Operation sources in Belgium: preliminary statistical analyses of the results and validation of the ``nitrates'' map

• Published in: Hydrological sciences journal 2000-02, Vol.45 (1), p.43-60
• Main Authors: Wattecamps, J M, Bernier, J, De Backer, L, Boreux, J J
• Format: Article
• Language: eng ; fre
• ISSN: 0262-6667
• DOI: 10.1080/02626660009492305

The Operation Sources of the WWF (Worldwide Fund for Wildlife) in Belgium is an environmental educational campaign focused on the groundwater quality. It involves pupils in the fifth and sixth grades of primary school in Belgium. Since 1994, several hundred analyses of nitrate have been carried out using colorimetric test strips at numerous springs and wells throughout Belgium. At the end of each campaign, the point sources of water surveyed were recorded on a map of Belgium, using different colours to indicate their range of nitrate concentration. The educational objective having been fulfilled, in order to validate these maps it was necessary to verify for each visited point source the relationship between its actual nitrate concentration (mg l super(-) super(1) ) and its colour on the map. To this end, verification was carried out on 308 point sources chosen at random from those tested. The statistical analysis shows that the relationship between the results of the colorimetric in situ tests and corresponding laboratory control checks is highly significant. This result warrants further investigations, notably the use of regional information to qualify a poorly surveyed source point and also to check the temporal changes of the maps.