budyko

The goal of budyko is to facilitate fitting of hydrologic data to Budyko-type curves. The package includes the original Budyko (1974) formulation, as well as several single-parameter formulations like those of Fu (1981), Turc (1954), Pike (1964), and Wang & Tang (2014).

Installation

You can install budyko from github using devtools:

devtools::install_github("tylerbhampton/budykoR")

Sample Plots and Data

We can use the function blankBC to create a blank Budyko Curve plot, which includes the energy and water boundaries.

library(ggplot2)
library(budyko)

blankBC

blankBC+coord_cartesian(xlim=c(0,3))

The package comes with a sample dataset. This is annual Water-Year (October through September) data for 30 years. blankBC has pre-set aesthetics for columns PET.P on the x axis and AET.P on the y axis. We can simply add testdata to the plot.

testdata=budyko::testdata
head(testdata)
#>   year     PET.P     AET.P
#> 1 1971 1.3544730 0.7792568
#> 2 1972 1.2196014 0.5995881
#> 3 1973 2.2301358 0.7945747
#> 4 1974 1.9327838 0.7699053
#> 5 1975 0.9333194 0.5579104
#> 6 1976 2.1029359 0.8223432
blankBC+geom_point(data=testdata)+coord_cartesian(xlim=c(0,5))

Curves and Curve Fitting

The package contains several Budyko-type curves. We can use the default setting of budyko_sim() to generate the original Budyko curve.

ogbudyko=budyko_sim()
blankBC+geom_line(data=ogbudyko)+coord_cartesian(xlim=c(0,5))

blankBC+
  geom_line(data=ogbudyko)+
  geom_point(data=testdata)+
  coord_cartesian(xlim=c(0,5))

We can also use budyko_fit() to custom fit the data.

fit1=budyko_fit(data=testdata,method="Fu",dif="mae",silent = TRUE)
fit1
#>           Fu
#> param 2.0500
#> mae   0.0698
#> rsq   0.6139
#> hs    0.0000
sim1=budyko_sim(fit=fit1)
blankBC+
  geom_line(data=ogbudyko,col=2)+
  geom_line(data=sim1)+
  geom_point(data=testdata)+
  coord_cartesian(xlim=c(0,5))