This study investigated flow characteristics around a cylindrical pier under a partially submerged bridge deck. The tests were carried out in clear water conditions for both free-surface and pressure-flow conditions. Three-dimensional velocity measurements were taken at different positions along the centreline of the flume using an acoustic Doppler velocimeter. The results showed that the longitudinal

The presence of a small seepage velocity in streams and rivers induces transfer of mass and momentum near the sediment boundary, causing bank failure and instability of hydraulic structures. This experimental study is intended to report near-bed hydrodynamics and morphological characteristics under the impact of downward seepage. A laboratory investigation was conducted in a sinuous rectangular alluvial

The interaction between confluence and vegetation is important for understanding the rules of flood control and ecological restoration. To this end, artificial flexible plastic grass was used in a 90° confluent open channel to simulate the ambient conditions of the natural state, and three-dimensional velocities were measured by an acoustic Doppler velocimeter. The velocities of different spatial distribution

A new approach for finding a cost-effective combination of groynes in a channel bend for the prevention of bend scour is presented. A linked simulation–optimisation model is proposed for this purpose. The morphological flow simulation model was developed by solving the shallow-water equations and the Exner sediment continuity equation in a boundary-fitted coordinate system. The optimisation model was

Stormwater management must address three direct threats to urban ecological security during the urbanisation of China: waterlogging, water pollution and shortages of water resources. Based on the theory of landscape security patterns, macro-level stormwater landscape security patterns (SLSPs) associated with regional flood security, runoff pollution control security structures and water resource utilisation

Brazilian cities, like other cities in developing countries, have changed in the last few decades due to accelerated population growth and rural–urban migration. Since these changes are not accompanied by urban planning, they represent a great risk to the maintenance of a balanced environment. This results in deforestation, excessive soil waterproofing, floodplain occupation, river pollution and much

The potential for a rainwater harvesting (RWH) system to supplement the water supply in Chittagong city, Bangladesh, was assessed. Two years were selected for the analysis (2006 and 2020); the projected rainfall for 2020 was evaluated using the Statistical Downscaling Model. Data on projected runoff, land use changes, population growth and catchment areas were also accumulated. The whole city was divided

The distribution of depth-averaged velocity is crucial to many engineering problems. This paper presents an analytical solution for the lateral depth-averaged velocity distribution in a 120° curved channel with asymmetric trapezoidal cross-sections in which the curved flow is not fully developed. The proposed analytical model was derived from the streamwise depth-integrated Reynolds-averaged Navier–Stokes

The installation of a labyrinth weir as the crest of a stepped chute significantly influences the downstream chute inflow conditions relative to published design standards for more traditional crest shapes. A current study at the Utah Water Research Laboratory (Utah State University) evaluated a 10.67° trapezoidal labyrinth weir crest discharging into a 0.8H:1.0V stepped chute. To better direct flows

Estimation of streamwise depth-averaged velocity and boundary shear stress are important requisites for modelling of river flows associated with flood events. Recently, many methods have emerged to predict these flow variables with great accuracy, but they provide unsatisfactory results in shear layer regions. This paper presents an improved methodology to predict depth-averaged velocity and bed shear

The planning of future supplies of agricultural water is beset by uncertainties stemming from inaccuracies in general circulation models, assumed greenhouse gases emissions scenarios (GHGESs), imperfect models employed for estimating reservoir inflows and approximate methods for estimating agricultural water demand. The uncertainty of providing agricultural water under climate change was assessed,

This paper presents the results of flow and turbulence characteristics measured by a down-looking 16 MHz micro acoustic Doppler velocimeter around partially submerged spur dyke founded in a clay–gravel sediment mixture. Velocity and turbulence data were collected at various cross-sections at the wake and upstream sides of the spur dyke within and outside of the scour hole. The longitudinal velocity

Headcut erosion is a very common process occurring at the head of rills, crop furrows and ephemeral gullies. A numerical model of the headcut flow was built to study the wall shear stress characteristics downstream of the scour hole, which is very important in headcut erosion prediction models. The calculated nappe parameters are very close to experimental data and/or equation results. The calculated

This paper presents a new data-driven modelling framework for forecasting probabilistic flood inundation maps for real-time applications. The proposed end-to-end (rainfall–inundation) method combines a suite of machine learning (ML) algorithms to forecast discharge and deliver probabilistic flood inundation maps with a 3 h lead time. To classify wet/dry cells, the method applies rainfall–discharge

A simple empirical method is proposed for computing the backwater level for different bridge shapes and crossings in compound channels. A series of parametric studies was conducted on the influence of the Froude number, opening ratio, discharge and roughness coefficient on the backwater depth. The results of the parametric studies, along with multiple regression analysis, were used to derive a simple

The wider benefits of natural flood management are increasingly used to engage local stakeholders and justify physical implementation. Previous studies have highlighted the potential for upstream natural flood management interventions to contribute to water level management strategies by mitigating downstream water levels and promoting free discharge at surface drainage outfalls from urban areas. The

