Ground evaporation formula (Water Overlay): Difference between revisions

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: <math>e_{w,t}</math> = the [[Evaporation_m_(Water_Overlay)|evaporation rate]] of the [[weather]] at time t
: <math>e_{w,t}</math> = the [[Evaporation_m_(Water_Overlay)|evaporation rate]] of the [[weather]] at time t
: <math>f_o</math> = the calculated feddes oxygen stress factor, calculated using the 3rd and 4th [[Root_depth_m_(Water_Overlay)|root depths]] and the feddes trapezium interpolation model and the ground water depth.
: <math>f_o</math> = the calculated feddes oxygen stress factor, calculated using the 3rd and 4th [[Root_depth_m_(Water_Overlay)|root depths]] and the feddes trapezium interpolation model and the ground water depth.
: <math>f_s</math> = the calculated feddes saturated zone root update factor, calculated using the 1st and 2nd [[Root_depth_m_(Water_Overlay)|root depths]] and the feddes trapezium interpolation model and the ground water depth.
: <math>d_{b,c}</math> = The ground bottom distance of the cell c, defined by a [[Bottom distance prequel (Water Overlay)|Bottom distance prequel]] or a general [[Ground_bottom_distance_m_(Water_Overlay)|GROUND_BOTTOM_DISTANCE_M]] of the Water Overlay.  
: <math>d_{b,c}</math> = The ground bottom distance of the cell c, defined by a [[Bottom distance prequel (Water Overlay)|Bottom distance prequel]] or a general [[Ground_bottom_distance_m_(Water_Overlay)|GROUND_BOTTOM_DISTANCE_M]] of the Water Overlay.  
: <math>d_{s}</math> = the column height of the saturated zone covered by the roots  
: <math>d_{s}</math> = the column height of the saturated zone covered by the roots  
: <math>d_{r,n}</math> = the nth [[Root_depth_m_(Water_Overlay)|root depth value]].
: <math>d_{r,n}</math> = the nth [[Root_depth_m_(Water_Overlay)|root depth value]].
: <math>f_s</math> = the calculated feddes saturated zone root update factor, calculated using the 1st and 2nd [[Root_depth_m_(Water_Overlay)|root depths]] and the feddes trapezium interpolation model and the ground water depth.
: <math>h_u</math> = the amount of water in the unsaturated zone.
: <math>h_u</math> = the amount of water in the unsaturated zone.
: <math>E_{max}</math> = the potential max evaporation
: <math>E_{max}</math> = the potential max evaporation

Revision as of 13:02, 25 January 2024

Underground evaporation is calculated per cell.

For all underground evaporation calculation, the ground water depth at time t is used.

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle d_{gw,t} = B_{c} - w_{g,t}}

Feddes oxygen stress factor:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f_o = \begin{cases} 1.0 & \text{if } d_{gw,t} \text{ is } \geq d_{r,3} \\ \frac{d_{gw,t} - d_{r,4}}{d_{r,3} - d_{r,4}} & \text{if } d_{gw,t} \text{ is } \geq d_{r,4} \\ 0.0 & \text{otherwise} \end{cases} }

Feddes saturated zone root update factor:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f_s = \begin{cases} 0.0 & \text{if } d_{gw,t} \text{ is } \geq d_{r,1} \\ 1.0 - \frac{d_{gw,t} - d_{r,2}}{d_{r,1} - d_{r,2}} & \text{if } d_{gw,t} \text{ is } \geq d_{r,2} \\ 1.0 & \text{otherwise} \end{cases} }

Max potential evaporation:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{max} = f_t \cdot e_{w,t} \cdot f_o}

Evaporation unsaturated:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{u} = \begin{cases} 0.0 & \text{if } d_{gw,t} \text{ is } \leq 0.0 \\ min(E_{max}, h_u \cdot \frac{d_{r,1}}{d_{gw,t}}) & \text{otherwise} \\ \end{cases} }

Potential evaporation saturated:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle d_{s} = w_{g,t} - ( B_{c} - d_{b,c} )}

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle d_{r} = max( 0.0 , w_{g,t} - ( B_{c} - d_{r,1} ))}

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{p,s} = (E_{max} - E_{u}) \cdot f_s}

Evaporation saturated zone:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{s} = max (0.0 , min ( E_{p,s}, d_{s}\cdot f_{gw}, d_r \cdot f_{gw}) ) }

Evaporation total is the sum of evaporation in the saturated and unsaturated zone:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_g = E_u + E_s}

where

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle B_{c}} = the datum height of the surface of cell c, set by the elevation or a Terrain elevation prequel.
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle w_{g,t}} = the ground water level (datum height) at time t.
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle d_{gw,t}} = the depth of the ground water level, which is equal to the column height of the unsaturated zone at time t.
= the transpiration factor of the buildings (plants) on the surface, or the surface terrain's transpiration factor if none present.
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle e_{w,t}} = the evaporation rate of the weather at time t
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f_o} = the calculated feddes oxygen stress factor, calculated using the 3rd and 4th root depths and the feddes trapezium interpolation model and the ground water depth.
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f_s} = the calculated feddes saturated zone root update factor, calculated using the 1st and 2nd root depths and the feddes trapezium interpolation model and the ground water depth.
= The ground bottom distance of the cell c, defined by a Bottom distance prequel or a general GROUND_BOTTOM_DISTANCE_M of the Water Overlay.
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle d_{s}} = the column height of the saturated zone covered by the roots
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle d_{r,n}} = the nth root depth value.
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle h_u} = the amount of water in the unsaturated zone.
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{max}} = the potential max evaporation
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{u}} = the evaporation in the unsaturated zone
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{p,s}} = the potential evaporation in the saturated zone
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{s}} = the evaporation in the saturated zone
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{g}} = the total evaporation from the underground.


Related

The following topics are related to this formula.

Formulas
Groundwater level formula
Models
Underground model
Evaporation model