Davide Wüthrich

• Ph.D. - Ing. Civ. dipl EPF
• Professor (Assistant) at Delft University of Technology

In the last decades the design of stepped spillways regained some interest because of their suitability with new construction methods including gabions. The hydraulic performances of gabion stepped weirs were investigated experimentally in terms of the flow patterns, air-water flow properties, and energy dissipation. A laboratory study was conducte...

Tsunamis, impulse waves, and dam failures are disasters that challenge humanity, often leading to massive casualties and extreme economic losses. The highly unsteady flow conditions generated by such events are often in the form of turbulent bores. The purpose of this study was to investigate and validate a new generation system for bores propagati...

Previous studies and field surveys showed that specific structural designs can decrease the load on free-standing buildings along the coast, providing safer vertical shelters. This experimental study investigated the effect of openings in buildings (windows, doors and foyers) on horizontal forces and tilting moments induced by both dry bed surges a...

Highly turbulent free-surface flows are characterised by complex and rapidly varying air–water surface features, leading to enhanced surface roughness, breakup and disintegration processes. Such a strong free-surface turbulence has an impact on a number of environmental flows, and a deeper understanding of its physical nature is fundamental. Unstea...

Chancy-Pougny is a run-of-river dam on the Swiss–French border constructed in the early 1920s. Since its commissioning, the operation of the four spillway gates has been responsible for a progressive erosion of the stilling basin. The future scour potential of the unlined stilling basin of the Chancy-Pougny dam was assessed by hybrid modeling, comb...

Highly unsteady flows, characterized by long-period, high- translatory waves, are common in nature. They describe coastal phenomena like tsunamis, storm surges, and flood waves, as well as more inland events such as tidal bores and dam failures. Recent incidents have shown that these phenomena significantly threaten densely populated coastal and ri...

More than 20 years have passed since the tragic 2004 Indian Ocean earthquake and tsunami, which killed over 227 000 people and devastated the coastlines of 14 countries surrounding the Indian Ocean. This tragic event kickstarted a worldwide effort in advancing knowledge towards mitigating the catastrophic effects of future tsunami. The ensuing rese...

Estimates of wave overtopping generally determine the required crest level of coastal structures. Wind affects wave overtopping, especially for coastal structures with crest walls because these can cause a vertical wave motion above the crest that is susceptible to wind. Within the relevant range of overtopping discharges, the expected wave overtop...

Estimates of wave overtopping generally determine the required crest level of coastal structures. Wind affects wave overtopping, especially for coastal structures with crest walls because these can cause a vertical wave motion above the crest that is susceptible to wind. Within the relevant range of overtopping discharges, the expected wave overtop...

This paper presents a dataset documenting 71 floating debris accumulations at bridges following an extreme hydrological event that hit Belgium and Germany in July 2021. Data were collected from various sources including public authorities’ documents, public online databases, post event pictures and field visits. The dataset covers bridges geometry,...

The July 2021 flood heavily affected many inhabitants, buildings and critical infrastructure throughout Germany, Belgium and the Netherlands. Specifically, the Ahr Valley (Germany) showcased the destructive power associated with these extreme events. Hence, this region was the focus of a field survey, aiming at describing the flood‐induced damage t...

Dam-break waves, induced by the failure of a dam, result in destructive flood waves with a rapid increase in water level and high wave front celerities. These events pose significant threats to downstream communities, which means that understanding their dynamics is crucial for effective disaster management and mitigation. This study used an experi...

This study investigates the effect of driftwood on submerged culverts through scale experiments, focusing on their accumulation and the hydrodynamic processes occurring underneath. Examining temporal evolution and velocity measurements, this research delves into the implications of driftwood accumulation, including its geometry, hydraulic condition...

During the European flood of 2021, large debris accumulations were observed at numerous bridges, causing backwater rise, increased upstream flooding, and extended damage. To date, debris accumulation studies mainly focused on debris consisting of logs, at bridge piers or debris racks. However, during the 2021 flood, debris contained a large share o...

In a time of climate emergency due to global warming, nature-based coastal defence systems are attractive solutions for flood mitigation and adaptation. Coastal forests such as mangroves have received a growing interest for their disaster mitigation effectiveness such as water flow energy dissipation, hence helping communities to become more resili...

Recent catastrophic events caused by tsunamis, storm surges, flood waves, and the failure of dams (e.g. in Ukraine and Libya) have shown to be a significant threat to densely populated coastal communities. Interactions with built environments can lead to violent wave impacts that may have severe consequences, including significant infrastructural d...

Plain Language Summary Accumulations of wood in rivers (log jams) can block the flow and thereby cause water level rise. Follett et al. (2020a, https://doi.org/10.1029/2020gl089346) developed a theoretical model to predict how this water level rise depends on log jam properties and local river conditions. For the local river conditions, they used t...

