|A probalistic analysis of the ecological effects of sand mining for maasvlakte 2|
|Van Kruchten, Y.J.G.; Vellinga, T.; Heinis, F. (2009). A probalistic analysis of the ecological effects of sand mining for maasvlakte 2. Terra et Aqua 114: 20-28|
|In: Terra et Aqua: International Journal on Public Works, Ports and Waterways Developments. International Association of Dredging Companies (IADC): The Hague. ISSN 0376-6411, more|
ANE, Netherlands, Maasvlakte [gazetteer]; Marine
For the construction of the new port area Maasvlakte 2 in the Netherlands, which is
an extension of the existing port, a large amount of sand has to be extracted from the North Sea. The potential ecological effects of the sand mining activities have been investigated in an Environmental Impact Assessment (EIA). One of the identified potential effects in this EIA was a temporary decrease in the number of eider ducks in the Natura 2000 area “Voordelta”. Within the impact-effect chain from dredging to eider ducks, a large number of uncertainties play a role. Keeping in mind the precautionary principle, worst-case assumptions were used in the EIA in case of uncertainties. Owing to this, the final predicted impact is a result of the accumulation of several safe assumptions. Therefore, the probability of occurrence of this predicted impact might be small. Information on this probability of occurrence will be useful in the discussion about the necessity of implementing mitigating or compensating measures. The main objective of this study was to give insight into the probability of occurrence of the possible effects of sand mining on eider ducks in the Voordelta. A probabilistic approach was used to analyse the uncertainties in the impact-effect chain and to find a method to take these uncertainties into account in the modelling of the ecological effect. The final result was a probability density function of the impact of the sand mining on eider ducks. This result led to the conclusion that the probability that the sand mining activities for Maasvlakte have a significant effect on eider ducks in the Voordelta is very small and can be considered negligible. The methodology that is used in this study is expected to be applicable as well to the assessment of ecological effects of other human activities.