Surface flow

The Table below shows the parameters (fields) of struct SurfaceFlow, including a description of these parameters, the unit, and default value if applicable. SurfaceFlow is used for river and overland flow. The parameters in bold represent model parameters that can be set through static input data (netCDF), and can be listed in the TOML configuration file under [input.lateral.river] and [input.lateral.land], for river and overland flow respectively, to map the internal model parameter to the external netCDF variable. For river flow two additionally parameters can be set, dl (river length) and width (river width) as follows, through the TOML file:

[input.lateral.river]
length = "wflow_riverlength"
width = "wflow_riverwidth"
parameterdescriptionunitdefault
dllengthm-
nManning's roughnesss m$^{\frac{1}{3}}$[1]
slopeslopem m$^{-1}$-
widthwidthm-
qdischargem$^3$ s$^{-1}$-
qininflow from upstream cellsm$^3$ s$^{-1}$-
q_avaverage dischargem$^3$ s$^{-1}$-
qlatlateral inflow per unit lengthm$^2$ s$^{-1}$-
inwaterlateral inflowm$^3$ s$^{-1}$-
volumekinematic wave volumem$^3$-
hwater levelm-
h_avaverage water levelm-
Δtmodel time steps-
itsnumber of fixed iterations--
alpha_powused in the power part of $\alpha$--
alpha_termterm used in computation of $\alpha$--
αconstant in momentum equation $A = \alpha Q^{\beta}$s$^{\frac{3}{5}}$ m$^{\frac{1}{5}}$-
epsmaximum allowed change in $\alpha$s$^{\frac{3}{5}}$ m$^{\frac{1}{5}}$-
celcelerity of kinematic wavem s$^{-1}$-
to_riverpart of overland flow that flows to the riverm s$^3$-
rivercellslocation of river cells (0 or 1)--
wb_pitlocation (0 or 1) of a waterbody (wb, reservoir or lake)--
reservoir_indexmap cell to 0 (no reservoir) or i (pick reservoir i in reservoir field)--
lake_indexmap cell to 0 (no lake) or i (pick lake i in lake field)--

Reservoirs

The Table below shows the parameters (fields) of struct SimpleReservoir, including a description of these parameters, the unit, and default value if applicable. The parameters in bold represent model parameters that can be set through static input data (netCDF), and can be listed in the TOML configuration file under [input.lateral.river.reservoir], to map the internal model parameter to the external netCDF variable.

Two parameters reservoir coverage areas and the outlet of reservoirs (unique id) locs that are not part of the SimpleReservoir struct are also required, and can be set as follows through the TOML file:

[input.lateral.river.reservoir]
areas = "wflow_reservoirareas"
locs = "wflow_reservoirlocs"
parameterdescriptionunitdefault
areaaream$^2$-
demandrelease ( demand)minimum (environmental) flow released from reservoirm$^3$ s$^{-1}$-
maxreleasemaximum amount that can be released if below spillwaym$^3$ s$^{-1}$-
maxvolumemaximum storage (above which water is spilled)m$^3$-
targetfullfractarget fraction full (of max storage)--
targetminfractarget minimum full fraction (of max storage)--
Δtmodel time steps-
volumevolumem$^3$-
inflowtotal inflow into reservoirm$^3$-
outflowoutflow into reservoirm$^3$ s$^{-1}$-
totaloutflowtotal outflow into reservoirm$^3$-
percfullfraction full (of max storage)--
precipitationoutflow into reservoirmm Δt⁻¹-
evaporationoutflow into reservoirmm Δt⁻¹-

Lakes

The Table below shows the parameters (fields) of struct NaturalLake, including a description of these parameters, the unit, and default value if applicable. The parameters in bold represent model parameters that can be set through static input data (netCDF), and can be listed in the TOML configuration file under [input.lateral.river.lake], to map the internal model parameter to the external netCDF variable.

Two parameters lake coverage areas and the outlet of lakes (unique id) locs that are not part of the NaturalLake struct are also required, and can be set as follows through the TOML file:

[input.lateral.river.lake]
areas = "wflow_lakeareas"
locs = "wflow_lakelocs"
parameterdescriptionunitdefault
areaaream$^2$-
bRating curve coefficient--
eRating curve exponent--
outflowfunctype of lake rating curve--
storfunctype of lake storage curve--
thresholdwater level threshold $H_0$ below that level outflow is zerom-
waterlevelwaterlevel $H$ of lakem-
lowerlake_ind (linkedlakelocs)Index of lower lake (linked lakes)-0
shdata for storage curve--
hqdata rating curve--
Δtmodel time steps-
inflowtotal inflow to the lakem$^3$-
storagestorage lakem$^3$-
outflowoutflow lakem$^3$ s$^{-1}$-
totaloutflowtotal outflow lakem$^3$-
precipitationaverage precipitation for lake areamm Δt⁻¹-
evaporationaverage precipitation for lake areamm Δt⁻¹-

Lateral subsurface flow

The Table below shows the parameters (fields) of struct LateralSSF, including a description of these parameters, the unit, and default value if applicable.

parameterdescriptionunitdefault
kh₀horizontal hydraulic conductivity at soil surfacem Δt$^{-1}$-
fa scaling parameter (controls exponential decline of kh₀)m$^{-1}$-
soilthicknesssoil thicknessm-
θₛsaturated water content (porosity)--
θᵣresidual water content--
ttime stepΔt s-
Δtmodel time steps-
βₗslope--
dldrain lengthm-
dwdrain widthm-
zipseudo-water table depth (top of the saturated zone)m-
exfiltwaterexfiltration (groundwater above surface level, saturated excess conditions)m-
rechargenet recharge to saturated storem-
ssfsubsurface flowm$^3$ Δt${-1}$-
ssfininflow from upstream cellsm$^3$ Δt${-1}$-
ssfmaxmaximum subsurface flowm$^2$ Δt${-1}$-
to_riverpart of subsurface flow that flows to the riverm$^3$ Δt${-1}$-
wb_pitboolean location (0 or 1) of a waterbody (wb, reservoir or lake)--
  • 1default value for Manning's roughness n, river = 0.036; land = 0.072