Hasil untuk "Hydraulic engineering"

Xiaojuan Sun, Haojie Jin, Mingyu Gao et al.

Abstract Reservoirs are essential for global water management and energy regulation, but sedimentation threatens their longevity. This study investigates a 130 km section of the Yellow River between the Sanmenxia and Xiaolangdi dams, using deep learning to predict long‐term erosion and deposition patterns. From 2009 to 2023, we gathered water depth data from 56 sites (840 measurements) with unmanned survey boats and drone‐based LiDAR (Light Detection and Ranging), alongside flow and sediment records. After preprocessing, we evaluated three machine learning models: Convolutional Network for Multimodal Time Series (CNN‐MTS), Convolutional Transformer for Multimodal Time Series (CNN‐Transformer‐MTS), and Convolutional Bi‐LSTM for Multimodal Time Series (CNN‐BiLSTM‐MTS). The CNN‐BiLSTM‐MTS model excelled, achieving a mean absolute error (MAE) of 17.84 m, a coefficient of determination (R2) of 0.9916, and reducing errors by up to 26% compared to alternatives. Key drivers of sediment dynamics included sediment load, maximum sediment concentration, and maximum flow. Data from 2009 to 2023 showed elevation shifts from −0.21 m near the dam to +1.158 m at the reservoir's tail. Predictions for 2024 to 2050 suggest varied riverbed changes, with the Guxian Reservoir's operation in 2036 expanding elevation ranges from −0.625 to 0.875 m. These findings highlight deep learning's potential for efficient sediment management in reservoirs and offer insights for sustainable hydraulic engineering. However, uncertainties persist in scaling the model, improving data resolution, and coordinating across regions.

Diego Panici, Prakash Kripakaran, Richard E. Brazier

ABSTRACT Bridge owners and regulatory agencies have a duty to assess risks derived from hydraulic actions including scour, uplift, drag, debris impact, deck displacement, and other consequences that can lead to a loss in the load carrying capacity of a bridge. In the UK, the CS469 (Management of scour and other hydraulic actions at highway structures) is the standard for the assessment of hydraulic actions to highway bridges. The methodology in CS469 for the calculation of the hydraulic characteristics of the flow at critical cross‐sections within the channel and the bridge crossing, although simplistic by design to minimize computational effort, is intrinsically inaccurate since it makes use of unrealistic (i.e., non‐physically based) approximations. This results in estimations of risk and vulnerability levels that could include high levels of uncertainty. In this paper, we propose to bypass these approximated hydraulic calculations by harnessing the computational power of 2D hydraulic models, which would not require any additional field data collection than needed for the original CS469 method. We recommend a fully 2D HEC‐RAS model with the inclusion of bridges as 1D elements within the flow areas and only requiring publicly available data or data obtained from existing assessments in order to future‐proof the approaches and adhere to an open‐source/open‐access philosophy, but also imposing only a marginal increase in cost for bridge management teams. Results from the two models—2D HEC‐RAS and the existing approach in CS469, are compared for a number of real‐world bridges. The comparisons show that the estimations by HEC‐RAS are substantially higher for water depth (up to 138%) and lower for flow velocity (down by 58%). When these values are applied to the estimation of hydraulic vulnerability and scour risk, the differences are significant. Scour depths with the use of HEC‐RAS models are typically much lower (up to 3.9 m, and on average 1.7 m) than with simplified hydraulic equations, and this translates into lower (yet, more appropriate) scour risk levels. Hydraulic vulnerability to submergence of the assessed bridges is also assessed very differently, typically higher by the 2D model method. Overall, the results show that 2D numerical hydraulic simulations present a much more accurate estimation than existing methods, better balancing risks deriving from scour and hydrodynamic actions and with comparable effort and data requirements. The model displays consistency across an exhaustive set of simulations for a range of variables and bridges, showing limited variability and proneness to errors, whilst values estimated by CS469 are in most cases significantly different. Future versions of CS469 and similar documents should prioritize this methodology to provide a more accurate and realistic risk estimation.

