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This article presents the effect of biological clogging on the hydraulic performance of geotextiles used for the construction of filter and drainage in landfills. Clogging tests were performed on specimens of woven and non-woven geotextiles in a discontinuous fermentation scenario using natural leachate and a nutrient solution. The consequences of biological clogging were assessed through experimental measurements of changes in the cross-plane hydraulic conductivity and the impregnation ratio of different geotextiles specimens at different immersion times. Porosity reduction was then back-calculated from the hydraulic conductivity results using the Kozeny-Carman equation. Additionally, the impact of an antibiotic and antifungal solution on biofilm development was evaluated. It was demonstrated that the cross-plane hydraulic conductivity of geotextile specimens decreases as biomass accumulation per unit area increases with immersion time. The application of an antibiotic and antifungal solution resulted in a porosity recovery of over 90% and a hydraulic conductivity recovery ranging from 78 to 83% for both woven and non-woven geotextiles. These results demonstrate that the clogging was primarily due to biological activity. Despite certain limitations in measurement and definition, the impregnation ratio proved to be a reliable parameter for the evaluation of biological clogging. • Bioclogging of geotextiles employed in filter and drainage layers was analyzed. • Influence of geotextile type on biological clogging was determined. • Biofilm formation in geotextile specimens was quantified. • Porosity reduction was determined using hydraulic conductivity models. [ABSTRACT FROM AUTHOR]

This paper presents a numerical model for simulating flows in open channel networks by discretizing the Saint-Venant equations via a Godunov-type scheme. The methodology integrates the Harten Lax van Leer (HLL) approximate Riemann solution scheme for interface flux, the slope flux method for water surface slope terms, and an explicit method for handling friction source terms. A novel aspect of this work is the introduction of the artificial area method to treat junction points as nodes with fixed, constant areas, thus eliminating the need for iterative computations. A generalized approach is proposed to calculate these fixed areas on the basis of the characteristics of adjacent river nodes. Additionally, two other junction calculation methods—the method of characteristics and the Riemann iteration method—are developed to assess the effectiveness of the artificial area method. The performance of various junction models is evaluated via simulations with three independent channels and three channel networks. The results show a high degree of consistency among the simulated outcomes, exact solutions, experimental measurements, and findings from the literature. Furthermore, the artificial area method demonstrates significant agreement with the other junction methods. Notably, the artificial area method significantly enhances computational efficiency at junction points, achieving speed improvements ranging from 30 to 290 times faster than those of the other two methods. In conclusion, the artificial area method is characterized by its simplicity, effectiveness, and ease of implementation. Its computational accuracy is on par with that of other methods, rendering it widely applicable for simulating flows in open channel networks. This work contributes valuable insights into numerical modeling techniques for hydraulic engineering applications. [ABSTRACT FROM AUTHOR]

Hydraulic impact mathematical modeling allows for the quantitative assessment of various assemblies of the flow-through piston, and the optimization of its design and increased operating efficiency. This research has practical value and can be applied in various fields, and within the framework of this study, form requirements for subsequent bench tests. Existing experimental studies confirm the possibility of using hydraulic activation technology, but the absence of a scientific basis for its operation hinders their widespread implementation. The study examines the hydraulic characteristics of the flow when passing through the flow-through piston. According to the modeling results, the value of the hydraulic drag force and the pressure differential at which the valve operates are represented as functions of the liquid density and the geometry of the confuser. The minimum critical value of the piston hole diameter is established, which will provide the necessary pressure differential at a given flow rate of the drilling mud. It was found that increasing the confuser angle does not completely eliminate the occurrence of a stagnant zone, but reduces its area and increases the flow rate in it. For the first time, the value of the confuser angles was found at which the force value remains conditionally constant, and the pressure differential decreases rapidly. The findings demonstrates recommendations on the choice of the confuser geometry depending on the density of the drilling mud. Depending on the requirements, the piston shape, its design, and hydraulic parameters can be optimized, studied in detail to achieve the required results. [ABSTRACT FROM AUTHOR]

Localization of anomaly events in near real-time (NRT) in water distribution networks is compelling but challenging for water utilities. This paper presents an integrated approach using both data-driven and hydraulic model–based methods to localize NRT anomaly events. Upon detecting an NRT anomaly event, the pressure drops at sensor locations are calculated, followed by estimating the pressure drops at junction nodes via an inverse-distance weighted interpolation method. Clustering is then performed based on the junction pressure drops and network topology to segregate and reduce the search areas. A genetic algorithm optimization is then performed with hydraulic model simulations to further locate the anomaly hotspots. The efficiency of the anomaly localization is enhanced by message passing interface (MPI)–based parallelization of optimization to facilitate NRT operations. The integrated method has been tested on both simulated simultaneous multiple leaks and real leakage events with field data, where the ground-truth leaks have been successfully covered in the clustered search areas. Leak hotspots are further pinpointed by hydraulic model–based parallel optimization within a distance of 300 m to the ground-truth leaks, indicating satisfactory accuracy in leak localization. [ABSTRACT FROM AUTHOR]

Ice formation and accumulation on aircraft is a major problem in aviation. Icing is directly responsible for aircraft incidents, limiting the safety of air travel and requiring expensive, and sometimes ineffective deicing strategies. Furthermore, electrification of aircraft platforms leads to difficulties with integration of legacy deicing methods such as pneumatic boots. In this work, we study electrothermal pulse deicing capable of efficient and rapid removal of ice from aircraft wings. The pulse approach enables the efficient melting of a thin (<100 µm) ice layer on the wing surface to limit parasitic heat losses. Only the interface is melted, with the rest of the ice sliding on the melt lubrication layer due to aerodynamic forces. To study pulse deicing, we developed a transient thermal-hydrodynamic numerical model that accounts for multiple phases and materials, specific and latent heating effects, melt layer hydrodynamics, as well as boundary layer effects. To identify optimal deicing strategies, we use our model to study the effects of heater thickness (50 µm < th <1 mm < 1 mm), substrate electrical insulation thickness (10 µm < ti <1 mm < 1 mm), pulse duration (0.4 s < Δ tpulse < 4.5s < 4.5 s), and pulse energy. Optimum operating points are identified for large (Boeing-747), midsize (Embraer-E175), and small (Cessna-172) aircraft. The scale-dependent thermal-hydraulic model results are used to estimate input conditions required for deicing and integrated into an electrical model considering energy storage, power electronics, integration, and layout, to achieve overall volumetric and gravimetric power density optimization. [ABSTRACT FROM AUTHOR]

