Contributions of non modelled sources to the acidfying and eutrophicating deposition

No more augmentation of acidifying and eutrophying depositions

Calculations of the acidifying and eutrophying depositions are traditionally made with the Operational Priority Substances model (OPS). The OPS model uses the input of anthropogenic emission data for ammonia, nitrogen oxide and sulphur dioxide. However, part of the deposition can be attributed to emissions from natural sources. Anthropogenic emissions outside Europe also contribute to depositions in the Netherlands, but are not incorporated in the calculations. To allow for these non-modelled contributions, a correction has been applied.

Evaluation leads to new insights

An evaluation has shown, that current data lead to another quantification of this correction. This is particularly due to the availability of more extensive data sets. On the basis of these data, several values of the correction can be derived. The choice of value will mainly depend on the specific intended use of the deposition data.

In future no more corrections

In future, the Netherlands Environmental Assessment Agency will publish data on acidifying and eutrophying depositions without any corrections. From now on, these results will be presented as 'deposition on the basis of European anthropogenic emissions'. Users can decide for themselves whether they wish the perform any corrections on the deposition figures. The report presents a number of suggestions for corrections.