V. Kosmalla, O. Lojek, J. Carus et al.

<p>This study investigates the biomechanical properties of marram grass (<i>Calamagrostis arenaria</i>, formerly <i>Ammophila arenaria</i>) over a 12-month period on the island of Spiekeroog, Germany, to enhance the modeling of coastal dune dynamics. The research reveals significant seasonal variations in the stiffness and Young modulus of the vegetation, with higher values observed in winter, indicating increased mechanical resistance important for dune stability during storm events. In summer, increased flexibility and density are prominent, enhancing dune accretion. To account for these dynamics, the study emphasizes the importance of incorporating seasonally adjusted parameters into models, particularly accounting for the increased horizontal density, the presence of flower stems in summer, and the longer leaf lengths in winter. The differentiation among plant parts is highlighted, with flower stems providing the highest structural support due to their greater stiffness, while leaves contribute more to flexibility and dynamic responses. Interestingly, the minimal differences between green and brown leaves suggest that these can be treated similarly in modeling efforts, simplifying parameterization without compromising accuracy. Additionally, the study found no consistent evidence that wind exposure significantly affects the biomechanical properties of marram grass, suggesting that wind influence may not need to be factored into biomechanical models. The results also demonstrate that the biomechanical properties of marram grass are broadly transferable between fixed and dynamic dune systems, supporting their applicability across various coastal environments. The key outcome of this research is the detailed compilation of the biomechanical traits of marram grass's aboveground vegetation, reflecting the seasonal dynamics found in dune processes, which will serve as a valuable resource for future modeling efforts of dune vegetation and their surrogates.</p>

Ramin Fazloula, Shadi Saraf, Javad Vejahat et al.

Today, the optimal use of water in various sections to increase productivity and reduce losses is one of the basic assumptions in consumption management. Therefore, in the present research, the concept of productivity in different water consumption sections, including groundwater, drinking water, and special attention to chemical properties in the sewage treatment plant in Sari City has been investigated. In each section, using the appropriate algorithm, the available data has been evaluated to measure productivity.  In the sewage treatment section, the analysis of effective parameters in Sari City sewage treatment was performed in two methods Artificial Neural Network and Wavelet. The output results of these models showed that due to the high value of the R2 statistic, there is an acceptable and direct relationship between the measured and estimated characteristics. In the groundwater sector, according to the results obtained, the wavelet network performed better in estimating the desired variables than the ANN method. In the water distribution network section, the results of wavelet analysis and the outputs of the WaterGems software revealed that the deterioration of the studied water distribution network plays a significant role in losses and reduced productivity, in such a way that about 47 percent of the water entering the network is out of reach and wasted in different ways.

Chen Ding, Kaixi Xue, Chaohui Zhou

Abstract Layered rock slope exists widely. Because of its special slope structure, it is prone to bending deformation and toppling failure, which is a serious threat to engineering construction and safety operation. At present, the research of layered rock slope still has great innovation potential. During the construction of Wudongde Hydropower Station on Jinsha River, safety and stability problems such as slope geological structure development, face rock unloading and relaxation, and even slip and large deformation were encountered. Through field exploration, it is found that the rock and soil stratification of the slope on both sides of Wudongde Hydropower Station is highly obvious. At present, there is a lack of research on-site long-term displacement monitoring of layered rock high-steep slope, especially for layered slope in complex hydrogeology and construction environment. In order to strengthen the research on the deformation and stability of layered rock slope, this paper analyzes the measured displacement data of Wudongde hydropower station slope, and establishes three-dimensional geological finite element model with the help of numerical simulation software. The stability of the slope is calculated by combining the finite difference method and the strength reduction method. Finally, the evolution mechanism of the deformation of the layered rock slope is explained according to the geological structure characteristics. The main conclusions of this paper are as follows: the layered slope in the dam reservoir area is prone to deformation under the combined action of long-term construction disturbance and fissure water seepage, and the construction disturbance has a strong influence on the artificial excavation area below 1070 m, and the maximum rock mass deformation and surface displacement in the artificial excavation area of the slope reach 92.2 mm and 312.5 mm, respectively. However, the influence of construction disturbance on the natural mountain above 1070 m is limited, the valley deformation of the natural mountain on the left bank of the reservoir area is higher than that on the right bank, and the cumulative deformation is still less than 20 mm. The influence of seepage on the displacement of the area with higher elevation at the top of the slope is more obvious, and the influence of excavation and other disturbances on the displacement of the artificial excavation area with lower elevation is more obvious. The deformation of the river valley in the water cushion pond behind the dam increases slowly, and the change trend of the field deformation data is mostly consistent with that of the numerical calculation. The horizontal shrinkage of the mountains on both sides shows a contraction trend on the whole, and the maximum horizontal shrinkage calculated by numerical simulation is close to 20 mm, which is located at the elevation of 990 m.

