<center>Goodness-of-fit Measures to Compare Observed and

In hydroGOF: Goodness-of-Fit Functions for Comparison of Simulated and Observed Hydrological Time Series

knitr::opts_chunk$set(echo = TRUE)

Installation

Installing hydroGOF:

install.packages("hydroGOF")

Setting up the environment

• Loading the hydroGOF library, which contains data and functions used in this analysis.

library(hydroGOF)

• Loading observed streamflows of the Ega River (Spain), with daily data from 1961-Jan-01 up to 1970-Dec-31

require(zoo)
data(EgaEnEstellaQts)
obs <- EgaEnEstellaQts

• Generating a simulated daily time series, initially equal to the observed values (simulated values are usually read from the output files of the hydrological model)

sim <- obs 

• Computing the numeric goodness-of-fit measures for the "best" (unattainable) case

gof(sim=sim, obs=obs)

• Randomly changing the first 2000 elements of 'sim', by using a normal distribution with mean 10 and standard deviation equal to 1 (default of 'rnorm').

sim[1:2000] <- obs[1:2000] + rnorm(2000, mean=10)

• Plotting the graphical comparison of 'obs' against 'sim', along with the numeric goodness-of-fit measures for the daily and monthly time series

ggof(sim=sim, obs=obs, ftype="dm", FUN=mean)

Removing warm-up period

• Using the first two years (1961-1962) as warm-up period, and removing the corresponding observed and simulated values from the computation of the goodness-of-fit measures:

ggof(sim=sim, obs=obs, ftype="dm", FUN=mean, cal.ini="1963-01-01")

• Verification of the goodness-of-fit measures for the daily values after removing the warm-up period:

sim <- window(sim, start=as.Date("1963-01-01"))
obs <- window(obs, start=as.Date("1963-01-01"))

gof(sim, obs)

Analysis of the residuals

• Computing the daily residuals (even if this is a dummy example, it is enough for illustrating the capability)

r <- sim-obs

• Summarizing and plotting the residuals (it requires the hydroTSM package):

library(hydroTSM)
smry(r) 

# daily, monthly and annual plots, boxplots and histograms
hydroplot(r, FUN=mean)

• Seasonal plots and boxplots

# daily, monthly and annual plots, boxplots and histograms
hydroplot(r, FUN=mean, pfreq="seasonal")

Software details

This tutorial was built under:

sessionInfo()$platform
sessionInfo()$R.version$version.string 
paste("hydroGOF", sessionInfo()$otherPkgs$hydroGOF$Version)

Version history

• v0.2: Mar-2020
• v0.1: Aug 2011

hydroGOF documentation built on March 14, 2020, 1:07 a.m.