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You searched for +publisher:"Delft University of Technology" +contributor:("Schuurman, F."). Showing records 1 – 3 of 3 total matches.

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Delft University of Technology

1. Nientker, Gustav (author). Porcupines for river training: A study on the near-field effect of porcupines.

Degree: 2018, Delft University of Technology

Braiding rivers are characterised as highly dynamic, and experience annual morphological changes in plan- form. This dynamic nature of the river leads to navigational hindrance and risk of unstable bifurcation points where discharge distributions might switch. In pilot studies, porcupines have shown promising results in re- tarding the flow and cause sediment deposition near river banks to prevent bank erosion. However the aim now becomes to apply the porcupines on a much larger scale to increase the channel roughness and influ- ence discharge distributions of bifurcation points such that the flow is mainly diverted to the channel where the highest discharge is required. This way the main channel receives the largest discharge and therefore sedimentation in these channels is prevented. Currently it is not known how porcupines should be modelled in a numerical model. It is simply assumed that porcupines can be modelled similar to vegetation which is schematised as rigid cylinders with a certain density, drag coefficient and resulting representative roughness. No measurements are available to validate the assumed roughness of porcupines and if the hydro- and mor- phodynamic behaviour, represented by the model, is true. In this thesis laboratory experiments are conducted to assess the near-field hydro- and morphodynamic ef- fect of porcupines and generate more knowledge about their behaviour. Experiments with a concrete bottom give a detailed insight in the hydrodynamic behaviour of porcupines without the interference of bedforms and morphological developments. Experiments with a sediment bottom give more insight in the morpho- logical development and flow patterns over time which clearly influenced the initial hydraulic behaviour. Experiments are conducted in a 12 metre long and 0.8 metre wide flume with a recirculating pump. The wa- ter level, discharge, density of the porcupine field and configuration of the field are systematically varied to identify the dependences on the drag and sedimentation/erosion volumes in the near-field domain of the porcupines. Additionally, general observations are performed, describing the flow structures and sedimenta- tion patterns in and around the porcupine field. From fixed-bed experiments it is observed how the flow is retarded by the presence of porcupines. Flow is pushed around the field in both transverse and vertical direction. Behind the porcupines, longitudinal flow vectors are downward directed and the flow velocity near the bed is significantly reduced. It is observed that staggered porcupine grids help to retard the flow stronger and captures sediment behind the field in wider strokes. Non-staggered grids only work effectively in the line of porcupines. Between those lines barely any retardation is observed and therefore only narrow strokes of sedimentation are observed behind the lines of porcupines. The reduction in flow velocity behind the porcupines is similar to the velocity reductions ob- served in experiments with vegetation. The velocity… Advisors/Committee Members: Uijttewaal, Wim (mentor), Sloff, Kees (graduation committee), Mosselman, Erik (graduation committee), Schuurman, F (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Porcupines; Permeable structures; Braiding rivers; River training; Flexible solutions; Laboratory experiment; Bank erosion

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APA (6th Edition):

Nientker, G. (. (2018). Porcupines for river training: A study on the near-field effect of porcupines. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:28298b28-8b7a-4c64-a5be-9561bc1180a5

Chicago Manual of Style (16th Edition):

Nientker, Gustav (author). “Porcupines for river training: A study on the near-field effect of porcupines.” 2018. Masters Thesis, Delft University of Technology. Accessed October 30, 2020. http://resolver.tudelft.nl/uuid:28298b28-8b7a-4c64-a5be-9561bc1180a5.

MLA Handbook (7th Edition):

Nientker, Gustav (author). “Porcupines for river training: A study on the near-field effect of porcupines.” 2018. Web. 30 Oct 2020.

Vancouver:

Nientker G(. Porcupines for river training: A study on the near-field effect of porcupines. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2020 Oct 30]. Available from: http://resolver.tudelft.nl/uuid:28298b28-8b7a-4c64-a5be-9561bc1180a5.

