In conformity with the requirements of the EU water framework directive, the Walloon Public Service has to monitor the nitrate concentrations in water tables and surface water. They thus have developed a network of more than 900 measurement sites with annual measurements often over more than 40 years.

In order to synthesize this bunch of data and extract from it the relevant diagnostic information, Ephesia has been solicited to develop a tool for routinely model the time series and test if an increase, decrease or a rupture in the sequence could be detected. The results were summarized using statistics and maps representing the various types of evolution.