A.H. Jalali, H. Salemi

IntroductionCumin (Cuminum cyminum L.) is an annual and herbaceous plant, with a vertical, round, narrow and branched stem, with a height of approximately 30-60 cm. This plant belongs to the Apiaceae family. This family is known for having plants with aromatic taste. Iran and some countries along the Mediterranean Sea are known as the primary origin for the cumin plant. In addition to Iran, cumin is cultivated in many countries such as Uzbekistan, Tajikistan, Turkey, Morocco, India, Syria, Mexico and Chile. About 300,000 tons of cumin seeds are produced in the world annually, of which China and Asian countries produce 70% and consume 90%. Short growing season (100 to 120 days), low water requirement and the possibility of rained cultivation, non-interference between cultivation and harvesting with other crops and no price fluctuation and proper economic justification are among the factors that interest farmers in cultivating this plant. In different regions, yields of 350 to more than 1000 kg of seeds are obtained from this plant, and 3350 cubic meters of pure water are needed for production. Materials and MethodsThis research was conducted in 2015 to 2017. The first year of the study included the collection and analysis of long-term climatic data of the region, and the second year included the implementation phase of the research. Analyzing meteorological data on the scale of decades and the cases of temperature, precipitation, wind speed, sunshine hours, relative humidity and evaporation from the pan were considered as criteria and by preparing the gradient equations, the rate of reference evaporation and transpiration was calculated. The required statistical information was obtained from 28 synoptic meteorological and climatology stations in Isfahan and some neighboring provinces. In the studies related to soil, apparent specific gravity and volumetric moisture content (field capacity and wilting point), soil salinity, soil texture and agricultural ability class of land in cultivation areas were considered. Soil-related information was used to calculate the soil evaporation coefficient (Ke), which describes the evaporation component in the trait (ETc). In fact, Ke is the basis for calculating the coefficient of reduction of evaporation from the surface layer (Kr) and the fraction of soil wet and exposed to air (few), and for its calculation, the presence of information related to soil characteristics is necessary. To calculate the soil characteristics, in addition to sampling from the fields in the research, the database of 1600 soil profiles in the soil and water research department of Isfahan province was also used. Results and DiscussionThe results showed that 18 cities in Isfahan province had cumin cultivation potential, which had a significant difference in terms of pure water requirement per hectare (5% level) and water consumption at different phenological stages (1% statistical level). In terms of water requirement per hectare, the cities of Isfahan province can be divided into three groups. Average water requirement per hectare in the first group (the cities of Golpayegan, Lenjan, Tiran and Karvan, Shahin and Shahr and Mime), the second group (the cities of Isfahan, Khomeini Shahr, Falavarjan, Shahreza, Kashan, Najaf Abad, Natanz), Mobarake, Dehaghan and Borkhar), and the third group (Aran and Bidgol, Ardestan, Khoor and Biabanak and Nain) were equal to 3000, 3240 and 3770 m-3 ha-1, respectively. The water requirement of the growth development stage in the cities of the third group was equal to 2029 m-3 ha-1, which was significantly different from the cities of the first and second groups (p < 1% level). According to the results, cumin might be a suitable plant for crop rotations in Isfahan province due to its low water requirement and tolerance to moisture stress. ConclusionThe water requirement for cultivating cumin in various regions of the province is notably lower compared to many common crops, such as wheat, barley, and safflower. In 10 out of the 18 cities included in the study, significant water savings of up to 3,240 cubic meters per hectare can be achieved by optimizing water transfer efficiency. For cumin cultivation, this water conservation can even reach 3,000 cubic meters in cities with cooler climates. Surprisingly, in the hot areas of Isfahan province, including Ardestan, Nain, Khoor, Biabanak, Aran, and Bidgol, it is feasible to grow cumin with a water consumption of just 3,770 cubic meters per hectare.

