Searched for: subject:"morphodynamic%5C+models"
(1 - 20 of 95)

Pages

document
Rozendaal, Marco (author)
Tidal inlet systems are often highly valuable and sometimes even unique ecosystems. However, field measurements show that tidal inlet systems are sensitive to changing exogenous conditions, such as rising sea levels. This thesis aims to investigate to what extent the adjacent sea influences the stability and equilibrium state of the tidal inlet....
master thesis 2019
document
Gradussen, Bas (author)
River discharge is an essential parameter in morphodynamic modelling. It proves to be highly variable in both time and space. In this thesis the impact of the schematisation of time-dependent discharge series on morphodynamic change is studied. The impact is governed by several factors such as the long-term discharge statistics, and both short-...
master thesis 2019
document
Luijendijk, A.P. (author), de Schipper, M.A. (author), Ranasinghe, Roshanka (author)
Thirty one percent (31%) of the world's coastline consists of sandy beaches and dunes that form a natural defense protecting the hinterland from flooding. A common measure to mitigate erosion along sandy beaches is the implementation of sand nourishments. The design and acceptance of such a mitigating measure require information on the expected...
journal article 2019
document
Tao, Jianfeng (author), Wang, Zhengbing (author), Zhou, Zeng (author), Xu, Fan (author), Zhang, Changkuan (author), Stive, M.J.F. (author)
The radial sand ridges (denoted as “RSRs” hereafter) in the Southern Yellow Sea, China, are morphologically striking because of the remarkable size and radial planar orientation, standing out as a unique coastal geomorphology among the worldwide sand ridge systems. The formation of this giant fan‐shaped geomorphic feature requires delicate...
journal article 2019
document
Singh, Umesh (author), Crosato, A. (author), Giri, Sanjay (author), Hicks, Murray (author)
The effects of sediment heterogeneity and sediment mobility on the morphology of braided rivers are still poorly studied, especially when the partial sediment mobility occurs. Nevertheless, increasing the bed sediment heterogeneity by coarse sediment supply is becoming a common practice in river restoration projects and habitat improvement...
journal article 2017
document
Li, W. (author), Su, Zhenghua (author), van Maren, D.S. (author), Wang, Z.B. (author), de Vriend, H.J. (author)
The downstream peak discharge increase during hyperconcentrated floods in the Yellow River has been attributed to bed erosion, roughness reduction and floodplain effects. While great improvements have been made on the nderstandings of the roles of bed erosion and roughness reduction, the effects of floodplain remain poorly understood. Here, as a...
journal article 2017
document
van Denderen, R. Pepijn (author), Schielen, Ralph M.J. (author), Blom, A. (author), Hulscher, Suzanne J.M.H. (author), Kleinhans, Maarten G. (author)
Side channel construction is a common intervention applied to increase a river's conveyance capacity and to increase its ecological value. Past modelling efforts suggest two mechanisms affecting the morphodynamic change of a side channel: (1) a difference in channel slope between the side channel and the main channel and (2) bend flow just...
journal article 2017
document
Walstra, D.J.R. (author)
Nearshore sandbars have a lifetime of many years, during which they exhibit cyclic, offshore directed behaviour with strong alongshore coherence. A bar is generated near the shoreline and grows in height and width while migrating offshore, before finally decaying at the seaward limit of the surf zone. It may take 10 to 15 years for a bar to...
doctoral thesis 2016
document
Walstra, D.J.R. (author), Wesselman, Daan (author), van der Deyl, Eveline (author), Ruessink, BG (author)
Inter-annual bar dynamics may vary considerably across sites with very similar environmental settings. In particular, the variability of the bar cycle return period (Tr) may differ by a factor of 3 to 4. To date, data studies are only partially successful in explaining differences in Tr, establishing at best weak correlations to local...
journal article 2016
document
van der Wegen, Mick (author), Jaffe, Bruce (author), Foxgrover, Amy (author), Roelvink, J.A. (author)
Estuarine tidal mudflats form unique habitats and maintain valuable ecosystems. Historic measurements of a mudflat in San Fancsico Bay over the past 150 years suggest the development of a rather stable mudflat profile. This raises questions on its origin and governing processes as well as on the mudflats’ faith under scenarios of sea level...
journal article 2016
