To understand which processes and what conditions are the most important when investigating the pollution in the Sannäs area a type of flowchart defining the most crucial sources, stressors and recipients and their connections was created. An attempt to establish their influencing capacity was also done by deciding whether or not the connection was of strong or small impact. What can be seen from the chart is that petroleum and oil products is the largest stressor followed by dissolved metals and accumulation.The golf course is the source with the largest number of connections, however they are of small impact according to the analysis. The marina with the marine petrol station is the parameter with most strong impact connections
To determined the sources and stressors relationship and size of impact on each other a cross-impact analysis was carried out. The relationship between the parameters were evaluated on a scale ranging from 0-6 (0,2,4,6 where 0= no impact, 6= high impact). Accumulation and nutrients and pesticides were the factors most affected by the other parameters. The factor most influenced by the other parameters were dissolved metals.
The cause effect diagram above is illustrating the relationship between the sources and stressors. From the diagram it seems like all parameters are highly connected and impacting on each other. The effect of the parameters are ranging between 14-26, meaning they all have an significant effect and plays an important role in the system. The factors causing largest effect are road dust, small boat harbour and marina, followed by boat traffic, residential housing, agriculture and lastly golf course. The largest effect is noted on the accumulation and dissolved metals. Petroleum and oil also has a large effect on the system.
Discussion & Conclusion
Crucial Processes/Conditions
In the flowchart accumulation, petroleum and oil and dissolved metals are the factors with most sources connections, however the actual size of impact is not seen.Through the impact evaluation it looks like these parameters are of significance and of great impact on the system.
The effect of nutrients and pesticides and surface runoff is not as high according to the cross-impact matrix, these parameters doesn’t have as many connections in the flowchart. If looking at the sources the golf course has the most connections in the flowchart but the significance of those doesn’t seem to have such a big impact.
This system analysis suggest that accumulation, dissolved metals, petroleum and oil are the most important stressors and road dust, small boat harbour and the marina are the largest pollutant sources.