References of "Erpicum, Sébastien"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailProcedural generation of flood-sensitive urban layouts
Mustafa, Ahmed Mohamed El Saeid ULiege; Zhang, Xiao Wei; Aliaga et al

in Environment and Planning B: Urban Analytics and City Science (in press)

Aside from modeling geometric shape, three-dimensional (3D) urban procedural modeling has shown its value in understanding, predicting and/or controlling effects of shape on design and urban planning. In ... [more ▼]

Aside from modeling geometric shape, three-dimensional (3D) urban procedural modeling has shown its value in understanding, predicting and/or controlling effects of shape on design and urban planning. In this paper, instead of the construction of flood resistant measures, we create a procedural generation system for designing urban layouts that passively reduce water depth during a flooding scenario. Our tool enables exploring designs that passively lower flood depth everywhere or mostly in chosen key areas. Our approach tightly integrates a hydraulic model and a parameterized urban generation system with an optimization engine so as to find the least cost modification to an initial urban layout design. Further, due to the computational cost of a fluid simulation, we train neural networks to assist with accelerating the design process. We have applied our system to several real-world locations and have obtained improved 3D urban models in just a few seconds. [less ▲]

Detailed reference viewed: 87 (22 ULiège)
Full Text
Peer Reviewed
See detailMitigation Techniques for Nappe Oscillations on Free-Overfall Structures
Lodomez, Maurine ULiege; Crookston, Brian ULiege; Tullis, Blake et al

in Civil Engineering ASCE (in press)

Nappe oscillation is a phenomenon that can have an undesirable impact to the local environmental (e.g., nearby residences, parks) as the phenomenon has been observed to produce a significant level of ... [more ▼]

Nappe oscillation is a phenomenon that can have an undesirable impact to the local environmental (e.g., nearby residences, parks) as the phenomenon has been observed to produce a significant level of noise caused by acoustic pressure waves. As a result, a detailed investigation was undertaken to identify practical and effective mitigation solutions to address these effects for free-overfall structures. Nappe oscillations were studied using a prototype-scale linear weir (weir length of 3.5 m and fall height of 3 m), a high-speed camera, and audio equipment. The effectiveness of various crest modifications to reduce nappe oscillation and any corresponding impacts to hydraulic efficiency were evaluated. The test matrix included the optimization (position and spacing of elements) of three mitigation solutions: 12 configurations with projecting elements, 5 configurations with deflectors and one configuration with a step. These three countermeasures proved to be effective after the optimization of their characteristics. In particular, deflectors or a step produced the maximum noise reduction while decreasing the discharge coefficient by less than 3 % over the range of experimental conditions. [less ▲]

Detailed reference viewed: 32 (4 ULiège)
Full Text
Peer Reviewed
See detailComparison of perturbation methods for rainfall and temperature data: case of a Belgian catchment
Peltier, Yann; Dewals, Benjamin ULiege; Erpicum, Sébastien ULiege et al

in International Journal of Hydrology Science and Technology (in press)

Analyses of hydrological impacts of climate change require appropriate methods for perturbing meteoric time-series to represent future climate conditions. Two readily available tools for perturbing ... [more ▼]

Analyses of hydrological impacts of climate change require appropriate methods for perturbing meteoric time-series to represent future climate conditions. Two readily available tools for perturbing rainfalls and temperatures are tested for a medium-sized catchment in Belgium. CCI-HYDR provides three scenarios, tailored for Belgium every decade until 2100. In contrast, KNMI-ADC tool provides 191 scenarios, at a regional level and for two horizons (near and far future). With its three contrasted scenarios of possible future climate conditions, CCI-HYDR is found suitable for forcing computationally intensive detailed hydrological models. With its broader spectrum of climate scenarios, KNMI-ADC tool is suitable for forcing multiple runs of fast conceptual hydrological models. As the two perturbation tools deliver stationary time-series, they are also compared to an alternate method producing transient time-series. Transient stochastic tools are particularly computationally demanding due to their stochastic nature, which is not optimal when combined with detailed distributed hydrological models. [less ▲]