A new simplified method of analysis is proposed for predicting the final steady state behaviour of sloping capillary barriers subjected to continuous rain of constant intensity. In contrast to an existing simplified method, the proposed new method assumes approximate final steady state suction profiles on vertical cross-sections of the finer layer that are appropriate for sloping capillary barriers, with flow parallel to the slope in the lower part of the finer layer. Numerical validation, performed by hydraulic FE modelling, shows that, in all cases studied, the final steady state profiles of suction, degree of saturation and horizontal seepage velocity predicted by the new simplified method are excellent matches to the corresponding results from FE simulations. As a consequence, values of water storage capacity and water transfer capacity are accurately predicted in all cases, together with the final steady state variation of water stored with horizontal coordinate. A parametric study shows the influence of key variables (slope angle, material of finer layer, thickness of finer layer and rainfall intensity) on water storage capacity and water transfer capacity of sloping capillary barriers. [ABSTRACT FROM AUTHOR]

Hydraulic conductivity of conifer sapwood varies greatly between and within annual rings due to varying dimensions and numbers of tracheids, lumina and bordered pits, complex relationships and non-linearities. Existing laboratory methods are too tedious and expensive for large scale studies for instance of genetics, tree improvement and silvicultural practices, and their spatial resolution is not enough for information on seasonal weather effects which may reflect vulnerability to drought. The article presents a set of integrated models estimating radial variations in hydraulic conductivity at the tracheid level, at 25 µm resolution. A rationalised model was designed for the organisation of tracheids and the water transport through lumina and bordered pits. Within this, pressure drops at flow along lumina and at passages of pits are estimated and integrated to provide local estimates of lumen and xylem conductivities with same radial resolution. The estimated lumen conductivities varied from maximum 0.030 m2/(s·MPa) in earlywood to minimum 0.001 m2/(s·MPa) in latewood. Estimated pressure drops on pit passages reduce these values with about 80 and 90 % into xylem conductivities of 0.006 and 0.0001 m2/(s·MPa) in same earlywood and latewood. Sample means of modelled trunk xylem conductivities were correlated with data from laboratory analyses, resulting in R2 > 0.50. [ABSTRACT FROM AUTHOR]

Functional traits like hydraulic conductivity and vulnerability to cavitation are increasingly important due to climate change. In conifers, water is transported through lumina of tracheids connected via bordered pits, which severely limit xylem conductivity by causing large pressure drops related to their number, dimensions and structure. According to literature, numbers and dimensions of pits correlate positively with tracheid and lumen dimensions. This reflects variations from earlywood to latewood and between rings formed under different grow conditions, contributing to major conductivity variations. The wider aim of the work is to estimate such conductivity variations in trunkwood from measurement data on radial and axial variations of tracheid dimensions. This requires several integrated models, including models estimating numbers and dimensions of pits. The article presents such models developed on data from 27 Norway spruce trees representing different sites, clones and growth rates. Measured and estimated variations of tracheid, lumen and pit properties within and between rings are illustrated, indicating on average about one third smaller and fewer pits in latewood than in earlywood tracheids, and variations in numbers and areas of pits per unit volume of xylem which may be interesting also in fields like wood drying and impregnation. [ABSTRACT FROM AUTHOR]

The EPA's Storm Water Management Model (SWMM) has been applied across the globe for citywide stormwater modeling due to its robustness and versatility. Recent research indicated that SWMM, with proper setup, can be applied in the description of more dynamic flow conditions, such as rapid inflow conditions. However, stormwater systems often have geometric discontinuities that can pose challenges to SWMM model accuracy, and this issue is poorly explored in the current literature. The present work evaluates the performance of SWMM 5 in the context of a real-world stormwater tunnel with a geometric discontinuity. Various combinations of spatiotemporal discretization are systematically evaluated along with four pressurization algorithms, and results are benchmarked with another hydraulic model using tunnel inflow simulations. Results indicated that the pressurization algorithm has an important effect on SWMM's accuracy in conditions of sudden diameter changes. From the tested pressurization algorithms, the original Preissmann slot algorithm was the option that yielded more representative results for a wider range of spatiotemporal discretizations. Regarding spatiotemporal discretization options, intermediate discretization, and time steps that lead to Courant numbers equal to one performed best. Interestingly, the traditional SWMM's link-node approach also presented numerical instabilities despite having low continuity errors. Results indicated that although SWMM can be effective in simulating rapid inflow conditions in tunnels, situations with drastic geometric changes need to be carefully evaluated so that modeling results are representative. [ABSTRACT FROM AUTHOR]

The efficient management of water resources is crucial due to increasing environmental and societal pressures, requiring advanced data handling capabilities. Traditional relational data models, while foundational, struggle to capture the complex relationships inherent in water systems, limiting analytical and decision-making effectiveness. To address these challenges, this paper proposes a comprehensive graph data model for water resource management. Our model includes conceptual, logical, and physical frameworks that enable the structured representation of hydraulic objects and their relationships. We categorize hydraulic objects, examine their spatial, structural, and operational interconnections, and construct an adaptable graph data model. This model provides the enhanced integration, mining, and analysis of hydraulic data, supporting intelligent, data-driven water management applications. Example applications demonstrate the model's utility in improving watershed management, hydropower scheduling, and uncovering latent relationships among hydraulic components through graph neural networks. This work establishes a robust data foundation for the sustainable and scientific management of water resources. [ABSTRACT FROM AUTHOR]

