A GIS analysis of the effect of diffuse PAH emissions on the sediment quality in the Hollands Noorderkwartier in the Netherlands using the WABOGIS model
Een analyse met GIS van de invloed van diffuse belasting met PAK op de waterbodemkwaliteit in het Hollands Noorderkwartier: WABOGIS
26 May 2012, PDF |
60 pages |
Puijenbroek PJTM van , Kampf R
RIVM Report 715651011
Watercourses have to be dredged once every 5 to 20 years to ensure suffcient depths for water inflow and outflow. Most of the resulting sediment is deposited on the adjacent land where polluting substances contribute to the emissions to the underlying soils. High level of PAHs (10 from VROM) in the sediment usually exceeds the sediment quality standard, putting the level of contamination in the watercourse mostly in class 2. From the survey on sediment quality in the area of the Hoogheemraadschap U.S.H.N. in Noord-Holland, regional differences in the quality of the sediment were observed. These differences could not be explained with local emissions. The sediment quality is a result of a combination of diffuse emissions. In this study, WABOGIS, the sediment quality was analysed with a geographical information system (GIS) to explain the differences in diffuse emissions. For all the local watercourses, the diffuse emissions from traffic, storm-water overflow or urbanisation are determined using geographical maps. Watercourses not influenced by these emissions are determined as delivering background pollution due to atmospheric deposition and surface runoff from surrounding soil. For background polluted locations with a sandy or clay soil, the sediment class is mostly 0 or 2, while peat soils lead to a class 2 sediment. Where there is an additional load, the greatest effect is seen in sandy soils. Locations where the combination of additional emissions determine the sediment quality mostly have a class 2 or 3 sediment.