•Landslide travel distance is considered for the first time in a predictive equation.•Predictive equation derived from databases using 3D physical and numerical modeling.•The equation was ...successfully tested on the 2018 Anak Krakatau tsunami event.•The developed equation using three-dimensional data exhibits a 91 % fitting quality.
Landslide tsunamis, responsible for thousands of deaths and significant damage in recent years, necessitate the allocation of sufficient time and resources for studying these extreme natural hazards. This study offers a step change in the field by conducting a large number of three-dimensional numerical experiments, validated by physical tests, to develop a predictive equation for the maximum initial amplitude of tsunamis generated by subaerial landslides. We first conducted a few 3D physical experiments in a wave basin which were then applied for the validation of a 3D numerical model based on the Flow3D-HYDRO package. Consequently, we delivered 100 simulations using the validated model by varying parameters such as landslide volume, water depth, slope angle and travel distance. This large database was subsequently employed to develop a predictive equation for the maximum initial tsunami amplitude. For the first time, we considered travel distance as an independent parameter for developing the predictive equation, which can significantly improve the predication accuracy. The predictive equation was tested for the case of the 2018 Anak Krakatau subaerial landslide tsunami and produced satisfactory results.
Flood hazard mapping methods: A review Mudashiru, Rofiat Bunmi; Sabtu, Nuridah; Abustan, Ismail ...
Journal of hydrology (Amsterdam),
December 2021, 2021-12-00, Letnik:
603
Journal Article
Recenzirano
•State-of-the-art review of related publications from 2000 to 2021 for the three discussed methods in FHM.•The review study gave a comprehensive overview of the methodologies in flood hazard ...mapping.•Explained the strengths and limitations of the physically-based, physical, and empirical modeling methods in flood hazard modeling.•Presented case studies of the methods, uncertainties, recent trends, and future directions associated with the methods in the review study.
Flood hazard mapping (FHM) has undergone significant development in terms of approach and capacity of the result to meet the target of policymakers for accurate prediction and identification of flood-prone or affected regions. FHM is a vital tool in flood hazard and risk management analysis. Previous review studies have focused on flood inundation modelling methods. This present study presents a thorough and current review of the physically-based, empirical, and physical modelling methods in FHM. The study gives insight into strengths, limitations, case studies, and uncertainties associated with the methods. It further discusses the approaches in handling uncertainties related to each method, and its recent development. The review study is targeted at enlightening researchers and decision-makers with an extensive understanding of the methods and of the recent improvements in FHM thereby empowering flood management agencies, decision-makers, design engineers, early warning system agencies, and responders in addressing and making accurate decisions in flood-related problems, employing best management practices in flood management, and adaption of climate decision-making towards building resilient infrastructures.
•Comprehensive physical modelling of corroded cast iron pipelines.•Statistical analysis of pipe failure data.•Use of hybrid reliability method for probabilistic analysis.•Comparison between physical ...modelling and statistical analysis of observed data.
Cast iron was the dominant material for buried pipes for water networks prior to the 1970s in Australia and overseas. At present, many water utilities still have a significant amount of ageing cast iron pipes. Cast iron is a brittle material and when large diameter cast iron pipes (diameters above 300mm) further deteriorate, the consequences of failure can be substantial. Focusing on the likelihood of failure to assist risk assessment, this paper examines the performance of large-diameter cast iron pipes using probabilistic analysis, incorporating uncertainties of governing variables. Finite element analysis is first conducted to study the physical mechanism of buried pipes subjected to complex environmental conditions. The deterioration of cast iron pipes due to corrosion is considered on the basis of recent research. The uncertainties of governing variables, such as the physical properties of soil, cast iron, water pressure and corrosion patterns, in pipe failure risk assessment are considered. Using probabilistic physical modelling, the lifetime probability of failure is derived and a time-dependent sensitivity analysis is presented. The results of this probabilistic physical modelling are compared with cohorts of failure data from two Australian water utilities to examine the underlying trends from both physical modelling and statistical analysis.
•Adsorption of Ag+, Cu2+, and Co2+ ions on faujasite-type zeolite Y was analyzed.•Physicochemical interpretation of adsorption mechanism was obtained via a physical model.•Characterization of the ...adsorption interactions was performed with DFT and statistical physics.