This paper demonstrates the influence of differential roughness on the boundary shear distribution for compound open channels. A mathematical relationship is derived between the percentage shear force carried by floodplains and five non-dimensional parameters (width ratio, relative flow depth, relative roughness, Reynolds number and Froude number). A procedure for assessing the flow distribution in

The effects of a cracked tunnel underneath a canal bed on water and sand inflow through the tunnel hole and distortion of the canal bed were experimentally examined. A circular hole in the centre of the base plate of the flume was used to simulate the cracked tunnel. In total, 108 tests were conducted to investigate four factors that affect canal bed morphology (four water depths, three bed material

Overtopping erosion is one of the main factors responsible for the destruction of earthen structures due to floods. Considering the shortage of existing studies and the need for further research to properly understand the processes leading to breaching failure, this study investigates the effect of compaction level (dry density) on the overtopping erosion response of model compacted silty sand dams

The effect of suspended sediment concentration on the characteristics of a hydraulic jump in a symmetrical trapezoidal channel was studied experimentally and compared with a classic jump. The first test series of the classical jump was performed in a rectangular flume, while the second series was conducted with two different trapezoidal side slopes. In both cases, the tests were conducted under clear

Concrete face rockfill dams are widely used in hydropower engineering because of their many advantages. As important structures, if the performance of the concrete face slab and the impervious curt...

A large number of multi-reservoir hydropower systems are in operation all over the world in order to meet increasing power demand. To date, different optimisation methods have been applied to multi...

The bar–pool morphology is a typical feature of meandering channels that strongly affects flow and transport patterns. In this study, the three-dimensional flow velocity was measured in detail at s...

Experiments were performed in a sand bed channel to investigate the effects of a mining pit on the hydrodynamics around circular bridge piers. Mean velocity profiles, Reynolds stresses, kinetic energy fluxes and scales of turbulence were analysed at critical locations along the channel bed as well as in the proximity of the pier. At the approach location where flow had passed over the pit and was approaching

Combined weir–gate structures are important structures for controlling the water level, measuring discharge and avoiding sediment deposition behind a weir. They can be used, for example, in irrigation channels and waste water systems. Using three-dimensional numerical software (Flow-3D) and experimental data from the literature, four combined systems of a triangular weir and a rectangular gate with

Laboratory experiments were conducted in a flume containing three types of artificial flexible submerged and emergent vegetation. Detailed measurements of velocity and sediment concentration in the channel were taken. The results showed that submerged and emergent vegetation generates a much greater resistance to flow and significantly alters the vertical distributions of velocity, especially in vegetated

For many remote and under-privileged communities, water filtration is the first step of treatments before boiling and/or other higher level treatments. Clogging is a common unavoidable hindrance to such systems, which causes reduced efficiency with regard to the flow rate of filtered water. Backwashing is commonly used to recover the filtration capacity of clogged filter media. This paper presents

Promoting economically efficient solutions to meet competing demands for water under uncertain and variable supplies requires knowledge about the economic value of water and costs for its scarcity....

In the process of rapid urbanisation, maintaining urban water supplies and reducing flood risks are increasingly serious global problems. To address these issues, in 2013, the Chinese government proposed a development plan for ‘sponge cities’, which involves the implementation of various water management systems for natural storage, infiltration and cleaning of water in urban areas. In 2016, 30 pilot

Global and regional challenges related to river basin water scarcity can effectively be managed through improved reservoir operations and reservoir sedimentation control. It is a well-known fact that increased sedimentation due to various reasons is adversely affecting reservoir capacities and threatening long-term water supplies; these implications are aggravated due to impact stresses such as climate

Data from the Gravity Recovery and Climate Experiment (Grace) satellite and stations were used to estimate variations of the monthly groundwater level in the Zayanderud basin, Iran, over the period 2000–2018. In addition, the annual and seasonal storage of groundwater in this basin was estimated and verified using Grace satellite data, and compared with data from the previous rainfall. The results

Riverbank erosion is a common natural river process that threatens the security of instream structures, as well as public and private property. In this study, two sets of tests were performed (direct shear tests and flume tests) to study the effects of riverbed soil composition on the stability of riverbanks. The results of the direct shear tests demonstrated that the riverbank material became increasingly

The seasonal variation characteristics of eutrophication based on HJ-1 data and synchronous observation data on the ground were studied to provide a theoretical basis for the restoration and management of eutrophication in Dongting Lake. The remote sensing model of chlorophyll-a concentration inversion was established through the comparative analysis of the linear model, exponential model, logarithmic

This paper introduces a hybrid non-linear Muskingum model for flood routing. The proposed hybrid model has more degrees of freedom for fitting observed data than other non-linear Muskingum models. The main goal of this work is to develop a comprehensive model for outflow routing. The proposed hybrid model's predictive skill is evaluated with experimental, real and multimodal hydrograph-routing problems

