Page History

Home

{scrollbar}

Introduction

Geert van Wirdum is one of the initiators of "Ecohydrology" “Ecohydrology” in The Netherlands. Geert has developed several techniques for field measurements and data-analysis for ecohydrological research. His methods are applied by Deltares as well as by research institutes and universities in the rest of the world. One of his mostly used data-visualisation techniques is the so called 'Van ‘Van Wirdum-diagram'diagram’. This diagram shows the chemical similarity of a water sample to atmocline water (rainwater), thalassocline water (seawater) and lithocline water (calcium rich, fresh groundwater).

...

In a Van Wirdum's diagram, the ionic ratio (IR) is plotted against the electric conductivity (EC), where:

Wiki MarkupIR = \ [Ca{^}²\⁺^\] / (\[Ca{^}²\⁺^\] + \ [Cl^\Cl^-^\]).

IR           = Ionic ratio (-)

...

The scientific background on this "Van “Van Wirdum diagram" diagram” is available through Geert van Wirdums PhD-thesis (Van Wirdum, 1990), which can be acquired by internet (http://www.scribd.com/doc/51589352/Vegetation-and-hydrology-of-floating-rich-fens). Figure 1 is an example of a 'Van ‘Van Wirdum-diagram'diagram’. These diagrams are regularly used by scientific institutes, universities, and ecohydrological consultants. The example comes from a study on flexible water level management (STOWA, Hoofdrapport Flexibel peilbeheer, 2012).

...

We have programmed the framework of the typical 'Van ‘Van Wirdum-diagram' diagram’ in R. R is a free open source software program used for data processing and visualization and for statistical analysis. R is used throughout the world and has gathered a large community of users.

...

In addition, we advice to install Rstudio (http://www.rstudio.com/ide/). Rstudio is a free enhanced graphical interface for R.

Function

...

“vanwirdum”

This text needs to be copy-pasted into R. Notice that for direct usage of the vanwirdum function in R you need to have access to internet.

...