loadcalc: Load calculation methods for dissolved and suspended matter...

In rsachse/limnotools: Help Tools of TU Dresden's Limnology Workgroup

Description

This function provides several load calculation routines known from the literature. Note: the code is experimental, several methods are not yet documented and not all methods are thoroughly tested!!!

Usage

loadcalc(c, Q, Qy, doy=NULL, method = "2", year = 364, ncl = 15, logclass = TRUE)

Arguments

c	vector with measured concentrations of dissolved substances
Q	vector of discharge measurements according to the concentration data
Qy	discharge measurements for the whole year
doy	day of year (or index of measurements), needed for method "4"
method	selects the load calculation algorithm
year	length of the year, maybe 364, 365 or 360
ncl	number of classes (for method "harned"
logclass	specifies if discharge classes for method "harned" should be based on dividing logarithmic (TRUE) or linear (FALSE) scale.

Details

We and others made extensive tests and suggest methods "2" (discharge weighted mean) or "harned" (method with discharge classes).

Value

The total load for the whole year (or period if specified ).

References

Coats R, Lju FJ, Goldman CR (2002). A Monte Carlo test of load calculation methods, Lake tahoe basin, California-Nevada. Journal of American Water Resources Association, 38(3), 719-730.

Dann MS, Lynch JA, Corbett ES (1986). Comparison of Methods for Estimating Sulfate Export from a Forested Watershed. J. Environ. Qual., 15(2), 140-145.

Harned DA, Daniell CCI, Crawford J (1981). Methods of discharge compensation as an aid to the evaluation of water quality trends. Water Resources Research, 17(5), 1389-1400.

Hilden M (2003). Ermittlung von Stoff-Frachten in Fließgewässern. Probenahmestrategien und Berechnungsverfahren. Konzepte und Strategien, Länderarbeitsgemeinschaft Wasser (LAWA).

Keller M, Hilden M, Joost M (1997). Vergleich von Schätzmethoden für jährliche Stofffrachten am Beispiel des IKSR-Meßprogrammes 1995. Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit, Maßnahme Nr. 4, Weitergehende Bewertung von Gewässergütedaten, JAP-BfG, Nr 413 (BfG-1078), Bundesanstalt für Gewässerkunde.

Schleppi P, Waldner PA, Fritschi B (2006). Accuracy and precision of different sampling strategies and flux integration methods for runoff water: comparisons based on measurements of the electrical conductivity. Hydrological Processes, 20, 395-410.

Swistock BR, Edwards PJ,Wood F, Dewalle DR (1997). Comparison of methods for calculating annual solute exports from six forested Appalachian watersheds. Hydrological Processes, 11, 655-669.

Zweynert U, Behrendt H, Zweynert M (2004). Berechnung jährlicher Stoffrachten in Fließgewässern - Ein neuer Ansatz im Vergleich mit etablierten Methoden. In: Deutsche Gesellschaft für Limnologie (DGL) - Tagungsbericht 2003 (Köln), Bd. II, S. 643-648.

Examples

## daily discharge meaures for one year
Qy <- rlnorm(365, meanlog=3, sdlog=1)
## sampling dates
t  <- floor(seq(1, 365, length=20))
## discharges and concentrations
Q  <- Qy[t]
c  <- runif(1:20, min=0, max=10)

loadcalc(c, Q, Qy, method="2")

## Method with discharge classes (e.g. 15 (default) or 10)
loadcalc(c, Q, Qy, method="harned")
loadcalc(c, Q, Qy, ncl=10, method="harned")
loadcalc(c, Q, Qy, method="harned", logclass=FALSE)

## average weighted concentrations
loadcalc(c, Q, Qy, method="2")/sum(Qy)
loadcalc(c, Q, Qy, method="harned")/sum(Qy)

## average non-weighted concentration
mean(c)

rsachse/limnotools documentation built on Jan. 8, 2021, 5:37 a.m.