R.M.J. Schielen

R.M.J. Schielen
Delft University of Technology | TU · Faculty of Civil Engineering and Geosciences (CEG)

PhD

About

87
Publications
14,530
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770
Citations
Citations since 2017
42 Research Items
450 Citations
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2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100

Publications

Publications (87)
Article
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The river bed level in low-land rivers like the Rhine branches in The Netherlands changes continuously on various spatial and temporal scales. Large-scale degradation occurs in many rivers due to river-wide engineering interventions, such as channelization, in the last decades and centuries. Local river interventions, such as the construction of si...
Article
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In recent years, Rivers2Morrow (www.rivers2morrow.nl) has initiated research on the morphology of the Dutch rivers Rhine and Meuse. Rivers2Morrow is a research programme financed by Rijkswaterstaat and the Ministry of Infrastructure and Water Management. In this programme, eight PhD-students are studying the response of these river systems to chang...
Article
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Nature-based solutions (NBSs) are measures reflecting the 'cooperation with nature' approach: mitigating fluvial flood risk while being cost-effective, resource-efficient, and providing numerous environmental, social, and economic benefits. Since 2015, the United Nations (UN) 2030 Agenda has provided UN member states with goals, targets, and indica...
Article
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Plain Language Summary Over two thirds of the world's large rivers are heavily engineered. Human intervention has important consequences for river channels, which erode and aggrade in response to measures like dam construction, channelization, and diversion. Such bed level change can directly (and severely) affect flood safety, navigation, and ecol...
Conference Paper
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Characterization of flow structures in the neighborhood of Pannerdense Kop bifurcation, Netherlands.
Conference Paper
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Flood retention basins are widely applied to improve flood safety. The effectiveness of such basins is more sensitive for (hydrologic) uncertainties compared to other flood protection measures. This paper shows how uncertainty can be included in the effectiveness of two major types of flood retention: with fixed sills and adjustable gates. Fixed si...
Technical Report
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Building with Nature (BwN) measures (also called Natural Flood Management (NFM), Nature Based Solutions (NBS)) are promising measures to reduce flood risk. They retain or slow down the water in the upper catchment, or increase discharge capacity in the lower catchment. BwN measures also have (potentially) many co-benefits, varying from increasing b...
Chapter
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Human interventions can result in changes in the equilibrium profile of rivers. It is difficult to identify the bed level changes that result from river interventions due to the various causes of bed level changes. Using wavelet filtering, we are able to isolate the effect of river interventions based on the length scale over which they occur. The...
Article
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In this reply, we would like to comment on the discussion paper of AlQasimi and Mahdi (Nat Hazards 97:1–4, 2020. https://doi.org/10.1007/s11069-020-03904-1). We discuss their view and possible improvements of the paper of Bomers et al. (Nat Hazards 97(1):309–334, 2019b. https://doi.org/10.1007/s11069-019-03643-y) in more detail and explain how larg...
Conference Paper
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Design discharges corresponding to large return periods are generally highly uncertain because of the relatively short data set of measured discharges. The uncertainty in these discharge predictions can be decreased by extending the data set of annual maximum discharges with historic flood events. However, efficient model approaches, in terms of co...
Conference Paper
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River interventions that are designed to re- duce the flood levels in the river or to in- crease the ecological value of the river, gener- ally cause aggradation in the navigation chan- nel. Such interventions withdraw discharge from the main channel and this reduces the sediment transport capacity. The reduced sed- iment transport capacity is comp...
Conference Paper
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Side channels are small secondary channels that are generally connected to the main channel at both ends. Side channels are (re)constructed to reduce the flood risk and to increase the ecological value of a river. Many such artificial side channels quickly aggrade (Riquier et al., 2015; Van Denderen et al., 2019) and therefore costly maintenance is...
Article
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The uncertainty in flood frequency relations can be decreased by adding reconstructed historic flood events to the data set of measured annual maximum discharges. This study shows that an artificial neural network trained with a 1‐D/2‐D coupled hydraulic model is capable of reconstructing river floods with multiple dike breaches and inundations of...
Article
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Overstromingsfrequentiecurves, die worden gebruikt om waterkeringen te ontwerpen, worden gebaseerd op relatief korte datasets van jaarlijks gemeten maximale afvoeren. Door de datareeks uit te breiden met historische overstromingen kan een overstromingsfrequentieanalyse uitgevoerd worden met minder onzekerheid.
Article
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Grid shape (curvilinear/structured versus triangular/unstructured) and grid size affect model output. In this study structured, unstructured and hybrid grids with a high and low resolution were compared. As a case study, we use the Waal River (with main channel and floodplains). We studied simulated water levels using the six grids, considering equ...
Conference Paper
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The severe 1374 Rhine river flood represents the largest flood in the past 1,000 years and exceeds the maximum discharge measured at Cologne, Germany, so far. The Dutch water policy is designed such that it should be able to withstand design discharges with a maximum return period of 100,000 years. The question arises whether the current flood prot...
Article
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Flood frequency curves are usually highly uncertain since they are based on short data sets of measured discharges or weather conditions. To decrease the confidence intervals, an efficient bootstrap method is developed in this study. The Rhine river delta is considered as a case study. We use a hydraulic model to normalize historic flood events for...
