dimension(ncid, dimid, len=n) )
+
+    ! Allocate variables
+    allocate( &
+        theta_res(n), theta_wp(n), theta_fc(n), theta_sat(n), &
+        gamma_sat(n), vg_a(n), vg_l(n), vg_n(n) )
+
+    ! Read variables
+    call check( nf90_inq_varid(ncid, 'theta_res', varid) )
+    call check( nf90_get_var(ncid, varid, theta_res) )
+
+    call check( nf90_inq_varid(ncid, 'theta_wp', varid) )
+    call check( nf90_get_var(ncid, varid, theta_wp) )
+
+    call check( nf90_inq_varid(ncid, 'theta_fc', varid) )
+    call check( nf90_get_var(ncid, varid, theta_fc) )
+
+    call check( nf90_inq_varid(ncid, 'theta_sat', varid) )
+    call check( nf90_get_var(ncid, varid, theta_sat) )
+
+    call check( nf90_inq_varid(ncid, 'gamma_sat', varid) )
+    call check( nf90_get_var(ncid, varid, gamma_sat) )
+
+    call check( nf90_inq_varid(ncid, 'alpha', varid) )
+    call check( nf90_get_var(ncid, varid, vg_a) )
+
+    call check( nf90_inq_varid(ncid, 'l', varid) )
+    call check( nf90_get_var(ncid, varid, vg_l) )
+
+    call check( nf90_inq_varid(ncid, 'n', varid) )
+    call check( nf90_get_var(ncid, varid, vg_n) )
+
+    call check( nf90_close(ncid) )
+
+end subroutine read_soil_table
+
+!
+! Convert soil hydraulic head to soil water content, using van Genuchten parameterisation.
+!
+pure function psi_to_theta(theta_res, theta_sat, vg_a, vg_n, vg_m, psi) result(res)
+    implicit none
+    real, intent(in) :: theta_res, theta_sat, vg_a, vg_n, vg_m, psi
+    real :: res
+
+    res = theta_res + (theta_sat - theta_res) * (1. / (1.+ abs(vg_a * psi)**vg_n))**vg_m
+end function psi_to_theta
+
+!
+! Convert soil water content to hydraulic head, using van Genuchten parameterisation.
+!
+pure function theta_to_psi(theta_res, theta_sat, vg_a, vg_n, vg_m, theta) result(res)
+    implicit none
+    real, intent(in) :: theta_res, theta_sat, vg_a, vg_n, vg_m, theta
+    real :: res
+
+    res = -(vg_a**(-vg_n) * (-1. + ((theta_res - theta_sat)/(theta_res - theta))**(1./vg_m)))**(1./vg_n)
+end function theta_to_psi
+
+!
+! Calculate hydraulic diffusivity using van Genuchten parameterisation.
+!
+pure function calc_diffusivity_vg( &
+        theta_norm, vg_a, vg_l, vg_m, lambda_sat, theta_sat, theta_res) result(res)
+    implicit none
+    real, intent(in) :: theta_norm, vg_a, vg_l, vg_m, lambda_sat, theta_sat, theta_res
+    real :: res
+
+    res = (1.-vg_m)*lambda_sat / (vg_a * vg_m * (theta_sat-theta_res)) * theta_norm**(vg_l-(1./vg_m)) * &
+             (  (1.-theta_norm**(1./vg_m))**(-vg_m) + (1.-theta_norm**(1/vg_m))**vg_m - 2. )
+end function calc_diffusivity_vg
+
+!
+! Calculate hydraulic conductivity using van Genuchten parameterisation.
+!
+pure function calc_conductivity_vg(theta_norm, vg_l, vg_m, lambda_sat) result(res)
+    implicit none
+    real, intent(in) :: theta_norm, vg_l, vg_m, lambda_sat
+    real :: res
+
+    res = lambda_sat * theta_norm**vg_l * ( 1.- (1.-theta_norm**(1./vg_m))**vg_m )**2.
+end function calc_conductivity_vg
+
+!
+! Check NetCDF calls
+!
+subroutine check(status)
+    integer, intent (in) :: status
+    if(status /= nf90_noerr) then
+        print *,'NetCDF error: ', trim(nf90_strerror(status))
+        stop
+    end if
+end subroutine check
+
+end module modlsm

src/modstartup.f90

@@ -63,6 +63,7 @@ subroutine startup(path)
     use modforces,         only : lforce_user
     use modsurfdata,       only : z0,ustin,wtsurf,wqsurf,wsvsurf,ps,thls,isurf
     use modsurface,        only : initsurface
+    use modlsm,            only : initlsm
     use modfields,         only : initfields
     use modpois,           only : initpois
     use modradiation,      only : initradiation
@@ -268,6 +269,7 @@ subroutine startup(path)
     call initradiation
     call initchem
     call initsurface
+    call initlsm
     call initsubgrid
 
     call initmicrophysics
@@ -348,6 +350,7 @@ subroutine checkinitvalues
   !isurf
     if (myid == 0) then
       select case (isurf)
+      case(-1)
       case(1)
       case(2,10)
       case(3:4)
@@ -1143,11 +1146,13 @@ subroutine exitmodules
     use modradiation,      only : exitradiation
     use modsubgrid,        only : exitsubgrid
     use modsurface,        only : exitsurface
+    use modlsm,            only : exitlsm
     use modthermodynamics, only : exitthermodynamics
 
     call exittimedep
     call exitthermodynamics
     call exitsurface
+    call exitlsm
     call exitsubgrid
     call exitradiation
     call exitpois

src/modsurface.f90

@@ -320,6 +320,8 @@ subroutine initsurface
         close(ifinput)
       else
         select case (isurf)
+          case (-1)
+            return
           case (1) ! Interactive land surface
             open (ifinput,file='surface.interactive.inp.'//cexpnr)
             ierr = 0
@@ -724,6 +726,10 @@ subroutine surface
     patchx = 0
     patchy = 0
 
+    if (isurf==-1) then
+       return
+    end if
+
     if (isurf==10) then
       call surf_user
       return

src/program.f90

@@ -107,7 +107,8 @@ program DALES
   use modboundary,       only : boundary, grwdamp! JvdD ,tqaver
   use modthermodynamics, only : thermodynamics
   use modmicrophysics,   only : microsources
-  use modsurface,        only : surface
+  use modsurface,        only : surface 
+  use modlsm,            only : lsm
   use modsubgrid,        only : subgrid
   use modforces,         only : forces, coriolis, lstend
   use modradiation,      only : radiation
@@ -211,8 +212,9 @@ program DALES
     call samptend(tend_rad)
 
 !-----------------------------------------------------
-!   3.2   THE SURFACE LAYER
+!   3.2   THE SURFACE LAYER / LAND-SURFACE
 !-----------------------------------------------------
+    call lsm
     call surface
 
 !-----------------------------------------------------