Publications

2875 results

  • Varende drones op de Noordzee : zijn autonoom varende boten de toekomst

    Author: Verheul, M.R.A. (2017)

    Het doel van de voorliggende studie is, om autonoom varende meetplatformen zo snel mogelijk te implementeren. Om dit voor elkaar te krijgen moet aan de ene kant het autonoom varen tezamen met het automatisch meten technologisch ver genoeg ontwikkeld zijn, en aan de andere kant moet het autonoom varen ook juridisch toegestaan worden. Aangezien er wereldwijd geen regelgeving, overeengekomen testscenario’s of validatie van de autonomiegraad van een varend systeem bestaat, hebben we tijdens dit project hieraan invulling moeten geven. Op aandringen van dit project heeft het ministerie van I&M (DGB Maritieme Zaken) opdracht verleend aan bureau Bloot consulting om een nautisch veiligheidsplan op te stellen.

  • The hyperturbid state of the water column in estuaries and rivers : the importance of hindered settling

    Authors: Dijkstra, Y.M.; Schuttelaars, H.M.; Winterwerp, J.C. (2018)
    Published in: Ocean Dynamics (2018), page 1-13

    Over the last few decades, some estuaries have undergone a transition to a hyperturbid state, characterised by suspended sediment concentrations of several grammes per litre averaged over the water column. To improve our understanding of this transition and of naturally hyperturbid estuaries, we systematically identify the processes allowing for high suspended sediment concentrations using a water column (1DV) model. Under a range of realistic forcing conditions, the state of the water column can be characterised by one of two equilibrium states. The first is an erosion-limited state, in which there still is sediment available for erosion at the bed. We find that this state only occurs with relatively low concentrations. The second is a supply-limited state, in which all erodable sediment is in suspension. The concentration in this state depends entirely on the amount of sediment in the system and can potentially be very high. We identify the conditions under which the state of the water column can jump from a low to a high concentration and identify hysteresis in the transition between the two states. The mechanism responsible for this hysteresis is hindered settling. It thus follows that hyperturbidity is only possible in a supply-limited state. From this observation we derive a necessary condition for an estuarine system to make the transition from low turbidity to hyperturbidity in a 1DV context. This is an important step towards understanding why some estuaries are hyperturbid and assessing the risk that particular estuaries may become hyperturbid in the future.

  • Definitieve memo spoedadvies stuw Grave

    Authors: Guchte, C. van de; Hegnauer, M.; Jong, J.S. de; Verkade, J.S.; Yossef, M.F.M. (2017)

    Door een aanvaring met een binnenvaartschip is de stuw bij Grave ernstig beschadigd. Omdat reparatie enkele maanden zal duren en het belangrijk is dat de waterstand in het stuwpand snel hersteld wordt, is een noodoplossing nodig. Die noodoplossing is waarschijnlijk minder "beweegbaar" dan de stuw normaal gesproken is. Er vindt dan dus ook obstructie van afvoer plaats bij afvoerniveaus waar dat normaal gesproken niet het geval is. Voorliggende notitie beschrijft de exercitie waarin geschat wordt wat de waterstandsverhogende effecten van noodoplossingen zijn.

  • Statistical modelling of Fat, Oil and Grease (FOG) deposits in wastewater pump sumps

    Authors: Nieuwenhuis, E.; Post, J.; Duinmeijer, S.P.A.; Langeveld, J.; Clemens, F.H.L.R. (2018)
    Published in: Water research : a journal of the International Water Association (2018), page 1-46

    The accumulation of FOG (Fat, Oil and Grease) deposits in sewer pumping stations results in an increase in maintenance costs, malfunctioning of pumps and, a potential increase of wastewater spills in receiving open water bodies. It is thought that a variety of parameters (e.g. geometry of the pump sump, pump operation, socioeconomic parameters of the catchment) influences the built-up of FOG. Based on a database containing data of 126 pumping stations located in five Dutch municipalities a statistical model was built. It is shown that 3 parameters are most significant in explaining the occurrence of FOG deposits: mean income of the population in a catchment, the amount of energy (kinetic and potential) per m3 per day and the density of restaurants, bars and hotels in a catchment. Further it is shown that there are significant differences between municipalities that can be traced back to the local ‘design paradigm’. For example, in Amsterdam, the design philosophy of discharging in the pump sump under the water surface (and hence maintaining a low level of turbulence in the pump sump) results in an increase of the probability of the formation of FOG.

