Hydraulic Model Research Articles

Hydrological and Hydraulic Modelling of Sekolo River Diversion for Coal Mining Activities

A Hydrological and hydraulic modeling of the proposed diversion of the Sekolo River for coal mining purposes will provide an overview and technical information on the proposed river realignment and identify potential impacts on the use of the Sekolo River. It is being carried out for River extension to maintain river sustainability and functionality. Sekolo River watershed modeling utilizes a combination of hydrological analysis and open-channel hydraulic modeling using HEC-HMS and HEC-RAS software. To meet the area criterion (volume), the dimensions of the diversion channel are planned with B = 15 m. H = 1.5 m; m = 1.5; L = 1253 m. These dimensions make the volume of the diversion approximately the same as the existing river. Hydraulic simulation results showed that the flood level would not rise downstream of the diversion channel. The upstream (Q25) peak flow rate is 41.90 m3/s, while the downstream peak flow rate after diversion is increased by 0.02% compared to the existing flow rate. After introducing the diversion channel, the difference in flood peak arrival time (Tp) will be 3 minutes earlier than before the diversion.

Evaluation of pavement resilience to flooding with inverted pavement structure

Conventional pavement structures are vulnerable due to degradation of unbound materials after water inundation. Inverted pavement structure has been proven to be cost-effective and energy efficient, while its resilience has not been investigated. This study is aimed at assessing the resilience of inverted pavements to flooding events using an integrated hydraulic and mechanical modelling approach. Two-dimensional hydraulic models were established to analyse flooding-induced moisture variations in the pavements. Based on the moisture distribution results, three-dimensional mechanical models were developed to calculate critical pavement responses under moving load. The results show that the subgrade with higher groundwater table or larger hydraulic conductivity was more likely to be invaded by water. Compared with conventional pavement, the increases of critical pavement responses in inverted pavement were significantly smaller after long-period flooding, which indicates the potential benefits of inverted pavement in enhancing the resilience to flooding impact.

Inundation mapping using hydraulic modeling with high-resolution remote sensed data: a case study in the Acre River Basin, Brazil

Inundation mapping using hydraulic modeling with high-resolution remote sensed data: a case study in the Acre River Basin, Brazil

Flood hazard assessment in Chenab River basin using hydraulic simulation modeling and remote sensing

Flood hazard assessment in Chenab River basin using hydraulic simulation modeling and remote sensing

Flood risk assessment, a case study in an arid environment of Southeast Morocco

Abstract Since the early 1980s, several regions of Morocco have experienced alternating series of wet and dry periods related to climate change, with significant consequences for the country’s economy. This study aims to map flood hazards by using a hydraulic modeling approach, with a specific focus on the Oued (river) Zaouiat Sidi Hamza passing through Zaouiat Sidi Hamza township belonging to the High Ziz watershed (province of Midelt, region of Drâa-Tafilalet, Morocco). Hydraulic modeling and flood simulation were carried out followed by mapping of the flood hazard. The Oued Zaouiat Sidi Hamza River can cause torrential flooding issues, particularly during periods of heavy storms, impacting agricultural land and certain buildings on both river banks. All the cultivated areas developed alongside the river are at risk of flooding. Moreover, undermining and erosion of the river’s banks lead to rising high-water levels and flooding agricultural terraces. The use of geographic information systems and hydraulic modeling tools is essential to gain a deeper understanding of this situation. Also, the mapping of lineaments and fractures in the study area, carried out by satellite image processing, helped to quantify the directional influence of these lineaments on the flow of the hydrographic network, on the orientation of the circulation of surface water, and on the storage of groundwater. According to this study, the most vulnerable areas to flooding and erosion are those that receive the most water in the basin and have steep slopes. Decision-makers can use the results to produce development plans tailored to combat these risks and raise awareness among the population concerned, improving water resource evaluation and forecasting, as well as improving agricultural production.

Adoption of a fast dynamic model to simulate transient operations of MNSR

After developing a thermal–hydraulic model, it should be coupled to a point kinetic model to completely simulate transient behavior of a miniature neutron research reactor (MNSR). In this study introduction and validation of such a dynamic model which could be used as computing source of a micro-simulator, is presented. A time dependent point kinetic model in association to a simple control algorithm and reactivity feedbacks calculation (poisons and temperature) is adopted. In order to validate the model, it is compared against MNSR operational data in different scenarios such as normal fixed power operations, and reactivity insertion operations, and post shutdown scenarios. Result indicates that the coupled model could estimate the critical rod position for different power levels with an error less than 5%. Although the control algorithm is simple, it could predict the actual trend of control rod position accordance to the actual data. The coupled model simulates different reactivity insertion accident similar to the reactor operations in such a way that the error between estimated power peak, peak time, and long-term power is less than 5%.

