S-Risk has some known inconsistencies in the soil-to-outdoor-air emission model. What is their impact?

The soil-to-outdoor-air emission model in S-Risk has some known inconsistencies. Under certain circumstances, it is possible that air concentrations predicted from topsoil contaminated layers are lower than air concentrations predicted from similarly contaminated, “buried” layers. This is counterintuitive and not realistic.

During the development of the S-Risk model, this inconsistency was acknowledged and discussed in detail. Together with the S-Risk steering committee (OVAM, VEB), the decision was made to leave the model as-is, since outdoor air concentrations rarely form the key issue in most soil investigations.

Due to this inconsistency, you may sometimes encounter strange results from S-Risk when comparing simulations with "buried" versus topsoil layers. An example can be seen in this picture:

 

This picture shows the value of the calculated critical soil concentration (Y axis), varying with the depth of an uncontaminated layer (X axis) covering the polluted layer. When the covering layer disappears (x → 0m), the soil-to-outdoor-air model inconsistency results in an unexpectedly high critical soil concentration.

last modified on 24/11/2014 - 08:59

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