Matthijs Kok

Matthijs Kok
Delft University of Technology | TU · Department of Design Engineering and Flood Risk

Doctor of Philosophy

About

121
Publications
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1,682
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Publications

Publications (121)
Article
Full-text available
Prioritisation of flood defence maintenance is typically based on visual inspection. However, literature shows that the Probability of Detection (PoD) of visual inspection can vary significantly. Here we investigate the PoD for visual inspections of flood defence structures, the consistency of damage classification, and the influence of different v...
Article
Full-text available
In this paper the safety of a double-dike system (or twin dikes) is assessed. Such a system consist of two parallel lines of flood defences. During storms the combined strength of the parallel flood defences must prevent flooding of the hinterland. A culvert can be implemented for the tidal exchange of sea water to enable new land-uses in the area...
Article
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Backward erosion piping is an internal erosion process, which compromises the stability of water retaining structures such as dams and levees. In this paper, we propose a numerical solution that combines a 2D Darcy groundwater solution with Exner’s 1D sediment transport mass conservation equation. As an estimate of sediment transport, we tested fou...
Article
Full-text available
Spatial variability and limited measurements often result in low reliability estimates of geotechnical failure modes of dikes (i.e., earthen flood defences). Required dike reinforcements are usually not executed within a few years after inception, which enables efforts to improve reliability estimates by reducing uncertainty. Often decision makers...
Article
Full-text available
Reliable hazard analysis is crucial in the flood risk management of river basins. For the floodplains of large, developed rivers, flood hazard analysis often needs to account for the complex hydrology of multiple tributaries and the potential failure of dikes. Estimating this hazard using deterministic methods ignores two major aspects of large-sca...
Preprint
Full-text available
During construction of a dike, slope stability often reaches critical levels, due to the excess pore water pressures in the foundation. The loading condition during construction has similarities with the design conditions during flood loading. Not only in terms of the pore water pressures as the main driving force, but also in terms of criticality...
Article
Full-text available
During construction of a dike, slope stability often reaches critical levels, due to the excess pore water pressures in the foundation. The loading condition during construction has similarities with the design conditions during flood loading. Not only in terms of the pore water pressures as the main driving force, but also in terms of criticality...
Article
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Climate change and deterioration require a continuous effort to reinforce flood defences and meet reliability requirements. To efficiently upgrade flood defence systems, insight in costs and benefits of measures at a system level is required throughout the process of planning and design. Due to the size of flood defence systems the number of possib...
Conference Paper
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Revetments protect flood defences against erosion from waves and currents. At several coastal dikes in the Netherlands asphalt has been used as a revetment material for protection against waves. Asphalt concrete revetments can degrade due to several shock-based and continuous degradation processes, for instance wave impacts, uneven settlements, cra...
Article
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Worldwide, rivers provide important socio-economic and environmental functions and are essential to human well-being. The growing demand of user-functions and the change in river conditions due to large-scale morphology and climate change, increase the pressure on lowland river systems (e.g. Rhine, Meuse, Danube and Mississippi). To ensure a multi-...
Article
Effective adaptation to sea-level rise is critical for future flood protection. Nature-based solutions including salt marshes have been proposed to naturally enhance coastal infrastructure. A gently sloping grass-covered dike (i.e. Wide Green Dike) can be strengthened with clay accumulating locally in the salt marsh. This study explores the feasibi...
Article
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Integrating natural components in flood defence infrastructure can add resilience to sea-level rise. Natural foreshores can keep pace with sea-level rise by accumulating sediment and attenuate waves before reaching the adjacent flood defences. In this study we address how natural foreshores affect the future need for dike heightening. A simplified...
Conference Paper
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Many flood defences in the Netherlands will have to be reinforced in the coming decades. Many dikes do not fulfill the safety standard due to geotechnical failure modes, largely due to epistemic, reducible uncertainties.. The Value of Information is a measure to indicate beforehand whether an investment towards reducing epistemic uncertainty is eco...
Article
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Digital Elevation Model (DEM) is an important component in flood inundation modelling as a part of flood risk analysis. However, Digital Surface Model (DSM) which still contains noises of artefacts is more common to be available than DEM. Then DSM misleads the inundation extent. This study will evaluate a measure to obtain a bare-earth surface (DEM...
Article
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One of the most rapidly emerging measures in infrastructure asset management is Structural Health Monitoring (SHM), which aims at reducing uncertainty in structural performance by using monitoring equipment. As earthen flood defence structures typically have large strength uncertainties, such techniques can be particularly promising. However, insig...
Article
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To make informed flood risk management (FRM) decisions in large protected river systems, flood risk and hazard analyses should include the potential for dike breaching. ‘Load interdependency’ analyses attempt to include the system-wide effects of dike breaching while accounting for the uncertainty of both river loads and dike fragility. The intensi...
Conference Paper