Novel approach to the derivation of dam breach parameters in 2D hydrodynamic modeling of earthquake induced dam failures

Current methods of dam breach analyses adopt a deterministic approach. Applying these methods to Concrete Faced Rockfill Dams (CFRD) is fraught with huge levels of uncertainty, especially in the context of natural hazards. The frequency and magnitude of rainfall and earthquakes are higher in today's world. In the literature, the complete collapse of dams is modelled on dam breach parameters that define the dam break outflow but are not related to the return periods of natural hazards. As more new dams are constructed to control the floods in intra-plate seismic regions, this study presents a novel approach to the derivation of generalized dam break parameters for CFRD based on the structural analysis of Finite Element Model (FEM) simulations for peak ground accelerations corresponding to 475 and 2475 year return periods. Furthermore, the occurrence of rainfall and earthquake for different return periods are modelled using 2D hydrodynamic simulations. Results show the significance of generalized dam breach parameters for planning and managing CFRDs during earthquakes. The study emphasizes the utilization of structural analysis outputs for the hydraulic modeling of dam breaks, which will result in more specific and accurate dam break parameters. Additionally, the study has shown that the flood risk and the severity will increase with the intensity of earthquake and rainfall magnitudes. Disaster mitigation strategies can be optimized by considering the integrated occurrence of rainfall and earthquakes based on the probability of occurrence, demonstrated using a case-study dam. Another significant outcome of the study is the effect of soil saturation condition during a dam break, which reveals that areas within 40 km of the dam breach location might be worst affected.

Modeling hydraulic conductivity function of frozen soil

Hydraulic conductivity function for frozen soils (HCFF) is crucial for accurately simulating the water transfer process in cold regions, impacting hydrological states and frost heave diseases. However, the HCFF model capturing the relation between hydraulic conductivity and unfrozen water content (θ) or temperature (T) remains an open question. This study delves into HCFF encompassing both empirical and prediction models. This study begins with introducing θ-form and innovative T-form empirical HCFF models, showcasing their solid performance in fitting measured hydraulic conductivity data. Furthermore, the extension of the T-form empirical model to incorporate vapor flow and bimodal soils, through the introduction of maximum vapor conductivity and weighting factors, demonstrates a closer alignment with physical mechanisms and observed trends. In terms of predicting HCFF, the study provides a theoretical foundation through statistical hydraulic conductivity models and thermodynamic equilibrium in frozen soils. Additionally, it clarifies three routes for HCFF prediction—single Soil Freeze Characteristic Curve (SFCC), single Soil Water Characteristic Curve (SWCC), and a combination of the two—and validates their effectiveness through test results and comparison of HCFF prediction outcomes using SWCC and SFCC data from specific soil samples. In practice, the empirical and prediction models are recommended for available hydraulic conductivity data and available SFCC or SWCC data, respectively. Overall, this study not only lays the theoretical groundwork for most prediction models but also presents a valid empirical equation for modeling hydraulic conductivity function tailored specifically for frozen soils.

Enhancing nutrient absorption through the influence of mangrove ecosystem on flow rate and retention time in salt marshes

This study investigates the impact of pneumatophores (the aerial roots of Avicenna marina) on water flow rate, retention time, contact time, and consequently on nutrient absorption through the sediment in sub-tropical salt marshes. The goal is to realize how the density of mangroves in salt marshes influences the kinematic factors of streamflow at estuaries. To this end, a field experiment was carried out to assess nutrient and organic compound levels in the sediment and water samples, spanning six sampling stations along the Chabahar River discharging to the Chabahar Bay, Iran. Then, we delved into the influence of altering environmental parameters, such as density and geometry, on the kinematic features of the flow through statistical analysis and hydraulic modeling. The results showed that the aerial roots reduce the flow rate and increase both retention and contact times. The longest retention time was observed at station #5 due to increased vegetation density and decreased instream velocity. In addition, measurements of total organic matter, total organic carbon, and total nitrogen indicated that an extended contact time resulted in increased absorption flux to the stream by sediments. As a result, pneumatophores can serve as an effective sink for organic matter in ecotones in salt marshes.