Jonas Olsson, Anita Verpe Dyrrdal, Erika Médus et al.

Short-duration rainfall extremes are associated with a range of societal hazards, notably pluvial flooding but in addition, e.g., erosion-driven nutrient transport and point-source contamination. Fundamental for all analysis, modelling and risk assessment related to short-duration rainfall extremes is the access to and analysis of high-resolution observations. In this study, sub-daily rainfall observations from 543 meteorological stations in the Nordic–Baltic region were collected, quality-controlled and consistently analyzed in terms of records, return levels, geographical and climatic dependencies, time of occurrence of maxima and trends. The results reflect the highly heterogeneous rainfall climate in the region, with longitudinal and latitudinal gradients as well as local variability, and overall agree with previous national investigations. Trend analyses in Norway and Denmark indicated predominantly positive trends in the period 1980–2018, in line with previous investigations. Gridded data sets with estimated return levels and dates of occurrence (of annual maxima) are provided open access. We encourage further efforts towards international exchange of sub-daily rainfall observations as well as consistent regional analyses in order to attain the best possible knowledge on which rainfall extremes are to be expected in present as well as future climates. HIGHLIGHTS Sub-daily annual rainfall maxima have been collected from national observation networks in the Nordic–Baltic region, including a total of 543 stations.; A consistent regional analysis of records, return levels, geographical and climatic dependencies, time of occurrence of maxima and trends is performed.; Gridded data sets with return levels and time of occurrence are provided open access.;

W. Zhou, Qirui Ma, G. Ma et al.

Abstract The flow of small particles in porous media is of interest in many branches of science. In geotechnical engineering, this phenomenon usually occurs in graded granular materials and is termed as internal erosion. In this work, graded granular materials are simplified as binary mixtures under vertical compression, and water flows perpendicular to the vertical direction. We use the coupled Lattice Boltzmann method (LBM) and discrete element method (DEM) to investigate the initiation of internal erosion under different stress levels and hydraulic gradients. Suffusion was observed as the fine particles are transported by the seepage flow. The change of void ratio due to water flow and vertical compression demonstrates three patterns: erosion, stability, and compaction. Particles with low engagement in force transmission are more prone to erosion, while the hydraulic gradient is an external disturbance factor. The ballistic, caging, and diffusive regimes are observed in the initial process of internal erosion.

Worlanyo Kwadjo Siabi, Emmanuel Degraft-Johnson Owusu-Ansah, Helen Michelle Korkor Essandoh et al.

Nearly 6494 boreholes with iron (Fe) and manganese (Mn) concentrations above permissible limits of 0.3 mg/L and 0.4 mg/L respectively in Ghana have been abandoned because of ineffective water treatment solutions. Activated carbon prepared from teak (Tectona grandis) and shea (Vitellaria paradoxa) charcoal (ACM), of effective grain sizes 0.075–0.2 mm and 0.2–2.0 mm was found to achieve 92.5–100% Fe and Mn removal in batch tests. The experiments, which were repeated for natural groundwater with a low flow similar to boreholes simulated with handpumps and limited mechanized water systems achieved similar Fe and Mn adsorption levels. Data on Fe and Mn adsorption for varying ACM mass and grain sizes, using fixed columns in continuous flow tests were fitted to Adam-Bohart, Thomas and Yoon-Nelson adsorption models to generate data for improvement in water treatment designs. The objective of this modelling process is to develop a prediction mechanism for ACM mass and grain size needed for the design of Fe and Mn removal plants for groundwater with various characteristics. Adsorption constants obtained for Yoon-Nelson; 0.3095 and Adams-Bohart; 0.07335 at R2 values of 0.9728 and 0.9841 respectively are appropriate for generating ACM mass needed, when the target contaminant is Fe and Mn

