Zoek binnen publicaties
Proceedings of the 38th IAHR World Congress : water connecting the world (Panama City, Panama, September 1-6, 2019)
Large-scale experiments of tsunamis generated by iceberg calving
Iceberg calving at outlet glaciers contributes to global sea-level rise in the context of climate change. This study investigates tsunamis generated by iceberg calving, so-called iceberg-tsunamis. Such tsunamis reached amplitudes of 50 m in the recent past and endanger human beings and coastal infrastructure. 66 unique large-scale experiments have been conducted in a 50 m × 50 m large basin. These experiments involved the five iceberg calving mechanisms: A: capsizing, B: gravity-dominated fall, C: buoyancy-dominated fall, D: gravity-dominated overturning and E: buoyancy-dominated overturning. Gravity-dominated icebergs essentially fall into the water body whereas buoyancy-dominated icebergs essentially rise to the water surface. The iceberg-tsunamis from gravity-dominated mechanisms (B and D) are roughly an order of magnitude larger than from mechanisms A, C and E. The maximum wave heights and their decay with distance from the calving locations are correlated with six dimensionless parameters, where the Froude number, the relative iceberg width and the relative released energy were identified as the most important ones. Empirical equations for preliminary iceberg-tsunami hazard assessment for the five iceberg-calving mechanisms individually and all mechanisms combined were derived predicting the wave heights reasonably well. Ongoing and future work aims to analyse the wave parameters in further detail, compare iceberg- with landslide-tsunamis and investigate iceberg-tsunamis numerically.
Mine Closure 2019 : proceedings of the 13th International conference on mine closure (
Numerical modeling of flow and bed evolution of bichromatic wave groups on an intermediate beach using nonhydrostatic XBeach
This paper analyzes the modeling of the hydro- and morphodynamics of bichromatic wave groups on an intermediate beach with an initial 1∶15 slope. The nonhydrostatic version of XBeach was used to simulate two incident wave conditions of the experiments carried out within the HYDRALAB-IV Coupled High Frequency Measurement of Swash Sediment Transport and Morphodynamic (CoSSedM) project. The chosen forcing conditions have different strengths of swash–swash interaction. A procedure was developed to generate boundary conditions for the model that are able to fully account for both the bound and free long waves measured during the experiments. Using the normalized root-mean-squared error as a measure, this paper finds a higher accuracy of the nonhydrostatic version of XBeach in simulating swash–swash interaction from the hydrodynamics point of view, and worse performances in capturing the details of intragroup sediment transport. Nevertheless, the model is able to distinguish the relative difference in offshore swash sediment transport among different types of swash–swash interaction, and it is overall more successful in simulating beach morphodynamics when the swash sediment transport is of the same order of magnitude as the surf zone one.
Process-based erosion modelling for shoreline rehabilitation design of a coal mine pit lake
This innovative study used the process-based hydro-morphodynamic models Delft3D to predict final pit lake shoreline erosion at the Eastern Batter (EB) domain region of the pit void. Shoreline erosion modelling was undertaken for three erosion treatments over a total of 10 scenarios: Effect of sediment type ; Effect of shore slope angle ; The effect of prevailing winds compared to episodic storm winds. Pit lake shoreline erosion modelling was found to be a useful design tool for to study pit lake shoreline developments. Further model findings were that relatively gentle (12°) slopes did not show substantially decreased erosion rates compared to design (17°) slopes. However, relatively steep (22°) slopes showed substantially greater erosion. Erosion rates were strongly influenced by sediment properties, which constituted the biggest uncertainty in the modelling. Lowest erosion rates were for cohesive grey clays, highest erosion rates for sands and erosion rates of mixed sediments were in-between. Eroded sands were also deposited nearby at slightly deeper water, thereby reducing shoreline slopes over longer timescales. However, eroded clays were dispersed throughout the lake, preventing an erosion/deposition equilibrium being reached. Short-term storm events simply mimicked erosion patterns of longer duration prevailing wind events. Consequently, slope and sediment characteristic choices to mitigate prevailing wind effects may be similar to those used for mitigating event-driven erosion.
Numerical prediction of background buildup of salinity due to desalination brine discharges into the Northern Arabian Gulf
Brine discharges from desalination plants into low-flushing water bodies are challenging from the point of view of dilution, because of the possibility of background buildup effects that decrease the overall achievable dilution. To illustrate the background buildup effect, this paper uses the Arabian (Persian) Gulf, a shallow, reverse tidal estuary with only one outlet available for exchange flow. While desalination does not significantly affect the long-term average Gulf-wide salinity, due to the mitigating effect of the Indian Ocean surface water inflow, its resulting elevated salinities, as well as elevated concentrations of possible contaminants (such as heavy metals and organophosphates), can affect marine environments on a local and regional scale. To analyze the potential effect of background salinity buildup on dilutions achievable from discharge locations in the northern Gulf, a 3-dimensional hydrodynamic model (Delft3D) was used to simulate brine discharges from a single hypothetical source location along the Kuwaiti shoreline, about 900 km from the Strait of Hormuz. Using nested grids with a horizontal resolution, comparable to a local tidal excursion (250 m), far field dilutions of about 28 were computed for this discharge location. With this far field dilution, to achieve a total dilution of 20, the near field dilution (achievable using a submerged diuser) would need to be increased to approximately 70. Conversely, the background build-up means that a near field dilution of 20 yields a total dilution of only about 12.
Unlocking European marine biodiversity under EMODnet Biology data using the FAIR principles
The European Marine Observation and Data Network (EMODnet), supported by the EU’s integrated maritime policy aims therefore to provide a single access point to European marine biodiversity data and products by assembling individual datasets from various sources and process them into interoperable data products. EMODnet Biology is a long term marine data initiative and is structuring its activities around four main pillars: making marine biological data findable, accessible, interoperable and reusable.
ODYSSEA: a novel, interoperable platform for products and services in the Mediterranean Sea : system architecture and design
ODYSSEA is an EU H2020-funded project aiming to develop, operate and demonstrate an interoperable and cost-effective platform that fully integrates networks of observing and forecasting systems across the Mediterranean basin, addressing both the open sea and the coastal zone. The project involves 28 partners: universities, research centres, international organizations, NGOs and private companies. When operational by 2021, the final platform will provide easy discovery and access to marine data and derived products to a variety of users to improve knowledge and decision-making capabilities in the Mediterranean.
The SeaDataCloud virtual research environment : researching the sea from the cloud
The SeaDataNet project offers a robust and state-of-the-art Pan-European infrastructure to harmonise metadata and data from marine data centres in Europe, and offers the technology to make these data accessible. To make life easier for users and data holders, as part of the SeaDataCloud project, SeaDataNet is moving its unrestricted data to the cloud. Virtual eesearch environments are web-based workspaces providing seamless access to all services researchers need to do their work and collaborate with their community. For SeaDataNet, this means that all the tasks that a researcher would usually do with the data, the entire workflow of data-driven science (finding data, accessing data, processing iteratively data with various tools, visualizing results, sharing results with colleagues, and publishing data) can be realized without having to download data to the desktop and using the local compute power, which might not be available to all users at the same rate.
IMDIS 2018 - International Conference on Marine Data and Information Systems (5-7 November 2018, Barcelona, Spain)