6.17. jules_irrig.nml

This file sets the irrigation options. It contains one namelist called JULES_IRRIG.

6.17.1. JULES_IRRIG namelist members

This namelist specifies the different options available for setting up the irrigation.

Note

Irrigation can be applied at a constant rate in three ways:
    1. To apply a constant irrigation to all tiles the irrigation settings are as follows: frac_irrig_all_tiles=T, set_irrfrac_on_irrtiles=F and set a value for const_frac_irr.
    1. To apply a constant irrigation to only specific tiles the irrigation settings are as follows: frac_irrig_all_tiles=F and set_irrfrac_on_irrtiles=T and set a value for const_irrfrac_irrtiles.
    1. To apply a constant irrigation to specific tiles as an average across the gridbox, which is the way irrigation on specific tiles was done prior to vn5.7, the irrigation settings are as follows: frac_irrig_all_tiles=F, set_irrfrac_on_irrtiles=F and set a value for const_frac_irr.

In both option 2 and 3, irrigtiles is the index of tiles you wish to irrigate, the length of which is nirrtile e.g. if you include wheat and maize in your run at index 5 and 6 then irrigtiles=5,6 and nirrtile=2.

JULES_IRRIG::l_irrig_dmd
Type:logical
Default:F

Switch controlling the implementation of irrigation demand code.

TRUE
Tiles are irrigated.
FALSE
No effect.
JULES_IRRIG::l_irrig_limit
Type:logical
Default:F

Switch controlling whether the amount of water used to irrigate tiles is limited.

TRUE

Water for irrigation is taken first from the deep soil (groundwater) store, and then from the river storage when the deep soil store is exhausted. Tiles are irrigated up to the critical point if the necessary water is available. This option requires l_irrig_dmd = TRUE, l_top = TRUE, l_rivers = TRUE and i_river_vn = 1,3.

Warning

The irrigation supply code in JULES is still in development, and is available in this release to support beta testing activities.

Users should ensure that results are as expected, and provide feedback where deficiencies are identified.

FALSE
Tiles will be irrigated to critical point from an unconstrained water supply.
JULES_IRRIG::irr_crop
Type:integer
Permitted:0, 1 or 2
Default:0
  1. Irrigation season (i.e. season in which crops might be growing on the gridbox) lasts the entire year.
  2. Irrigation season is determined from driving data according to Döll & Siebert (2002) method. No irrigation is applied outside the irrigation season.
  3. Irrigation season is determined by maximum dvi across all tiles. Requires ncpft > 0. No irrigation is applied outside the irrigation season.
JULES_IRRIG::frac_irrig_all_tiles
Type:logical
Default:T

If T, then irrigation fraction is applied to all tiles, and F, it is applied only to the tiles specified in irrigtiles.

JULES_IRRIG::set_irrfrac_on_irrtiles
Type:logical
Default:F

If F then irrigation is applied as an average across the gridbox and not to specific tiles. If T, then the irrigation fraction is only applied to the tile specified in irrigtiles. Both frac_irrig_all_tiles and set_irrfrac_on_irrtiles cannot be set to T.

JULES_IRRIG::nirrtile
Type:integer
Default:None

The number of tile types to be irrigated. Only used if frac_irrig_all_tiles = F.

JULES_IRRIG::irrigtiles
Type:integer(nirrtile)
Default:None

Indices of the tiles to be irrigated. Only used if frac_irrig_all_tiles = F.

6.17.2. JULES_IRRIG references