# baseflow: Calculate the baseflow of a river In lfstat: Calculation of Low Flow Statistics for Daily Stream Flow Data

## Description

Given a stream flow hydrograph of flows (regular time series), the baseflow is separated. The minima of a period (default `block.len = 5)` is calculated and turning points are identified. At turning points the baseflow equals the actual flow, in between, linear interpolation is carried out.

## Usage

 `1` ```baseflow(x, tp.factor = 0.9, block.len = 5) ```

## Arguments

 `x` numeric vector containing flows `tp.factor` numeric vector of length one. Towards high flows, allow the central value of three consecutive minima only to be of a factor `(1 - tp.factor)` higher than the surrounding values `block.len` numeric vector of length one.

## Value

A numeric vector of `length(x)`. It contains `NA`s as until the first turning point, the baseflow cannot be determined.

## References

Tallaksen, L. M. and Van Lanen, H. A. J. 2004 Hydrological Drought: Processes and Estimation Methods for Streamflow and Groundwater. Developments in Water Science 48, Amsterdam: Elsevier.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16``` ```## reproducing Tallaksen and van Lanen (2004) ## Example 5.3 Base Flow Index" data(ray) ray <- as.xts(ray) # calculate baseflow and plot it ray\$baseflow <- baseflow(ray\$discharge) ray96 <- ray[format(time(ray), "%Y") == "1996", ] plot(ray96\$discharge, type = "l") lines(ray96\$baseflow, col = 2) # aggregated base flows for river Ray # these are mean flow totals per day, not per year as written # in Tallaksen and van Lanen (2004) round(colSums(ray96[, c("discharge", "baseflow")]), 2) ```

lfstat documentation built on May 30, 2017, 1:46 a.m.