Article
Full-text available
Side channels are commonly constructed to reduce the flood risk or to increase the ecological value of a river. Such artificial side channels generally aggrade. We categorize the development of side channels based on the sediment that is deposited in these channels. Based on this categorization, we determine the main mechanisms that affect their de...
Article
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Currently, the effect of dike breaches on downstream discharge partitioning and flood risk is not addressed in flood safety assessments. In a bifurcating river system, a dike breach may cause overland flows which can change downstream flood risk and discharge partitioning. This study examines how dike breaches and overflow affect overland flow patt...
Article
Two dimensional hydraulic models are useful to reconstruct maximum discharges and uncertainties of historic flood events. Since many model runs are needed to include the effects of uncertain input parameters, a sophisticated 2D model is not applicable due to computational time. Therefore, this papers studies whether a lower-fidelity model can be us...
Article
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A two-dimensional model describing river morphodynamic processes under mixed-size sediment conditions is analysed with respect to its well posedness. Well posedness guarantees the existence of a unique solution continuously depending on the problem data. When a model becomes ill posed, infinitesimal perturbations to a solution grow infinitely fast....
Article
Full-text available
Flood frequency curves are usually highly uncertain since they are based on short data sets of measured discharges or weather conditions. To decrease the confidence intervals, an efficient bootstrap method is developed in this study. The Rhine river delta is considered as a case study. A hydraulic model is used to normalize historic flood events fo...
Article
Side channel construction is a common intervention to increase both flood safety and the ecological value of the river. Three side channels of Gameren in the river Waal (The Netherlands) show amounts of large aggradation. We use bed level measurements and grain size samples to characterize the development of the side channels. We relate the bed lev...
Conference Paper
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Can floodplain excavation help to mitigate bed erosion
Conference Paper
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The effect of dike breaches on downstream discharge partitioning
Conference Paper
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Long term development of low-land rivers: Rivers2Morrow, a research programme
Conference Paper
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The added value of Nature-based solutions
Conference Paper
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Measuring and modelling the development of side channels
Conference Paper
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Response of the upper Rhine-Meuse delta to climate change and sea level rise
Article
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We derive an idealized model of a gravel-sand river bifurcation and analyze its stability properties. The model requires nodal point relations that describe the ratio of the supply of gravel and sand to the two downstream branches. The model predicts changes in bed elevation and bed surface gravel content in the two bifurcates under conditions of a...
Article
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Hard structures, i.e., roads, are commonly found over flood defences, such as dikes, in order to ensure access and connectivity between flood protected areas. Several climate change future scenario studies have concluded that flood defences will be required to withstand more severe storms than the ones used for their original design. Therefore, thi...
Conference Paper
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Side channels are a common intervention to reduce the flood levels or to increase the ecological value in the river. Most of the constructed side channels ag-grade. We apply a simple method to estimate the development and its time scale of a side channel system.
Article
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Side channel construction is a common intervention applied to increase the 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 upstream...
Article
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The Rhine River in the Netherlands still has some characteristics of a delta, although the river is extremely engineered and confined between dikes. An important characteristic are the bifurcation points where the river bifurcates into different branches. The discharge partitioning at the bifurcates is predefined, as this is an important element fo...
Article
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Coping with uncertainties is inherent to river management planning and policymaking. Yet, policymakers often perceive uncertainty as a complicating factor. We examine the challenges faced by policymakers when coping with uncertainties and provide an action perspective on how to best cope with these challenges to inform the policy debate. Integratin...
Article
Piping erosion is one of the major causes of failure of flood defences. The occurrence of this failure mechanism is difficult to predict and it can be triggered during a flood event. The inclusion of hard structures under flood defences will change the probability of occurrence of this erosion process. The present study aimed at understanding the e...
Conference Paper
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Side channels are popular methods to reduce flood levels or to increase the ecological value of rivers. Here we asses four side channels in the River Ain (France). In combination with 1D model simulations, we identify the characteristics and processes regarding the erosion and sedimentation patterns. The relative slope of the channels, the bifurcat...
Article
Piping erosion has been proved to be one of the failure mechanisms that contributes the most to the total probability of failure on the Dutch flood defence systems. The present study aimed to find the impact of correlation and tail dependence between soil parameters present in the Sellmeijer revised limit state equation for piping safety assessment...
Conference Paper
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The multi-functional flood defences are one of the many solutions proposed for climate adaptation in deltaic areas. This kind of defences can also be found in literature as Delta-dikes, un-breachable dikes or super-levees. Yet all of them have two key design requirements to tackle. The first one is to improve their reliability given the uncertainty...
Conference Paper