Integrating FMI and ML/AI models on the open‐source digital twin framework OpenTwins

AbstractThe realm of digital twins is experiencing rapid growth and presents a wealth of opportunities for Industry 4.0. In conjunction with traditional simulation methods, digital twins offer a diverse range of possibilities. However, many existing tools in the domain of open‐source digital twins concentrate on specific use cases and do not provide a versatile framework. In contrast, the open‐source digital twin framework, OpenTwins, aims to provide a versatile framework that can be applied to a wide range of digital twin applications. In this article, we introduce a re‐definition of the original OpenTwins platform that enables the management of custom simulation services and the management of FMI simulation services, which is one of the most widely used simulation standards in the industry and its coexistence with machine learning models, which enables the definition of the next‐gen digital twins. Thanks to this integration, digital twins that reflect reality better can be developed, through hybrid models, where simulation data can feed the scarcity of machine learning data and so forth. As part of this project, a simulation model developed through the hydraulic software Epanet was validated in OpenTwins, in addition to an FMI simulation service. The hydraulic model was implemented and tested in an agricultural use case in collaboration with the University of Córdoba, Spain. A machine learning model has been developed to assess the behavior of an FMI simulation through machine learning.

Spatially quantifying and mapping the riverbed roughness of a tropical river via acoustic Doppler current profiler (ADCP) measurements to develop a 2-D numerical model

Field measurement of the bed roughness of tropical tidal rivers is a long and expensive process. In this study, we quantified the roughness coefficient from the acoustic Doppler current profiler (ADCP) measurements considering flow characteristics along a 240 km length of the Vu Gia Thu Bon River system, in central Vietnam. Our approach entailed the application of the logarithmic velocity distribution trend of turbulent flows to determine the bottom roughness height. Then, we applied the equation suggested by Strickler (1923) to calculate the Manning roughness coefficient. The TELEMAC-2D hydraulic model was then used to simulate the effect of the roughness coefficient on the estimated water level. Despite its uncertainty, the estimated bed roughness was sufficient for the accurate calculation of the hydraulic variables. Compared to those in previous research, the statistical indicators showed good performance in the first simulation process during both the calibration and validation periods along the river system.

Flood hazard comparison based on geomorphic flood index and hydraulic HEC-RAS (Case study in Ciliwung Watershed, Jakarta)

The Jakarta Special Capital Region is a highly vulnerable area to floods due to its location on wetlands laced by 13 major rivers and borders the Java Sea, with more than 40% of its land below sea level and groundwater extraction leading to the ground sinking. The city has experienced several major flood disasters, and climate change has increased the risk, frequency, and severity of flooding in Jakarta. The present study aims to identify areas with flood potential in the Jakarta Special Capital Region (Provinsi DKI Jakarta) using the Geospatial Flood Index (GFI) method recommended by the National Disaster Management Agency (BNPB). The GFI method is an alternative rapid assessment that utilizes the Digital Elevation Model for National Spatial (DEMNAS) data with an 8-meter spatial resolution and employs ARCGIS and QGIS software to identify areas with high potential for flooding and the extent of inundation. To assess the effectiveness of this method, a comparison is made with the Hydraulic HECRAS model for the section from the Automatic Water Level Recorder (AWLR) MT. Hartono to the Manggarai Flood Gate, considering flood return periods Q50 and Q100. The modeling results indicate that the inundation area estimated by the conventional GFI modeling is 150% larger than that the HECRAS Hydraulic model predicted.

Delayed pipe replacement halves environmental impacts but quadruples water loss

AbstractScheduling pipe replacement is critical for water distribution systems (WDSs) when managing finances and water loss. WDS replacements are often delayed due to high immediate costs without considering long‐term environmental consequences. This study is the first to examine a real‐world WDS using a novel workflow transferrable to other WDSs that integrates GIS, hydraulic modeling, breakage prediction, and life cycle analysis to evaluate environmental impacts and water loss of five replacement schedules (25‐, 50‐, 75‐, 100‐, 150‐year intervals). Environmental impacts were reduced by half when replacement interval changed from 25 year to 150 years, yet volume of water leaked from the system quadrupled. Benefits plateaued beyond 50–75‐year replacement while water loss steadily increased. Lowering water loss through break management enabled one‐sixth pipe replacement without exceeding original leakage at 25‐year replacement. Results were robust to uncertainty parameters and assert the importance of equilibrating environmental impacts and water loss when designing pipe replacement frequency.

