|
Acronym/symbol |
Description |
Dimension |
|
r |
bulk density (kg m-3, g cm-3) |
M L-3 |
|
m |
drainable pore space (m3 m-3) |
- |
|
a |
empirical shape parameter (cm-1) |
L-1 |
|
l |
empirical shape parameter depending on dK/dh |
- |
|
q |
volumetric water content (m3 m-3) |
- |
|
qfc |
volumetric water content at field capacity (m3 m-3) |
- |
|
Dh |
drop in groundwater table (m) |
L |
|
DMss |
changes in storage of soluble soil salts (kg, t) |
M |
|
DMxc |
changes in storage of exchangeable cations (kg, t) |
M |
|
DS |
change in salt storage in the rootzone (ECmm) |
T3I2M-1L-2 |
|
DW |
change in moisture content in the rootzone (mm) |
L |
|
DWrz |
change in water storage in the rootzone (mm) |
L |
|
DWsz |
change in water storage in the saturated zone (mm) |
L |
|
DWvsz |
change in water storage in the vadose and saturated zone (mm) |
L |
|
DWvz |
change in water storage in the vadose zone (mm) |
L |
|
A |
salinity threshold (bars) |
ML-1T-2 |
|
a |
salinity threshold (dS/m) |
T3I2M-1L-3 |
|
AW |
applied water (mm) |
L |
|
B |
slope expressed in percent per bar |
- |
|
b |
slope expressed in percent per dS/m |
T3I2M-1L-3 |
|
BI |
boron concentration in irrigation water (mg litre-1) |
M L-3 |
|
BOD |
biochemical oxygen demand (mg litre-1) |
M L-3 |
|
Bss |
boron concentration in the soil solution (mg litre-1) |
M L-3 |
|
Bss0 |
initial boron concentration in the soil solution (mg litre-1) |
M L-3 |
|
Bsst |
desired boron concentration in the soil solution (mg litre-1) |
M L-3 |
|
Cdw |
salt concentration of drainage water (kg m-3 or mg litre-1, g litre-1) |
M L-3 |
|
CEC |
cation exchange capacity (meq 100g-1 or mMol © 100g-1) |
N M-1 |
|
Cgw |
salt concentration of groundwater (mg litre-1 or kg m-3) |
M L-3 |
|
CI |
salt concentration of irrigation water (kg m-3 or mg litre-1, g litre-1) |
M L-3 |
|
CIMIS |
California Irrigation Management Information System |
- |
|
CIW |
salt concentration of the infiltrated water (mg/litre) |
M L-3 |
|
Ck |
solute species (mMol litre-1) |
N L-3 |
|
COD |
chemical oxygen demand (mg litre-1) |
M L-3 |
|
CR* |
salt concentration of the net percolation water (mg/litre) |
M L-3 |
|
CVRWQCB |
Central Valley Regional Water Quality Control Board |
- |
|
|
exchangeable form of solute species(mMol © 100g-1) |
N M-1 |
|
|
mineral form of solute species (mMol © 100g-1) |
N M-1 |
|
D |
dispersion coefficient (m2 d-1) |
L2 T-1 |
|
Drz |
depth of the rootzone (m) |
L |
|
DL |
depth of leaching water (mm) |
L |
|
Dr |
drainage water reuse (mm) |
L |
|
Dra |
artificial subsurface drainage (mm) |
L |
|
Drn |
natural drainage (mm) |
L |
|
Ds |
depth of soil to be reclaimed (mm) |
L |
|
E |
evaporation (mm) |
L |
|
ea |
irrigation application efficiency |
- |
|
EC |
electrical conductivity (dS m-1, mS cm-1) |
T3I2M-1L-3 |
|
ec |
water conveyance efficiency |
- |
|
EC0 |
ECe at which the crop yield is reduced to zero (dS m-1) |
T3I2M-1L-3 |
|
EC50 |
ECe at which the crop yield is reduced to 50 percent (dS m-1) |
T3I2M-1L-3 |
|
ECDra |
EC of subsurface drainage water (dS m-1) |
T3I2M-1L-3 |
|
ECe |
EC of soil water of the saturated paste (dS m-1) |
T3I2M-1L-3 |
|
ECe0 |
initial ECe (dS m-1) |
T3I2M-1L-3 |
|
ECet |
desired ECe (dS m-1) |
T3I2M-1L-3 |
|
ECfc |
EC of soil water at field capacity (dS m-1) |
T3I2M-1L-3 |
|
ECfrR |
EC of percolation water mixed with soil solution (dS m-1) |
T3I2M-1L-3 |
|
ECgw |
EC of groundwater (dS m-1) |
T3I2M-1L-3 |
|
ECI |
EC of the irrigation water (dS m-1) |
T3I2M-1L-3 |
|
ECIW |
EC of the infiltrated water (dS m-1) |
T3I2M-1L-3 |
|
ECIWi |
EC of the infiltrated water mixing with soil solution (dS m-1) |
T3I2M-1L-3 |
|
ECR |
EC of the percolation water (dS m-1) |
