Environmental Design of a Quay Using Water Renewal
Manel Grifoll, Joan Pau Sierra, Manuel Espino and Agustín Sánchez-Arcilla
This contribution describes a case study in which water renewal is considered in the project design for a new quay in Bilbao harbour (Bay of Biscay, NE Atlantic). Three different designs of a new quay are evaluated with the environmental objective of maximizing water renewal. Water circulation and renewal is obtained from the implementation of a numerical model validated with observations for each of the three designs. Integral and local parameterizations of water renewal, derived from numerical analyses of Eulerian tracers, were used to determine flushing in the three different design scenarios. Local characterization of water renewal confirmed a significant spatial variability. Consequently, the results proved that an integral description can result in a misleading analysis of water renewal. A comparative analysis suggests the best solution from an environmental perspective and allows the evaluation of the modification in water renewal from the original configuration. These results can be extrapolated to other cases with similar geometries and tidal range. The proposed methodology (based on a practical example) can also be used to support exploitation decisions or contingency plans to mitigate spills or manoeuvrability accidents.
Keywords: water renewal, numerical modelling, environmental design, Bilbao harbour, water quality