3027 resultaten

  • Europe’s focused approach to environmental hydraulic research : bridging the gap between research and societies

    Auteur: Hamer, F.C. (2018)

    The HYDRALAB+ project brings together European researchers, industry and stakeholders to improve experimental hydraulic research aimed at adapting to climate change. This project is funded by the EU Horizon 2020 research and innovation programme. Greater access to top research facilities, knowledge sharing and multi-disciplinary teamwork is helping societies adapt to climate change. Project Coordinator Frans Hamer discusses the importance of the research and building strong collaborations.

  • Global probabilistic projections of extreme sea levels show intensification of coastal flood hazard

    Auteurs: Vousdoukas, M.I.; Mentaschi, L.; Voukouvalas, E.; Verlaan, M.; Jevrejeva, S.; Jackson, L.P.; Feyen, L. (2018)
    Gepubliceerd in: Nature Communications (2018) nummer 9, pagina 1-12

    Global warming is expected to drive increasing extreme sea levels (ESLs) and flood risk along the world’s coastlines. In this work we present probabilistic projections of ESLs for the present century taking into consideration changes in mean sea level, tides, wind-waves, and storm surges. Between the year 2000 and 2100 we project a very likely increase of the global average 100-year ESL of 34–76 cm under a moderate-emission-mitigation-policy scenario and of 58–172 cm under a business as usual scenario. Rising ESLs are mostly driven by thermal expansion, followed by contributions from ice mass-loss from glaciers, and icesheets in Greenland and Antarctica. Under these scenarios ESL rise would render a large part of the tropics exposed annually to the present-day 100-year event from 2050. By the end of this century this applies to most coastlines around the world, implying unprecedented flood risk levels unless timely adaptation measures are taken.

  • Modelling and scenario assessment of water quality in Lagune Lake, The Philippines

    Auteurs: Schueder, R.; Vatvani, D.K.; Boderie, P.M.A. (2018)

    This is the final report of the project ‘Water quality modelling of Laguna Lake’. It represents a synthesis of information from previous reports in this project, as well as new information about model improvement and items related to training and capacity building. The project was divided into two phases. Model improvements recommended at the end of phase 1 were also investigated during phase 2 of the project, in parallel with the scenario assessment. Improvements to the grid, bathymetry, bed roughness, and water quality processes were made and the effects of these improvements were presented and discussed. Steps for further calibration and model improvement were provided along with some advice for applying what was taught during the hands-on training.

  • Verkenning zoet-zoutgradienten in het Volkerak-Zoommeer gericht op ecologische kwaliteit : modelstudie

    Auteurs: Tiessen, M.C.H.; Nolte, A.J. (2018)

    De voorkeursvariant in de Rijksstructuurvisie Grevelingen-Volkerak-Zoommeer is een zout Volkerak-Zoommeer met 30 cm getij. In dit rapport wordt onderzocht met welke waterbeheermaatregelen optimalisatie van de zoet-zoutgradiënt mogelijk is gericht op het maximaliseren van de ecologische kwaliteit van de onderwaternatuur en intergetijdengebieden. De beschouwde maatregelen zijn debieten door de Volkeraksluizen, de Philipsdam, de Oesterdam en de Bathse spuisluis.

  • Zoutindringing in de Rijn-Maasmonding : knelpunten en effectiviteit stuurknoppen

    Auteurs: Huismans, Y.; Wijk, R.M. van der; Fujisaki, A.; Sloff, C.J. (2018)

    Door klimaatverandering en diverse ingrepen zal de zoutindringing in de Rijn-Maasmonding toenemen. Daarmee rijst de vraag of we in de toekomst nog aan onze zoetwatervraag kunnen blijven voldoen, waar er knelpunten ontstaan en welke stuurmogelijkheden er zijn om de zoutindringing tegen te gaan. Volgens het Warm2050 scenario zal verzilting dus sterk toenemen en naar verwachting een veel groter effect hebben dan de vermindering van de verzilting die met inzet van de bestudeerde stuurknoppen bereikt kan worden. Uitzondering hierbij is naar verwachting de inzet van de stuw bij Hagestein voor het tegengaan van de verzilting op de Lek.

  • Efficient uncertainty quantification for impact analysis of human interventions in rivers

    Auteurs: Berends, K.D.; Warmink, J.J.; Hulscher, S.J.M.H. (2018)
    Gepubliceerd in: Environmental modelling and software, volume 107 (2018), pagina 50-58

    Human interventions to optimise river functions are often contentious, disruptive, and expensive. To analyse the expected impact of an intervention before implementation, decision makers rely on computations with complex physics-based hydraulic models. The outcome of these models is known to be sensitive to uncertain input parameters, but long model runtimes render full probabilistic assessment infeasible with standard computer resources. In this paper we propose an alternative, efficient method for uncertainty quantification for impact analysis that significantly reduces the required number of model runs by using a subsample of a full Monte Carlo ensemble to establish a probabilistic relationship between pre- and post-intervention model outcome. The efficiency of the method depends on the number of interventions, the initial Monte Carlo ensemble size and the desired level of accuracy. For the cases presented here, the computational cost was decreased by 65%.

