Darstellung der Grundwasserbeschaffenheit mit der Methode der Hassediagrammtechnik (HDT) / A comparative evaluation and description of groundwater conditions using the Hasse Diagram Technique (HDT)

The documentation of facts about groundwater in order to perform a site-specific evaluation is still an open topic of research. Typically, the status of groundwaters is presented in the form of a coloured map. However, numerical aggregation of parameters is needed to obtain a relationship between parameters describing they status of groundwater, and a scale from which the colour code can be derived. This is often the subject of controversy, in view of the arbitrariness which it introduces into the documentation process. This paper shows how to avoid numerical aggregation of parameters The central point is the use of partially ordered sets and their visualisation by Hasse diagrams. The so-called Hasse diagram technique (HDT) is explained and we show how colouring of maps can be established. As an example 74 groundwater sample sites were selected, with an evaluation based on 10 typical parameters.