In smwesten-usgs/autobeale-R: autobeale: code to calculate loads by means of Beale's Ratio Estimator.

Data preparation

In order to use the beale function and supporting classes, a dataframe must be prepared with the following fields:

1) *date* the sample date, encoded as an R `Date` type,
2) *discharge* the daily mean discharge, provided in cubic meters per second, and
3) *concentration* the concentration corresponding to the daily discharge, in milligrams per liter (NA if no sample taken that day).

library(autobeale)
library(dplyr)

The autobeale::beale function expects the incoming data to be provided in pairwise fashion. There should be a discharge value provided for every day within the timeframe for the laoding calculation, with a concentration value provided on days that were sampled. dplyr::left_join can be used to quickly create an input dataset suitable for use with the beale function.

discharge_file     <- system.file( "extdata", "ROCKFLOW.DAT", package="autobeale")
concentration_file <- system.file( "extdata", "ROCKNO23.DAT", package="autobeale")

discharge_data     <- read.table( discharge_file, header=TRUE )
concentration_data <- read.table( concentration_file, header=TRUE )
discharge_conc_df  <- NULL
discharge_conc_df  <- dplyr::left_join(discharge_data, concentration_data, by=c("date" = "date") )

# don't forget to convert the discharge value to cubic meters per second!
discharge_conc_df$discharge <- cfs_to_cms( discharge_conc_df$discharge )

The resulting dataframe looks like this:

knitr::kable(head(discharge_conc_df, 10))

Example #1: load by means of the unstratified Beale ratio estimator

Once the dataset is in good shape, we can call beale to calculate the load. Note that the beale function expects discharge to be provided in units of cubic meters per second, with concentration data provided in units of milligrams per liter.

result_list <- beale( discharge_cms=discharge_conc_df$discharge, concentration_mg_L=discharge_conc_df$concentration )
print( result_list, digits=2 )

smwesten-usgs/autobeale-R documentation built on May 30, 2019, 5:04 a.m.