document
Scheel, F. (author), De Boer, W.P. (author), Brinkman, R. (author), Luijendijk, A.P. (author), Ranasinghe, R.W.M.R.J.B. (author)
A variety of uncertainty sources are inherent in process-based morphodynamic modelling applications. There is an increasing demand for the quantification of these uncertainties. This contribution introduces a probabilistic-morphodynamic (PM) modelling framework that enables this quantification. The PM modelling framework provides a systematic...
conference paper 2014
document
Reyns, J. (author), Dastgheib, A. (author), Ranasinghe, R.W.M.R.J.B. (author), Luijendijk, A.P. (author), Walstra, D.J.R. (author), Roelvink, J.A. (author)
A hampering factor in the application of morphodynamic models is the potential excessive time needed to complete a simulation. One way to upscale a model run is the use of a morphological factor, or MORFAC. In this paper, we investigate the upper limit to the value of the MORFAC as a function of model geometry and timestep for a schematized case...
conference paper 2014
document
Bosboom, J. (author), Reniers, A.J.H.M. (author)
Although it is generally acknowledged that the practical predictability at smaller scales may be limited, output of high-resolution morphodynamic area models is mostly presented at the resolution of the computational grid. The so- presented fields typically are realistic looking, but not necessarily of similar quality at all spatial scales....
conference paper 2014
document
Roos, P.C. (author), Schuttelaars, H.M. (author), Brouwer, R.L. (author)
Barrier coasts display a chain of islands, separated by tidal inlets that connect a back-barrier basin to a sea or ocean. Observations show that barrier island length generally decreases for increasing tidal range and increasing basin area. However, this has neither been reproduced in model studies nor explained from the underlying physics. This...
journal article 2013
document
Walstra, D.J.R. (author), Ruessink, G. (author), Hoekstra, R. (author), Tonnon, P.K. (author)
Input reduction is imperative to long-term (> years) morphodynamic simulations to avoid excessive computation times. Here, we discuss the input-reduction framework for wave-dominated coastal settings introduced by Walstra et al. (2013). The framework comprised 4 steps, viz. (1) the selection of the duration of the original (full) time series of...
conference paper 2013
document
De Vet, P.L.M. (author)
The effective thickness of the bedload layer over a river bed can be schematised as the total volume of bedload sediment that is in transport, divided by the surface. In practice, this layer is considered to have a constant thickness over time. Main question of this thesis is whether this assumption is valid. By analyzing the mass balance, it is...
bachelor thesis 2012
document
McCall, R. (author), Plant, N. (author), Van Thiel de Vries, J.S.M. (author)
This paper describes an application of the XBeach model to investigate the effect of longshore topographic variance on overwash. The model is used to simulate the morphological response of an eight-kilometer section of Santa Rosa Island, Florida, due to Hurricane Ivan (2004). The influence of longshore scales in the bed elevation is investigated...
conference paper 2011
document
Hanegan, K.C. (author)
In this study, a process-based, depth-averaged Delft3D hydrodynamic and morphologic model of the Wax Lake Delta in Atchafalaya Bay, Louisiana was developed to simulate a five year period of delta development. The purpose of this modeling effort was to test the ability of process-based modeling tools to successfully simulate typical delta...
master thesis 2011
document
Bos, M.F.M. (author)
The wetlands in the Mississippi delta (USA) are drastically subsiding and eroding. Many projects and researches are ongoing to determine how this “drowning effect” of the delta can be stopped. One of the solutions that could be feasible is implementing sediment diversions in the levees of the Lower Mississippi River in order to divert sediment...
master thesis 2011
document
Ranasinghe, R.W.M.R.J.B. (author), Swinkels, C. (author), Luijendijk, A.P. (author), Bosboom, J. (author), Roelvink, D. (author), Stive, M.J.F. (author), Walstra, D.J.R. (author)
The Morphological Acceleration Factor (MORFAC) approach for morphodynamic upscaling enables the simulation of long term coastal evolution. However the general validity of the MORFAC concept for coastal applications has not yet been comprehensively investigated. Furthermore, a robust and objective method for the a priori determination of the...
conference paper 2010
Searched for: subject:"morphodynamic%5C+models"
(1 - 20 of 95)

Pages