Hydrodynamic numerical model of waves and currents at Landeyjahöfn Harbour

• Main Author: Sunna Viðarsdóttir 1982-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2019
• Subjects: Umhverfisverkfræði; Landeyjahöfn; Dýptarmælingar; Reiknilíkön; Iceland
• Online Access: http://hdl.handle.net/1946/33380

Landeyjahöfn harbour is situated on the sandy southern coast of Iceland in a high-energy environment exposed to large waves and sediment transport. Since its opening in 2010, the harbour is often closed during winter time because a safe navigation depth cannot be maintained due to extensive sedimentation. Despite extensive bathymetric surveys and continuous wave, current and wind measurements, a better understanding of the sediment transport is required in order to conduct preventive dredging operations based on weather forecasts. The thesis goal was to develop a 2D hydrodynamic numerical model of waves and currents that could be used as a foundation for sediment transport modelling at Landeyjahöfn harbour. The open source suite of solvers TELEMAC-MASCARET and the freeware QGIS and BlueKenue for pre- and post-processing data were used. The model was calibrated for a storm with wave height over 3 m from the prevalent southwest wave direction. The simulated waves and spatial variations of currents compared well to measured values from a wave buoy and a radar. The current direction pattern at different times in the tidal cycle was almost identical to the currents detected by the radar and the average simulated significant wave height at the buoy was within 2% of the measured significant wave height. The calibrated model could reproduce spatial current fields during a large storm from the less prevalent southeast direction, but the simulated wave height was underestimated. The reason for the deviation was a lack of realistic offshore wave data to use as boundary conditions. Landeyjahöfn er staðsett á suðurströnd Íslands, sandströnd sem er útsett fyrir háum, orkumiklum öldum og með miklum sandflutningum. Frá opnun hafnarinnar árið 2010 hefur hún oft verið lokuð á veturna þar sem ekki hefur tekist að viðhalda öruggu siglingadýpi. Þrátt fyrir tíðar dýptarmælingar og öldu-, straum- og vindmælingar er þörf á betri skilningi á sandflutningum á svæðinu, t.d. svo hægt sé að skipuleggja fyrirbyggjandi dýpkunaraðgerðir út ...