This work evaluated the potential of a synthesized faujasite-type zeolite Y as an adsorbent for the removal of relevant heavy metals such as silver (Ag+), copper (Cu2+), and cobalt (Co2+). The adsorption data of Ag+, Cu2+, and Co2+ ions were determined experimentally at pH 6 and temperatures of 298, 308, and 318 K. Two theoretical approaches have been applied based on statistical physics modeling and density functional theory (DFT) to understand and characterize the ion exchanges involved in the removal of all metals. Results showed that this zeolite was more efficient for the adsorption of Ag+ via cation-exchange. Based on the physical modelling, the removal of heavy metals on this zeolite was mono and multi-ionic (simple and multi-interactions), where the ions interacted via one and two adsorption sites. It was also noted that the temperature increment generated more available functional groups of the zeolite, facilitating the access to the smaller cavities and the interactions with the adsorbent. Adsorption energies for removing these metals with tested zeolite were slightly endothermic and were consistent with the typical values reported for ion exchange systems of heavy metals + zeolites. DFT results demonstrated that these cationic exchange energies depend on the nature of precursor salt, but with the same ranking. Both statistical and DFT approaches agreed that exchange Ag+ in zeolite Y was easier than Cu2+ and Co2+. Overall, the application of both theoretical approaches provided a reliable interpretation of the adsorption mechanism.
Testing of small-scale physical models of masonry structures can be useful both to study Soil Structure Interaction problems and to provide large enough datasets to statistically validate the global ...level assumptions of masonry numerical models. This paper proposes the use of a sand-based Binder Jet 3D printer to manufacture 1:10 scaled physical models of masonry walls, that can be used within a centrifuge. As such printers can only print one material, mortar is emulated by controlling the micro-geometry of the printed material at the position of the joints (i.e., by printing joints). Walls were printed and tested in compression and cyclic shear under fixed-fixed conditions and constant compressive load. Different notch geometries were tried. The tested specimens were found to behave similarly in compression and shear to full scale masonry walls. A numerical model using a concrete damage plasticity model was built in Abaqus. It captured the cyclic response of the masonry walls with a reasonable accuracy. Therefore, such small-scale models can be used to expand centrifuge modeling in structural engineering.
•Novel approach for the physical modelling of masonry walls.•Scale 1:10, models to be used in the centrifuge.•Models were manufactured via 3D printers.•Compressive and shear tests showed that they behave similarly to true masonry.
Turbine-induced damping is a critical parameter affecting the performance of oscillating water column (OWC) wave energy converters. Therefore, selecting the appropriate turbine-chamber combination is ...an essential step in their design. In this work, a methodology is developed to determine the optimum turbine diameter for a given chamber, i.e., the diameter which maximizes the pneumatic energy capture of the chamber under an extensive set of wave conditions—covering virtually the entire range of wave conditions relevant for wave energy exploitation. This novel approach combines physical and numerical modelling with dimensional analysis. Importantly, it results in a turbine diameter that enables the turbine to operate at maximum efficiency. Through the different modelling techniques applied, the methodology accounts for air compressibility effects and other non-linear effects. It is applicable to non-linear turbines, with the study focusing on the promising biradial turbine. The results indicate that using the proposed methodology to select the turbine diameter significantly improves the capture-width ratio of the OWC, with increases of up to 100% for individual sea states. Two turbine diameters were identified as appropriate for the proposed OWC chamber design, 1.1 m for low-energy sites, and 1.4 m for mid- and high-energy sites.
•A thorough method was developed to match a non-linear turbine to an OWC chamber.•The method is based on determining the turbine that provides the optimum damping.•The turbine operates at maximum performance while providing the required damping.•Turbine selection through this method highly improves the OWC capture-width ratio.
This work reviews the recent progress in physical and mathematical modelling of electrochemically assisted soil remediation processes and focuses especially on those treatments that aim to remove ...organic pollution. It introduces the importance of modelling and simulation, not only to understand, but also to manage more efficiently the remediation of polluted sites. Special emphasis is taken in the information generated in the last five to ten years, trying to shed light on how the understanding of these treatments has improved in this period. To do this, two different sections introduce the main challenges in mathematical and physical modelling, merging in a final section, that shows the expected future trends in electrochemically assisted soil remediation modelling. Regarding physical modelling, the size of the installation used in the study and the novelty of the application of the technology have been used as the key inputs for this review. Regarding mathematical modelling, the inputs used to conduct the review have been the typology of numerical code, the processes included in the model and the way in which the electrolyte is considered in the model. Final remarks highlight the importance that modeling will take in the near future to increase the technology readiness level of these treatments and to promote their massive application to the remediation of polluted sites.