A. McGarr

Q. Lei, B. Guan, B. Cai et al.

Abstract Through reviewing the development history of reservoir hydraulic fracturing technology, this paper demonstrated the latest research progress at home and abroad and summarized six technical gaps between China and the world, that is fracture propagation mechanism, fracturing software development, fracturing vehicle equipment, downhole tools temperature and pressure resistance, proppant replacement and big data information database. The technical difficulties include lack of geological-engineering deep integration, unclear factors on horizontal well multi-fracture propagation, difficulty in reducing construction costs, environment protection pressure, lack of new experimental and field test equipment, immature techniques for fracturing fluid, and low efficacy of factorized fracturing equipment. We proposed six suggestions on China's future reservoir hydraulic fracturing technology: (1) strengthen the mechanism study of unconventional reservoir hydraulic fracturing; (2) accelerate the development of geological-engineering integration software; (3) promote the upgrading of EOR fracturing techniques; (4) carry out low-cost multi-functional fracturing fluid formula experiment; (5) complete high-efficiency fracturing equipment; (6) build big database, informational and remote decision-making system of hydraulic fracturing.

C. Montgomery

When fracturing, viscosity play a major role in providing sufficient fracture width to insure proppant entrance into the fracture, carrying the proppant from the wellbore to the fracture tip, generating a desired net pressure to control height growth and providing fluid loss con‐ trol. The fluid used to generate the desired viscosity must be safe to handle, environmental‐ ly friendly, non-damaging to the fracture conductivity and to the reservoir permeability, easy to mix, inexpensive and able to control fluid loss. This is a very demanding list of re‐ quirements that has been recognized since the beginning of Hydraulic fracturing. This paper describes the history of fracturing fluids, the types of fracturing fluids used, the engineering requirement of a good fracturing fluid, how viscosity is measured and what the limitations of the engineering design parameters are.

Vladimir. I. Batuyev, Igor L. Kalyuzhniy

The article presents results of the analysis of interaction of the factors determining the process of the winter and spring runoff formation on the basis of integrated hydro/meteorological observations at the Lammin-Suo (Leningrad Oblast) and ILass (Archangel Oblast) oligotrophic bogs during the period of stabilization (1950-980) and the period of climate change (1981-2018). We have stated that the freezing depth is a factor that regulates the ratio between the winter runoff and spring runoff. It has been shown that the layer of the winter runoff-forming moisture increase with its decrease and, consequently, the winter runoff is increasing while the spring runoff is decreasing. Analysis of results of the observation over the hydrological regime of the bogs of the north and north-west of Russia has shown that it is exactly the 1978-1980 period that is the boundary, which the freeze depth decrease and the change of the characteristics of runoff from bogs can be observed.

I. Albayrak, Carl Robert Kriewitz, W. Hager et al.

L. Björkman

G. Tan, H. Fang, S. Dey et al.

Professor, Dept. of Civil Engineering, Indian Institute of Technology Kharagpur, West Bengal 721302, India; Adjunct Professor, Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata, West Bengal 700108, India; Distinguished Visiting Professor, Dept. of Hydraulic Engineering, State Key Laboratory of Hydro-Science and Engineering, Tsinghua Univ., Beijing 100084, China. Email: sdey@iitkgp.ac.in

Yafang Cheng, Ping Feng, Jianzhu Li et al.

