method5: Load estimation with time and discharge weighted method

Description

Estimate the load with the time and discharge weighted concentration method (Moatar & Meybeck, 2005; Worrall, Howden, & Burt, 2013). The estimation is performed on the time period spanned by flow records. It is also possible to estimate the load monthly or annually specifying an optional argument.

Usage

method5(db, ncomp, period)

Arguments

An input data frame with at least three column. A column with DateTime in standard format (yyyy-mm-dd HH:MM:SS) labeled "datetime", a column with flow records in cubic meter per second labeled "flow", and columns with scattered concentration data in milligram per litre. Alternatively, it can be used the output matrix of the function db.union.

ncomp

Number of compounds in the input data frame for which the load must be estimated.

period

Optional argument. It can be "month" for a monthly estimation of load, or it can be "year" for annual estimation of load. If it misses, the calculation is performed on the time period spanned by the streamflow data.

Value

A matrix with the estimated load with time and discharge weighted concentration method for the different compounds. If the optional argument 'period' misses, the matrix will have only one row with the load estimation done throughout the time period spanned by streamflow data. Otherwise, if the period is specified, the load is estimated in the different months/year and the load values are returned in different rows, named with the month/year considered. The load is expressed in gram per period of estimation.

References

Moatar, F., & Meybeck, M. (2005). Compared performances of different algorithms for estimating annual nutrient loads discharged by the eutrophic River Loire. Hydrological Processes, 19(2), 429<U+2013>444. https://doi.org/10.1002/hyp.5541. Worrall, F., Howden, N. J. K., & Burt, T. P. (2013). Assessment of sample frequency bias and precision in fluvial flux calculations - An improved low bias estimation method. Journal of Hydrology, 503, 101<U+2013>110. https://doi.org/10.1016/j.jhydrol.2013.08.048.

Examples

Run this code

# NOT RUN {
data("flow.data1", "conc.data1")
union<-db.union(flow.data1, conc.data1)
met5<-method5(union, 2)
met5.month<-method5(union, 2, "month")
met5.year<-method5(union, 2, "year")
# }