Plastic pollution is a threat for all ecosystems due to its effects on people, animals, and environment. Rivers are estimated to transport around 0.5 millions tons of plastic per year. When plastic enters a river system, it is transported downstream towards the sea but it is also likely to accumulate at specific cross sections and locations, includ...

Coastal dikes have been built for millennia to protect inhabited lands from exceptional high tides and storm events. Currently, many European countries are developing specific programs to integrate the construction of new dikes (or the raising of existing ones) into the built environment to face sea level rising. Technical difficulties in succeedin...

In a world affected by climate change and sea-level rise, intense storms are expected to become more frequent in the future. This implies that our coastal protections will be more often and more intensely affected by overtopping waves, potentially endangering the safety of our coastal communities. The objective of the present study is to investigat...

Wave transmission at low-crested coastal structures has been studied, based on physical model tests with trapezoidal impermeable, permeable and perforated structures. The differences between wave transmission at impermeable and permeable structures are relatively limited. For a perforated hollow structure with an impermeable vertical screen in the...

Heavy flash floods in Germany, which occurred in the aftermath of intense and long-lasting rainfalls (up to 150-200 l/m² within 48 h; CEDIM, 2021) in July 2021, led to serious damage to people, buildings and infrastructure. According to CEDIM (2021), the flash-flood caused at least 170 fatalities and 820 injuries. It is expected that it will take s...

The crest level of seawalls is often based on estimates of the amount of wave overtopping. Methods to estimate the mean overtopping discharge have been provided in several guidelines. One of the important parameters affecting wave overtopping is the wind. However, the effects of wind have not been accounted for in detail in present design guideline...

Transient motion, turbulence and bubble dynamics make any velocity quantification extremely difficult in unsteady gas-liquid flows. In the present study, novel Eulerian and Lagrangian techniques of velocimetry were developed, using both intrusive and non-intrusive measurements. The selected unsteady gas-liquid flow was a breaking bore, featured wit...

Continuing from the part 1 (Shi et al., 2022) this paper presents an experimental investigation of transient void fraction and bubble statistics in a highly turbulent breaking bore with Fr1=2.4. The measurements were conducted using a combination of dual-tip phase-detection probes and an ultra-high-speed video camera. The enclosed bubble detection...

At hydraulic structures, some strong interactions may develop between fast flowing waters and the air adjacent to the water in motion that enhance the air-water transfer of atmospheric and volatile gases in the flow. In turn, in-stream structures may contribute to the aeration and re-oxygenation during overflow. The present study aims to characteri...

On a stepped spillway, the staircase invert profile generates some intense turbulent dissipation during the spill, associated with a significant reduction of kinetic energy, as well as strong self-aeration. The present study focused on the effects of inclined downward steps on the air–water flow properties, flow resistance, and head losses because...

Hydraulic jumps are commonly employed as energy dissipators to guarantee long-term operation of hydraulic structures. A comprehensive and in-depth understanding of their main features is therefore fundamental. In this context, the current study focused on hydraulic jumps with low Froude numbers, i.e. Fr 1 = 2.1 and 2.4, at relatively high Reynolds...

In a world influenced by climate change and consequently sea-level rise, extreme floods are expected to become more frequent in the future, representing a serious threat for riverine and coastal settlements. Therefore, flood protection is a large component of climate adaptation and should be closely related to other measures of climate adaptation a...

The propagation of dam-break waves on different rough beds was observed to be quasi-steady in the range $11.3 , where $x$ is measured from the dam position. These quasi-steady propagation speeds converge with the steady ideal fluids model of Stoker ( Water Waves , 1957, Interscience) when the tailwater depth $h_2$ becomes greater than ${\sim }0.5k_...

Breaking bores are commonly observed in a number of natural processes, often associated with the presence of a transient mixture of air and water, with intense recirculation, air bubble entrainment, and splashing. Two-phase flow measurements in such highly unsteady flows cannot be based on long-duration measurements and require novel ensemble-stati...

Partially-filled pipe flows are commonly observed in urban hydraulics, sewers and road crossings. The occurrence of a compression wave in the confined space may result from flash flooding, transient operation or accidental blockage, inducing explosive conditions. In this study, the propagation of a compression wave was studied in a relatively large...

A hydraulic jump is a stationary transition from an upstream supercritical to a downstream subcritical flow. Weak hydraulic jumps may be observed downstream of low-head hydraulic structures and their physical properties were often neglected. In the present study, the hydraulic properties were investigated experimentally in weak hydraulic jumps with...

Self-aerated free-surface flow studies have a more recent history compared to classical fluid dynamics. Traditional velocimetry techniques are adversely affected by the presence of gas-liquid interfaces. In the present study, detailed air-water flow measurements were performed in a highly turbulent free-surface flow, and three velocimetry approache...

