Hasil untuk "Hydraulic engineering"

S. Hughes

Jianchao Cai, Tingxu Jin, Jisheng Kou et al.

Fluid flow in porous systems driven by capillary pressure is one of the most ubiquitous phenomena in nature and industry, including petroleum and hydraulic engineering as well as material and life sciences. The classical Lucas-Washburn (LW) equation and its modified forms were developed and have been applied extensively to elucidate the fundamental mechanisms underlying the basic statics and dynamics of the capillary-driven flow in porous systems. The LW equation assumes that fluids are incompressible Newton ones and that capillary channels all have the same radii. This kind of hypothesis is not true for many natural situations, however, where porous systems comprise complicated pore and capillary channel structures at microscales. The LW equation therefore often leads to inaccurate capillary imbibition predictions in such situations. Numerous studies have been conducted in recent years to develop and assess the modifications and extensions of the LW equation in various porous systems. Significant progresses in computational techniques have also been attained to further improve our understanding of imbibition dynamics. A state-of-the-art review is therefore needed to summarize the recent significant models and numerical simulation techniques as well as to discuss key ongoing research topics arising from various new engineering practices. The theoretical basis of the LW equation is first introduced in this review and recent progress in mathematical models is then summarized to demonstrate the modifications and extensions of this equation to various microchannels and porous media. These include capillary tubes with nonuniform and noncircular cross sections, discrete fractures, and capillary tubes that are not straight as well as heterogeneous porous media. Numerical studies on the LW equation are also reviewed, and comments on future works and research directions for LW-based capillary-driven flows in porous systems are listed.

Marcelo H. García

Sedimentation Engineering: Theories, Measurements, Modeling, and Practice (ASCE Manuals and Reports on Engineering Practice No. 110) is intended to supplement ""Sedimentation Engineering: Classic Edition"" (ASCE Manuals and Reports on Engineering Practice No. 54), a seminal text on the nature and scope of sedimentation problems, methods for their investigation, and practical approaches to their solution.""Sedimentation Engineering: Theories, Measurements, Modeling, and Practice"" updates selected topics in the original manual and addresses new topics, such as the hydraulic action of flowing water in the context of rivers and inland water bodies.

A. Peirce

PEI Xiangli, XU Zhenghe, LIU Miao et al.

【Background and Objective】Soil salinization is a major constraint to sustainable agricultural production, and amending such soils with salt-tolerant microorganisms has been found to be effective in improving soil quality and enhancing crop tolerance to water and salinity stress. This paper analyzes international research in this area.【Method】Bibliometric analysis was conducted using VOSviewer and CiteSpace to systematically examine publications from 2004 to 2024 on saline-alkali soil microbiology retrieved from the China National Knowledge Infrastructure (CNKI, 652 articles) and the Web of Science Core Collection (WOS, 982 articles).【Result】Annual publications in saline–alkali soil microbiology showed a substantial increase during this period, with publications in English journals consistently and markedly overshadowing those in Chinese journals. China led the world, publishing 1 103 papers and collaborating with 26 countries, including Canada and the United Kingdom. Keyword clustering analysis showed that research hotspots in this field were: ①microbial community structure and its environmental drivers; ②mechanisms underlying plant-microbe interactions and their ecological functions; and ③ screening of salt-tolerant and growth-promoting microorganisms, as well as the mechanisms underlying biological remediation of saline-alkali soils. From 2004 to 2024, research on microbiology in saline-alkali soil can be divided into three stages: an early stage (2004—2015) emphasizing species identification and soil improvement; a middle stage (2016—2020) focusing on microbial community ecology and functional characterization; and the most recent stage (2021—2024) characterized by increased attention to the regulation of the microbe-soil-plant system.【Conclusion】Future research in saline-alkali soil microbiology will depend on international collaboration and interdisciplinary cooperation. Advances in multi-omics approaches, big data and artificial intelligence will enable systematic elucidation of microbial community assembly and functional regulation mechanisms, which will promote precision microbial management, functional strain development, and microbiome restoration. These advances will provide environmentally friendly solutions for remediating saline-alkali soils and sustaining agricultural production to meet the growing demand for food.