•Need of mathematical and physical modelling to understand deeply soil remediation.•Sizing and novelty of the applications are the two key inputs in physical modelling.•Type of numerical code, processes, and electrolyte as key inputs in mathematical modelling.•Need of modelling to raise the TRL of electrochemically assisted soil remediation.
Landslides into water can generate massive tsunamis which are major natural hazards in coastal regions. In this study, waves were generated in a series of 41 laboratory experiments by releasing 4 ...different slide volumes ranging from 0.1-0.4 m3 of highly mobile material down a 6.73 m long slope into a reservoir of depth varying from 0.15-0.65 m, to achieve a wide range of dimensionless landslide parameter values. Water is used as the sliding material and with zero internal shear strength it is representative of the upper limit of high landslide mobility. The slide characteristics of thickness and velocity were measured at impact using high speed cameras and the time series of the resulting changes in water surface elevation were measured using nine wave probes along the 33.8 m long flume. The experimental results indicate that in the near-field the maximum wave amplitude is dependent on the landslide thickness and velocity and is relatively independent of the reservoir water depth. As waves propagate to the far-field, the depth-limited breaking reduces the wave amplitude, such that the maximum wave amplitude is highly dependent on the reservoir depth. The wave breaking limit, which differentiates the breaking from the non-breaking waves, is defined by the relationship am/h = 0.6 that is very closely adhered to for all source volumes and reservoir depths. The time and length over which the waves are generated are determined from the digital imagery, and are used to describe the scales of the momentum transfer. These observations are compared with previously published empirical and theoretical equations for granular landslides and positively buoyant avalanches, indicating that water is a useful source material for simulating highly mobile landslides. Since these parameters are difficult to obtain in field cases, a simplification of the theoretical equation is presented and this yields reasonable results for the maximum wave amplitude generated by slides with high mobility.
•Amplitudes of near-field waves generated by highly mobile flows are independent of slide volume for a given reservoir depth.•Depth-limited breaking is the primary control on the wave amplitude as waves propagate into the far-field.•Effective time and length of forcing are important factors that influence momentum transfer.
•Adsorption of sulfamethoxazole and acetaminophen on thin coated adsorbent was reported.•Chemical bonding and electrostatic forces were involved in the pharmaceuticals adsorption.•Adsorption geometry ...of pharmaceuticals was described via physical modelling analysis.
Sulfamethoxazole (antibiotic) and acetaminophen (analgesic) are classed as common Contaminants of Emerging Concern (CEC) that have been detected in significant quantities in sewage treatment plants in Malaysia and other countries. Unfortunately, the conventional sewage treatment plants are not effective to reduce the concentrations of these compounds. Therefore, this study introduces a novel Contaminant Emerging Remover (COATER) to face the pollution caused by these CECs. This COATER was formulated using epoxidized neutral rubber (ENR-50) and poly(vinyl) chloride (PVC) as binders besides activated carbon as an adsorbent, which was coated on white cotton fabric (substrate) via brushing technique. Characterization analysis of this COATER was performed using SEM-EDX, FTIR and BET quantifications to study the surface chemistry and to obtain insights about the adsorption mechanism. Results of surface morphology analysis showed a good distribution of activated carbon onto the substrate where the surface area and pore volume of the COATER were 64.3 m2/g and 0.07 cm3/g, respectively. Adsorption isotherms of tested CECs on COATER were experimentally quantified at different temperatures. A monolayer adsorption model based on statistical physics was used to understand the adsorption mechanism. Modelling results showed that the adsorption orientation of tested molecules was similar but it could occur a change in the interaction of these pollutants with the adsorption sites of COATER surface during the removal process since this adsorbent contained a variety of functional groups. It was concluded that the adsorption mechanism of tested adsorbates on COATER included pore interaction, chemical bonding and electrostatic forces.