Council of Science Editors:

Nientker G(. Porcupines for river training: A study on the near-field effect of porcupines. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:28298b28-8b7a-4c64-a5be-9561bc1180a5


Delft University of Technology

2. Kersten, René (author). Hydraulic and morphological impact of a closure dam in the Gulf of Khambhat.

Degree: 2018, Delft University of Technology

Tidal basins are highly dynamic environments with a complex behavior that is often disturbed by human activities. Considering that tidal dynamics have a direct impact on surrounding engineering infrastructures, adjacent coastlines, nature environment and socio-economic human activities, it is crucial to know the impact of human interventions on these dynamics. This research focuses on the closure of the Gulf of Khambhat in India, which aims at the creation of a fresh water reservoir in the gulf by partly closing the current estuary with the Kalpasar dam. The most recent design of the closure concerns a 30 km dam from the eastern bank near Aladar to the western bank near Bhavnagar. This closure will significantly reduce the total basin area. Consequently, major and morphodynamic changes are expected in the basin. The Kalpasar project has been on the Indian Government's agenda since 1986. Royal HaskoningDHV was involved in the pre-feasibility study, which was presented in the late 1990s. Since then, the existence of a detailed report study has not been confirmed and the status of the announced feasibility studies by the Indian government is unknown. The main objective of this research is to investigate the morphodynamic response at the seaward side of the dam after the closure. A process-based morphodynamic model has been developed to study this response. Deltares and NIOT have provided a two-dimensional (2DH) numerical model of the Gulf of Khambhat to study the tidal propagation in the basin. After calibration and validation of the hydrodynamic predictions, the model has been extended to a morphodynamic model in order to perform morphological calculations. Several adaptations have been made to improve the hydrodynamic simulations of the model; the main contributing factor was the new initial bathymetry. An extensive spin-up simulation has been performed to gather this. To deal with introduced model artefacts, the model results are compared to the reference case. Therefore, two almost identical simulations are performed: the only difference is that one run contains the Kalpasar dam while the other does not. This way, the relative effect of the dam is determined. Moreover, the morphological results have to be interpreted qualitatively, since the predictive skill of the model has not yet been determined. Model results show an overall increase of the tidal range in the basin after the closure, which will have effect up to 100 km from the dam. Close to the dam, the range will initially increase from 7.88 to 10.25 m, and up to 10.50 m after 96 years. Besides, the tidal signal switches from being ebb-dominant to flood-dominant. The velocities around the dam become negligible and the velocities at the main western channel significantly decrease. The eastern channel remains the main channel of the gulf, although its maximum flood- and ebb-velocities also decrease. As a consequence of the hydrodynamic changes, the basin will start importing sediment, directly becoming a sink. On the long term, the area up to 40 km southward of… Advisors/Committee Members: Wang, Zhengbing (mentor), Walstra, Dirk-Jan (mentor), Voorendt, Mark (mentor), Schuurman, F. (mentor), Van Heereveld, M. (mentor), Delft University of Technology (degree granting institution).

Subjects/Keywords: Morphodynamics; Delft3D; ebb-tidal delta; Gulf of Khambhat; Coastal morphology; Closure; dam; Tidal basin; Human interventions; Gujarat

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kersten, R. (. (2018). Hydraulic and morphological impact of a closure dam in the Gulf of Khambhat. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:3ab48021-40fb-47c0-b9d4-995d868ffc3a

Chicago Manual of Style (16th Edition):

Kersten, René (author). “Hydraulic and morphological impact of a closure dam in the Gulf of Khambhat.” 2018. Masters Thesis, Delft University of Technology. Accessed October 30, 2020. http://resolver.tudelft.nl/uuid:3ab48021-40fb-47c0-b9d4-995d868ffc3a.

MLA Handbook (7th Edition):

Kersten, René (author). “Hydraulic and morphological impact of a closure dam in the Gulf of Khambhat.” 2018. Web. 30 Oct 2020.

Vancouver:

Kersten R(. Hydraulic and morphological impact of a closure dam in the Gulf of Khambhat. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2020 Oct 30]. Available from: http://resolver.tudelft.nl/uuid:3ab48021-40fb-47c0-b9d4-995d868ffc3a.

Council of Science Editors:

Kersten R(. Hydraulic and morphological impact of a closure dam in the Gulf of Khambhat. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:3ab48021-40fb-47c0-b9d4-995d868ffc3a


Delft University of Technology

3. Bax, Rutger (author). Mixed Sediment Dynamics at a Tide-Dominated Confluence: A case study on the Yangon Estuary, Myanmar.