  • Exploratory study for the development of ship landing facilities at Niutao and Nanumanga (Tuvalu) : inception report

    Authors: Giardino, A.; Nederhoff, K.; Gawehn, M.; Jong, M.P.C. de; Hout, A.J. van der; Capel, A.; Vroeg, J.H. de; Huisman, B.J.A. (2017)

    The maritime sector is crucial for connecting the outer islands of Tuvalu with the main port in Funafuti. The small size of the outer islands and the infertile soil make inhabitants heavily reliant on shipping operations. The client (The World Bank) has approached Deltares to carry out an exploratory study to be used as a basis for the development of new maritime infrastructures at the two islands. The study includes the quantification of present and future coastal hazards at the two islands and, based on a multi-criteria analysis, the identification of potential locations for the development of two new ports. At those locations, preliminary port layouts have been outlined, including different configurations for different port sizes, accompanied by initial cost-estimates of the proposed infrastructures. The vulnerability of these infrastructures to present and future coastal hazards has been evaluated. Finally, the possible impact of the new maritime infrastructures on the surrounding coastline (i.e. in terms of morphadynamie changes and coastal flooding) has been analysed. This inception report includes a description of the objectives of the study, the data and numerical models which will be used and the methodology to be applied, with detailed time planning and list of expected deliverables.

  • Adaptation planning principles for integrated coastal zone development of Quintana Roo, Mexico

    Authors: Brière, C.D.E.; Perdon, R.; Beccan Davila, N. (2017)

    The assignment consists of outlining the key elements needed to develop an integrated strategy for coastal resilience with a regional focus on the development of sustainable touristic zones and defining concrete project(s) as a bottom-up implementation of this strategy.

  • Beperking zoutindringing Nieuwe Waterweg : CCIP 2017 : studie naar de effecten van openingen in de Splitsingsdam, pompschepen en bellenboten

    Authors: Groenenboom, J.; Veenstra, J. (2017)

    In de voorliggende studie is gestart met het uitvoeren van een beknopte evaluatie van het OSR-model op basis van de eerder in het kader van het CIP-project verzamelde meetgegevens. Uit de data-modelvergelijking is gebleken hoe het model verschillende doelvariabelen reproduceert. De belangrijkste bevinding is dat het model, gemiddeld genomen, de stratificatie in de Nieuwe Waterweg onderschat. De verwachting is dat hierdoor het door het model berekende effect van pompschepen en bellenboten onderschat wordt.

  • Eutrophication from land to sea : progress 2017

    Authors: Blauw, A.N.; Zijl, F.; Kramer, L. (2017)

    Assessment levels in use for eutrophication are presently incoherent between different countries, between MSFD and WFD and between different eutrophication indicators. This report describes preliminary results of a study to propose a set of coherent assessment levels for eutrophication in the North Sea.

  • Strategy for implementation of ferryboxes for eutrophication monitoring in the North Sea

    Authors: Blauw, A.N.; Rijkeboer, M.; Aardema, H. (2017)

    This report evaluates what would be the added value of inclusion of Ferrybox monitoring in the monitoring strategy and how this added value can be maximized. First the information needs for eutrophication monitoring are reviewed and the extent to which these are accommodated by the present monitoring strategy combining MWTL data and satellite data. Then the current status of Ferrybox monitoring in the North Sea is reviewed.

  • Support for the implementation of the 2nd cycle of EU Flood Risk Directive in Denmark : climate change scenarios discussion paper

    Authors: Brière, C.D.E.; Bouwer, L.M. (2017)

    The Danish Coastal Authority (DCA) is preparing for the second cycle of the implementation of the EU Floods Directive. Within this framework, the DCA aims to also determine the effect of climate change on the flood risk. This memo discusses climate change scenario's, that include sea-level rise and changes in storminess. An overview is provided of best practices in neighbouring countries on including climate change in coastal risk management and urban development plans. Finally, advice is provided on the choice of middle, high, and upper-end scenarios, as well as on levels of acceptable risk and flood protection norms on the basis of economic criteria.

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