Maria Kalista Hadia Sabu, Doddi Yudianto, Obaja Triputera Wijaya

Accuracy of rainfall data is very important in hydrological analysis, especially in areas with limited data such as Labuan Bajo City, Indonesia. Global climate data generated from satellite observations and assimilation products, which are freely available, have great potential for use in data scarce areas. However, this data needs to be evaluated to measure its accuracy in rainfall estimates. This research aims to evaluate the accuracy of eight global rainfall data products, namely Global Precipitation Measurement (GPM), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks – Cloud Classification System (PERSIANN-CCS), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks - Climate Data Record (PERSIANN-CDR), Precipitation Data Integration and Retrieval - Now (PDIR-Now), European Reanalysis for the 5th Generation (ERA5), European Reanalysis for the 5th Generation Land (ERA5-LAND), and Climate Hazards Group InfraRed Precipitation with Station Data (CHIRPS) at two temporal scales: monthly and 15-daily. Evaluation is carried out using an assessment matrix which includes Root Mean Square Error (RMSE), Nash-Sutcliffe Efficiency (NSE), correlation (r), and Relative Bias (RB). The evaluation results show that on a monthly scale, ERA5, PERSIANN, and GPM provide the best results, with ERA5 being the top. On a 15-daily scale, ERA5 also shows the best performance, followed by GPM and ERA5-LAND. These findings confirm that ERA5 is the main choice for monitoring rainfall in Labuan Bajo City, which is very important for water resource management in areas with limited direct observation data.

Guofa WANG, Jinhu ZHANG, Huaiwei REN et al.

Summarizing the current development status of intelligent and digital technologies in the coal industry, analyzing the new situations and requirements for research and application of intelligent technologies and complete sets of equipment for efficient coal mining. Addressing challenges such as comprehensive perception of the state of high-strength mining surrounding rock and equipment under different coal seam conditions and integrated coordinated advancement and linked control of equipment groups, the paper explores the deep integration of advanced information technologies such as the Internet of Things, cloud computing, big data analytics, and high-precision inertial navigation with coal mining technologies. This integration has enabled condition monitoring and data integrated management of coal mining equipment, improving monitoring, management, and decision-making efficiency in the coal mining process through precise perception, real-time data analysis, and intelligent control. It has also enhanced the adaptability of complete mining equipment sets to different coal seam conditions. To address the challenges of integrated advancement and coordinated control of equipment groups in ultra-long workfaces for medium-thick coal seams, the paper introduces synchronous mapping of geological information ahead of the mining face through dynamic perception of geographical information and real-time model updating technology. High-power rapid advancement equipment suitable for ultra-long workfaces has been developed, and a multi-area synchronous advancement process system covering all aspects of support, mining, and transportation has been established. This forms a linked mechanism for support equipment groups in ultra-long workfaces and achieves coordinated control among equipment groups, significantly improving mining efficiency and resource recovery rates for medium-thick coal seams. For complex geological conditions in deep thick coal seams, refined control of supports and intelligent coordinated control technologies for equipment groups have been developed, enabling perceptual coordination and adaptive precise control between equipment, thus improving system reliability and efficiency. Addressing challenges such as coal wall protection in ultra-large mining spaces, intense dynamic loads on surrounding rock in the workface, and significant variations in coal flow loads in 8−10 m ultra-high mining height workfaces, the paper proposes adaptive control technology for coupling hydraulic supports with surrounding rock, enhancing the adaptability of equipment to ultra-high mining height workface environments. Key technologies such as a guard plate monitoring system, adaptive cutting technology for shearer stability, coal flow load balancing, and dynamic chain tensioning control have been developed, enabling efficient mining under conditions of significant coal seam thickness variations and strong mining pressure. In the overseas promotion of intelligent and digital complete sets of equipment for efficient coal mining, the paper addresses challenges such as differences in coal mine conditions, safety requirements, and technical standards through customized adjustments to technical equipment. An integrated monitoring and big data analytics system has been developed, improving the response to abnormal situations and enabling autonomous perception, high-reliability data transmission, intelligent analysis and decision-making, precise control and execution among equipment groups within the workface. A technical system for intelligent and digital complete sets of equipment for efficient coal mining adaptable to different working conditions has been established and has achieved good results in engineering practice. This provides support for the high-quality development of coal mine intelligence and solutions to key technical challenges in coal mine intelligent construction.

GAO Lihua, PAN Hongzhou, HE Yingqing et al.

