A vertically discretized multi-paddle wavemaker is proposed that generates various wave types without the depth-invariant flow condition limitation associated with conventional piston type wavemakers. A first-order mathematical formulation for the paddle stroke is derived and used to selectively generate free surface waves similar to either piston type or flap type wavemakers, depending on the number

In a recent paper, Zhang et al. (2019) statistically analyzed the pile group effect of nine piles in a side-by-side arrangement exposed to multi-directional irregular waves. In this study, the corresponding data are further analyzed and their probabilistic distributions are examined. The Weibull distribution is used to fit the measured wave force, and the relationships between parameters A and B of

Wave-induced sediment transport is an important issue in coastal engineering. It is of fundamental significance to manifest the boundary layer behavior of nonlinear waves to accurately describe sediment transport in coastal areas, where wave forms are typically cnoidal or forward leaning rather than sinusoidal or symmetrical. In the present work, a novel expression of the near bed orbital velocity

The autonomous ship carrying valuable cargoes and passengers in a more effective and cost-saving manner will soon be state of the art technology, which most likely shall be introduced into the public horizon as the remote control mode within the foreseeable future. The highly connected intelligent systems though come at the cost of the increased system vulnerability to cyber-attacks. To smooth this

Accurate modeling of low-frequency (LF) wave loads and responses is important but challenging in the design of spar-type floating offshore wind turbines (FOWTs), especially for shallow and intermediate water depths. A 6 MW spar-type FOWT system designed for a water depth of 100 m is investigated both experimentally and numerically to study the nonlinear hydrodynamics responses in waves. The second-order

In the present work, numerical simulation of structural damage subjected to the near-field underwater explosion is carried out by coupling the SPH and RKPM. The fluid solver is established based on the compressible SPH method, while the dynamic response of the structure is calculated based on the RKPM shell formulation. Since large deformation with contact will occur in the underwater explosion problem

Peregrine breather solution of the nonlinear Schrödinger (NLS) equation can be treated as one of the excellent backbone models for abnormal wave in the ocean. Fully nonlinear numerical simulations performed with the higher-order spectral method reveal that its maximum amplification factor can be larger than the theoretical prediction in the regular background wave and that such breather dynamics has

Oscillating Water Column (OWC) with its mechanism based on converting hydrodynamic energy into pneumatic energy is one of the earliest wave energy converters studied by researchers. While the focus of the previous studies were mainly on hydrodynamic efficiency, this paper addresses free surface fluctuation inside the OWC chamber emphasizing on sloshing phenomenon through irregular wave impingement

Cruise ships have large and long superstructures, which are almost extending the whole ship length with discontinuous characteristics, such as side shell recess and many window openings. The superstructure effectiveness on hull girder longitudinal strength is a complicated but unavoidable issue in ship design stage. This paper has carried out a collapse experiment of steel model with superstructures

Burst pressure prediction of pipelines with interacting defects is essential in the integrity assessment of steel pipelines. A series of evaluation criteria have been proposed to predict the burst pressure. However, the burst pressure is not accurately estimated by the existing evaluation methods for some defect distribution cases, especially for circumferentially aligned defects. In this study, a

Discussers (Hariri-Ardebili and Sattar) address the paper “Seismic assessment of deep water bridges in reservoir considering hydrodynamic effects using endurance time analysis” written by the coauthors of this response. They present the fundamental assumptions on the generation of Endurance Time Excitation Functions (ETEFs) and the derivation of fragility functions by Endurance Time Analysis (ETA)

Design flood, which plays a paramount role in reservoir construction and operation, is often calculated by the annual maximum sampling method (AMSM). However, the AMSM can only use a small amount of data and reflect the extreme value distribution of inflow flood. As a result, the annual maximum design flood or the seasonal design flood is not sufficient to formulate the reservoir operation scheme in

Landuse change and climate change are the main drivers of hydrological processes. The purpose of this study was to analyse the separate and combined future effects of climate and landuse changes on water balance components on different spatial and temporal scales using the integrated hydrological Soil and Water Assessment Tool model. The study focused on the changes and relationship between water yield

Chromium (Cr) in water bodies is considered as a major environmental issue around the world. In the present study, aqueous Cr(VI) adsorption onto rice husk was studied as a function of various environmental parameters. Equilibrium time was achieved in 2 h and maximum Cr(VI) adsorption was 78.6% at pH 5.2 and 120 mg L−1 initial Cr(VI) concentration. In isotherm experiments, the maximum sorption was