  • Impact of industrial waste water treatment plants on Dutch surface waters and drinking water sources

    Auteurs: Wezel, A.P. van; Hurk, F. van den; Sjerps, R.M.A.; Meijers, E.M.; Roex, E.W.M.; Laak, T.L. ter (2018)
    Gepubliceerd in: Science of the total environment, volume 640-641 (2018), pagina 1489-1499

    Direct industrial discharges of Chemicals of Emerging Concern (CEC) to surface water via industrial wastewater treatment plants (IWTP) gained relatively little attention compared to discharges via municipal sewage water treatment plants. IWTP effluents may however seriously affect surface water quality. Here we modelled direct industrial emissions of all 182 Dutch IWTP from 19 different industrial classes, and derived their impact on Dutch surface water quality and drinking water production. We selected industrial chemicals relevant for drinking water production, however a lack of systematic information on concentrations in IWTP effluents for many chemicals of interest was found. Therefore, we used data from the European Pollutant Release and Transfer Register and data on Dutch IWTP as surrogate. We coupled these to a detailed hydrological model under two extreme river discharge conditions, and compared the predicted and measured concentrations. We derived relative impact factors for the IWTP based on their contribution to concentrations at surface water locations with a drinking water function. In total, a third of the abstracted water for drinking water production is influenced by the IWTP. Fromall Dutch 182 IWTP, only a limited number has - based on themodel approach using surrogate parameters - a high impact on surface waters with a drinking water function. Mitigation measures can be taken costefficiently, by placing extra treatment technologies at the IWTP with high impact. Finally, we propose recommendations for licensing and controlling industrial aqueous emissions and give suggestions to fill the currently existing knowledge gaps and diminish uncertainties in the approach.

  • Do microplastics affect marine system productivity?

    Auteurs: Troost, T.A.; Desclaux, T.; Leslie, H.A.; Meulen, M.D. van der; Vethaak, A.D. (2018)
    Gepubliceerd in: Marine pollution bulletin : the international journal for marine environmentalists, scientists, engineers, administrators, politicians and lawyers, volume 135 (2018), pagina 17-29

    Marine and coastal ecosystems are among the largest contributors to the Earth's productivity. Experimental studies have shown negative impacts of microplastics on individual algae or zooplankton organisms. Consequently, primary and secondary productivity may be negatively affected as well. In this study we attempted to estimate the impacts on productivity at ecosystem level based on reported laboratory findings with a modelling approach, using our biogeochemical model for the North Sea (Delft3D-GEM). Although the model predicted that microplastics do not affect the total primary or secondary production of the North Sea as a whole, the spatial patterns of secondary production were altered, showing local changes of ±10%. However, relevant field data on microplastics are scarce, and strong assumptions were required to include the plastic concentrations and their impacts under field conditions into the model. These assumptions reveal the main knowledge gaps that have to be resolved to improve the first estimate above.

  • Marine microplastic debris : an emerging issue for food security, food safety and human health

    Auteurs: Barboza, L.G.A.; Vethaak, A.D.; Lavorante, B.R.B.O.; Lundebye, A.; Guilhermino, L. (2018)
    Gepubliceerd in: Marine pollution bulletin : the international journal for marine environmentalists, scientists, engineers, administrators, politicians and lawyers, volume 133 (2018), pagina 336-348

    Recent studies have demonstrated the negative impacts of microplastics on wildlife. Therefore, the presence of microplastics in marine species for human consumption and the high intake of seafood (fish and shellfish) in some countries cause concern about the potential effects of microplastics on human health. In this brief review, the evidence of seafood contamination by microplastics is reviewed, and the potential consequences of the presence of microplastics in the marine environment for human food security, food safety and health are discussed. Furthermore, challenges and gaps in knowledge are identified. The knowledge on the adverse effects on human health due to the consumption of marine organisms containing microplastics is very limited, difficult to assess and still controversial. Thus, assessment of the risk posed to humans is challenging. Research is urgently needed, especially regarding the potential exposure and associated health risk to micro- and nano-sized plastics.

  • Etude expérimentale de la formation de ressauts ondulés sur un récif frangeant

    Auteurs: Tissier, M.F.S.; Dekkers, J.M.; Dongeren, A.R. van; Pearson, S.G.; Reniers, J.H.M. (2018)

    L’hydrodynamique sur les récifs frangeants est généralement dominée par des ondes longues, dites infragravitaires. Une bonne compréhension de leur transformation sur les récifs est donc primordiale pour mieux comprendre et prédire les risques de submersion dans de tels environnements. Dans cette étude, nous analysons la transformation de vagues longues (houle et ondes infragravitaires) en ressauts ondulés sur un récif frangeant à partir d’une série d’expériences en canal (échelle 1/20). L’objectif de ces expériences est de caractériser l’effet de ces transformations sur l’hydrodynamique du platier récifal et ses conséquences sur les mouvements de la ligne d’eau sur la plage qui y est accolée. Nous présentons ici les résultats obtenus pour 6 cas de vagues régulières, choisis de manière à ce que leurs caractéristiques soient représentatives de houles longues et d’ondes infragravitaires. Nous montrons que des ressauts ondulés se développent dans tous les cas considérés, et que ces transformations modifient significativement le spectre d’énergie. Dans le cas des ondes de type infragravitaire, cela peut résulter en une diminution importante (jusqu’à 80%) de l’énergie initialement contenue dans les basses fréquences lorsque les vagues atteignent le bas de plage.

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