The first step in the system analysis was to identify the most significant parameters involved with contaminant mobility processes in the Sannäs area. The relationships of these parameters were evaluated by creating a flowchart, where connections were drawn between them. The parameters selected was water exchange in the fjord, water stratification, turbulence, discharge from freshwater streams, groundwater flow, surface run-off, leakage from terrestrial sources, contaminats from marine sources and organic content in sediments. With organic content in sediments both the marine and terrestrial sediments were taken into accunt. One of the parameters with most connection seemed to be leakage from terrestrial sources, which was influenced by groundwater flow, discharge from freshwater streams and surface run-off. In addition, leakage from terrestrial sources did also have an impact on surface runoff, discharge from freshwater streams and the organic content in sediments. The parameter with the largest number of influencing connections was discharge from freshwater streams, which had an impact on the water stratification, groundwater flow, leakage from terrestrial sources and organic content in sediments.
To determined the parameters size of impact and the relationship between them, a cross-impact analysis was carried out. Relationship between the parameters were evaluated on a scale ranging from 0-6 (0,2,4,6 where 0= no impact, 6= high impact). The matrix above shows that the organic content is largely effected by the other parameters.
Discussion & Conclusion
In the diagram most of the parameters are plotted on the cause-side of the diagram with exception of the organic content in sediments. The most significant parameters are water stratification, water exchange fjord, discharge fresh water streams and turbulence. Groundwater flow and surface runoff and contaminants from marine sources seems to be of less importance.
What can be concluded when comparing the results from the flowchart and cross-impact matrix is that there are some features which isn’t noted up by only looking at the flowchart. Water exchange in the fjord for instance, didn’t have many connections in the flowchart but received a high effect value in the cross-impact matrix.
The difference between the result from the flowchart and cross-impact is that the flowchart is only showing that there is a relationship but not how strong that connection is. This is what the cross-impact is for, to distinguish the size of impacts by applying a scale. This is why the cross-impact is an important part of the system analysis since it is not only showing the relationship between parameters but also the size.