Flooding, one of the most destructive and recurrent natural catastrophes, causes severe loss of life and property. The destructive effect of floods has increased with climate change and unplanned urbanization. To prevent this devastation and find solutions to potential flooding, it is important to improve engineering, ecological, hydrological, and hydrogeological precautions, as well as potential flood simulations. Using hydraulic models to perform flood simulations is a common and successful approach globally. In this study, HEC-RAS (1D) was used to simulate three different flood scenarios on the Boğaçay sub-basin in Antalya, the most important tourism destination of Türkiye. Flood scenarios were developed based on the data of the floods that occurred in the region in 2003 and 2006, with measured flow rates of 1899.9 m3/s and 1450 m3/s, respectively, and with the maximum flow rate (2408 m3/s) determined by the relevant ministry. Then, the landscape composition of the region at the sub-basin scale was determined and the impacts of flood scenarios on the landscape composition around the riverbed were evaluated. The results of the analysis show that the water height will increase, ranging from 1.4 m to 3.6 m, and the landscape composition of the region will be significantly affected by this increase in water height in the three different flood scenarios. Especially in the part where the river meets the sea, 580.74 ha of urban settlement is estimated to be damaged by flooding, according to the worst-case scenario. Finally, the study will guide decision-makers to take the necessary measures under the relevant scenarios. [ABSTRACT FROM AUTHOR]

Copyright of Pearl River is the property of Pearl River Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Global radiation is a key climate input in process-based models (PBMs) for forests, as it determines photosynthesis, transpiration and the canopy energy balance. While radiation is highly variable at a fine spatial resolution in complex terrain due to shadowing effects, the data required for PBMs that are currently available over large extents are generally at a spatial resolution coarser than ∼9 km. Downscaling large-scale radiation data to the high resolution available from digital elevation models (DEMs) is therefore of potential importance to refine global radiation estimates and improve PBM estimations. In this study, we introduced a new downscaling model that aims to refine sub-daily global radiation data obtained from climate reanalysis data or projections at large scales to the resolution of a given DEM. First, downscaling involves splitting radiation into a direct and diffuse fraction. The influences of surrounding mountains' shade on direct radiation and the "bowl" (deep valley) effect (or sky-view factor) on diffuse radiation are then considered. The model was evaluated by comparing simulated and observed radiation at the Mont Ventoux study site (southeast of France) using the recent ERA5-Land hourly data available at a 9 km resolution as input and downscaled to different spatial resolutions (from 1 km to 30 m resolution) using a DEM. The downscaling algorithm improved the reliability of radiation at the study site, in particular at scales below 150 m. Finally, by using two different PBMs (CASTANEA, a PBM simulating tree growth, and SurEau, a plant hydraulic model simulating hydraulic failure risk), we showed that accounting for fine-resolution radiation can have a great impact on predictions of forest functions. [ABSTRACT FROM AUTHOR]

This work aims to improve the accuracy of traditional models for analyzing the hydraulic properties of unsaturated soil by integrating digital imaging measurement with deep learning techniques. The work first reviews current research on the basic characteristics of unsaturated soil and the applications of deep learning in this field. Next, it examines the impact of soil specimens' physical properties on their hydraulic properties. This includes acquiring hydraulic parameters and the soil-water characteristic curve through full-surface digital imaging measurements. Finally, a soil hydraulic property model based on the backpropagation neural network (BPNN) is implemented, trained, and validated. Results indicate that the model's predicted soil-water characteristic curve aligns closely with the experimental findings from previous studies. Moreover, the proposed BPNN-based unsaturated soil hydraulic property model uses the Levenberg–Marquardt algorithm, which reduces computational time and noise compared to alternative algorithms. Meanwhile, analysis of the model parameters suggests that ten neurons in the hidden layer provide optimal performance. By incorporating correlations between physical parameters, such as soil particle size and soil hydraulic properties, the model demonstrates lower error rates compared to other literature models. Overall, this BPNN model effectively represents the relationship between soil's physical and hydraulic parameters, streamlining traditional soil correlation coefficient estimation. [ABSTRACT FROM AUTHOR]

Storm Water Management Model (SWMM) was widely used in hydrological simulation, river network calculation, flood control, and disaster reduction, but it was rarely used in ship lock hydraulics simulation. In this paper, SWMM is used to simulate the water filling and emptying process in ship lock. One‐dimensional hydraulic mathematical models are established for the centralized filling and emptying system, simple decentralized filling and emptying system, and complex decentralized filling and emptying system, respectively, and they are applied to Mengli Ship Lock of North River in Guangdong Province, Qiaogong Ship Lock of Hongshui River, and Bajiangkou Ship Lock of Gui River in Guangxi Province of China. Compared with the results from the physical model experiments of ship lock hydraulics, it is shown that SWMM has better simulation effects on the centralized filling and emptying system with short corridor and the simple decentralized filling and emptying system, and their relative errors of filling and emptying time and maximum flow are totally less than 5%. For the complex decentralized filling and emptying system, SWMM has a good simulation effect on the water level change process, but the simulation error of the flow change process is larger relatively, and the relative errors of filling and emptying time and maximum flow are totally less than 10%. In addition, the filling and emptying process simulations are all completed within 5 s for three types of filling and emptying systems. The results show that the mathematical model of ship lock filling and emptying based on SWMM has high operation efficiency and good simulation accuracy and can not only be used as an effective tool for hydraulic calculation of ship lock but also provide mathematical model support for navigation intelligent scheduling. [ABSTRACT FROM AUTHOR]

A model that describes the water distribution of a single fixed spray plate sprinkler (FSPS) based on the harmonic analysis was proposed. The relationship between the pressure head, nozzle diameter, mean sprinkler irrigation depth, and amplitude was established. An analytical model for evaluating the sprinkler irrigation uniformity coefficient of a multi-sprinkler combination was developed by introducing a weighting coefficient. In conjunction with the sprinkler irrigation system's finite element hydraulic calculation model, the impact of the pipe diameter, sprinkler number, and sprinkler spacing on system energy loss, pressure head, and sprinkler irrigation system uniformity was assessed. The results demonstrated that under varying pressures and nozzle diameters, the Camargo and Sentelhas coefficient (c) between the measured and fitted mean value of the sprinkler irrigation depth of a single FSPS was greater than 0.99, while the c between the measured and fitted amplitude value was approximately 0.93. Under different combinations of nozzle, pressure head, and sprinkler spacings, the measured, derived, and calculated values of 54 sprinkler irrigation uniformity combinations were basically consistent. The uniformity of the combined FSPS under a linear-move sprinkler system was significantly affected by nozzle diameter, pipe diameter, sprinkler spacing, and inlet pressure head at 0.01 level. The number of sprinklers also had a significant impact at 0.05 level. The findings of this study could serve as a theoretical foundation for the proper design of linear-move sprinkler irrigation systems. • The harmonic analysis was used to describe sprinkler water distribution. • Weighting coefficient can predict the uniformity of sprinkler combinations. • Nozzle diameter exhibit highly significant effects on sprinkler field uniformity. [ABSTRACT FROM AUTHOR]