Water distribution system modelling of GIS-remote sensing and EPANET for the integrated efficient design

Abstract Urban settlement depends on water distribution networks for clean and safe drinking water. This research incorporates geographic information systems (GIS), remote sensing (RS), and hydraulic modelling software EPANET to analyse and construct water distribution systems in Bota town, India. Satellite images and hydrological data have been utilized for the management of the Bota town's water supply network, sources to cater the demand for urban centres. EPANET simulates hydraulic behaviour in the water distribution system under different operating situations. EPANET simulation shows network leaks, low pressure, and substantial head loss. These findings have advised for water distribution system improvements by analysing network shortcomings. Booster pumps, new pipelines, and repairing of existing leakages are examples of such improvements. GIS, RS, and EPANET provided a comprehensive water distribution system study and more accurate and efficient improvement identification. This study emphasizes the necessity of new technologies in water distribution system analysis and design. The study solves Bota town's water distribution system problems of low pressure, high head loss, and leaks utilizing GIS, RS, and EPANET. The findings of this research can help in enhancing the water delivery systems in other towns with comparable issues.

Simulation of the Hydraulic Model HEC-RAS Coupled with GIS and Remote Sensing to Study the Effect of River Cross-section Width in Detecting Flood-prone Areas

Abstract Flooding is one of the extreme hydrological phenomena. It is a recurring natural disaster that causes loss of life and property in many parts of the world, particularly during the monsoon season. It is important to address such issues for local government and policymakers to manage the flood properly. One such flood management activity is to develop a flood-prone area that depicts the spatial and temporal extent of flood accurately. The integration of the Hydrologic Engineering Centre - River Analysis System (HEC-RAS) model and geospatial tools have emerged as a crucial approach for identifying and mapping flood-prone areas. The successful application of the HEC-RAS model generally depends on the topographical data, which represents the channel and floodplain geometry. In floodplain geometry, discrete cross-sections play a vital role to develop the floodplain map, particularly in the flat topographical region. To extract these data it needs a high-quality digital elevation model (DEM), such as light detection and ranging (LiDAR). However, due to a lack of high-resolution topographical data, flood hazard mapping in developing countries is rare. In common practice, the centerline of the river is considered the flow path for the channel. The orientation of the cross-sections is perpendicular to this line and extends to reach the limits of the floodplain. But, it is difficult to define the limits and it may depend on the magnitude of the flood. Hence, in this study, the HEC RAS model coupled with ArcGIS has been applied to the Ganga River, which traverses through the Bihar state of India to study the effect of cross-sectional width to define the floodplain. The Bihar state is facing substantial hardships from annual flooding events with approximately 16.5% of India’s flood-prone area. The extreme flood values for 5, 10, and 25 years of return period have been determined and the influence of the three different cross-sectional widths to mapping the floodplain has been investigated. This novel perspective adds dimension to the understanding of flood dynamics and its implications for flood risk assessment. In this analysis, it has been observed that, with an increase in the width of the cross-section, the floodplain area also getting increased. In this topographical region, keeping a fixed flow path will underestimate the flood-prone area. The width of the flow path depends on the topography of the region and the river flow. The outcomes of this analysis provide valuable insights into the flood-inundated areas for the specified return periods, enabling the identification and prioritization of flood-prone zones.

TEACHING AND APPLYING WATER CONSUMPTION SIMULTANEITY IN RESIDENTIAL: AN ACTIVE LEARNING PROJECT-BASED ENGINEERING APPROACH

In the present project, spanning from April 2020 to August 2022, the study focused on Hydraulic Engineering I within the Civil Engineering program and the Hydrosanitary Installation Project in the Architecture program. The objectives included calculating the simultaneity coefficient and determining the maximum probable flow for each student's residence. To achieve these objectives, active learning methodologies, specifically project-based learning (PBL), were adeptly employed to enrich students' practical knowledge and foster collaboration. The process began with architectural surveys of residential properties, followed by inventories of pipes, sanitary appliances, and wet rooms. Measurements of flow rates at various faucet openings (25%, 50%, 75%, and 100%) were conducted, along with the recording of operating pressures within home networks. This data served as the foundation for creating calibration curves, a process carried out over 120 days. Using the collected data, each student developed a hydraulic model of their network and compared the software results to practical measurements. The participants calculated the simultaneity coefficient (Ks) and maximum possible flow for their dwellings using hydraulic design concepts and regulatory standards. The results were documented in technical reports, a video tutorial, and infographics. The research highlights the importance of understanding residential water usage patterns and their potential for optimizing water delivery systems. It also underscores the value of experiential learning, which helps students bridge theory and practice, enhancing technical skills and their understanding of hydraulic engineering.