The presence of pharmaceutical compounds in the whole environment is a growing concern. These compounds might be present in the effluents of wastewater treatment plants and, hence, irrigation with treated sewage may be a source of groundwater pollution. The volcanic aquifer that lies NE of Gran Canaria (Spain) was studied to address the relationship of the occurrence of pharmaceutical compounds and

Microplastics have been documented in aquatic and terrestrial ecosystems throughout the world. However, few studies have investigated microplastics in freshwater fish diets. In this study, water samples and three trophic levels of a freshwater food web were investigated for microplastic presence: amphipods (Gammarus lacustris), Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), and lake trout

Concrete sewer pipes can be deteriorated by sulfuric acid (H2SO4), which is created by the oxidation of hydrogen sulfide in the presence of certain bacteria inside the sewers. This process is called biocorrosion. In this paper, H2SO4 (i.e., chemical, non-biogenic) was used to study acid attack on concrete samples. The authors conducted experiments under different acid flows and concentrations, to account

This study presents an integrated modeling system for the evaluation of the quantity and quality of water resources of coastal agricultural watersheds. The modeling system consists of coupled and interrelated models, including (i) a surface hydrology model (UTHBAL), (ii) a groundwater hydrology model (MODFLOW), (iii) a crop growth/nitrate leaching model (REPIC, an R-ArcGIS-based EPIC model), (iv) a

Structural resilience describes urban drainage systems’ (UDSs) ability to minimize the frequency and magnitude of failure due to common structural issues such as pipe clogging and cracking or pump failure. Structural resilience is often neglected in the design of UDSs. The current literature supports structural decentralization as a way to introduce structural resilience into UDSs. Although there are

Excess sludge reduction has been a research hotspot for a long time. Ultrasonic treatment of excess sludge was an efficient and green pretreatment method, and also can be combined with the addition of oxidants. To improve the effect of ultrasound treatment on sludge destruction, hydrogen peroxide (H2O2) was added to examine the combined results in the current study. The effects of the ultrasound/hydrogen

Due to the development of the scale of tractor-ploughed terraces, terraces have been increasing in number, while global climate change is causing frequent extreme rainfall events in the Loess Plateau, resulting in many terrace landslides. To study the mechanism and process of shallow landslides and deep slip surface of terraces induced by extreme rainfall in loess hill and gully area, we conducted

Worldwide, consumption of resources such as water, energy and food continues to rise exponentially despite environmental and climatic change related challenges. Centralized sewerage systems continue to be implemented worldwide despite being very water and energy intensive, and although this is not always the best option for regions facing water scarcity. Deploying the Water-Energy-Food (WEF) Nexus

Spatio-temporal distribution and leachability of some trace elements (TE) were investigated in sediments of the Xiangjiang River, tributary of the Yangtze River. Based on data collected during 2015–2017, a literature review and geoaccumulation indexes, the pollution level was the highest for Cd, Sb and Hg (Igeo > 3). Over the period reviewed, the TE contamination level displayed almost no temporal

The Mekong River, well known for its aquatic biodiversity, is important to the social, physical, and economic health of millions living in China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. This paper explores the social and environmental impacts of several Mekong basin hydropower dams and groupings of dams and the geographies of their impacts. Specifically, we examined the 3S (Sesan, Sekong Srepok)

Use of green stormwater infrastructure (GSI) to mitigate urban runoff impacts has grown substantially in recent decades, but municipalities often lack an integrated approach to prioritize areas for implementation, demonstrate compelling evidence of catchment-scale improvements, and communicate stormwater program effectiveness. We present a method for quantifying runoff reduction benefits associated

Accurate estimation of pan evaporation (Ep) is vital for the development of water resources and agricultural water management, especially in arid and semi-arid regions where it is restricted to set up the facilities and measure pan evaporation accurately and consistently. Besides, using pan evaporation estimating models and pan coefficient (kp) models is a classic method to assess the reference evapotranspiration

The accuracy of two-dimensional hydrodynamic models (2D models) is improved when high-resolution Digital Elevation Models (DEMs) are used. However, the entailed high spatial discretisation results in excessive computational expenses, thus prohibiting their implementation in real-time forecasting especially at a large scale. This paper presents a sub-model approach that adapts 1D static models to tailor