A hydraulic jump is a region of rapidly-varied flow that is extremely turbulent. While the one-dimensional continuity and momentum principles have been successfully applied to express the relationships between upstream and downstream conditions, the three-dimensional equations cannot be resolved without some complicated turbulence closure, often in...

Shear plates have previously been used to measure bed shear stresses under swash and dam-break waves. The present study has been focused on the large bed shear stresses near the tip and even at distances less than one plate length from the tip. In order to resolve this rapid stress variation, the shear plate was calibrated with respect to its step...

Steady free-surface flows around buildings occurring during flood or tsunami events can produce major damages and a quantification of the post-peak forces is essential for safety and resilience of coastal structures. The loading process is highly affected by the flow Froude number and the drag coefficient, commonly defined for highly subcritical fl...

Tsunamis, impulse-waves and dam-break waves have affected humanity in recent decades and the construction of vertical shelters can provide safety to people. However, for non-critical infrastructures, typically residential houses of lower height, overtopping is accepted during such events. This study experimentally quantifies the effect of building...

A breaking bore in a translating system of reference is mathematically comparable with a stationary hydraulic jump, whose dissipative nature is used in hydraulic structures to limit damage during floods. Although visually similar, analogies and dissimilarities between hydraulic jumps and bores have been discussed for decades. Recent developments in...

A high-speed water jet plunging into a slower receiving waterbody results in an air entrainment process. In hydraulic engineering, a plunging jet is commonly used as an energy dissipater downstream of a hydraulic structure, such as stepped chute flow and water treatment plants. The energy dissipation is related to the bubble turbulence interplay as...

Hydraulic jumps are commonly employed as energy dissipators to guarantee long-term operation of hydraulic structures. Thus, a comprehensive and in-depth understanding of its main features is fundamental. In this context, the current study focused on a hydraulic jump with a low Froude number (Fr = 2.4) and a relatively high Reynolds number (Re = 1.8...

Breaking bores are an unsteady flow motion observed in flood waves, rejection surges by hydropower plants, tidal bores, and tsunamis propagating in rivers. For large Froude numbers (Fr1 > 1.5), the bores exhibit a non-stationary breaking roller characterised by a recirculating motion with large air entrainment and splashes resulting in a highly flu...

Les tsunamis, les vagues d'impulsion et les ruptures de barrages représentent des phénomènes extrêmes qui mettent en danger la vie des personnes et la fonctionnalité des infrastructures. Des événements récents dans l'Océan Indien (2004), au Japon (2011) et en Indonésie (2018) ont montré que des mesures constructives peuvent réduire les charges indu...

Tsunamis, impulse waves, and dam-break waves are rare but catastrophic events, associated with casualties and damage to infrastructures. An adequate description of these waves is vital to assure human safety and to generate resilient structures. Furthermore, a specific building geometry with openings, such as windows and doors, reduces wave-induced...

Breaking surges and bores are observed during flood events, tidal bores and tsunamis propagating in rivers. The sudden increase in water depth generates an aerated and recirculating region, called the roller, whose turbulent behaviour is poorly understood. Based on ensemble-average analyses with multiple repetitions, this experimental work processe...

Unsteady flows such as tsunamis, impulse waves and dam-break waves can lead to damages and human losses. Hence, specific research to limit casualties and reconstruction costs is needed. The complexity of the phenomena involved suggests that a hybrid experimental-numerical approach should be used to gain a more comprehensive understanding of the pro...

A comprehensive understanding of physical phenomena based on a hybrid experimental-numerical approach supports a safer design of critical infrastructures. However, for large-scale tsunami-like waves, the reliability of numerical models was insufficiently validated. Herein, we validate our numerical model of tsunami-like waves by comparing simulatio...

Tsunami, impulse-waves and dam-break waves afflict humanity with casualties and damages. Insight into the flow mechanisms of these waves, is important to provide safety and reduce reconstruction costs. This experimental study focuses on the effect of bed roughness on the main hydrodynamic properties of surges propagating on dry bed. Further, the re...

Tsunamis, landslide-generated waves, and dam failures are rare, but highly destructive phenomena, associated with extreme loading on infrastructure. Recent events showed that specific measures must be taken to guarantee safety of both people and the built environment. This experimental study investigates the forces and moments exerted on free-stand...

Recent studies showed that a specific design can reduce the impact of water waves on structures, thus limiting the damages. Herein the impact of waves on buildings is addressed, pointing out the influence of orientation on the hydrodynamic process.

Uncontrolled scour is affecting multiple mobile dams. The plunge pool of the Chancy-Pougny barrage, located on the Rhone River bordering France and Switzerland, has recently been reported to develop in a potentially unfavourable direction after almost 100 years of acceptable scour development. In order to estimate the future scour potential of this...

