On 15 December 2015 AERIUS Calculator 2015 was officially released for production. Please see the release notes (in Dutch) for important information about the differences between the current version and the previous version, and for information on the use of the instrument as well as on known software bugs.
The system is closely monitored. Imperfections that could have an immediate impact on the working of the instrument are thus quickly and effectively solved. These are the so-called hot fixes. For an overview see ‘hot fixes’ (in Dutch).
AERIUS Calculator is used for calculating the nitrogen emissions caused by economic activity and their deposition on Natura 2000 areas. Under the PAS, calculation results can be used in permit applications, on the basis of the Dutch Nature Conservation Act 1998, or when submitting a notification of activities with deposition levels below the limit value.
AERIUS Calculator is the calculation tool used for determining the nitrogen emissions from a certain source, their dispersion in the air and their deposition on Natura 2000 areas. Calculator also shows the magnitude of the impact on nitrogen-sensitive habitats. The user merely enters a number of characteristics for his or her project, such as spatial location, type of activity and the altitude at which nitrogen will be emitted.
On the basis of the AERIUS Calculator results, initiators can subsequently use a decision tree to determine whether they will be required to apply for a permit, or whether submitting a notification of the emissions will suffice, or none of the above. In the first case, the user can export the calculation results directly and attach them to the permit application that is submitted to the competent authority. This will also ensure that the content of the application is documented properly, as this is important later on in the enforcement phase. Reporting on an activity that is expected to stay below the limit value can be done directly via Calculator.
Fields of application
Calculator calculates for agriculture, industry, residential housing, offices and shops, waste treatment plants, power plants, mobile machinery, sea shipping and inland shipping, and road, air and railway traffic.
Comparing planning variants
Calculator also enables the user to make a comparison between various alternatives for spatial plans, by calculating and comparing their nitrogen impact. In this way, initiators are able to make an educated choice between variants, also on the basis of the impact on Natura 2000 areas.
Data and methods
AERIUS contains all the basic data needed for calculation. The user therefore no longer needs to collect information and is always ensured of using the right maps and data. This concerns, for example, the map of nitrogen-sensitive habitats in Natura 2000 areas, and the base map that contains nitrogen background deposition calculated by the RIVM (GCN/GDN maps; in Dutch).
The core of the AERIUS calculation tool is formed by RIVM’s Operational Priority Substances model (OPS). This model calculates the dispersion of nitrogen in the air and its deposition. In doing so, OPS takes various factors into account that may influence the dispersion and deposition of nitrogen, such as wind direction and speed, terrain roughness and vegetation height. For road traffic, AERIUS uses the Standard Calculation Method 2 (SRM2). Here, AERIUS is in line with the modelling method used in the Dutch national air quality plan ‘Nationaal Samenwerkingsverband Luchtkwaliteit’.
External reviews are regularly conducted as part of the quality assurance for AERIUS Calculator. Reviewers, to date, have concluded that the instrument is suitable for the purpose for which it was designed, that it is scientifically state of the art, and that it is user-friendly. The following review studies have been or are currently being conducted:
- Suitability study AERIUS Calculator and Monitor, conducted by TNO (annual report) (in Dutch)
- International scientific reviews
- User Acceptance Tests