Quantitative assessment of the impact of marine construction projects on suspended sediment transport and diffusion in estuaries is crucial for flood control, post-project evaluations, and estuarine ecological protection. This paper proposed a technical framework of "remote sensing inversion, path extraction, and phase comparison" and a zonal and block-optimized computational methodology, which accounted for variations in hydrodynamic conditions and differences in suspended sediment diffusion, effectively reducing cross-interference. This paper focused on the Shenzhen-Zhongshan Link as a case study. Using multi-temporal Landsat and Sentinel-2 satellite imagery, the paper employed remote sensing quantitative inversion to retrieve suspended sediment concentration (SSC), and an analysis method based on geometric features of SSC contours was applied to extract information about sediment plumes. In the study area, the suspended sediment diffusion was compressed by the freshwater discharge from the Shiziyang, resulting in a sharp gradient in the concentration isolines at the diffusion boundary. Concurrently, the diffusion exhibited anisotropy under flow action, characterized by downstream-dominated transport and outwardly convex isolines. Based on these characteristics, the plume front position was extracted to determine the diffusion extent. Furthermore, the geometric center of the isolines was computed, and a weighted principal component analysis was employed to derive the principal axis direction, thereby identifying the overall diffusion direction. The spatial extent and direction of suspended sediment diffusion before and after the project's construction were extracted from six satellite images captured at typical tidal levels (covering 2014-2016 pre-construction and 2020-2024 post-construction) along with DEM topographic data from 2011 to 2019. A comparative analysis of the extraction results was conducted. Key findings reveal enhanced southeastward diffusion intensity and expanded plume extent at Hengmen, Hongqimen, and Jiaomen's southern extension, increased diffusion angle south of the project with a south-eastward directional bias, and distinct morphological changes in sediment plume geometry post-construction. Following the completion of the project, a net increase exceeding 12 square kilometers in suspended sediment dispersion area is observed, accompanied by a northward deflection in the dispersion pattern of approximately 23 degrees. This research provides critical technical support for ecological impact assessment and integrated management of major engineering projects in the Pearl River Estuary.

R. Loritz, A. Dolich, E. Acuña Espinoza et al.

<p>Comprehensive large-sample hydrological datasets, particularly the CAMELS datasets (Catchment Attributes and MEteorology for Large-sample Studies), have advanced hydrological research and education in recent years. These datasets integrate extensive hydro-meteorological observations with landscape features, such as geology and land use, across numerous catchments within a national framework. They provide harmonised large-sample data for various purposes, such as assessing the impacts of climate change or testing hydrological models on a large number of catchments. Furthermore, these datasets are essential for the rapid progress of data-driven models in hydrology in recent years. Despite Germany's extensive hydro-meteorological measurement infrastructure, it has lacked a consistent, nationwide hydrological dataset, largely due to its decentralised management across different federal states. This fragmentation has hindered cross-state studies and made the preparation of hydrological data labour-intensive. The introduction of CAMELS-DE represents a step forward in bridging this gap. CAMELS-DE includes 1582 streamflow gauges with hydro-meteorological time series data covering up to 70 years (median length of 46 years and a minimum length of 10 years), from January 1951 to December 2020. It includes consistent catchment boundaries with areas ranging from 5 to 15 000 km<span class="inline-formula">²</span> along with detailed catchment attributes covering soil, land cover, hydrogeologic properties, and data on human influences. Furthermore, it includes a regionally trained long short-term memory (LSTM) network and a locally<span id="page5626"/> trained HBV (Hydrologiska Byråns Vattenbalansavdelning) model that were used as quality control and that can be used to fill gaps in discharge data or act as baseline models for the development and testing of new hydrological models. Given the large number of catchments, including numerous relatively small ones (636 catchments <span class="inline-formula"><i>&lt;</i></span> 100 km<span class="inline-formula">²</span>), and the time series length of up to 70 years (166 catchments with 70 years of discharge data), CAMELS-DE is one of the most comprehensive national CAMELS datasets available and offers new opportunities for research, particularly in studying long-term trends and runoff formation in small catchments and in analysing catchments with strong human influences. This article describes CAMELS-DE version 1.0, which is available at <a href="https://doi.org/10.5281/zenodo.13837553">https://doi.org/10.5281/zenodo.13837553</a> (Dolich et al., 2024).</p>

Mikhail M. Trofimchuk

Assessment of the biological systems’ state in case of anthropogenic impact is the most important aspect of monitoring of the surface waters’ state and pollution. The state of more than 100 water bodies of the European territory of Russia and Siberia was assessed in various natural and climatic zones with different levels of pollution and different mineralization, as one of the significant environmental factors of natural origin.

Alfredo Iglesias-Rey, Carlos Alfonso López Hojas, F. Javier Martínez-Solano et al.

