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Impact Hypotheses

An impact hypothesis describes how an impact of encroachment (NSR-activity) may influence a VEC. The impact hypothesis includes all system components and linkages in a 'chain of influence'.

The system of linkages is shown in a schematic flowchart for each of the selected VECs. The flowchart is accompanied by a brief explanation of each link.

After the preparation of the IHs, a screening procedure is made for each IH, putting them into one of the following categories:

A. The hypothesis is assumed not to be valid.

B. The hypothesis is valid and already verified. Research to validate or invalidate the hypothesis is not required. Surveys, monitoring and/or management measures can possibly be recommended.

C. The hypothesis is assumed to be valid. Research, monitoring or surveys is recommended to validate or invalidate the hypothesis. Mitigating measures can be recommended if the hypothesis is proved to be valid.

D. The hypothesis may be valid, but is not worth testing for professional, logistic, economic or ethical reasons, or because it is assumed to be of minor environmental influence only or of insignificant value for decision making.

In the active assessment system, only IHs placed in category B or C have been given priority.

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See also

Evaluated impact hypothesis - Documentation formulary items