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Reliability of flood defences is one of the main concerns of water managers in low land countries such as the Netherlands. Population growth, economic development and climate change are main drivers for the development of solutions such as multifunctional flood defences (MFFD). This type of structure combines the primary flood defence function with...
Conference Paper
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Design water levels are needed for the design of flood defences along the Dutch river Meuse. Current practise is that these water levels are determined by hydrodynamic simulation of a standard design hydrograph at the upstream gauging station Borgharen. The peak discharge of this synthetic hydrograph is based on a frequency analysis of the 100-year...
Article
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Decisions about flood risk management are usually based on the reduction in flood risk compared to the cost of the strategy. It is common practice to express this flood risk (the combination of flood probabilities and potential flood damages) in a single number. The downside of this approach is that explicit information about how the system respond...
Conference Paper
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Reliability studies for safety assessment of flood defences now days demand a large amount of stochastic calculations. Therefore mathematical simplifications of the models are used to describe the failure state of the flood defence structures. The present study implemented emulation techniques of different flood defence failure mechanisms, in order...
Conference Paper
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In the Netherlands, the design water levels are the starting point for the calculation of the heights of the dikes In the western part, close to the sea, the design water levels depend also on wind and the sea level due to storm surges. In that part of the country, the procedure to determine the design water levels is that a large number of determi...
Conference Paper
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Flood defences of particularly riverine deltaic areas are mainly composed of soil embankments artificially made. As any kind of structure, the materials, geometry and possible loads, might experience different deterioration processes that will compromise the stability of the structure. In order to estimate the probability of failure of such structu...
Conference Paper
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Accurate forecasts of water levels are essential for flood protection management. The hydraulic roughness of the river bed is dominated by bed forms. Under flood conditions the river bed is highly dynamic; bed forms grow and decay as a result of the changing flow conditions, thereby influencing the roughness. Hydrodynamic models are applied to pred...
Conference Paper
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In the field, bed formshardly reach their equilibrium conditions,which complicates the prediction of bed formevolution under varying discharge. The objective of this paper is to assess the differences in bed form evolution under varying discharge between flume and field data and explain the interaction between primary and secondary bed forms. We sh...
Conference Paper
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In hydraulic models, either in 1-, 2- or 3-D, the roughness coefficients of the main channel often are the most important calibration coefficients to reproduce measured water levels. The dynamics of dunes and associated hysteresis effects are not explicitely included in such calibrated models. In this paper we present a 1-D Sobek model of the river...
Conference Paper
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The morphological behaviour of side channels are not fully understood in real field situations. In this paper,we model side channels as a bifurcating system of branches and compare analytical studies with 1D and 2D numerical studies. In an analytical approach, either one of the branches closes off, or a stable configuration with two open channels r...
Article
This paper presents an approach to incorporate time-dependent dune evolution in the determination of bed roughness coefficients applied in hydraulic models. Dune roughness is calculated by using the process-based dune evolution model of Paarlberg et al. (2009) and the empirical dune roughness predictor of Van Rijn (1984). The approach is illustrate...
Conference Paper
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The Netherlands have a long lasting history of water management. In the early days, water management mainly focused on safety against floodings, and many other elements such as nature development, recreation or housing were not concerned or just forbidden to take place in the floodplains. Nowadays, this no longer holds, and water management asks pr...
Article
To support decision making on complex environmental issues, models are often used to explore the potential impacts of different management alternatives on the environmental system. We explored how different model outcomes affect decision making. Two topics have our particular interest, namely (1) the influence of quantification of qualitative infor...
Article
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a b s t r a c t The coherence between different aspects in the environmental system leads to a demand for comprehen-sive models of this system to explore the effects of different management alternatives. Fuzzy logic has been suggested as a means to extend the application domain of environmental modelling from physical relations to expert knowledge....
Chapter
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Conference Paper
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Weakly nonlinear analyses have proved their validity in the field of morphodynamic instability to describe the evolution of finite amplitude perturbations of the bed topography. In a recent study, Colombini and Stocchino (2008) analyzed theoretically the case of dunes and antidunes that develop, under suitable conditions, in an infinitely wide open...
Article
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Computer models can support policy development in environmental management, but often suffer from a lack of practical application. This is part due to a ‘gap’ between the ways in which various participants in the policy process deal with information. The framework described in this paper provides a structured approach to information analysis in pol...
Conference Paper
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In most well developed countries, the basic level of safety against floods is up to date. In a low lying country like the Netherlands, the protection levels are even among the highest ones found in the world, with return periods between 1.250 and 10.000 years. For the Netherlands, this brings along the fortunate consequence that floods have seldom...