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Data Products and Interpolation

Oak Ridges Moraine Groundwater Program


upper case

$D$ soil moisture deficit (L)

$E$ total evaporation (L)

$E_a$ atmospheric demand/potential evaporation (L)

$F_{x}$ fraction of $x$, $[0,1]$

$G$ net groundwater exchange $(\text{recharge}-\text{discharge})$

$K_\text{sat}$ saturated hydraulic conductivity (m/s)

$P_R$ precipitation in the form of rain (L)

$P_S$ precipitation in the form of snow (depth of snow water equivalent—SWE)

$P_M$ snowmelt/drainage from snowpack (L)

$R$ runoff, generated at a particular location

$S$ a storage reservoir with know capacity (L)

$T_a$ temperature of air (°C)

$T_c$ critical air temperature (°C) where precipitation likely falls as snow

$T_n$ minimum daily air temperature (°C)

$T_x$ maximum daily air temperature (°C)

$Y_a$ atmospheric yield, i.e., precipitation in its liquid/mobile form: $Y_a=P_R+P_M$

lower case

$b$ groundwater discharge to streams (L)

$e$ vapour pressure of water in air (Pa)

$e_s$ saturation vapour pressure of water in air (Pa)

$f$ infiltration (L)

$p_a$ atmospheric pressure (Pa)

$q$ lateral groundwater flux (m²/s)

$r$ relative humidity (-)

$u$ windspeed (m/s)

$x$ saturation excess (L)

$z_\text{ext}$ extinction depth (m): depth where evaporation becomes negligible.

upper case Greek

$\Delta t$ model timestep (s)

lower case Greek

$\alpha_u$ wind direction (degrees CW north)

$\beta$ land surface gradient

$\phi$ porosity (-)

$\theta_\text{fc}$ water content at field capacity (-)


Certain parameter pairs are present typically in upper- and lower-case form. This is mainly used to differentiate data distributed at the regional scale (upper) vs. processed occurring at a point in space (lower), for instance:

\[Y_a \longmapsto y\]

meaning atmospheric yield collected within the ORMGP region maps to any particular point in space. Similarly:

\[E \longmapsto a\] \[G \longmapsto g\]