This study investigates the water supply risk of Panjiakou reservoir in the Luanhe River basin of China during 1956–2016 under environmental change. Since the monthly runoff series during 1956–2016 is a time series with change points, it is necessary to find a new stochastic streamflow series generation approach to preserve the statistical characteristics of the original series and to refine the reliability of water supply risk analysis. This paper improves a known stochastic streamflow simulation method of previous research to better reflect the characteristics of series with change points. And this paper simulates the monthly runoff series with change point of Panjiakou reservoir during 1956–2016 by three different methods, including Thomas–Fiering model, copula function stochastic simulation method, and copula function stochastic simulation method with the mixed distribution model. Among the three methods, the copula function stochastic simulation method with the mixed distribution model which is improved on the basis of copula function stochastic simulation method in this study performs best in simulating the observed monthly runoff series during 1956–2016, and the water supply risk indices including reliability (time-based and volume-based), resilience, vulnerability, drought risk index (DRI), and sustainability index (SUI) are evaluated for Panjiakou reservoir and analyzed by using the stochastic simulation results. By comparing with the previous studies, all indicators are between the corresponding results of 1956–1979 and 1980–2016 with stationary inflows; it can be seen that change point seriously affects the water supply risk of Panjiakou reservoir. These results make it easy to formulate water supply strategies and schemes in changing environment for water resources managers.

Hongbo Li, Hao Sun, Juncang Tian et al.

Based on the urban shantytown renovation project in Hongguang Town, Helan County, Ningxia, in Northwest China, the influence of fly ash and silica fume admixture on the mechanical properties of Self-compacting Concrete (SCC) was tested and analyzed in this work. The experimental tests including compressive strength, splitting strength, triaxial strength and an ultrasonic nondestructive test. Furthermore, the Back Propagation (BP) neural network algorithms were established. The results show that there is an obvious difference between the development law of compressive strength of SCC and that of ordinary concrete. The splitting pressure ratio of SCC is 1/10 to 1/8, while that of ordinary concrete is 1/13 to 1/10. Moreover, the peak strain, peak stress and initial stiffness of SCC increase with the increase of the confining pressure when compressed from three directions. In addition, the ultrasonic amplitude of SCC can reflect the changing laws of its compressive strength. As a conclusion, the addition of fly ash and silica fume increases the splitting pressure ratio of SCC. More importantly, the compressive strength formula for SCC with silica fume and a low content of fly ash is proposed, and the model equation between the amplitude and compressive strength is given. This study provides a reference for the mixture ratio of fly ash and silica fume in the application of SCC.

Ana Gloria Montes Peña, Adán Pocasangre Collazos

El presente artículo muestra los resultados de la evaluación de un reactor anaeróbico con bafles (ABR) construido a escala laboratorio, para determinar su eficiencia en el tratamiento del agua miel generada en un beneficio húmedo de café ubicado en Santa Rosa Guatemala. Con base a los análisis fisicoquímicos realizados se determinó que el reactor era capaz de aumentar el potencial de hidrógeno en un 23% pasando de 3.5 a 4.3 unidades, la alcalinidad disminuyó de 4,100 a 1,833 mg/L de CaCO3 obteniendo una eficiencia del 54%, la demanda química de oxígeno disminuyó un 61% modificándose con el tratamiento de 20,816 a 6,700 mg/L y la demanda bioquímica de oxígeno pasó de 16,511 a 5,541 mg/ teniendo una disminución del 37%.

Mohsen Soltani, Rouhollah Amirabadi

This study aims to investigate the capability of two common numerical methods, Homotopy Analysis Method (HAM) and Variational Iteration Method (VIM), and to suggest more efficient approximate solution method to the governing equations of nonlinear surface wave propagation in shallow water. To do so, semi-flat, moderate, and sharp slope of shore which are connected to an open ocean with a uniform depth are exposed to a solitary wave with initial wave height H=2 and stationary elevation d=20. Then, the surface elevation and velocity curves for these profiles are determined and compared by HAM and VIM.  To verify the numerical modeling, two slopes i.e. semi-flat and moderate slope are considered and modeled in Flow-3D. Afterwards, the results of surface elevations are compared to each other by using correlation coefficient. The correlation coefficients for the slopes represent that the results coincide well. Ultimately, although the results of both methods are quite similar, using HAM is highly recommend rather than VIM since it makes solution procedure fast-converging and more abridged.