Geografiska informationssystem för studier av polyaromatiska kolväten (PAH)
undersökning av djupvariation i BO01-området, Västra hamnen, Malmö, samt utveckling av en matematisk formel för beräkning av PAH-koncentrationer från ett kontinuerligt utsläpp
Physical geographyGeomorphologyHydrologiHydrologyGrundvattenGroundwaterEmissionsPolycyclic aromatic hydrocarbonsPedologyCartographyClimatologyNaturgeografiGeomorfologiMarkläraKartografiKlimatologiEarth and Environmental Sciences
At the end of August 1999, the local government council of Malmö city decided thatthe area known as Kvarteret Bilen would be made available for the European HousingExhibition 2001 (Bo01-mässan). Kvarteret Bilen extends over approximately 80hectars and includes the western parts of the Western Harbour area (Västra hamnen)of Malmö.Kvarteret Bilen as a whole, but especially the western sections of this area, the socalledBo01 section, has been the subject of heated discussions. This is mainly due tothe fact that the ground in question has proven to be contaminated to a certain extentby different chemical compounds. Investigations undertaken during 1998 showed sporadically high concentrations forespecially one chemical group: polycyclic aromatic hydrocarbons (PAH).The first part of the paper describes the use of a mathematical equation (Fetter 1994)to calculate the concentration of PAH from a continuous discharge at a given time byemploying Geographical Information System (GIS). Even the constraints of theequation are discussed, as well as the consequences that follow as a result of usingGIS.The second part of the paper focuses on the connections between the content ofcarcinogenic PAH in Kvarteret Bilen and the ground water level and type of fillingmaterial. It also describes several interpolation methods, none of which was successfulin the analysis however. Known point values of PAH had to be used in the analysisinstead.In order to study the relationships (mentioned above), four hypotheses were putforward: 1) the PAH will show low concentration values in the interval where theground water is fluctuating; 2) the concentration level of PAH will be higher in thesaturated zone as well as in the uppermost layer of the unsaturated zone; 3) everyPAH compound will vary in a similar way from the ground level and downwards and,4) areas containing remains of asphalt, foundry discharge and impregnated wood,ought to present the highest concentration levels.During the analysis, all of the hypotheses were confirmed. The interpolationtechniques could not be carried out since the levels of concentration of PAH variedtoo much between known points.Applying GIS to the mathematical equation in Fetter (1994) had some advantages.One was the possibility to calculate concentrations for an entire area and not just for aspecific point.The results showed that if there is a continuous discharge, the concentration values gethigher closer to the discharge area compared to values further away, if the time levelis set to be the same. Also, a longer time limit generates higher concentration valuesprovided the distances are the same.