Detailed reference viewed: 47 (10 ULiège)
Full Text
See detailData requirements for computational modelling at the network level
Dewals, Benjamin ULiege; Erpicum, Sébastien ULiege; Pirotton, Michel ULiege et al

E-print/Working paper (2019)

Detailed reference viewed: 19 (6 ULiège)
Full Text
Peer Reviewed
See detailUncertainties in laboratory modelling of urban flooding
Li, Xuefang ULiege; Erpicum, Sébastien ULiege; Mignot, Emmanuel et al

in Geophysical Research Abstracts (2019, April)

In the first part of this communication, we will discuss the main uncertainties affecting laboratory scale modelling of urban flooding and their relative importance. These include uncertainties in ... [more ▼]

In the first part of this communication, we will discuss the main uncertainties affecting laboratory scale modelling of urban flooding and their relative importance. These include uncertainties in hydrological data, on roughness representation, on exchanges between overland flow and the drainage network, measurement uncertainties as well as the influence of overlooked processes. In a second part, we will focus on the issue of scaling, particularly for lab experiments representing urban flooding at the district level. Laboratory scale models of urban flooding tend to use distinct scale factors (ratio between prototype and model dimensions) along the horizontal and vertical directions (to avoid millimetre-scale water depths in the lab, or giant lab setups hardly possible to fit in a hydraulic lab). This leads to so-called geometrically distorted scale models. It is believed that this strategy ensures improved accuracy and representativeness of the measurements; but specific artefacts also arise from the model distortion. Here, we provide first quantitative insights into the effects of model distortion, based on a recent reanalysis of existing experimental datasets. In the tested configurations, the influence of model distortion on the predicted values of water depth and street discharges is found of the order of 10%. We will conclude with recommendations on the way to go to make the optimal use of laboratory scale modelling for addressing the needs of the flood risk community. [less ▲]

Detailed reference viewed: 33 (5 ULiège)
Full Text
Peer Reviewed
See detailTechnical note: Laboratory modelling of urban flooding: strengths and challenges of distorted scale models
Li, Xuefang ULiege; Erpicum, Sébastien ULiege; Mignot, Emmanuel et al

in Hydrology and Earth System Sciences (2019), 23

Laboratory experiments are a viable approach for improving process understanding and generating data for the validation of computational models. However, laboratoryscale models of urban flooding in street ... [more ▼]

Laboratory experiments are a viable approach for improving process understanding and generating data for the validation of computational models. However, laboratoryscale models of urban flooding in street networks are often distorted, i.e. different scale factors are used in the horizontal and vertical directions. This may result in artefacts when transposing the laboratory observations to the prototype scale (e.g. alteration of secondary currents or of the relative importance of frictional resistance). The magnitude of such artefacts was not studied in the past for the specific case of urban flooding. Here, we present a preliminary assessment of these artefacts based on the reanalysis of two recent experimental datasets related to flooding of a group of buildings and of an entire urban district, respectively. The results reveal that, in the tested configurations, the influence of model distortion on the upscaled values of water depths and discharges are both of the order of 10 %. This research contributes to the advancement of our knowledge of small-scale physical processes involved in urban flooding, which are either explicitly modelled or parametrized in urban hydrology models. [less ▲]

Detailed reference viewed: 37 (10 ULiège)
Full Text
Peer Reviewed
See detail7th international symposium on hydraulic structures: a retrospect
Bung, Daniel; Tullis, Blake; Erpicum, Sébastien ULiege et al

in Hydrolink (2019), 2019(1), 26-27

Report on 7th Int. Symp. on hydraulic structures, Aachen, Germany, 14-18 May 2018

Detailed reference viewed: 25 (1 ULiège)
Full Text
Peer Reviewed
See detailAutomatic design of flood-resilient urban layouts
Dewals, Benjamin ULiege; Mustafa, Ahmed Mohamed El Saeid ULiege; Bruwier, Martin ULiege et al

in Geophysical Research Abstracts (2019)

Urban planning is central to flood risk prevention. Flood-sensitive urban planning pursues two goals: reducing flood exposure and vulnerability [1]; but also addressing the influence of urban ... [more ▼]

