PISCES (HydralabIV)

PISCES is a Joint Research Activity within HYDRALAB IV and focuses on enhancing the capabilities of experimental facilities, methods and instruments with respect to ecological research and the inclusion of plants and animals in hydraulic experiments.

The general aim is to develop innovative new technologies, experimental protocols and improved methodologies for incorporating organisms, both plants and animals, into physical hydraulic models and to evaluate the extent to which laboratory experiments can replicate field conditions. To achieve these aims, the team is conducting a set of experiments at a field site in Norway and in a laboratory in the UK. At both locations the identical setup of instruments will be used to measure the flow field around brown macroalgae and evaluate how well the natural environment found in Sletvik, Norway, can be reconstructed in the lab. In a next step, the natural complexity will be reduced by removing selected plants and rearranging plants in an organised manner (in line or staggered) compared to the natural random distribution. In a third step, the natural vegetation will be replaced by inert surrogates and their ability to represent live plants from a hydrodynamic point of view will be evaluated.

FZK is responsible for the workpackage that addresses the replacement of vegetation with inert surrogates.Keeping vegetation in laboratories poses problems with respect to plant health, vitality and adaptation to different and changing environmental conditions. One way to avoid these problems is to use surrogates made of inert materials to simulate the effects of plants. While surrogates are widely used to investigate the interaction between vegetation and hydrodynamics, little is known about how well such experiments replicate field conditions.Thus, we use the comparative setup within the PISCES project and develop surrogates for the dominant species at the field site, the brown macroalgae Laminaria digitata. Earlier work has identified plant shape, stiffness and buoyancy as key parameters that drive the interaction between vegetation and hydrodynamic forcing. Consequently, this study focuses on these parameters when designing a surrogate that reproduces the hydraulic roughness of L. digitata as closely as possible.

The natural population in Sletvik was sampled for size, shape, buoyancy and stiffness. The latter was measured for blades in addition to the stems for the first time. Based on the values determined for the natural population, various artificial materials were tested and a range of surrogates were developed that can be considered similar to real L. digitata. Comparison of the flow fields around, and the behaviour of, these surrogates with prototype plants under laboratory and field conditions reveals the extent to which L. digitata's hydraulic roughness can be modelled by such surrogates.

Publikationen

Paul, Maike; Thomas, Robert E.; Keevil, G. M. (2013): Concurrent field measurements of turbulent velocities, plant reconfiguration and drag forces on Ranunculus penicillatus, In: Parsons, D.; Ashworth et al. (Ed.) 2013 – Conference Programme and Abstracts Volume, 10th International Conference on Fluvial Sedimentology. Leeds, UK

Thomas, R.E., Johnson, M.F., Frostick, L., Parsons, D., Bouma, T.J., Dijkstra, J.T., Eiff, O., Gobert, S., Henry, P.-Y., Kemp, P., McLelland, S., Moulin, F., Myrhaug, D., Neyts, A., Paul, M., Penning, E., Rice, S.P., Puijalon, S., Stanica, A., Tagliapietra, D., Tal, M., Tørum, A., Vousdoukas, M.I. (2013): Physical Modeling of Water, Fauna and Flora: A Foresight Study for Ecohydraulics, in: Proceedings of the 35th IAHR World Congress. The wise find pleasure in water. 35th IAHR World Congress, Chengdu, China. 8-13 September.

Paul, M. (2013): Wie bringt man Pflanzen ins Labor – Methoden zur öko-hydraulischen Modellierung, 9. FZK Kolloquium “Modellierung im Seebau und Küsteningenieurwesen”, Forschungszentrum Küste, Hannover

Paul, Maike; Thomas, Robert E.; Keevil, G. M. (2013): Concurrent field measurements of turbulent velocities, plant reconfiguration and drag forces on Ranunculus penicillatus, EGU General Assembly 2013, Vienna

Johnson, M. F.; Thomas, Robert E.; Dijkstra, J. T.; Paul, Maike; Penning, Ellis; Rice, S. P. (2014): Using surrogates, including scaling issues, in laboratory flumes and basins, Chapter 3, In: Frostick, L., Thomas, R.E., Johnson, M.F., Rice, S.P., McLelland, S. (Eds.), Users Guide to Ecohydraulic Modelling and Experimentation. Experience of the Ecohydraulic Research Team (PISCES) of the HYDRALAB Network. IAHR Design Manual, CRC Press/Balkema, Leiden, The Netherlands

Paul, Maike; Thomas, Robert E.; Dijkstra, J. T.; Penning, Ellis; Vousdoukas, M. I. (2014): Plants, hydraulics and sediment dynamics, Chapter 6, In: Frostick, L., Thomas, R.E., Johnson, M.F., Rice, S.P., McLelland, S. (Eds.), Users Guide to Ecohydraulic Modelling and Experimentation. Experience of the Ecohydraulic Research Team (PISCES) of the HYDRALAB Network. IAHR Design Manual, CRC Press/Balkema, Leiden, The Netherlands

Paul, Maike; Henry, Pierre-Yves T.; Thomas, Robert E. (2014): Geometrical and mechanical properties of four species of northern European brown macroalgae, Coastal Engineering 84, 73-80

Thomas, Robert E.; Johnson, Matthew F.; Frostick, Lynne E.; Parsons, Daniel R.; Bouma, Tjeerd J.; Dijkstra, Jasper T.; Eiff, Olivier; Gobert, Sylvie; Henry, Pierre-Yves; Kemp, Paul; Mclelland, Stuart J.; Moulin, Frederic Y.; Myrhaug, Dag; Neyts, Alexandra; Paul, Maike; Penning, W. Ellis; Puijalon, Sara; Rice, Stephen P.; Stanica, Adrian; Tagliapietra, Davide; Tal, Michal; Tørum, Alf; Vousdoukas, Michalis I. (2014): Physical modelling of water, fauna and flora: knowledge gaps, avenues for future research and infrastructural needs, Journal of Hydraulic Research 52(3)

Paul, Maike; Henry, Pierre-Yves T. (2014): Evaluation of the Use of Surrogate Laminaria digitata in eco-hydraulic Laboratory Experiments, Journal of Hydrodynamics, Ser. B, 26(3), 374–383

Paul, Maike; Thomas, Robert E. (2014): Assessing the reality of 'realistic' experiments with macroalgae: How real can they really be? - Outcomes from the Joint Research Activity PISCES, Proceedings of the HYDRALAB IV Joint User Meeting, Lisbon, Portugal.

Paul, M.; Penning, E.; Dijkstra, J.; Johnson, M.F. (2014): Using surrogate organisms in hydraulic research: guidance on their design and implementation, ZENODO