This study investigates the dynamics of air-water flow and the resulting forces on a broad-crested weir with a vertical face under both ventilated and non-ventilated cavity conditions. The focus is on measured forces and flow characteristics across various upstream water depths and flume outlet heights, categorized by distinct groups based on flow regimes. The experimental setup incorporates measurements of air-water mixture density, air cavity pressure, cavity water depth, and velocity profiles in the recirculation pool downstream of the weir. Results indicate that under supercritical downstream flow conditions, the forces exerted on the weir are directly proportional to the upstream water depth, while the downstream flume depth has a minimal impact. Conversely, in subcritical downstream conditions, the downstream flume depth significantly influences stabilizing forces due to increased cavity water depth. Additionally, pressure profile estimations on the downstream-facing wall of the weir using hydrostatic, Bernoulli, and Navier-Stokes equations show that the hydrostatic assumption is inadequate for estimating pressures and sliding forces in non-ventilated cavities. This study offers crucial insights into air-water flow dynamics in weirs, underscoring the importance of incorporating dynamic factors into weir design and hydraulic modeling. [ABSTRACT FROM AUTHOR]

Current standard methods of measuring permeability of interlocking-block permeable pavements (IBPPs) do not correctly measure the actual infiltration rates of IBPPs. The test results vary with test area size and location. In this study, employing the standard ASTM-1781 test apparatus, an improved procedure that adopts an experiment-based numerical approach is developed to overcome the problem. It involves the following steps: (i) Perform falling-head infiltration tests using ASTM-1781 apparatus to obtain infiltration flow data; (ii) Develop computational fluid dynamic (CFD) finite-volume models for different infiltration test conditions; and (iii) Apply appropriate finite-volume model to calculate the effective IBPP infiltration rate under any given surface water depth on the IBPP. Experimental tests were conducted to validate the proposed method. [ABSTRACT FROM AUTHOR]

In this study, a new articulated concrete armor unit named Couple-Lock, which can be enlarged in size to cope with high waves, is easy to secure binding force between units, and can be applied to various field conditions, was developed. The Couple-Lock consists of two symmetrical blocks. One symmetrical block has four legs installed in all directions on one end of the body. Since two left-right symmetrical blocks are connected with a wire rope and behave, a pair of blocks can be treated as a single block and enabling large size to cope with high waves. Also, the Couple-Lock responds flexibly to topographical changes. In order to examine the hydraulic performance and stability of the developed armor unit, a hydraulic model experiment was conducted. As a result, the average reflection coefficients of ordinary wave and storm wave conditions were calculated as 0.433 and 0.533, respectively. The average transmission coefficients under ordinary wave and storm wave conditions were calculated as 0.046 and 0.147, respectively. Among the 62 storm wave conditions, wave overtopping occurred in 50 storm waves. The stability factor of the Couple-Lock was calculated to be about 18, which is twice of the stability factor of the tetrapod. [ABSTRACT FROM AUTHOR]

Stormwater management in urban environments typically involves regulation of release rates of stored water from control structures to mitigate enhanced peak flows that can cause damaging flooding. The extent to which this mitigation influences stream geomorphic stability remains largely unexplored. Moreover, few, if any, studies have examined how instability is related to hydraulic effects of in-channel structures within urban stream systems. This paper assesses the potential for channel instability under existing conditions in two urban streams in Cook County, Illinois using a stream-power modeling approach. It also evaluates the impact of watershed-specific release rates intended to mitigate flooding from future development on instability potential. The analysis utilizes hydrologic and hydraulic modeling to estimate stream power per unit area for 2-year and 50-year storm events for both the existing base condition and for four release-rate scenarios. Stream power exceeding the critical power required to mobilize channel bed material is integrated over time to determine excess work. Results show that the spatial distribution of excess work for the base condition varies by more than nine orders of magnitude within individual reaches, confirming high potential for instability. Release-rate scenarios both increase and decrease the magnitude of excess work relative to the base conditions within specific reaches of the two streams but do not alter substantially the high variability in excess work. The results demonstrate that instability potential in these urban fluvial systems is governed primarily by spatial variability in hydraulic properties associated with fragmentation of the streams by multiple in-channel structures. [ABSTRACT FROM AUTHOR]

Ice jamming is the primary mechanism that can generate overland flooding and recharge the isolated basins of the Peace–Athabasca Delta (PAD), a valuable ecosystem of international importance and the ancient homeland of the Indigenous Peoples of the region. Focusing on the regulated Peace River and the Peace Sector of the delta, which has been experiencing a drying trend in between rare ice-jam floods over the last ~50 years, this study describes recent notable breakup events, associated observational data, and numerical applications to determine river discharge during the breakup events. Synthesis and interpretation of this material provide a new physical understanding that can inform the ongoing development of a protocol for strategic flow releases toward enhancing basin recharge in years when major ice jams are likely to form near the PAD. Additionally, several recommendations are made for future monitoring activities and improvements in proposed antecedent criteria for early identification of "promising" breakup events. [ABSTRACT FROM AUTHOR]