Urban planning is central to flood risk prevention. Flood-sensitive urban planning pursues two goals: reducing flood exposure and vulnerability [1]; but also addressing the influence of urban characteristics on flood flow severity (flow depths and velocities) [2]. Focusing on the latter, we present here a unique software which automatically optimizes the geometry of urban layouts to enhance flood resilience [3]. The optimized parameters describe the arrangement of the road network, the blocks, the parcels, and the buildings. The proposed approach is particularly innovative since, so far, such automatic urban design tools were developed only for totally different objectives (e.g. optimizing sun exposure or distance to parks); but not in the context of flood risk management. Our automatic urban design system consists of three components: (i) a procedural urban model, (ii) a surrogate for a hydraulic model and (iii) an optimization engine. • Starting from a set of input parameters pi (typical road length, width, curvature …) the procedural urban model generates urban layouts which mimic fairly realistically real-world urban patterns [3]. • To achieve interactive feedback (i.e. getting the results within a few seconds), the system uses a neural network (NN) to approximate the relationship between urban layout and flood flow characteristics. The NN was trained using a relatively fast 2D porosity-based hydraulic model [4], which in turn was calibrated against a detailed shallow-water model [2]. • A Markov Chain Monte Carlo optimization is used to adjust iteratively the procedural model parameters pi so as to yield the desired urban layout. The system was tested for optimizing the layout of an urban district of 1 km by 1 km subject to river flooding. The system runs about one minute to find the optimal urban layout. The system tends to improve the flow conveyance through the urban area by increasing the voids in-between the buildings (e.g., increase road width) and by promoting a more “fragmented” urban pattern (e.g., decrease road length). The optimization reduces the flood water depths in the district by up to 20 to 25%. Several real-world examples showcase the operationality of the system for improving flood resilience through flood-sensitive urban design [3]. In practice, such an interactive digital tool can valuably assist urban planners and architects to assess the implications of various design decisions on flooding and end up with improved flood-sensitive urban layouts. The approach should be further developed to accommodate more diverse flooding scenarios (e.g. pluvial floods, coastal floods, etc.). References [1] Mustafa, A. et al. (2018). Effects of spatial planning on future flood risks in urban environments. J. Environ. Manage. 225, 193–204. [2] Bruwier, M. et al. (2018). Influence of urban pattern on inundation flow in floodplains of lowland rivers. Sci. Total Environ. 622-623, 446–458. [3] Mustafa, A. et al. (2019). Procedural Generation of Flood-Sensitive Urban Layouts. Environ Plan B Urban Anal City Sci. In press. [4] Bruwier, M. et al. (2017). Shallow-water models with anisotropic porosity and merging for flood modelling on Cartesian grids. J. Hydrol. 554, C, 693–709. [less ▲]

Detailed reference viewed: 51 (8 ULiège)
Full Text
Peer Reviewed
See detailOptimization of hydropower production in a water supply network using CasADi
Pirard, Thomas ULiege; Erpicum, Sébastien ULiege; Bruwier, Martin ULiege et al

Conference (2019)

Installation of (micro-)turbines in water supply networks has become an attractive strategy for small hydropower production in urban environment. It has virtually no impact on ecosystems and offers side ... [more ▼]

Installation of (micro-)turbines in water supply networks has become an attractive strategy for small hydropower production in urban environment. It has virtually no impact on ecosystems and offers side-benefits such as leakage reduction by turning excess pressure into hydropower. Our research aims at improving the modelling and optimization of existing tools for sizing and selecting the optimal location of turbines in urban water supply systems. A critical component of the analysis is the hydraulic model of the system. In most existing studies, the flow variables in the water supply network are computed under the assumption of a quasi-steady flow. Here, we opt for an in-house hydraulic model which achieves a more realistic description of time-varying flow. We will present comparisons of the two approach to assess the potential benefits of the unsteady computation. For optimizing the size and location of turbines in the network, most research uses meta-heuristics [1-3]. In this research, we explore an alternative operational strategy, based on the detailed hydraulic computation of the water supply network prior to the installation of turbines, followed by formal optimization techniques. Both the hydraulic model and the optimization technique are implemented in the CasADi framework for nonlinear optimization and optimal control [4]. The operationality of our developments is shown for a range of standard case studies as well as a real-world case study representing the urban water supply system of Liege, Belgium, which includes 3,600 km of pipes and more than 200 hydraulic structures, such as interconnected reservoirs. Monitoring data from around 700 gauges throughout the water supply network are used to provide a deep understanding of the system operation and a validation of the hydraulic model. [less ▲]