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One of the failure mechanisms of dikes is slope instability at the landward side. Often, one instability does not lead to flooding, and several successive instabilities are needed before the dike overtops, and erosion and breaching can occur, especially at lower water levels. In this paper we propose a method to estimate the probability of flooding...
Article
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It is not uncommon for a flood defence to be combined with other societal uses as a multifunctional flood defence, from housing in urban areas to nature conservation in rural areas. The assessment of the safety of multifunctional flood defences is often done using conservative estimates. This study synthesizes new probabilistic approaches to evalua...
Article
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Transformation models are used to infer geotechnical properties from indirect measurements. A site-specific transformation model can be calibrated with direct and indirect measurements from a site. When such a model is used, then spatial variability, measurement errors and statistical uncertainty propagate into the uncertainty of the spatial averag...
Article
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Hazard analysis is a crucial step in flood risk management, and for large rivers, the effects of breaches need to be taken into account. Hazard analyses that incorporate this overall “system behaviour” have become increasingly popular in flood risk assessment. Methods to perform such analyses often focus on high water levels as a trigger for dike b...
Article
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Multifunctional use of flood defences is often seen as a disadvantage for flood protection. Safety assessments of multifunctional dikes only require functions do not negatively affect safety but leave potential synergies untapped. This study synthesizes the new probabilistic approaches to evaluate the safety of multifunctional flood defences employ...
Article
The application of risk‐based approaches for the design of flood infrastructure has become increasingly common in flood management. This approach, based on risk reduction and reliability, is used to assess the performance of conventional interventions (e.g., flood defences and dams) and to support decisions regarding their implementation. However,...
Conference Paper
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Since 2017 Dutch flood protection standards are defined as target flood probabilities that all primary flood defences have to comply with by 2050. Explicitly accounting for uncertainties in probability distributions of load and resistance is an integral part of estimating the actual flood probability. Based on such estimates, many flood defences wi...
Article
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Polders in the Netherlands are protected from flooding by flood defence systems along main water bodies such as rivers, lakes or the sea. Inside polders, canal levees provide protection from smaller water bodies. Canal levees are mainly earthen levees along drainage canals that drain excess water from polders to the main water bodies. The water lev...
Article
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Flood defence systems can be seen as multiple interdependent flood defences. This paper advances an approach for finding an optimal configuration for flood defence systems based on an economic cost-benefit analysis with an arbitrary number of interdependent flood defences. The proposed approach is based on a graph algorithm and is, thanks to some b...
Conference Paper
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The Netherlands has always lived with the risk of flooding. Without flood defenses about 60% of the Netherlands would be regularly flooded and our way of life would not be possible. Quantitative risk analyses can be used to inform decisions with regard to the risk, such as the selection of mitigation measures and investments in flood protection....
Article
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Flood defences can be designed as multiple lines of defence. This paper presents an approach for finding an optimal configuration for flood defence systems, based on an economic cost-benefit analysis with an arbitrary number of interdependent lines of defence. The proposed approach is based on a graph algorithm and is, thanks to some beneficial pro...
Article
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General risk management standard, e.g. ISO 31000:2009, approaches risk as a coin with a pair of two sides, i.e. the threat and the opportunity. However, it is hardly the case of flood events which mainly come as threats. Despite the contrary, this study explores the potential applicability of the available risk management standards specifically for...
Article
Dike reinforcement decision making under uncertainty is a challenging task. This paper examines whether increasing the managerial flexibility of a reinforcement strategy can improve the lifecycle cost-effectiveness for the Dutch flood defences. Two flexible strategies are developed and compared to an inflexible baseline strategy. The strategies are...
Article
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Coastal flood defense systems can consist of multiple lines of defense. In case of a system with a front and a rear defense (e.g. a storm surge barrier and levees), the front defense can improve the reliability of the rear defense by reducing the load on this rear defense. This paper develops a framework in order to assess whether including the inf...
Article
Given the large investments in dike construction and reinforcements, optimization of these interventions could contribute to significant cost savings. In this paper a probabilistic method is developed for obtaining the geometry of a river dike cross-section that fulfils a specified target reliability at a minimal cost. The method takes into account...
Article
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Here we examine whether a study conducted 25 years ago (1992) would have had different conclusions if concepts and analytical methods developed since then had been used. The 1992 problem was to identify a strategy for reducing flood risk in the Netherlands by, for example, strengthening the river dikes against the risk of flooding. Since then, cond...
Article
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In the Netherlands, the concept of a multifunctional dike has already often been implemented, and has been identified as a promising climate adaptation measure. In a multifunctional dike, functions like urban development, transport infrastructure, recreation, agriculture or nature are deliberately combined with its primary flood protection function...
Conference Paper
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A breach in a flood defence will affect the downstream water levels in a riverine system, and therefore the flood risk of the system. The effect of this changed flood risk is used in an economical optimization to assess if this significantly changes the economically optimal safety targets of the flood defences in a riverine system. The impact of br...
