Property:Describe key physical parameters
From CSDMS
This is a property of type Text.
T
Equations Used by the Degree-Day Method
M = (c_0 / 86400) * (T_air - T_0) = meltrate (mm / sec)
M_max = (1000 * h_snow / dt) * (ρ_water / ρ_snow) = max possible meltrate (mm / sec)
dh_snow = M * (ρ_water / ρ_snow) * dt = change in snow depth (m) +
Equations Used by the Energy-Balance Method
M = (1000 * Q_m) / (ρ_water * L_f) = meltrate (mm / sec)
M_max = (1000 * h_snow / dt) * (ρ_water / ρ_snow) = max possible meltrate (mm / sec)
dh_snow = M * (ρ_water / ρ_snow) * dt = change in snow depth (m)
Q_m = Q_SW + Q_LW + Q_h + Q_e - Q_cc = energy flux used to melt snow (W / m^2)
Q_h = ρ_air * c_air * D_h * (T_air - T_surf) = sensible heat flux (W / m^2)
Q_e = ρ_air * L_v * D_e * (0.662 / p_0) * (e_air - e_surf) = latent heat flux (W / m^2)
D_n = κ^2 * u_z / LN((z - h_snow) / z0_air)^2 = bulk exchange coefficient (neutrally stable conditions) (m / s)
D_h = D_n / (1 + (10 * Ri)), (T_air > T_surf) = bulk exchange coefficient for heat (m / s) (stable)
= D_n * (1 - (10 * Ri)), (Tair < Tsurf) = bulk exchange coefficient for heat (m / s) (unstable)
D_e = D_h = bulk exchange coefficient for vapor (m / s)
Ri = g * z * (T_air - T_surf) / (u_z^2 (T_air + 273.15)) = Richardson's number (unitless)
Q_cc = (see note below) = cold content flux (W / m^2)
E_cc(0) = h0_snow * ρ_snow * c_snow * (T_0 - T_snow) = initial cold content (J / m^2) (T0 = 0 now)
e_air = e_sat(T_air) * RH = vapor pressure of air (mbar)
e_surf = e_sat(T_surf) = vapor pressure at surface (mbar)
e_sat = 6.11 * exp((17.3 * T) / (T + 237.3)) = saturation vapor pressure (mbar, not KPa), Brutsaert (1975) +
Equations Used by the Green-Ampt Method
f_c = K_i + ((K_s - K_i) * (F + J) / F) = infiltrability (m / sec) (max infiltration rate)
= K_s + (J / F) * (K_s - K_i) = infiltrability (m / sec) (max infiltration rate)
J = G * (θ_s - θ_i) = a quantity used in previous equation (meters)
v_0 = min((P + M), f_c) = infiltration rate at surface (mm / sec) (K_s < (P + M))
= (P + M) = infiltration rate at surface (mm / sec) (K_s > (P + M))
F = ∫ v_0(t) d_t, (from times 0 to t) = cumulative infiltration depth (meters) (vs. I' in Smith (2002) +
Equations Used by the Smith-Parlange 3-Parameter Method
f_c = K_s + γ * (K_s - K_i) / (exp(γ * F / J) - 1) = infiltrability (m / sec) (max infiltration rate)
J = G * (θ_s - θ_i) = a quantity used in previous equation (meters)
v_0 = min((P + M), f_c) = infiltration rate at surface (mm / sec) (K_s < (P + M))
= (P + M) = infiltration rate at surface (mm / sec) (K_s > (P + M))
F = ∫ v_0(t) dt, (from times 0 to t) = cumulative infiltration depth (meters) +
W
Equations focused on are the radiative transfer equations, and equations governing haze microphysics +
C
Flow depths calculated using version of mannings implemented across a cellular grid using a scanning algorithm.
Sediment tranport using either Einstein or Wilcock and Crowe functions
Slope model using simple slab failure and psuedo USLE implementation
Dune model adaption of DECAL and Werner slab model +
I
Flow direction: the direction to the immediately neighboring cell (N,NE,E,...) to which flow from a cell is directed.
Drainage area: The size of the total number of cells that drain through a cell. +
S
Flow modeling is based on the Ikeda, Parker, and Sawaii (1984) and Johannesson and Parker (1989) linearized flow models. See the model documentation and published papers documented therein. Floodplain sedimentation is modeled as described in the documentation and in Howard(1992, 1996). Backwater flow routing and bed sediment routing is based upon Gary Parker's ebook spreadsheet RTe-bookAgDegBW.xls:. See the program documentation for further details. +
P
G
Global population values is assumed to be the most important controlling factor on the area of a specific agricultural land use area. +
L
Heat conduction equations, lake ice growth-decay equations +
I
C
In each cell and at each time step the following are computed: bottom elevation, above-ground vegetation, water level, wave height, tidal current velocity, bottom shear stress, and suspended sediment concentration. +
P
Incompressible Navier-Stokes equations coupled to a convective-diffusive equation to describe the concentration field of the particles. +
S
Incompressible flow equations: Navier-Stokes with or without Boussinesq approximation. Transport equation to describe the motion of particles (or Salanity or Temperature). +
G
Incompressible flow equations: Navier-Stokes with Boussinesq approximations. Transport equation to describe the motion of particles (or Salanity or Temperature). +
S
Incompressible flow equations: Navier-Stokes with Boussinesq approximations. Transport equation to describe the motion of particles (or Salanity or Temperature). +
H
Infiltration capacity, water balance equation
Hydraulic conductivity, 2-D Dupuit groundwater movement equation +
O
Instream mass transport based on the Advection-Dispersion equation with additional terms to consider inflow, transient storage, and chemical transformation. +
K