Rheological experiments and measurements of particle settling velocity under static conditions were conducted for two types of polyacrylamide (PAA-based) fluids. The flow behavior of the viscoelastic fluids is described by a simplified, three-parameter model that integrates a constant viscosity at low shear rates with a power-law viscosity dependency at higher shear rates. The estimated dependencies of the rheological parameters and particle settling velocity on PAA concentration align with the classical power-law scaling for semi-dilute polymer solutions. The identified scaling offers valuable insight for optimizing the chemical composition of fracturing fluids, thereby improving the efficiency of hydraulic fracturing technology. By applying the lubrication approximation to the Navier–Stokes equations, a set of equations for the suspension flow in a vertical plane channel, characterized by the three-parameter rheology model, was derived. In typical fracturing conditions, the conventional power-law viscosity model used in current fracturing simulators significantly overestimates the gap-averaged apparent fluid viscosity compared to the proposed model. The novel model of the suspension flow aims to enhance the accuracy of proppant transport models applied in hydraulic fracturing simulators. Based on the three-parameter rheology model, a new model of particle settling in the studied PAA-based fluids is developed. It is based on smart Stokes' law, where viscosity is calculated according to either the plateau or power-law region, depending on the self-induced shear rate. The new model more accurately approximates experimentally determined settling velocity of proppant under static conditions across a broad range of PAA concentrations than existing models. [ABSTRACT FROM AUTHOR]

Copyright of Larhyss Journal is the property of Biskra University, Research Laboratory in Subterranean & Surface Hydraulics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to investigate the influence of land use changes on the occurrence of flood hazards in the Pondok Karya area, Jakarta, Indonesia. Landsat OLI 8 and 7 from 2002 to 2023 were analyzed with a supervised classification tool using Envi and ArcGIS to investigate land use changes over the period. Additionally, the HEC-HMS and HEC-RAS tools were utilized for hydrological and hydraulic assessments under 25 discharge return periods (Q25), using a daily rainfall dataset from 2004 to 2021. The flood hazard index was produced using statistical and GIS methodologies and was based on Neighbourhood Associations (NAs) after qualified hydraulic model performance, indicating a Nash 0.65-Nash-Sutcliffe model efficiency (NSE) value. The analysis revealed considerable alterations in land use and cover within the Pondok Karya watershed. Consequently, the percentage of urban areas surged 30%, whereas vegetative cover declined 24%. Additionally, bare land decreased 9%, and water bodies marginally increased 3%. This indicates a 10% increase in the peak flood river flow of Mampang, from approximately 90 m³/s to 100 m³/s within this period. Subsequently, the percentage of high-risk areas increased from 42.85% (six NAs) to 57.14% (eight NAs), whereas the percentage of low-risk areas decreased from 14.29% (two NAs) to 7.14% (one NAs). Moderate-risk areas also decreased from 42.85% (six NAs) to 35.71% (five NAs). The study found that despite vegetative cover exceeding 30%, the capacity of the Mampang River remained inadequate, and the risk of flooding increased with the impact of its conversion. Additionally, the soil properties and social intervention factors contributed to the performance of the inundation model. Our study underscores the need for further research to mitigate flood risks and advocate interventions such as reservoir construction or river normalization in the upper Mampang catchment area. This study is useful for both local and central governments, which act as decisionmakers to reduce the risk of flooding. [ABSTRACT FROM AUTHOR]

This paper employed a hydraulic model to investigate the transient flow and its hydrodynamic effects in a failed water supply pumping pipeline system during a sudden and unplanned power outage. The model was developed and then properly calibrated to make the system more efficient in locating and determining the change in pressure and discharge throughout the length of the pipeline. The simulation of the transient process was utilized using the method of characteristics. The model was conducted on a practical problem in a hydraulic system of pipelines and pumping station of a water supply-pumping station, which is possessed by Nasiriyah Water Supply Project No.1 The Giant Nasiriyah Water Project (GNWP), Thi-Qar, Iraq, where the power outage is the most common and unsolved problem. The project transmits water for more than 77 km to supply more than 800 thousand inhabitants in the dry areas in southern Iraq with drinking water. The pressure variation and flowrate change at different points for the system with the different timings shutting down were analyzed. The study results showed that the sudden shutdown of the pump generates fluid transients with highpressure variations and flowrate in different locations and times. The characteristics of pumping under the transient conditions showed high fluctuations during the movement between the pump shut-off point and mass flow points, and the magnitudes of the fluctuations decreased with the fading of the impact of the water hammer. The results also indicated that the studied system is experiencing high-pressure pulsations in the discharge of the pumping system in addition to negative pressures, and consequently threatening problems of collapses and severe cavitations are expected along the pipeline in the system. This study may help to prevent the pipeline pumping system from hazards due to transient pressure fluctuations using the most principal recommendations for engineering solutions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydraulic modelling of culverts relating to the flood risk posed by debris in watercourses has previously only assessed the impact of fixed culvert blockage levels, without analysing the change in flooding as blockage levels increase. With increasing flow rates in rivers during flood events, there is concern that existing culverts may be undersized and therefore already posing a substantial flood risk regardless of them becoming blocked by debris. In this article, two‐dimensional (2D) flood modelling is used to produce flood maps detailing the change in flood area and property flooding as culverts become increasingly blocked at several sites in the Northwest of England. The results show a clear distinction between sites where the accumulation of blockage is the key contributing factor towards local flood risk, and sites where the presence of the culvert itself is the predominant flood risk factor. The blockage induced flood risk metric is introduced to characterise the contribution of culvert blockage to the overall flood risk. [ABSTRACT FROM AUTHOR]

Copyright of LHB: Hydroscience Journal is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of LHB: Hydroscience Journal is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of LHB: Hydroscience Journal is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rational method (RM) adopting steady uniform flow assumption is a simple and mainstream approach for the design of urban stormwater-drainage systems (USDSs). However, when designing large-scale USDSs, the RM significantly deviates from the actual flow regime due to inappropriate assumptions. To improve the accuracy and reliability of the design method, a dynamic-wave-simulation-based method (DWSBM) is proposed. Firstly, a numerical model which is equivalent to the surface runoff yield process of RM is established and validated. Then the dynamic wave module is adopted for pipe flow calculations. This method integrates hydraulic models for the whole design process. Both DWSBM and RM are used for USDS design of two areas, and design comparison demonstrates that the design flow rates computed using DWSBM are greater than obtained by RM. With the increase in pipeline length, the design flow differences between the two methods in the two areas increased from 3.09% to 28.97% and from 16.01% to 45.40% respectively. Adopting the DWSBM for design flow rate calculation can effectively improve the design reliability and drainage capacity of USDSs. [ABSTRACT FROM AUTHOR]