Dam failures, impulse waves, tsunamis and storm surges are disasters that challenge humanity, often leading to massive casualties and important economic losses. These events generate highly unsteady flow conditions in the form of surges or turbulent bores, associated with extreme loading on infrastructure. In the past, the impact on these flows on...

Chancy-Pougny is a run-of-river dam on the Swiss–French border constructed in the early 1920s. Since its inauguration, the operation of the four spillway gates was responsible for a progressive erosion of the stilling basin. Thus, a hybrid modelling was performed to study the scour potential and to determine adequate solutions to maintain future sc...

The objective of this study is the stilling basin downstream of the Chancy-Pougny dam, facing some scour problems. A physical model was constructed with a scaling ration of 1:55, with the purpose of better understanding the origin of this erosion. The non-symmetrical geometry of the stilling basin generated a recirculating flow that interacted with...

Natural hazards such as tsunamis, impulse waves and dam-break waves are rare, but extremely destructive. In recent times, more importance was given to structures that could withstand such events, however, uncertainties still exist in the estimation of wave velocities. This project focuses on the estimation of wave front celerity in a laboratory env...

Tsunamis, Impulse waves and the sudden collapse of dams are rare phenomena, but highly destructive. Nevertheless recent events showed that structures with openings can effectively reduce impact forces, ensuring people’s safety and limiting reconstruction costs. The present experimental study systematically investigates the impact of a dry bed surge...

Chancy-Pougny is a run-of-river dam on the Swiss-French border constructed in the early 1920s. Since its inauguration, the operation of the four spillway gates was responsible for a progressive erosion of the stilling basin. Thus, a hybrid modelling was performed to study the scour potential and to determine adequate solutions to maintain future sc...

Hydrodynamic waves are an unsteady flow motion generated by rapid water level rise. In nature, such events can be found in dam-break waves, impulse waves and tsunamis. These phenomena are rare, but highly destructive. The present study is based on an experimental approach and it investigates the hydrodynamic behavior of bores propagating on wet bed...

Waves impacting against structures can create damages and devastation. This topic regained interest after some recent catastrophic events and the present paper investigates the main phases of a wave impacting against a residential house commonly observed in areas subject to tsunami hazards. The project is based on an experimental approach and both...

Hydrodynamic waves are characterised by unsteady, highly turbulent and irregular behaviours. In nature, such phenomena can be observed in dam breaks, impulse waves and tsunamis. Both wet bed bores and dry bed surges were experimentally reproduced on smooth and rough surfaces. For all tested scenarios a front propagating in the channel was observed,...

The development of alternative energy solutions to meet the increasing energy demand requires the expansion of the production network. In this context hydropower plants (HPPs) represent a reliable renewable energy source [3] and the possibility of integrating a pumping storage system makes HPPs an excellent way to stock energy. Besides energy gener...

In the context of a comprehensive research project investigating the hydrodynamic loading on structures with openings, this paper focuses on the wave generation techniques currently used and the test results associated with it, proposing a particular tsunami-like wave using a vertical water volume release mechanism. The latter allowed a certain vol...

The appearance of the regular vegetated ridge patterns observed in some ephemeral rivers of semi-arid regions (Nanson, Tooth, & Knigthon 2002) has previously been explained by hydraulic arguments (optimization of the bed load transport capacity, see Huang & Nanson (2007)) without including the role of vegetation in the process. Those arguments prov...

The stepped spillway design has been used for more than 3,300 years. A simple structure is the gabion stepped weir. A laboratory study was performed herein in a large size facility. Three gabion stepped weirs were tested with and without capping, as well as a flat impervious stepped configuration. For each configuration, detailed air–water flow mea...

In the last three decades the design of stepped spillways regained some interest because of their suitability with new construction methods including gabion placement. In this study, the hydraulic performances of gabion stepped weirs were investigated experimentally in terms of the air-water flow properties and energy dissipation rate. A physical s...

Stepped spillway structures have been used for more than 3,000 years. Recently the design of stepped chutes regained some interest because of their suitability with roller compacted concrete (RCC) construction methods and gabion placement. In this study, the hydraulic performances of gabion stepped weirs were investigated experimentally in terms of...

Several research investigations have explored the interaction between morphodynamic and vegetation growth processes from both the modelling and the experimental viewpoints. Results have mainly been concerned with morphologic analyses of the effects of vegetation on long term riverbed evolution without addressing the relative role of the timescales...

Part of investigations on the feedbacks between vegetation and the river morphodynamics, we study how the flow-mediated interaction between riparian vegetation located at different points in the channel can lead to the appearance of the regular vegetated ridge patterns found in various riverine environments (for an example, see Tooth and Nanson, 19...