Detailed reference viewed: 43 (3 ULiège)
Full Text
Peer Reviewed
See detailFluvial dike breaching induced by overtopping: lessons from experimental and numerical studies
El kadi Abderrezzak, Kamal; Rifai, Ismail; Dewals, Benjamin ULiege et al

Conference (2019)

Overtopping of fluvial dikes (i.e. dykes or levees) can lead to the initiation of breaching and potentially brutal dike failure and inundation of the protected area. Flood risk management and prevention ... [more ▼]

Overtopping of fluvial dikes (i.e. dykes or levees) can lead to the initiation of breaching and potentially brutal dike failure and inundation of the protected area. Flood risk management and prevention require a precise quantification of the hazard. Accurate estimate of the flow through the breach is paramount, for which a precise understanding of the breach formation and expansion is required. Existing methods are often the result of investigations conducted on overtopping of frontal dikes (embankment dams). The application of such approaches to fluvial dikes is not reliable and processes underpinning breach expansion are still under research. An experimental program was conducted to fill this gap by investigating the physical processes involved in fluvial dike gradual breaching induced by overtopping. Experiments were conducted within the framework of a collaboration between the National Laboratory of Hydraulics and Environment (LNHE) of the R&D division of EDF and the research team of Hydraulics in Environmental and Civil Engineering (HECE) of University of Liège. Experiments were conducted in two distinct experimental setups, each consisting of a main channel and a floodplain area separated by an erodible fluvial dike. The focus was made to study the spatial erosion of homogenous, non-cohesive dikes induced by overtopping. Measurements included continuous scanning of the dike geometry using a non-intrusive method (Laser Profilometry Technique), designed and developed specifically for the present work. Tests conducted under controlled flow and dike configurations allowed assessing the effects of channel inflow discharge, downstream channel regulation system, and floodplain confinement on the breach development and outflow. Effects of main channel size, dike material size, apparent cohesion, and bottom erodibility were studied as well. In the present paper, the most important findings of the experimental study are presented. Additionally, the flow and dike breaching were simulated using the two-dimensional depth averaged code TELEMAC-2D. This allowed assessing the performance of a detailed morphodynamic code for dike breaching processes. [less ▲]

Detailed reference viewed: 34 (1 ULiège)
Full Text
Peer Reviewed
See detailOvertopping induced fluvial dike breaching: lessons from experimental and numerical studies
Rifai, Ismail; El kadi Abderrezzak, Kamal; Violeau, Damien et al

in Digues Maritimes et Fluviales de Protection contre les Inondations (2019)

Overtopping of fluvial dikes (i.e. levees) can promote breach formation and potentially brutal dike failure, leading to the inundation of the protected area. Flood risk management and prevention require a ... [more ▼]

Overtopping of fluvial dikes (i.e. levees) can promote breach formation and potentially brutal dike failure, leading to the inundation of the protected area. Flood risk management and prevention require a precise quantification of the hazard. Accurate estimate of the flow through the breach is paramount, for which a precise understanding of the breach formation and expansion is required. An experimental program was conducted to fill this gap by investigating the physical processes involved in overtopping induced fluvial dike gradual breaching. Experiments were conducted on two distinct experimental setups, each consisting of a main channel and floodplain area separated by an erodible fluvial dike. The focus was made to study overtopping induced spatial erosion of homogenous, non-cohesive dikes. Measurements included continuous scanning of the 3D dike geometry using a non-intrusive method (Laser Profilometry Technique), which was designed and developed specifically for the present works. Tests conducted under controlled flow and dike configurations allowed assessing the effects of channel inflow discharge and floodplain confinement on the breach development and outflow. Effects of dike material size, apparent cohesion, and bottom erodibility were studied as well. In the present paper, the most important findings are presented. Additionally, the flow and dike breaching were simulated using the two-dimensional depth-averaged code TELEMAC-2D. This allowed assessing the performance of a detailed morphodynamic code for dike breaching processes. [less ▲]

