TY - JOUR

T1 - Large-scale investigation of wave dampening characteristics of organic, artificial floating islands

AU - Landmann, Jannis

AU - Hammer, Tim C.

AU - Günther, Henning

AU - Hildebrandt, Arndt

N1 - Funding Information: The presented analyses are embedded in the investigations of the project “33496/01 - “BioSchWelle“: Erprobung der Wellendämpfung durch „lebende Inseln“ zur Erhöhung der Artenvielfalt in Gewässern”, funded by the Deutsche Bundesstiftung Umwelt (DBU). The authors thank the staff of the GWK for their support during the preparation of the experiments as well as during the tests.

PY - 2022/8

Y1 - 2022/8

N2 - The concept of floating vegetation-based islands for the bioremediation of aquatic ecosystems is well known. Less so, their hydrodynamic capabilities regarding the damping performance, positional stability and water-structure interactions. To this end, physical model tests with fully organic, reed-based gabions were carried out in a large-scale facility in this study. The initial, reflected, and transmitted waves were recorded and analyzed regarding transmission and reflection coefficients. A motion tracking system was utilized to allow for an investigation regarding the motion of the artificial floating islands under waves. The results show that the artificial floating islands significantly dampen shorter waves with a wave period of T ≤ 2.25 s. The transmission of the incident waves is reduced by 50% for the smallest wave periods (T = 1.5 s). The incident waves are reflected between 20 and 50% for the same wave period. The incident wave energy is dissipated by up to 85% for the smallest wave height and period (H = 0.10 m, T = 1.5 s). The comparable performance regarding more traditional floating breakwaters is discussed as well as the width of the structure as the key parameter for the layout of artificial floating islands in rivers and still waters regarding the damping performance.

AB - The concept of floating vegetation-based islands for the bioremediation of aquatic ecosystems is well known. Less so, their hydrodynamic capabilities regarding the damping performance, positional stability and water-structure interactions. To this end, physical model tests with fully organic, reed-based gabions were carried out in a large-scale facility in this study. The initial, reflected, and transmitted waves were recorded and analyzed regarding transmission and reflection coefficients. A motion tracking system was utilized to allow for an investigation regarding the motion of the artificial floating islands under waves. The results show that the artificial floating islands significantly dampen shorter waves with a wave period of T ≤ 2.25 s. The transmission of the incident waves is reduced by 50% for the smallest wave periods (T = 1.5 s). The incident waves are reflected between 20 and 50% for the same wave period. The incident wave energy is dissipated by up to 85% for the smallest wave height and period (H = 0.10 m, T = 1.5 s). The comparable performance regarding more traditional floating breakwaters is discussed as well as the width of the structure as the key parameter for the layout of artificial floating islands in rivers and still waters regarding the damping performance.

KW - Artificial floating islands

KW - Large scale experiment

KW - Reflection coefficient

KW - Transmission coefficient

KW - Wave dampening

UR - http://www.scopus.com/inward/record.url?scp=85130787327&partnerID=8YFLogxK

U2 - 10.1016/j.ecoleng.2022.106691

DO - 10.1016/j.ecoleng.2022.106691

M3 - Article

AN - SCOPUS:85130787327

VL - 181

JO - Ecological engineering

JF - Ecological engineering

SN - 0925-8574

M1 - 106691

ER -