ET.MattShuttleworth {Evapotranspiration} | R Documentation |
Matt-Shuttleworth Formulation
Description
Implementing the Matt-Shuttleworth formulation for reference crop evapotranspiration
Usage
## S3 method for class 'MattShuttleworth'
ET(data, constants, ts="daily", solar="sunshine hours",
alpha=0.23, r_s=70, CH=0.12, message="yes", AdditionalStats="yes", save.csv="no", ...)
Arguments
data |
A list which contains the following items (climate variables) required by Matt-Shuttleworth formulation: |
constants |
A list named The following constants are also required when argument |
ts |
Must be either |
solar |
Must be either |
alpha |
Any numeric value between 0 and 1 (dimensionless), albedo of evaporative surface representing the portion of the incident radiation that is reflected back at the surface. |
r_s |
Any value (seconds per metre), surface resistance depends on the type of reference crop. |
CH |
Any value (metres), crop height depends on the reference crop. |
message |
Must be either |
AdditionalStats |
"yes" or "no" indicating whether monthly averaged and annual averaged ET should be calculated. |
save.csv |
Must be either |
... |
Dummy for generic function, no need to define. |
Details
The alternative calculation options can be selected through argument solar
, please see Arguments
for details.
User-defined evaporative surface is allowed through arguments alpha
, r_s
and CH
, please see Arguments
for details.
Value
The function generates a list containing the following components:
ET.Daily |
Daily aggregated estimations of Matt-Shuttleworth reference crop evapotranspiration. |
ET.Monthly |
Monthly aggregated estimations of Matt-Shuttleworth reference crop evapotranspiration. |
ET.Annual |
Annually aggregated estimations of Matt-Shuttleworth reference crop evapotranspiration. |
ET.MonthlyAve |
Monthly averaged estimations of daily Matt-Shuttleworth reference crop evapotranspiration. |
ET.AnnualAve |
Annually averaged estimations of daily Matt-Shuttleworth reference crop evapotranspiration. |
ET_formulation |
Name of the formulation used which equals to Matt-Shuttleworth. |
ET_type |
Type of the estimation obtained which is Reference Crop Evapotranspiration. |
message1 |
A message to inform the users about how solar radiation has been calculated by using which data. |
Author(s)
Danlu Guo
References
Shuttleworth, W. & Wallace, J. 2009. Calculating the water requirements of irrigated crops in Australia using the Matt-Shuttleworth approach. Transactions of the ASABE, 52, 1895-1906.
McMahon, T., Peel, M., Lowe, L., Srikanthan, R. & McVicar, T. 2012. Estimating actual, potential, reference crop and pan evaporation using standard meteorological data: a pragmatic synthesis. Hydrology and Earth System Sciences Discussions, 9, 11829-11910.
See Also
ET
,processeddata
,defaultconstants
,constants
Examples
# Use processed existing data set and constants from kent Town, Adelaide
data("processeddata")
data("constants")
# Call ET.MattShuttleworth under the generic function ET
results <- ET.MattShuttleworth(processeddata, constants, ts="daily",
solar="sunshine hours", alpha=0.23, r_s=70, CH=0.12,
message="yes", AdditionalStats="yes", save.csv="no")