wql : Exploring Water Quality Monitoring Data

Project Status: Active – The project has reached a stable, usable state and is being actively developed. CRAN_Status_Badge


Stable version from CRAN


or development version from GitHub

install.packages('devtools')  # package devtools needed


The main purpose of wql is to explore seasonal time series through plots and nonparametric trend tests. It was created originally to examine water quality data sets (hence, wql) but is suitable as a more general purpose set of tools for looking at annual or seasonal time series.

One of the more tedious tasks in exploring environmental data sets is creating usable time series from the original complex data sets, especially when you want many series at will that group data in different ways. So wql also provides a way of transforming data sets to a common format that then allows a diversity of time series to be created quickly. A few functions are specific to the fields of limnology and oceanography.

The plots are designed for easy use, not for publication-quality graphs. Nonetheless, extensive customization is possible by passing options through …, adding annotations in the case of base graphics, and adding layers in the case of ggplot2 objects.

Two functions are used mainly for preparing the times series:

The WqData class can be easily adapted to non-aquatic data. Obviously, the depth field can be used for elevation in atmospheric studies. But more generally, the site and depth fields can be used for many two-way classifications and don’t need to refer to spatial location.

Some of the time series functions include:

A few functions are specialized for the aquatic sciences:


The capabilities of wql are more fully explained in the accompanying vignette: wql: Exploring environmental monitoring data


This package is an independent fork of the archived CRAN package wq. To date, improvements have been focused on improving the documentation and code readability.

#> To cite wq in publications use:
#>   Alan D. Jassby and James E. Cloern (). wq: Some tools for exploring
#>   water quality monitoring data. R package version 1.0.0.
#>   https://cran.r-project.org/package=wq
#> A BibTeX entry for LaTeX users is
#>   @Manual{jassbywq,
#>     title = {wq: Exploring water quality monitoring data},
#>     author = {Alan D. Jassby and James E. Cloern},
#>     note = {R package version 1.0.0},
#>     url = {https://CRAN.R-project.org/package=wq},
#>   }