cmf::upslope::ET Namespace Reference

Contains different flux_connection classes for the description of evaporation and transpiration. More...

Detailed Description

Contains different flux_connection classes for the description of evaporation and transpiration.

Classes
class	CanopyStorageEvaporation
	Calculates the evaporation from a canopy storage. More...
class	constantETpot
	A constant evapotranspiration. More...
class	ContentStress
	A simple water content based stress model based on Feddes (1978) More...
class	HargreaveET
	Calculates the Evapotranspiration using Hargreave's equation. More...
class	OudinET
	Calculates ETpot after Oudin et al 2005. More...
class	PenmanEvaporation
	Calculates evaporation from an open water body. More...
class	PenmanMonteithET
	Calculates the potential evapotranspiration according to FAO(1998) More...
class	PriestleyTaylorET
	Calculates the Evapotranspiration using Priestley-Taylor equation. More...
class	RootUptakeStressFunction
	An abstract class to calculate the actual transpiration from potential transpiration. More...
class	ShuttleworthWallace
	Calculates the sum of soil evaporation and transpiration according to Shuttleworth & Wallace 1985, as implemented in BROOK 90 (Federer 1990) More...
class	stressedET
	An abstract base class for ET Methods with a WaterStressFunction. More...
class	SuctionStress
	The classical suction depending transpiration Stress curve after Feddes. More...
class	SW_evap_from_canopy
	Connection for Shuttleworth-Wallace canopy interception evaporation. More...
class	SW_evap_from_layer
	Connection for Shuttleworth-Wallace ground evaporation. More...
class	SW_evap_from_snow
	Connection for Shuttleworth-Wallace canopy interception evaporation. More...
class	SW_evap_from_surfacewater
	Connection for Shuttleworth-Wallace canopy interception evaporation. More...
class	SW_transpiration
	Connection for Shuttleworth-Wallace transpiration. More...
class	timeseriesETpot
	A timeseries driven evapotranspiration. More...
class	TurcET
	Calculates ETpot after Turc (DVWK). More...
class	VolumeStress
	A WaterStressFunction based on the stored water volume of a layer. More...

Functions
real	PenmanMonteith (cmf::atmosphere::Weather A, const cmf::upslope::vegetation::Vegetation &veg, double h)
	Returns the potential ET after Penman-Monteith using some simplifications for a weather and a vegetation object.
real	PenmanMonteith (real Rn, real ra, real rs, real T, real vap_press_deficit)
	Returns the potential ET after Penman-Monteith using some simplifications for a given Radiation balance, aerodynamic and surface resistances, and a vapor pressure deficit.

Function Documentation

PenmanMonteith() [1/2]

real PenmanMonteith	(	cmf::atmosphere::Weather	A,
		const cmf::upslope::vegetation::Vegetation &	veg,
		double	h )

Returns the potential ET after Penman-Monteith using some simplifications for a weather and a vegetation object.

aerodynamic and surface resistances, and a vapor pressure deficit

Parameters

A	Current weather
veg	Vegetation data
h	Height above sea level in m (for air pressure estimation)

PenmanMonteith() [2/2]

real PenmanMonteith	(	real	Rn,
		real	ra,
		real	rs,
		real	T,
		real	vap_press_deficit )

Returns the potential ET after Penman-Monteith using some simplifications for a given Radiation balance, aerodynamic and surface resistances, and a vapor pressure deficit.

\[ ET = \frac{\Delta R_n}{\lambda \Delta + \gamma + \gamma \frac{r_s}{r_a}} + \frac{c_p\rho_a}{\Delta + \gamma + \gamma \frac{r_s}{r_a}} \frac{e_s - e_a}{r_a} \]

where

• \( ET \) is the evapotranspiration in \(\frac{kg}{m^2 day}\approx \frac{mm}{day}\)
• \( \Delta \left[\frac{kPa}{k}\right]= 4098\ 0.618 \exp\left(\frac{17.27 T}{T+237.3}\right (T+237.3)^{-2} \) is the slope of vapor pressure
• \( R_n \left[\frac{MJ}{m^2 day}\right]\) is the radiation balance
• \( r_s \left[\frac s m\right] \) is the surface resistance
• \( r_a \left[\frac s m\right] \) is the aerodynamic resistance
• \( \gamma = 0.067 \left[\frac{kPa}{k}\right] \) is the psychrometer constant
• \( e_s - e_a \left[kPa\right]\) is the vapor pressure deficit

Parameters

Rn	Radiation balance in \( \frac{MJ}{m^2 day} \)
ra	Aerodynamic resistance in \( \frac s m \)
rs	Surface resistance in \( \frac s m \), is 0 for free water
T	Actual Temperature in \( ^\circ C \)
vap_press_deficit	Deficit of vapor pressure \( kPa \)