A systematic comparative evaluation of mainstream multiphase models for specific hydraulic structures is essential to investigate aerated flow characteristics and promote the models' application. However, such evaluations remain scarce. In this paper, four multiphase models, namely the VOF, Mixture, and Eulerian models in Ansys Fluent and the aerated flow model in FLOW-3D (AFM-F3D), were comparatively introduced and tested for the aerated flow over stepped spillways. Simulation results, including water surface profiles, inception points of aeration, air concentrations, velocities, and turbulent kinetic energies from four models, are compared with each other and with available experimental data. It is discovered that both the VOF and Mixture models fail to reproduce the self-aeration and subsequent downward transport phenomenon. In contrast, AFM-F3D and the Eulerian models predict reliable aerated water surface profiles. AFM-F3D and the Eulerian model demonstrate superior performance in velocity and air concentration calculations, respectively. Based on overall performance, the Eulerian model is recommended for simulating aerated stepped spillway flows. These insights provide valuable guidance for selecting appropriate multiphase models based on specific engineering requirements. [ABSTRACT FROM AUTHOR]

Under the dual pressures of climate change and urbanization, cities in China are experiencing increasingly severe flooding. Using the Yushan Lake area in Ma'anshan City, Anhui Province, as a case study, we employed the InfoWorks Integrated Catchment Management (ICM) hydraulic model to analyze the drainage and flood prevention system of the region and assess the current infrastructure for drainage and flood control. There are 117 pipelines with a return period lower than one year for stormwater and combined sewer systems, accounting for 12.3% of the total number of pipelines. The number of pipelines meeting the one-year but not the three-year return period standard is 700, representing 70.2%. Only 17.5% of the pipelines are capable of handling events exceeding the one-year standard. In simulating a 24 h, 30-year return period rainfall event, the results indicate that floodwater accumulation in the study area is predominantly between 0.15 m and 0.3 m. Most risk areas are classified as low risk, covering an area of 36.398 hectares, followed by medium and high-risk areas, which cover 8.226 hectares and 3.087 hectares, respectively. The Ma'anshan Yushan Lake area has, overall, certain flood control capabilities but faces flood risks during storms with return periods exceeding three years. This research offers valuable insights for improving urban flood management in Ma'anshan City through the development of a stormwater management model for the Yushan Lake area. [ABSTRACT FROM AUTHOR]

Floods are the climate hazard that has the greatest socio-economic and territorial impact on the world. The root causes of these events are atmospheric and hydrological phenomena. However, human action usually aggravates their effects, as it alters the normal functioning of the river courses and water flows. The installation of road, rail and hydraulic infrastructures in a floodplain with no prior calculation or appropriate adaptation exacerbates the negative consequences of floods, increasing the extension of the flooded area and the height of the flood waters. This study addresses the problem of the barrier effect generated, on the one hand, by the layout of the N-332 road, as it is built at the same level as the ground, hindering the flow of overflowing water during episodes of flooding, and on the other hand, the channelling wall of the Segura River in the final stretch of its mouth, in the towns of San Fulgencio and Guardamar del Segura. These elements have aggravated flooding in this area. In order to analyse the consequences of the flood, IBER (v.3.3) software has been used to model a flood with similar effects to that of the episode of September 2019. The current situation has also been analysed with two openings in order to determine the effects that a future flood would have. After analysing the results, a proposal to correct the barrier effect of the N-332 road and the new channelling wall of the River Segura has been elaborated upon and then modelled. The results are positive and effective in reducing the negative effects of floods in the lower basin of the River Segura. [ABSTRACT FROM AUTHOR]

A single planar hydraulic fracture is typically the primary component used to simulate hydraulic fracturing stimulation in conventional reservoirs. However, in ultra-low-permeability shale reservoirs, a large system of fracture networks must be generated to produce hydrocarbons economically. Therefore, traditional modeling approaches centered on single planar fractures are inadequate for accurately representing the intricate geometry and behavior of fractures in these reservoirs. In previous works, 2D fractal fracture networks (FFNs) have been used to generate sets of hydraulic and natural fractures based on microseismic event (MSE) data. Since microseismic data are retrieved in 3D space, the aforementioned model cannot accurately represent induced fracture properties. The objective of this paper is to study in detail the recently developed 2D FFN model and propose a novel solution by expanding the previous model to accommodate real 3D microseismic data. First, the definitions of the 2D FFN model are described, and associated calibration mechanisms are proposed. Next, the 3D FFN model and its calibration system are demonstrated. While the novel 3D calibration solution utilizes an identical matching concept to the 2D methodology, the residual distances between the nodes and the MSE are calculated in 3D spaces. Finally, a set of real microseismic data are used to calibrate the generation of 3D fractals using the proposed workflow. The interactions between microseismicity and fractured reservoir dynamics are represented through the integration of fractal fracture models and microseismic data. This work contributes to advancing the current understanding of hydraulic fracturing in unconventional reservoirs and provides a valuable framework for improving fracture modeling's accuracy in reservoir engineering applications. [ABSTRACT FROM AUTHOR]