Detailed reference viewed: 49 (1 ULiège)
Full Text
Peer Reviewed
See detailFormation de brèche dans les digues fluviales soumises aux surverses : apports de la modélisation expérimentale et numérique
Rifai, Ismail; El kadi Abderrezzak, Kamal; Violeau, Damien et al

in Digues 2019 - 3eme Colloque National sur les digues maritimes et fluviales de protection contre les inondations (2019)

Detailed reference viewed: 25 (0 ULiège)
Full Text
Peer Reviewed
See detailEffects of spatial planning on future flood risks in urban environments
Mustafa, Ahmed Mohamed El Saeid ULiege; Bruwier, Martin ULiege; Archambeau, Pierre ULiege et al

in Journal of Environmental Management (2018), 225

Urban development may increase the risk of future floods because of local changes in hydrological conditions and an increase in flood exposure that arises from an increasing population and expanding ... [more ▼]

Urban development may increase the risk of future floods because of local changes in hydrological conditions and an increase in flood exposure that arises from an increasing population and expanding infrastructure within flood-prone zones. Existing urban land use change models generally consider the expansion process and do not consider the densification of existing urban areas. In this paper, we simulate 24 possible urbanization scenarios in Wallonia region (Belgium) until 2100. These scenarios are generated using an agent-based model that considers urban expansion and densification as well as development restrictions in flood-prone zones. The extents of inundation and water depths for each scenario are determined by the WOLF 2D hydraulic model for steady floods corresponding to return periods of 25, 50, and 100 years. Our results show that future flood damages and their spatial distributions vary remarkably from one urbanization scenario to another. A spatial planning policy oriented towards strict development control in flood-prone zones leads to a substantial mitigation of the increased flood damage. By contrast, a spatial planning policy exclusively oriented to infill development with no development restrictions in flood-prone zones would be the most detrimental in terms of exposure to flood risk. Our study enables the identification of the most sensitive locations for flood damage related to urban development, which can help in the design of more resilient spatial planning strategies and localize zones with high levels of flood risk for each scenario. [less ▲]

Detailed reference viewed: 73 (21 ULiège)
Full Text
See detailDimensional analysis for hydraulic modelling of urban flooding
Li, Xuefang ULiege; Erpicum, Sébastien ULiege; Mignot, Emmanuel et al

Report (2018)

This document conducts a dimensional analysis for the experimental models of urban flooding. It highlights the key parameters for the flow characteristics of urban flood. The experimental test program is ... [more ▼]

This document conducts a dimensional analysis for the experimental models of urban flooding. It highlights the key parameters for the flow characteristics of urban flood. The experimental test program is also defined. [less ▲]

Detailed reference viewed: 34 (5 ULiège)
Full Text
Peer Reviewed
See detailImprovement of anisotropic porosity models with a merging technique
Bruwier, Martin ULiege; Archambeau, Pierre ULiege; Erpicum, Sébastien ULiege et al

in Proc. River Flow 2018 (2018, September)

Detailed reference viewed: 20 (6 ULiège)
Full Text
Peer Reviewed
See detailNumerical study of the Martelange mine to be used as lower reservoir for constructing an Underground Pumped Storage Hydropower plant
Pujades, Estanis; Orban, Philippe ULiege; Archambeau, Pierre ULiege et al

in Advances in Geosciences (2018), 45

Underground Pumped Storage Hydropower (UPSH) using abandoned mines has been considered as a potential high capacity Energy Storage Systems. In UPSH plants, the excess of electricity is stored in the form ... [more ▼]