Degree: 2019, Delft University of Technology

This thesis research has been conducted to analyse the sediment dynamics in the Yangon Estuary, in order to define the cause for the sedimentation in Monkey Point Channel. For years, Yangon Port has been suffering from limited accessibility due to the sedimentation in the channel and currently daily dredging is required in order to let ships enter the port. The main characteristics of Yangon Estuary are; tidal range of 6 m, high suspended sediment concentrations (up to 6 g/l), a monsoon climate and the presence of a confluence within the tidal range. Research to the cause of sedimentation is done by making a conceptual model of the estuary based on a study area analysis and a literature study to estuarine, riverine and sediment processes. In addition, numerical models are used to improve the conceptual model in a quantitative manner. The conceptual model resulted in the following findings. The fluctuations in SSC are dominantly determined by the tide. During the monsoon season suspended sediment is brought in the system mainly by the Yangon River discharge, causing for averaged SSC values of 1 g/l during the season. In dry season, the SSC shows a fortnightly rhythm caused by the spring/neap cycle. Strong spring tidal currents cause for high bed shear stresses on the shoals, exceeding 1 N/m2, which erodes the stationary fluid mud layers. Due to the dispersion of the mud, the SSC rises rapidly up to 5 g/l. During neap tides the bed shear stress is much less, enabling the fine sediments to settle on the shoals and restore the fluid mud layers. Hence, the SSC values reduce to less than 0.5 g/l. During the monsoon, the spring flood current is reduced due to the seaward directed river discharge. Therefore, the spring flood currents are insufficient to erode the stationary fluid mud layers, hence the SSC are less than during spring tide in the dry season. In contrast to the fluctuations in erosion and deposition of mud on the shoals, almost continuously deposition and consolidation of mud is possible in Monkey Point Channel. This is possible because the channel is located in the stagnation-zone where both during flood (bifurcation) and ebb (confluence) the flow velocities and bed shear stresses sufficiently low to let mud settle. After deposition the mud is not resuspended, and consolidation causes the mud layer to become thicker and become problematic for the ship traffic. To conclude; the combination of high SSC with the possibility of consolidation of deposited mud in the stagnation-zone results in too hard layers to sail through. This potential cause corresponds with the dredged material from the channel bed and the sedimentation rate in the channel. It is recommended to relocate the navigation channel outside the stagnation-zone. The combination of land reclamation at the western estuary bank downstream of the confluence and a dredged channel shows the most promising results. However, more research is required to determine the long-term sedimentation rates in the new channel.

Hydraulic…

Advisors/Committee Members: Aarninkhof, Stefan (mentor), Blom, Astrid (graduation committee), van Maren, Bas (graduation committee), Janssen, M.P.J. (graduation committee), Schuurman, F. (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Estuaries; Confluence; Bifurcation; fluid mud

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Bax, R. (. (2019). Mixed Sediment Dynamics at a Tide-Dominated Confluence: A case study on the Yangon Estuary, Myanmar. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:92f6a8a5-b779-4777-88b5-2c4e42de9d2a

Chicago Manual of Style (16th Edition):

Bax, Rutger (author). “Mixed Sediment Dynamics at a Tide-Dominated Confluence: A case study on the Yangon Estuary, Myanmar.” 2019. Masters Thesis, Delft University of Technology. Accessed October 30, 2020. http://resolver.tudelft.nl/uuid:92f6a8a5-b779-4777-88b5-2c4e42de9d2a.

MLA Handbook (7th Edition):

Bax, Rutger (author). “Mixed Sediment Dynamics at a Tide-Dominated Confluence: A case study on the Yangon Estuary, Myanmar.” 2019. Web. 30 Oct 2020.

Vancouver:

Bax R(. Mixed Sediment Dynamics at a Tide-Dominated Confluence: A case study on the Yangon Estuary, Myanmar. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2020 Oct 30]. Available from: http://resolver.tudelft.nl/uuid:92f6a8a5-b779-4777-88b5-2c4e42de9d2a.

Council of Science Editors:

Bax R(. Mixed Sediment Dynamics at a Tide-Dominated Confluence: A case study on the Yangon Estuary, Myanmar. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:92f6a8a5-b779-4777-88b5-2c4e42de9d2a

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