Traditional analytical models in groundwater studies often simplify the complexities arising from spatial variations in aquifer geometry and anisotropy, limiting their ability to capture the full theoretical nuances of groundwater flow. In this study, we present a novel methodology that integrates geodesic distances within the intrinsic geometry of confined, constant‐thickness aquifers, while also accounting for directional anisotropy in hydraulic properties. This approach provides a rigorous mathematical framework for accurately capturing the true distances along the aquifer geometry between pumping and observation wells, in contrast to traditional Euclidean distances. Our methodology is compatible with various analytical solutions, including the Theis (1935, https://doi.org/10.1111/jawr.1965.1.3.9) and Papadopulos and Cooper (1967, https://doi.org/10.1029/wr003i001p00241) solutions, extending their theoretical applicability to more complex aquifer geometries and anisotropic conditions. Numerical simulations of synthetic examples illustrate the theoretical consistency of the proposed approach, aligning drawdown patterns within this advanced framework. While primarily focused on enhancing existing analytical models, this methodology sets the stage for future theoretical advances in groundwater modeling, offering a conceptual expansion of analytical solutions to better address geometric and anisotropic complexities. Plain Language Summary: Groundwater models often simplify aquifers as flat, two‐dimensional spaces, but this limits their ability to represent complex aquifer shapes and flow patterns. This study introduces a new method using geodesic distances—the shortest paths on curved surfaces—to provide a more accurate theoretical framework for modeling aquifer geometry and anisotropy. By replacing traditional straight‐line estimates with more precise distance calculations, the method extends established models like the Theis and Papadopulos‐Cooper solutions to more complex aquifers. While primarily theoretical, this approach sets the stage for future advances in understanding groundwater flow in real‐world conditions. Key Points: Geodesic distance was used to capture real‐world aquifer geometry, providing insights into groundwater hydraulicsThe methodology was extended to incorporate directional anisotropy, enhancing the ability to model complex hydraulic conditionsThe method extends existing analytical solutions to complex aquifer geometries, demonstrating applicability [ABSTRACT FROM AUTHOR]

This paper explores different methods of computing backwater depth for open-channel flow, such as one- to multi-dimensional models, finite difference approaches, and artificial intelligence methods. This paper primarily focuses on one-dimensional methods and states the implication, advantages, and disadvantages, verification process, and performance of each method. This paper discusses different parameters that influence backwater and their impact. Additionally, this paper compares the discussed one-dimensional methods with each other due to their common usage of experimental and field datasets as well as their popularity in implementation. It was concluded that while the WSPRO method significantly overestimated and the Yarnell's method underestimated the afflux value, the measured afflux values are closest to the values computed by the energy and momentum methods. [ABSTRACT FROM AUTHOR]

Linking habitat availability with hydraulic models integrates river engineering in the ecological field. Field observation for species presence and physical habitat availability mapping is inherently limited due to time and access constraints for field data collection. This study leverages hydraulic modeling to supplement larval fish population monitoring data, effectively expanding mapped physical habitat and allowing for monitoring bias analysis. The inundation extents and character of streamflow from hydraulic modeling were used to refine habitat suitability indices relative to total habitat availability from discrete fish monitoring events. Given the flexibility in hydraulic modeling to simulate a range of flows, the habitat suitability index is then translated to an effective habitat curve according to areal inundation and hydrologic frequency. With this framework, forecasting the impacts of long‐term trends, such as geomorphic or hydrologic change, can be reasonably and quantitatively assessed. This manuscript uses a case study of Rio Grande silvery minnow monitoring at restoration sites where the floodplain has been lowered via earthwork. Comparisons are made for habitat suitability indices developed from field observation data alone and field observation supplemented by hydraulic modeling. Known biases of field sampling data (targeting slow, shallow areas where fish are most often found) were confirmed based on simulated hydraulic conditions across entire restoration sites. In the case of Rio Grande silvery minnow, a heavily studied species, such field monitoring biases are an effective use of resources. However, this framework may be helpful for assessing alternative management approaches and monitoring strategies of species that are less studied. [ABSTRACT FROM AUTHOR]

Estimating the impacts of water allocation decisions on fish populations and habitat availability is an important part of environmental flow assessments, especially in locations where water resources are limited. Two‐dimensional hydrodynamic models (2DHMs) are commonly coupled with biological models to estimate fish habitat quality, area, and capacity across a range of proposed streamflows. Increasingly, resource managers are relying on landscape‐scale model domains with coarse model resolutions to maintain feasible computational loads, but this may affect habitat estimates if the mesh element size of the model exceeds the spatial scale relevant to the organism. We investigated how coarsening the resolution of a 2DHM influences the area and spatial distribution of estimated Coho Salmon (Oncorhynchus kisutch) fry habitats. We used an interpolation scheme that upscaled mesh elements from a high‐resolution (0.25 m2) 2DHM to quantify and visualize the effects of 2DHM resolution on estimates of Coho Salmon fry habitat for two contrasting channel morphologies and across a broad range of streamflows. Estimates of Coho Salmon fry habitat at increasingly coarser resolutions led to 20%–50% reductions in weighted usable habitat area (WUA) across several streamflow scenarios for a complex channel type, but did not impact estimates in a confined, flume‐like channel. Additionally, flow‐to‐habitat area relationships were not congruent at a given streamflow when resolution coarsened. Along with almost 500% more high‐quality habitat area estimated in the complex channel type over the confined, discrepancies in habitat area increased with higher flows in areas defined as optimal for rearing Coho Salmon fry. Considering that complex channel types contain critical habitat for Coho Salmon fry, this study suggests coarse 2DHM resolutions may exclude important wetted edge and off‐channel habitats from environmental flow assessments. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Tight sandstone gas reservoirs are rich in reserves and are an important part of unconventional oil and gas resources. However, natural fractures' impact on hydraulic fracture propagation behavior and network formation mechanisms remain unclear. Exploring how to optimize fracturing parameters to maximize post-fracturing productivity requires further investigation. Therefore, this study focused on the characteristics of tight sandstone gas reservoirs and established a three-dimensional numerical simulation model for hydraulic fracture propagation and post-fracturing productivity using production history matching to validate the reliability of the model. Based on this model, this study investigated the influence mechanisms of natural fracture angles, density, and lengths on hydraulic fracture propagation behavior and network formation. The spatial distribution of hydraulic fracture widths in three dimensions is also explored. When natural fracture angles are lower, a greater number of natural fractures are activated, leading to more developed secondary hydraulic fractures and the formation of complex fracture networks. Hydraulic fractures tend to penetrate directly through high-angle natural fractures. Single-well cumulative gas production increases initially with increasing natural fracture angles, then decreases, but increases with higher natural fracture density and length. Optimal fracturing in areas with longer natural fractures, lower angles, and higher density distribution enhances single-well productivity effectively. [ABSTRACT FROM AUTHOR]