T3I2M-1L-3 |
|
ECSi |
EC of Si intercepted by subsurface drains (dS m-1) |
T3I2M-1L-3 |
|
ECSW |
EC of the soil water (dS m-1) |
T3I2M-1L-3 |
|
ECts |
threshold EC of the extract from saturated soil paste (dS m-1) |
T3I2M-1L-3 |
|
ed |
distribution efficiency |
- |
|
ESP |
exchangeable sodium percentage |
- |
|
ET |
evapotranspiration (mm) |
L |
|
ETcrop |
crop evapotranspiration (mm) |
L |
|
ETo |
reference crop evapotranspiration (mm) |
L |
|
f |
leaching efficiency coefficient |
- |
|
fi |
leaching efficiency coefficient of water mixing with soil solution |
- |
|
fr |
leaching efficiency coefficient of the percolation water |
- |
|
G |
capillary rise (mm) |
L |
|
H |
hydraulic head (m) |
L |
|
h |
soil pressure head (m) |
L |
|
I |
total applied irrigation water (mm) |
L |
|
ICUC |
irrigation consumptive use coefficient |
- |
|
IE |
irrigation efficiency |
- |
|
IFDM |
integrated farm drainage management |
- |
|
Ig |
groundwater irrigation (mm) |
L |
|
Ii |
infiltrated irrigation water (mm) |
L |
|
IS |
irrigation sagacity |
- |
|
Is |
surface irrigation (mm) |
L |
|
IW |
infiltrated water (mm) |
L |
|
K |
hydraulic conductivity (m d-1) |
L T-1 |
|
Kc |
crop coefficient |
- |
|
K(q) |
unsaturated hydraulic conductivity (m d-1) |
L T-1 |
|
Ks |
saturated hydraulic conductivity (m d-1) |
L T-1 |
|
LF |
leaching fraction |
- |
|
LFi |
leaching fraction of water mixing with the soil solution |
- |
|
LR |
leaching requirement |
- |
|
LRi |
leaching requirement of water mixing with soil solution |
- |
|
Mc |
mass of salts removed by harvested crops (kg) |
M |
|
Md |
mass of salts dissolved from mineral weathering (kg) |
M |
|
Mf |
mass of salts from fertilisers and amendments (kg) |
M |
|
Mp |
mass of salts precipitated in soils (kg) |
M |
|
MPN |
most probable number of faecal coliform |
- |
|
MSe |
mass of selenium (kg) |
M |
|
n |
dimensionless empirical shape parameter |
- |
|
OPfc |
osmotic potential at field capacity (bar) |
ML-1T-2 |
|
O&M |
operation and maintenance |
- |
|
P |
precipitation (mm) |
L |
|
Pe |
effective precipitation (mm) |
L |
|
q |
soil water flux or specific discharge (m d-1) |
L T-1 |
|
R |
deep percolation (mm) |
L |
|
R* |
net deep percolation (mm) |
L |
|
RO |
surface runoff (mm) |
L |
|
S |
salts in rootzone (ECmm) |
T3I2M-1L-2 |
|
SAR |
sodium adsorption ratio (meq½ litre-½) |
N½L-1½ |
|
Sc |
seepage from canal (mm) |
L |
|
SCARP |
Salinity Control and Reclamation Project |
- |
|
Se |
water extraction sink (m3 m-3 d-1) |
T-1 |
|
Sehp |
maximum selenium concentration in harvested product (mg kg-1) |
- |
|
SeI |
selenium concentration in irrigation water (mg litre-1) |
M L-3 |
|
Send |
salts in the rootzone at the end of the period (ECmm) |
T3I2M-1L-2 |
|
Sp |
lateral seepage (mm) |
L |
|
Sess |
selenium concentration in soil solution (mg litre-1) |
M L-3 |
|
Sessm |
maximum selenium concentration in soil solution (mg litre-1) |
M L-3 |
|
Si |
seepage inflow (mm) |
L |
|
SIW |
salts in infiltrated water (ECmm) |
T3I2M-1L-2 |
|
SR |
salts in percolation water from the rootzone (ECmm) |
T3I2M-1L-2 |
|
Sstart |
salts in the rootzone at the start of the period (ECmm) |
T3I2M-1L-2 |
|
Sv |
vertical seepage (mm) |
L |
|
t |
time (d) |
T |
|
TDS |
total dissolved solids (mg litre-1, g litre-1) |
M L-3 |
|
TSS |
total suspended solids (mg litre-1, g litre-1) |
M L-3 |
|
Vdw |
volume of drainage water (m3) |
L3 |
|
Vgw |
volume of groundwater (m3) |
L3 |
|
Vi |
volume of irrigation water (m3) |
L3 |
|
Y |
empirical correction factor |
- |
|
Yr |
relative yield |
- |
|
Wfc |
moisture content at field capacity (mm) |
L |
|
WT |
water table depth (m) |
L |
|
z |
vertical coordinate (m) |
L |