A comprehensive study on free and submerged hydraulic jumps in different stilling basins was carried out. The effects of three adverse slopes, three bed roughnesses and three positive step heights on the hydraulic jump characteristics with a Froude number of 4·56–9·55 and a submergence factor of 0·1–1·5 were investigated. Two semi-theoretical solutions based on the momentum equation were developed

The energy gradient is a fundamental physical quantity of flow motion. To date, many studies have concentrated on uniform flow or fully developed curved flow, with the energy gradient approximated as the bed slope. This paper presents a new method to assess the lateral distribution of the apparent energy gradient in curved channels when curved flow is not fully developed. A dimensionless apparent energy

The ability of green roof systems to impact stormwater runoff from buildings has been covered in many research studies. However, a lot of these studies looked at long-term retention, with much less work focused on how to model a green roof's response to larger design storms. Work that has examined flow routing for individual rainfall events has focused on empirical routing models that are tuned to

This paper describes the use of surface flow image velocimetry (SFIV) to analyse flow velocity fields near grated inlets. This will help to understand the flow-capture process of grated inlets and improve their design. The technique allows approximation of the surface flow velocity field where other techniques can fail. Especially in cases when the flow near the inlet is supercritical, and with small

This paper presents a systematic investigation into modelling capacities of three conventional data-driven modelling techniques, namely, wavelet-based artificial neural network (WANN), support vect...

Infrastructure assets require suitable management and assessment protocols due to age-related deterioration, extreme weather events and climate change impacts. Above-ground river crossings are weak...

This paper presents a consistent and transparent methodology for the prioritisation of the pipeline sections to be renewed in the whole Aigues de Barcelona (AB) urban water network. The prioritisat...

The type of ownership (public or private) influences the management and planning of water resources with an engineering base in the urban sphere. The objectives, interests, resources and working co...

Sediment transport predictor based on a review and update of the theory of Ackers and White is proposed. While the core of the theory was retained, the approach to predicting transport rates was updated by introducing some new ideas and modified where opportunities for improvement were identified. A large dataset compiled from the existing literature was used for model calibration and validation. The

The goal of this research was to investigate the feasibility of using electrocoagulation (EC) as a primary surface water treatment process that could be used with solar panels in decentralised loca...

A new round of reform of China's electricity market was launched in 2015 to encourage competition among power generation companies. For cascade hydropower stations under multi-partite ownership, an...

A study on scour around submerged tandem and offset cylinders was carried out with the aim of characterising the scour process and the influence of various parameters on the variation of scour dept...

Scour hole development around a circular bridge pier protected by a collar under steady and unsteady flow conditions is thoroughly investigated. At the first stage, formation of a scour hole around...

After continuous use of any filtration device, clogging of the filter media becomes apparent, which eventually causes poor performance of the filtration process. Back-washing is a common technique ...

Across sub-Saharan Africa many communities lack reliable access to mains electricity, and therefore depend upon unconventional power sources to recharge their mobile phones. Many of these informal ...

Understanding the hydrological behaviour of urban surfaces is imperative in the design of surface water drainage systems and flood mitigation strategies, as well as for the modelling of groundwater...

Building water dissipation (BWD) refers to the change of water into vapour during water use activities in the building. The intention of the work described in this paper was to explore the BWD mech...

One challenge facing water managers is how to supply various downstream claims with conflicting priorities, especially during droughts. This study calculates the total volumes of water released fro...

A series of experiments were conducted to reveal the effects of the sidewall shear stress distribution (SSSD) on homogeneous cohesive bank erosion processes in a U-shaped flume. The three-dimension...

The flow and turbulence structure of a brush fish pass was investigated in a 1:2 physical model for Reynolds numbers of 5·46 × 104–1·78 × 105 and Froude numbers of 0·18–0·72. Experiments were perfo...

The influence of rigid vegetation on the longitudinal dispersion coefficient in a compound open channel was examined using an image processing technique. To simulate floodplain vegetation, cylinder...

In the past, the islands of Carriacou and Petite Martinique in the Grenadines have depended on domestic rainwater harvesting (RWH) for their water supply. Although the availability of water from th...

Defluoridation of water through adsorption using biosorbents is currently attracting attention. A thermo-chemically developed biosorbent derived from Ficus glomerata bark was used in the present st...

Flow characteristics downstream of free and submerged hydraulic jumps with and without blocks were experimentally studied for Froude numbers ranging from 3·48 to 6·85. The streamwise variation of t...

Remarkable channel degradation has occurred in a braided reach of the Lower Yellow River owing to the recent operation of Xiaolangdi reservoir, and downstream progressive incision has caused a sign...

This study explored the disposal strategies of menstrual sanitary products through in-depth semi-structured interviews with women aged 18–30 years. There have been many educational campaigns to imp...