Numerical groundwater models are key tools to calculate the deployable output from pumped boreholes. Their calibration requires undertaking multiple runs to optimise the parameter values. To maintain computational efficiency, the hydrogeological complexity of fractured and weathered aquifers is often represented in numerical models using a simplified approach consisting of a mathematical equation that describes the vertical variation of horizontal hydraulic conductivity (Kh$$ {K}_h $$) value with depth. In this article, we present the inclusion of the variation of the vertical hydraulic conductivity (Kv$$ {K}_v $$) with depth to a radial flow model. We derive the mathematical equation controlling the flow vertically between the numerical nodes. We show that the inclusion of Kv$$ {K}_v $$ variation with depth have a limited impact on the shape of the time drawdown curve at the early times of a pumping test but its significance is higher at later times. This also has a measurable impact on the water level inside the pumped borehole especially when the variations of both Kh$$ {K}_h $$ and Kv$$ {K}_v $$ are accounted for. We use a simple linear variation of Kv$$ {K}_v $$ with depth but the method is also applicable to complex profile of aquifer heterogeneity if this complexity can be represented using polynomial approximation. This illustrates the applicability of the proposed method to a wide range of weathered aquifer settings. [ABSTRACT FROM AUTHOR]

Fluid contamination is a significant concern in hydraulic and fluid systems, as contaminants in hydraulic, lubrication, or process fluids lead to equipment wear, corrosion and even catastrophic failures in sensitive equipment. Effective contamination control is essential for maintaining system reliability, optimizing performance and extending the life of both fluids and equipment. With advances in sensing, modelling and filtration technologies, industries are better equipped to manage fluid contamination and ensure system resilience. This paper presents the fluid contamination general aspects, main sources, the principal contaminants types, represented by different particles of solid contaminants (metallic fragments, dust and wear particles from machinery components) and its implications for system efficiency. The contaminant particles can be abrasive and cause wear on surfaces, water droplets often found in hydraulic and lubrication systems, leading to corrosion, degradation of additives and further reduced fluid operational performance, other air and gas particles entrained into hydraulic fluid volume leading to cavitation, reduced lubrication and oxidation. Main models describing the hydraulic fluid contamination are presented and further the numerical analysis results based on parameters primary considered for a hydraulic actuation type. [ABSTRACT FROM AUTHOR]

This paper presents a volumetric efficiency model for high-pressure motor-driven 2D piston pumps, incorporating key factors such as axial internal and external leakage, circumferential leakage, and reverse flow. The model integrates hydraulic fluid compressibility and variations in flow coefficients to improve simulation accuracy. Co-simulation using AMESim and Simulink, along with experimental validation, demonstrates the model's reliability across various operating conditions. The results show that rotational speed enhances volumetric efficiency due to its minimal effect on leakage and reverse flow, while pressure significantly reduces efficiency, particularly through reverse flow and circumferential leakage. Reducing trapped volume proves to be an effective strategy for minimizing reverse flow and improving overall pump performance. Additionally, refining flow coefficients to improve the accuracy of the simulation model remains an important area for further development. [ABSTRACT FROM AUTHOR]

AbstractDialogical Self Theory has not emerged in a historical vacuum. Its forerunners, whether the Eastern Atman, the tripartite Platonic self with its clear hierarchical relations, the Cartesian “ghost in the machine,” the Freudian ego-id hydraulic model or the Jungian topography of ego and unconscious, represent the theoretical grounding from which the dialogical self has emerged and self-articulated as much as have William James, George Herbert Mead and Mikel Bakhtin. Most of them, including DST, center on developmental models, and see the self as intrinsically oriented toward a more integrated sense of itself that Jung called “wholeness,” although their internal politics differ. Plato is an authoritarian, for whom the rational dimension must rule the spirited and the appetitive; otherwise, disorder and injustice prevail. Freud’s battle cry “where id was, ego shall be” is continually compromised by his realization that “ego is not master in its own house”; and Jung’s notion of wholeness involves a process of compensatory integration of conscious and unconscious contents of the personality that demands intensive shadow work. DST borrows from them all in one guise or another, but, in contrast with its predecessors, places its emphasis on intersubjectivity, polyphony and boundary-work, and as such is positioned for dialogical relations, not only between the I positions within its boundaries, but with the I positions of subjects who are grounded in other social, cultural and political systems. As such, the acronym DST might also stand for Democratic Self Theory, reflecting its historical emergence at a moment of rapidly increasing globalization of the information environment, and the resulting confrontation between disparate ideological traditions and forms of life that were hitherto invisible to each other. This paper represents a preliminary meditation on the infrastructure of DST within the context of the larger theoretical ground from which it emerges. It aims, not to seek exact correspondences or contradictions with other theories, but to act as a “bridging theory” between psychodynamic, constructivist, and humanist theories, thereby exploring the family resemblances that ground it, and acting to deconstruct the boundaries between it and other conceptual landscapes. [ABSTRACT FROM AUTHOR]

A wide range of applications of unsaturated hydraulic conductivity is well known in geotechnical, hydrological, and agricultural engineering fields. The standard prediction models for hydraulic conductivity function overlook the complexity of soil pore structure and employ a simplistic approach based on the bundle of capillary tubes. This study proposes an alternative approach employing pore network models calibrated to match soil water retention data to predict the hysteretic hydraulic conductivity function of granular soils. A novel approach to constructing a multidirectional pore network built on an irregular lattice with variable coordination numbers is presented for the realistic representation of soil voids. The geometric and topological parameters of the pore network model are optimized using the genetic algorithm, and adequate pore‐scale processes (piston‐like advance and corner flow during drainage and piston‐like advance, pore body filling, and snap‐off during imbibition) are modeled to get reasonable predictions of hysteretic hydraulic conductivity functions over the entire suction range of granular soils. Comparisons between the pore network model results, standard physically based models, and measured data for a variety of granular soils show that the proposed pore network has a superior performance over other models and compares favorably to the experimental data. [ABSTRACT FROM AUTHOR]