Modeling benefits and tradeoffs of green infrastructure: Evaluating and extending parsimonious models for neighborhood stormwater planning

Green infrastructure is often proposed to complement conventional urban stormwater management systems that are stressed by extreme storms and expanding impervious surfaces. Established hydrological and hydraulic models inform stormwater engineering but are time- and data-intensive or aspatial, rendering them inadequate for rapid exploration of solutions. Simple spreadsheet models support quick site plan assessments but cannot adequately represent spatial interactions beyond a site. The present study builds on the Landscape Green Infrastructure Design (L-GrID) Model, a process-based spatial model that enables rapid development and exploration of green infrastructure scenarios to mitigate neighborhood flooding. We first explored how well L-GrID could replicate flooding reports in a neighborhood in Chicago, Illinois, USA, to evaluate its potential for green infrastructure planning. Although not meant for prediction, L-GrID was able to replicate the flooding reported and helped identify strategies for flood control. Once evaluated for this neighborhood, we extended the model to include water quality through the representation of dispersion and settling mechanisms for two pollutant surrogates—total nitrogen and total suspended solids. With the extended model, Landscape Green Infrastructure Design Model-Water Quality (L-GrID-WQ), we examined benefits, costs, and tradeoffs for different green infrastructure strategies. Bioswales were slightly more effective than other green infrastructure types in reducing flooding extent and downstream runoff and pollution, through increased infiltration and settling capacity. Permeable pavers followed in effectiveness and are suggested where spatial constraints may limit the installation of bioswales. Although green infrastructure supports both flooding and pollution control, small tradeoffs between these functions emerged across spatial layouts: strategies based on only curb-cuts better controlled pollution, while layouts that followed the path of water flow better controlled flooding. By illuminating such tradeoffs, L-GrID-WQ can support green infrastructure planning that prioritizes unique concerns in different areas of a landscape.

Hydraulic flow and downstream scouring behavior on spillway system of Surumana Dam

Surumana Dam is designed to meet various needs of water in Donggala, Central Sulawesi, and its surroundings. It is planned to be equipped with a side channel spillway, which sequentially consists of an approach channel, side spillway, side channel, transition channel, slide channel, energy absorber type USBR II, and an escape channel to the main river. The safety of the spillway system design, which affects the overall safety of the dam, is determined by the hydraulic behavior. This study aims to investigate the hydraulics flow in the side spillway system and scouring in downstream due to the flood discharge through the spillway dam by using a physical model test in the laboratory with a scale of 1:60. The model was used to measure the hydraulic parameter as velocity, depth, and pressure, under Q100, Q1000 and QPMF discharge. The result of the analysis showed the hydraulic flow behavior, especially in the phenomenon of damping the energy of water flow in stilling ponds (energy damper) and scouring in the downstream river bed. The results of this hydraulic model test provided a better picture of the flow behavior of the spillway system in terms of energy dissipation and scour.

Double sill stilling basin to enhance energy dissipation for a strong hydraulic jump with a high Froude number

Roller Compacted Concrete (RCC) is a new and viable construction material for concrete gravity dams. It is gaining popularity due to its low cost and fast deployment. The design of a stilling basin, part of a dam that controls the hydraulic jump and dissipates energy, is crucial. One of the important considerations is the Froude number at the spillway toe (F1), which determines the type of hydraulic jump that will occur. An energy dissipator is also required to prevent scour caused by the change in flow conditions from supercritical to subcritical. Double sills installed downstream of the steep chute way channel can be used as an energy dissipator. This study uses hydraulic modeling to evaluate the flow energy reduction and subcritical flow conditions in a stilling basin with double sills. The investigation is expected to provide better information on hydraulic jump control.

Improving pressure monitoring and control in order to reduce water loss in water urban public systems

Water losses from distribution systems are present in all situations. Reducing them to zero is impossible. Modern technologies for operating water distribution networks are an effective means of reducing water losses. In this sense, the conducted research aimed at testing some solutions to improve the monitoring and control of pressure in a distribution network. The mathematical model of the water distribution network was developed and calibrated (Mike Urban application) and the hydraulic modeling of the network was carried out. The results were obtained through: periodic simulations with the help of the monitoring application; comparisons for flow and pressure values, data collected from field measurements, data obtained from SCADA application. These complex analyzes allow the identification, in the shortest possible time, of existing problems and areas with losses.