Underground Pumped Storage Hydropower (UPSH) using abandoned mines has been considered as a potential high capacity Energy Storage Systems. In UPSH plants, the excess of electricity is stored in the form of potential energy by pumping water from an underground reservoir (abandoned mine in this paper) to a surface reservoir, while electricity is produced (when the demand increases) discharging water from the surface into the underground reservoir. The main concerns may arise from the water exchanges occurring between the underground reservoir and the surrounding medium, which are relevant in terms of environmental impact and UPSH efficiency. Although the role of the water exchanges has been previously addressed, most studies are based on synthetic models. This work focuses on a real abandoned slate mine located in Martelange (Belgium). The effects of different rehabilitation works to prepare the mine as an underground reservoir are assessed in terms of groundwater exchanges and their associated consequences. [less ▲]

Detailed reference viewed: 66 (4 ULiège)
See detailSupporting dataset for: "Floodplain Backwater Effect on Overtopping Induced Fluvial Dike Failure"
Rifai, Ismail; El kadi Abderrezzak, Kamal; Erpicum, Sébastien ULiege et al

Textual, factual or bibliographical database (2018)

Supporting data for the manuscript: "Floodplain Backwater Effect on Overtopping Induced Fluvial Dike Failure" Included in this repository the data used in: - Figure 2 : Longitudinal profiles at dike crest ... [more ▼]

Supporting data for the manuscript: "Floodplain Backwater Effect on Overtopping Induced Fluvial Dike Failure" Included in this repository the data used in: - Figure 2 : Longitudinal profiles at dike crest for Tests 3 and 14 - Figure 3 : Elevations of 3D reconstructions of dike breaching for Tests 2, 5, and 14 - Figure 4 : Selected longitudinal profiles of Tests 14, 2, 3, and 5 - Figure 5 : Time series of water levels, breach discharges, breach widths, and channel Froude numbers for Tests 14, 1, 2, 4, and 5 - Figure 6 : Elevations of final 3D reconstructions of dikes for Tests 14, 1, 2, 4, and 5 - Figure 7 : Time series of the breach widening and deepening. [less ▲]

Detailed reference viewed: 36 (7 ULiège)
Full Text
See detailDesign of experimental urban flood model
Li, Xuefang ULiege; Erpicum, Sébastien ULiege; Archambeau, Pierre ULiege et al

Conference (2018, June 11)

In this Master class, I presented the detailed design of the experimental model of my PhD research, including the model geometry design, laboratory setup and the measurement techniques. Useful discussions ... [more ▼]

In this Master class, I presented the detailed design of the experimental model of my PhD research, including the model geometry design, laboratory setup and the measurement techniques. Useful discussions were acheived for the model design, which confirms also the deep scientific interest of the PhD project. [less ▲]

Detailed reference viewed: 37 (6 ULiège)
Full Text
Peer Reviewed
See detailExperimental and numerical modelling of fluvial dike breaching due to flow overtopping
Rifai, Ismail; El kadi Abderrezzak, Kamal; Violeau, Damien et al

in Armanini, Aronne; Nucci, Elena (Eds.) New challenges in hydraulic research and engineering (2018, June)

Laboratory experiments have been conducted to in-vestigate the breaching of fluvial dikes under flow overtopping conditions. The measurements have been used to assess the performance of a 2D depth ... [more ▼]

Laboratory experiments have been conducted to in-vestigate the breaching of fluvial dikes under flow overtopping conditions. The measurements have been used to assess the performance of a 2D depth-averaged model. [less ▲]

Detailed reference viewed: 53 (1 ULiège)
Full Text
Peer Reviewed
See detailHydrodynamics of shallow reservoirs: recent advances
Dewals, Benjamin ULiege; Erpicum, Sébastien ULiege; Ferrara, Vélia et al

in Armanini, Aronne; Nucci, Elena (Eds.) New challenges in hydraulic research and engineering (2018, June)

The reliable prediction of the flow field in shallow reservoirs is crucial to guide the optimal design and operation of these structures. We highlight here configurations leading to bi-stable flow fields ... [more ▼]

The reliable prediction of the flow field in shallow reservoirs is crucial to guide the optimal design and operation of these structures. We highlight here configurations leading to bi-stable flow fields and we present a radically new, energy-based, approach to predict theoretically the flow fields. [less ▲]

Detailed reference viewed: 40 (5 ULiège)