Add_Onzekerheidsanalyse Initiator (BO-43.20-101-001, BO-43-101-036)

The spatial distribution of ammonia emissions in the Netherlands is calculated by using the INITIATOR model. The ammonia emission results from INITIATOR are used as input for the OPS and AERIUS models for deposition calculations. The INITIATOR results, however, are subjected to major uncertainties, especially at the local scale. A systematic analysis of the uncertainties in INITIATOR results has not yet been performed. There is strong evidence that some of the uncertainties arise from the uncertainty the input data and how they are spatially distributed. This concerns, among other things, emission factors that are based on a (very) limited number of data have been derived, but also the way in which the spatial distribution of manure is calculated. Improved emission factors and data to validate the fertilizer distribution will be obtained in other research trajectories and should be involved in INITIATOR. This project aims to: (i) quantify the uncertainties in the model results and (ii) provide insight into the effects of newly derived emission factors on the spatial distribution of ammonia emissions.