Article
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In many parts of the world, flooding is a big risk. There are numerous strategies to reduce flood risk. The amount of flood risk reduction strategies grows exponentially with the amount of possible measures that can be implemented and possible timings when measures can be implemented. In this paper, the use of a financial method called “equivalent”...
Article
A great deal of coastal communities throughout the world are threatened by large-scale flooding caused by tsunamis, tropical cyclones, or extra-tropical storms. In order for those areas to stay protected, investments in multi-layer safety projects are often contemplated. This chapter presents a procedure to derive cost-efficient design specificatio...
Conference Paper
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Flow sliding of submerged slopes in front of dikes can affect the reliability of flood defences. The occurrence of flow sliding may result, sometimes with delay, in a failure mode and consequent flooding. The current safety assessment method for flow sliding does not consider the interaction between flow sliding and failure modes which can cause a...
Article
Emergency measures, such as sand bags, are often used during flood events to prevent breaches in flood defences. However, there is limited insight into their contribution to flood prevention. This paper describes a method to determine the reliability of a system of flood defences including emergency measures. The reliability of the emergency measur...
Article
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After the flood disaster of 1953, the Netherlands adopted a rational approach to flood risk management with the use of protection standards determined by means of cost-benefit analysis. Due to scientific and political developments that have recently taken place, an update of the Dutch protection standards is being undertaken. One of the major prior...
Conference Paper
Full-text available
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...
Chapter
Large parts of the Netherlands are below sea level. The deepest parts are more than 4 m below sea level. These are the relatively new polders, built in the last century. Prevention of floods is and remains the main pilar of the Dutch Flood Risk policy. In the last decades, however, more attention is paid to disaster management.
Conference Paper
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In the Netherlands, flood risk analysis is usually carried out for a location, without considering potential flood defence failures in upstream areas. This may result in significant over-or underestimation of flood risks. The effect of upstream failures on failure probabilities and flood risks in other areas is called load interdependence of flood...
Article
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Flood damage prediction models are essential building blocks in flood risk assessments. Little research has been dedicated so far to damage of small-scale urban floods caused by heavy rainfall, while there is a need for reliable damage models for this flood type among insurers and water authorities. The aim of this paper is to investigate a wide ra...
Article
In the light of changes in climate, economy and demography, civilians, politicians and scientists alike often wonder how far into the future the Dutch polder approach will last. The polder approach refers to the drainage and flood protection of low-lying areas by means of pumps, canals and flood defences. An increase in river discharges and sea lev...
Conference Paper
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This paper reports on work, which is currently conducted under the Dutch Technology Foundation STW-Perspectief program " Multi Functional Flood Defences ". This program aims to develop both the technology and the governance required for the implementation of multifunctional flood defences. It involves in total 12 PhD students and 4 postdocs. This p...
Conference Paper
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Recent experience of large-scale water disasters such as Hurricane Katrina in 2005 and the Great Eastern Japan Earthquake and Tsunami in 2011 has reminded mankind that disasters cannot be ruledout. Unprecedented low-probability events can happen even in the most well monitored areas, causing major social-economic disruption. Failing to prepare for...
Article
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In this paper we show how applying an analytical framing of hegemony to policy making can draw out strategic positioning and negotiation of the actors involved that would remain hidden with a more rationalistic analysis. We show how long established flood protection management from the Dutch lowlands was imported into Limburg after two major flood...
Article
Preventive evacuation can save human lives, but it also incurs costs. In some cases, the costs can exceed the benefits of preventive evacuation, making it economically undesirable. To assist authorities in decision making concerning preventive evacuation, probabilistic evacuation decision criteria are derived within the context of flood risk in the...
Article
Probability forecasts for natural loads, such as river discharge or wind speed, allow deriving predictive dike failure probabilities within a future time interval, the so-called operational dike failure probabilities. The operational dike failure probabilities can be used to assess the safety of dikes and can support decision making in the face of...
Article
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In this paper, a database of water-related insurance damage claims related to private properties and content was analysed. The aim was to investigate whether the probability of occurrence of rainfall-related damage was associated with the intensity of rainfall. Rainfall data were used for the period of 2003–2009 in the Netherlands based on a networ...
Article
Flood risk reduction can be obtained in many ways and by many measures. A common approach in the Netherlands is to divide the measures into three layers: flood prevention, land-use planning and emergency management. An important question is how to divide the investment between these layers. In this paper we follow an economic approach: the selectio...
Article
Evacuation of people in case of a threat is a possible risk management strategy. Evacuation has the potential to save lives, but it can be costly with respect to time, money, and credibility. The consequences of an evacuation strategy depend on a combination of the time available, citizen response, authority response, and capacity of the infrastruc...