The influence of large-scale climate variability on winter river discharge and precipitation across western Europe is investigated. We analyze 60 years of monthly precipitation and river flow data from 18 major western-European rivers and its relationship with dominant teleconnection patterns and climate indices in this region. Results show that winter river flow is characterized by large interannual

Precautionary measures and governmental regulations during the COVID-19 pandemic’s first wave have drastically altered daily activities and hence water consumption patterns. Many people had to change their working routines, the organization of childcare and hygiene practices. While first evidence appears on the impacts of COVID-19 on, e.g., carbon emissions, energy demand and water treatment, even

Economic and population growth has increased the demand for freshwater worldwide, generating pressure on the environment and creating conflicts among users. Water markets have emerged as a solution for managing this resource, and Chile has been a pioneer in implementing this approach. However, most Chilean water markets are inefficient due to incomplete information, the poor flexibility of the water

The airwake behaviour around a ship provides useful information for the safe operation of helicopters on naval ships as well as in helicopter pilot training. This study investigates the impact of ship motions on the airwake behind the superstructure of a naval ship using Detached Eddy Simulation. A full-scale simplified frigate geometry is analysed stationary and in head waves at three different wavelengths

Embankment rockfill dams are the most common dam construction types used in the world today. One third of all embankment dam failures are caused by dam slope instability. The dam is stable when the slopes are stable. Slope safety of the dam is assessed through pore and total pressure data analysis registered on pressure measurement cells installed in the dam. During the service life of a dam, one or

Adapting to new climate conditions will require an intricate mix of knowledge, planning, coordination, and foresight. There is increasing sectoral evidence on the implementation of successful adaptation actions. However, the success of these actions when we consider the interdependencies among sectors remains debatable. This paper aims to assess who benefits from implementing adaptation options in

A highly accurate SPH method with a new stabilization paradigm has been introduced by the authors in a recent paper aimed to solve Euler equations for ideal gases. We present here the extension of the method to viscous incompressible flow. Incompressibility is tackled assuming a weakly compressible approach. The method adopts the SPH-ALE framework and improves accuracy by taking high-order variable

Note: In lieu of an abstract, this is an excerpt from the first page. After more than three years of implementing the 2030 Agenda for Sustainable Development, the 2019 World Water Week in Stockholm chose to focus on inclusiveness with the theme “Water for society—Including all” [...]

Recent advances in image-based methods for environmental monitoring are opening new frontiers for remote streamflow measurements in natural environments. Such techniques offer numerous advantages compared to traditional approaches. Despite the wide availability of cost-effective devices and software for image processing, these techniques are still rarely systematically implemented in practical applications

A systematic variation of the exposure level of a spherical particle in an array of multiple spheres in a high Reynolds number turbulent open-channel flow regime was investigated while using the Large Eddy Simulation method. Our numerical study analysed hydrodynamic conditions of a sediment particle based on three different channel configurations, from full exposure to zero exposure level. Premultiplied

The study applied the method of hydrological season identification in a time series of river total and base flows and in groundwater levels. The analysis covered a series of daily measurements from the period 2008–2017 in nine catchments located in different geographical regions of Poland. The basis of the classification of hydrological seasons, previously applied for river discharges only, was the

This paper presents a simplified parametric model for the estimation of depth-limited hurricane wave spectra, accounting for swell and wind-sea components, for coastal engineering applications. The model was evaluated against observations obtained from three shallow water sites in Florida during Hurricane David in September 1979. It was revealed that the parametric approach increases in accuracy with

The current knowledge of the spatial variability of precipitation in High Mountain Asia is based on the remotely-sensed estimates (coarse spatial and temporal resolution) or data from sparsely-distributed rain gauges. However, as precipitation is strongly affected by topography in mountainous terrain, the spatially varying precipitation and the resulting water balances are currently poorly understood

Estimating transpiration as an individual component of canopy evapotranspiration using a theoretical approach is extremely useful as it eliminates the complexity involved in partitioning evapotranspiration. A model to predict transpiration based on radiation intercepted at various levels of canopy leaf area index (LAI) was developed in a controlled environment using a pasture species, tall fescue (Festuca

