In decision-making on construction and modification of transport infrastructure, the Directorate-General for Public Works & Water Management (Rijkswaterstaat) and the Ministry of Transport & Water Management use so-called GCN maps depicting the contours of large-scale air pollution in the Netherlands. Based on the given air quality, it is then determined whether or not new infrastructure will lead to European standards being exceeded. In the latest update of the GCN maps the contribution made by inland shipping was far greater than was previously the case. This is due above all to a marked change in the heat emissions of the vessels concerned. This prompted Rijkswaterstaat to take a closer look at the models and data used for determining the share of inland shipping in Dutch air pollution.
This brief report explains the emissions and fleet data and models used for this purpose, most of them from the national research institutes TNO and PBL. It is concluded that various parameters (including emission factors, emission height, heat emissions and physical parameters of vessels and waterways) have a major influence on the ultimate contribution of inland shipping to ambient air quality. It is recommended to carry out a sensitivity analysis and examine the main parameters in greater detail.