rvn_monthly_vbias: Monthly Volume Bias

Description

Creates a plot of the monthly volume biases in the simulated flow series.

Usage

rvn_monthly_vbias(
  sim,
  obs,
  add_line = TRUE,
  normalize = TRUE,
  add_labels = TRUE,
  incomplete_month = FALSE
)

Value

mvbias: monthly volume biases

Arguments

sim: time series object of simulated flows
obs: time series object of observed flows
add_line: optionally adds a horizontal line to the plot for reference (default TRUE)
normalize: option to normalize the biases and report as percent error (default TRUE)
add_labels: optionally adds labels for early peak/late peaks on right side axis (default TRUE)
incomplete_month: whether to include months with missing days in the summation (default FALSE)

Details

Calculates the monthly volume biases and optionally creates a plot of them. The monthly volume biases are averaged across all years of data. If normalized, the biases are calculated as:

(Vi_sim - Vi_obs)/Vi_obs*100

to be expressed as a percent error.

The sim and obs should be of time series (xts) format and are assumed to be of the same length and time period. The flow series are assumed to be daily flows with units of m3/s. Note that a plot title is purposely omitted in order to allow the automatic generation of plot titles.

The add_labels will add the labels of 'overestimated' and 'underestimated' to the right hand side axis if set to TRUE. This is useful in interpreting the plots. Note that the biases are calculated as sim_Volume - obs_Volume, which means that negative values mean the volume is underestimated, and positive values mean the volume is overestimated.

Examples

Run this code

# load sample hydrograph data, two years worth of sim/obs
data(rvn_hydrograph_data)
sim <- rvn_hydrograph_data$hyd$Sub36
obs <- rvn_hydrograph_data$hyd$Sub36_obs

# check the monthly volume bias; normalizes by default
rvn_monthly_vbias(sim, obs)

# check unnormalzied monthly volume biases; see the larger volumes in certain periods
rvn_monthly_vbias(sim,obs,normalize = FALSE)