As one of the most crucial indices of sustainable development and water security, water resources carrying capacity (WRCC) has been a pivotal and hot-button issue in water resources planning and management. Quantifying WRCC can provide useful references on optimizing water resources allocation and guiding sustainable development. In this study, the WRCCs in both current and future periods were systematically

Predicted climate-induced changes in the Great Lakes include increased variability in water levels, which may shift periphyton habitat. Our goal was to determine the impacts of water level changes in Lake Superior on the periphyton community assemblages in the Keweenaw Peninsula with different surface geology. At three sites, we identified periphyton assemblages as a function of depth, determined surface

The risk from erosion and flooding in the coastal zone has the potential to increase in a changing climate. The development and use of coupled hydro-morphodynamic models is therefore becoming an ever higher priority. However, their use as decision support tools suffers from the high degree of uncertainty associated with them, due to incomplete knowledge as well as natural variability in the system

In the present paper, hydrodynamic behavior and bottom wetted surfaces of two-stepped planing hull are investigated by conducting towing tank tests. To this accomplishment, hydrodynamic resistance, reattachment length, trim angle, and bottom wetted surfaces are determined under different geometric variables of the two transverse steps and planing hull speeds. Qualitative investigation is also conducted

In the glaciated mountains of the Upper Indus Basin of Pakistan, glacier‐ and snowmelt‐ based irrigation systems have been established over several centuries to secure water for cultivation. However, these systems are now facing several challenges, being sensitive to climate change and thus exposed to the resulting extreme events such as glacial lake outburst floods (GLOFs) and flash floods, also difficult

On matters of sustainability, the complement to resilient recovery is adaptive adjustment. Many of the water industry's efforts focus on a system's ability to maintain services and recover from disruptions, but just as important are efforts to understand when and how to change things when situations fall unexpectedly outside of the norm. All things considered, the water industry has proved extremely

Climate change was the top environmental focus during Biden's 2020 presidential campaign, so it is reasonable to assume that is where his administration's environmental efforts will be focused initially. In fact, at the time of this writing, the lead candidates for heading up the US Environmental Protection Agency (USEPA) all work in positions that champion ambitious climate policies. However, with

A diverse workforce is important because it increases productivity and engagement and creates an organization that better represents the community it serves.

Having recently published an article in AWWA Water Science, Giridhar Upadhyaya answered questions from the publication's editor‐in‐chief, Kenneth L. Mercer, about the research.

Every 10 years, AWWA releases a survey of disinfection practices in the water sector; taken together, these surveys frame the evolution of potable water disinfection.

A water agency used geographic information system (GIS) predictive modeling and likelihood‐of‐failure (LOF) analysis for prioritizing infrastructure replacement.

Homeowners’ decisions to replace their lead service lines (LSLs) can be complicated by factors including understanding of the science, perceptions of lead exposure risks, and cost of the work.

In response to severe drought in the state of California, local, regional, and state water agencies implemented rebate programs to encourage reductions in water use.

Passage of the 2008 Drought Management Act provided momentum for North Carolina's water loss control efforts; AWWA Manual M36 and the AWWA water audit formed the foundation.

From determining future water demands to setting rates, it's a given that most planning related to water requires managers to deal with uncertainties.

When a utility makes a mistake that affects its customers, an apology is warranted from the utility's management, not from its customer service staff.

As we begin a new year—AWWA's 140th, by the way—I cannot help but feel hopeful. Even though there isn't a true bright line between years and we still need to wear masks to protect each other's health (at least as 2021 begins), I feel hope. From time to time I have been known to say, “The world is run by those who show up.” The last time I publicly used that phrase was at the Young Professionals Summit

The outbreak of the new coronavirus disease (COVID-19) led to an unprecedented number of policy responses from public institutions involved in the health and economic sectors. Nonetheless, the water, sanitation, and hygiene (WASH) sector remained in the background of this decision-making arena. The objective of the study presented herein was to observe and discuss political responses to the new coronavirus

Among the most notable emerging hybrid technologies for water treatment are those that combine reverse osmosis (RO) membrane systems with alternative energy sources such as solar photovoltaic (PV). Solar PV modules can enable systems disconnected from the electricity grid, and in some locations can also be used for water heating as photovoltaic-thermal (PVT) units, a process in which water removes