In general, plants are not very tolerant of saturated soil in their root zone. Saturated soil is quickly depleted of oxygen and the roots will soon die. MIKE SHE normally takes care of this automatically by removing ET from ponded water before calculating transpiration from the unsaturated or saturated zones. If there is sufficient ponded water then the entire ET will be satisfied from the ponded water.
However, some plants, such as rice, are more tolerant of saturated soils and still extract ET from saturated soils, although normally at a reduced rate. If ET from the soil zone is ignored, then the distribution of water supplied to ET will be incorrect.
The transpiration during ponding option changes the order in which the ET is calculated. In this case, the ET rate is multiplied by an anaerobic tolerance factor and ET is removed from the soil before being removed from the ponded water.
|
Parameter Name |
Type |
Value |
|---|---|---|
|
allow transpiration during ponding |
Boolean |
On |
|
global anaerobic tolerance factor |
Float |
Greater than or equal to 0 Less than or equal to 1 |
|
optional (instead of global value) |
||
|
anaerobic tolerance factor dfs2 file name |
file name |
.dfs2 file |
|
anaerobic tolerance factor item number |
integer |
item number in dfs2 file, greater than zero |