This paper demonstrates the synergistic use of engineering judgment and statistical/deep learning models, implemented through a four-step process using the software SAS Viya 4. Initial data filtering, input variable determination, and simultaneous application of RNN, LSTM, and GRU forecasting algorithms are conducted. Results are evaluated based on Battle of Water Demand Forecasting criteria, refining parameters iteratively for enhanced prediction accuracy. The methodology iteratively incorporates new data, streamlining neural network resolution.

Liren Ban, Zefan Wang, Weisheng Du et al.

To explain the effect of joint roughness on joint peak shear strength (JPSS) and investigate the effect of different contact states of joint surface on JPSS, we try to clarify the physical mechanism of the effect of joint cavity percentage (JCP) on JPSS from the perspective of the three-dimensional (3D) distribution characteristics of the actual contact joint surface, and propose a JPSS model considering the JCP. Shear tests for red sandstone joints with three different surface morphologies and three different JCPs were performed under constant normal load condition. Based on test fitting results, the reduction effect of the JCP on JPSS is investigated, and a JPSS model for cavity-containing joints is obtained. However, the above model only considers the influence of JCP by fitting test data, and does not reveal the physical mechanism of JCP affecting the JPSS. Based on the peak dilation angle model for consideration of the actual contact joint morphology, and the influence of JCP on the roughness of the actual contact joint surface, a theoretical model of the JPSS considering the JCP is proposed. The derivation process does not depend on the test fitting, but is entirely based on the joint mechanical law, and its physical significance is clear. It is proposed that the essence of the influence of the JCP on JPSS is that the JCP first affects the normal stress of the actual contact joints, further affects the roughness of actual contact joints, and then affects the shear strength.

CHEN Xuanxuan, WANG Lina

Water yield is one of the important service functions of the urban ecosystem,and land use change has a certain influence on regional water yield change.Therefore,it is of great significance to analyze the correlation between water yield and land use change.With Guangdong Province as the research object,the influence of land use change on water yield was explored by comprehensively applying tools such as InVEST,ArcGIS,and SPSS.The results showed that from 1980 to 2020,the variation range of the average water yield depth in the whole province was 974~1 375 mm.Spatially,it showed the spatial distribution characteristics of higher water yield in the central cities of Guangdong Province and lower water yield in the northeast and southwest.The increase in urban and rural land areas had a certain positive correlation with the increase in water yield.The increase in the area of cultivated land,forest land,grassland,and water area had a certain negative correlation with the water yield.

Ng Wei Soon, Lee Min Lee, T. C. Khun et al.

Heping XIE, Ru ZHANG, Li REN et al.

The Sichuan—Tibet railway faces the most complicated engineering geological conditions in the world. Affected by deep environment and engineering disturbance, the instability and catastrophe of rock masses surrounding deep-buried tunnels along the line became prominent; the analysis and research on surrounding rock catastrophe that accord with the deep characteristics are not only a major practical need for the safe construction of deep-buried and long tunnels along the Sichuan—Tibet Railway, but also the key to improving the development capabilities of deep engineering under special geological conditions. Therefore, taking “the analysis of deep surrounding rock catastrophe” as the research core, starting with the in-situ geological environment and engineering disturbance effect of deep surrounding rock catastrophe, this paper focuses on the study and thought on theory and method of deep surrounding rock quality classification, large deformation identification and rockburst disaster. Firstly, the in-situ geological environment characteristics of deep surrounding rock disaster in Sichuan—Tibet railway were summarized, and the engineering disturbance effect on deep surrounding rock disaster gestation was revealed from two aspects of experimental simulation and theoretical analysis; furthermore, based on the revised <italic>BQ</italic> method, a classification method of surrounding rock quality which can comprehensively reflect the influence of in-situ stress, geothermal and groundwater was developed, which was preliminarily applied to the classification of tunnel surrounding rock quality under the deep multi-field coupling environment on Sichuan—Tibet railway; finally, aiming at the two typical forms of surrounding rock disaster (e.g., large deformation and rockburst) of deep-buried tunnels along Sichuan—Tibet railway, the multi-factor stepwise evaluation method of large deformation classification of surrounding rock, as well as the research idea and prediction model and comprehensive prediction method of deep rockburst were proposed. The relevant research results and academic ideas can provide a reference for the disaster analysis and stability research of surrounding rock of deep tunnels along Sichuan—Tibet railway.

Shang Mao, Tao Zhou, Yao Yao et al.

