When are groundwater data enough for decision-making?

Abstract

In groundwater studies, especially complex environmental geohydrological investigations, there is a tendency for analysts and reviewers to require more data. The question is whether more data are actually better? The role of data and information in the decision-making process was evaluated, with the aim of characterising the decision process in terms of the influence of data and information in that process. When data are analysed, information is generated which upon interpretation increases the level of knowledge and understanding that is used to base management decisions on. To determine the effect of data and information on the decision-making process, data from a field site were evaluated. The depth-to-groundwater level was used as the required variable on which information was required. The evaluation was done for all 715 data points collected for the Middelburg Site aquifers. The analysis showed that the decision-making process has a logarithmic nature which means that less and less information becomes available with more data. The value of data was assessed in a data-worth or data-cost evaluation. The information gained and cost can be determined when sufficient and when optimal data have been gathered. More data are not better from a decision-making and cost perspective