Description Usage Arguments Details Value Author(s) References See Also Examples
View source: R/Evapotranspiration.R
Implementing the Penman-Monteith formulation (including the method for FAO-56 hypothetical short grass and the method for ASCE-EWRI Standardised crop) for estimating reference crop evapotranspiration
1 2 3 |
data |
A list which contains the following items (climate variables) required by Penman-Monteith formulation: |
constants |
A list named |
ts |
Must be either |
solar |
Must be either |
wind |
Must be either |
crop |
Must be either |
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. |
The alternative calculation options can be selected through arguments solar
and wind
, please see Arguments
for details.
User-defined evaporative surface is allowed through arguments crop
, please see Arguments
for details.
The function generates a list containing the following components:
ET.Daily |
Daily aggregated estimations of Penman-Monteith rerference crop evapotranspiration. |
ET.Monthly |
Monthly aggregated estimations of Penman-Monteith rerference crop evapotranspiration. |
ET.Annual |
Annually aggregated estimations of Penman-Monteith rerference crop evapotranspiration. |
ET.MonthlyAve |
Monthly averaged estimations of daily Penman-Monteith rerference crop evapotranspiration. |
ET.AnnualAve |
Annually averaged estimations of daily Penman-Monteith rerference crop evapotranspiration. |
ET_formulation |
Name of the formulation used which equals to either |
ET_type |
A character string containing the type of the estimation obtained which is |
message1 |
A message to inform the users about how solar radiation has been calculated by using which data. |
message2 |
A message to inform the users about if actual wind data has been used in the calculations or alternative calculations has been performed without wind data. |
Danlu Guo
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.
Allen, R. G., Pereira, L. S., Raes, D. & Smith, M. 1998. Crop evapotranspiration-Guidelines for computing crop water requirements-FAO Irrigation and drainage. paper 56. FAO, Rome, 300, 6541.
Allen, R. G. 2005. The ASCE standardized reference evapotranspiration equation. Amer Society of Civil Engineers.
ET
,processeddata
,defaultconstants
,constants
1 2 3 4 5 6 7 | # Use processed existing data set and constants from kent Town, Adelaide
data("processeddata")
data("constants")
# Call ET.PenmanMonteith under the generic function ET
results <- ET.PenmanMonteith(processeddata, constants, ts="daily", solar="sunshine hours",
wind="yes", crop = "short", message="yes", AdditionalStats="yes", save.csv="no")
|
Loading required package: zoo
Attaching package: ‘zoo’
The following objects are masked from ‘package:base’:
as.Date, as.Date.numeric
Penman-Monteith FAO56 Reference Crop ET
Evaporative surface: FAO-56 hypothetical short grass, albedo = 0.23 ; surface resistance = 70 sm^-1; crop height = 0.12 m; roughness height = 0.02 m
Sunshine hour data have been used for calculating incoming solar radiation
Wind data have been used for calculating the reference crop evapotranspiration
Timestep: daily
Units: mm
Time duration: 2001-03-01 to 2004-08-31
1280 ET estimates obtained
Basic stats
Mean: 3.56
Max: 11.05
Min: 0.66
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.