Better understanding of the dispersion and deposition of sub-micron particles in supercritical CO2 (SCO2) is crucial for the safe operation of supercritical thermal equipment. In present study, the numerical simulation was carried out to evaluate the deposition features of sub-micron particles in SCO2. The anisotropic flow in the gas phase was predicted using the Re-Normalization Group (RNG) k-ε turbulent model and the particle trajectory was tracked using the discrete particle model (DPM). Moreover, the particle deposition under heating and cooling condition were presented. The effects of particle type, wall temperature, inlet flow velocity, temperature and pressure on particle deposition were investigated. The analysis found that the deposition velocity is more applicable to judging the particle deposition than the dimensionless deposition velocity. When SCO2 is cooled, it promotes particle deposition, and when it is heated, it prevents deposition due to thermophoretic forces. Particles are easily deposited when SCO2 exceeds the pseudo-critical point in the gaseous-like region. Moreover, stainless steel has greater deposition velocity than graphite due to the large density. The inlet flow velocity has different effects on particle deposition. It promotes the deposition of small particles, medium particles remain stable, and large particles first decrease and then increase. The particle diameter is closely related to the deposition distance. The deposition probability for 1 μm, 10 μm and 50 μm is 63%, 77% and 85% at 0–0.2 m, respectively.

K. Flack, M. Schultz

QI Yonghui, Chelimuge, YU Huanghao et al.

Water intake and water consumption have an important impact on the runoff of the Yellow River Basin.Based on the measured runoff data from the main control stations of the mainstream of the Yellow River and its water resources bulletin data,this paper preliminarily analyzes the runoff changes of the main sections of the upper and lower reaches of the mainstream and the impact of water intake and consumption on the mainstream runoff.The results show that:①The annual runoff measured at all three stations,namely Lanzhou (1919—2018),Huayuankou (1919—2018),and Lijin (1950—2018),shows a decreasing trend,with non-significant decrease in Lanzhou station in the upper reaches,but significant decrease in the two stations in the middle and lower reaches.②During the period of 1998—2019,the annual runoff of the 11 main hydrological stations on the mainstream of the Yellow River shows a consistent increasing trend,which may results from the increase in average precipitation in the basin.③The changes in water intake and total water consumption in the basin from 1998 to 2019 show an increasing trend,indicating that the water intake along the Yellow River increases steadily.The influence of water intake and consumption on the runoff changes in the section above Lanzhou is small,with the contribution less than 20%.In the middle and lower reaches,the impact of water intake and consumption on the reservoir storage is big,especially in the Longmen-Sanmenxia subarea,where the proportion of restored surface runoff to the natural river runoff reaches 55.4%.

Hiroyuki Suzuki, Kenji Oonaka, Atsushi Hashimoto

In this study, a field survey of fecal contamination indicators and Clostridium perfringens cpe(+) in river environments was conducted to verify the effectiveness of C. perfringens cpe(+) as a microbial source tracking indicator in public water bodies. In the Saijo River, which serves as a model of point source contamination from human sewage effluents, the concentrations of Escherichia coli, enterococci and C. perfringens increased after the inflow of sewage effluents, with the cpe-positive prevalence rate of C. perfringens isolates increasing from 13.3 to 21.5%. In the Nagaike River, contaminated with household sewage effluents from non-point sources, high concentrations of E. coli, enterococci, and C. perfringens cpe(+) were detected, with high cpe-positive prevalence rates of 27.6 and 26.4%. Contrarily, in the Koayu River, which is contaminated with treated wastewater from a large swine farm, an increase in the concentration of fecal contamination indicators and C. perfringens was observed; however, the cpe-positive prevalence rate of C. perfringens isolates remained unchanged, ranging as low as 3.6 and 3.9%. Altogether, our results revealed that the concentration and pollution load of C. perfringens cpe(+) is an effective microbial source tracking indicator of human fecal contamination in freshwater environments.

Endene Emmanuel, V. Anggraini, M. Raghunandan et al.

Abstract The possibility of improving the engineering properties of a marine clay by adding forsteritic olivine is explored. Strength improvement was recorded with ascending values of olivine contents and curing time. An olivine content of 30% was identified as the optimum value to achieve the targeted improvement for all curing durations. Formation of magnesium-aluminate-hydrate and magnesium-silicate-hydrate were found to be the key components responsible for this strength improvement based on morphological and mineralogical analyses. Comparative studies with identical lime-treated marine clay samples revealed that olivine treatment achieved higher mechanical strength and lower hydraulic conductivity relative to lime treatment for a limited curing duration.