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Abstract While the shear behavior of granular soils is directly related to the microstructure of contacts which often leads to the coaxiality between Cauchy stress and Satake fabric tensors, it is generally accepted by the geomechanics and geotechnical engineering community that the capillary effects are isotropic. At low saturation levels, however, the pore fluid tends to form interparticle menisci that can also manifest an anisotropic structure, which may result in the development of anisotropic capillarity in wetted granular media. To study the interplay between the solid grain contacts and the liquid bridges at the micro-scales, this study adopts a coupled discrete element method that utilizes a linear contact model combined with a capillary model, and explores their effects by conducting a series of numerical experiments. The distributions of contact and capillary force orientations during the experiment are further investigated to better understand how their alignments affect the global response of the granular assembly subjected to a deviatoric loading. The results indicate that the global shear stress response is not only affected by the contact fabric but also by the network of liquid bridges, and we also observe that the particles may lose contact while the pendular menisci may not be destroyed during the elastic unloading.

Se caracteriza la infraestructura hidráulica de esta empresa, identificando problemáticas que afectan su productividad y uso eficiente del agua de riego, a partir de entrevistas a directivos y personal técnico, para establecer criterios de selección de técnicas de riego en áreas potencialmente agrícolas en secano. Del levantamiento realizado en la infraestructura de riego y drenaje, fondo de tierra de unidades productivas y análisis del complejo Agua, Suelo, Planta, el 58.6 % de las máquinas de Pivote Central están en explotación y se aprovecha, menos del 50 % del agua para el riego, por pérdidas por infiltración y otras causas, en los canales que conducen el agua. De la superficie agrícola, el 35 % del área está bajo riego y las instalaciones funcionan sin previa evaluación de los parámetros de manejo.

El creciente déficit de agua potable ha motivado a la comunidad científica a incorporar nuevos métodos y tecnologías para elevar su calidad. El tratamiento magnético se presenta como una tecnología innovadora, económica, eficiente, amigable con el medio ambiente y de fácil aplicación. A partir de las características físico-químicas presentadas por las aguas analizadas, se evidencian efectos favorables y significativos con la aplicación del tratamiento magnético para la conductividad, el pH y la turbidez. Se observó que el pH a modo general aumenta sus valores hasta un 11.03 %, mientras que la turbidez disminuye hasta 44.44 %. En el caso de la conductividad los valores de la misma manifiestan aumentos y descensos reportando valores de 0.31 % y 2.79 % respectivamente. Estos resultados podrían ser el preámbulo para el estudio de los procesos de coagulación floculación.

El abasto de agua en Cuba se ve afectado por limitaciones económicas y financieras, además de los efectos del cambio climático, que han incrementado la sequía, afectando los servicios básicos a la población. Los sistemas de saneamiento resultan ineficientes debido a su insuficiencia. Para enfrentar estos desafíos, el gobierno cubano, con apoyo del Fondo de Cooperación para Agua y Saneamiento (FCAS), implementó el proyecto “Mejora y Ampliación de los Sistemas de Agua Potable y Saneamiento de Pequeñas Ciudades Cubanas” (2010), que incluyó la construcción y rehabilitación de plantas potabilizadoras, redes, metrocontadores y plantas de tratamiento. Se diseñó una metodología para evaluar los impactos sociales y técnicos del proyecto, permitiendo corregir deficiencias y lograr los objetivos planteados.

El desarrollo del pensamiento científico-técnico constituye una exigencia de la formación de los profesionales universitarios de especialidades de las ciencias técnicas. El objetivo de este artículo es exponer las manifestaciones peculiares de las características del pensamiento científico-técnico que deben formarse en estudiantes de Ingeniería Hidráulica de acuerdo a los estilos de aprendizaje activo, reflexivo, teórico y pragmático. Se utilizaron los métodos de la sistematización de la teoría y la práctica, el inductivo-deductivo, el hipotético-deductivo, el test de estilo de aprendizaje de Honey-Alonso y técnicas experimentales basadas en la solución de problemas. La utilización de técnicas de correlación permitió establecer relaciones entre los estilos de aprendizaje y las características del pensamiento científico-técnico en la muestra de sujetos estudiada.

Tradicionalmente la información relacionada con el comportamiento de las bombas rotodinámicas ha sido brindada de forma gráfica, mediante sus cuatro curvas características: carga-capacidad, eficiencia-capacidad, potencia-capacidad y NPSHr-capacidad. En la actualidad y estimulados por la extensión del uso de la computación, los fabricantes de bombas rotodinámicas han comenzado a generalizar el empleo de ecuaciones matemáticas en sustitución de la forma gráfica para brindar la información relacionada con sus bombas y como medio más expedito para el estudio del comportamiento hidráulico de los sistemas de bombeo. De esta manera, resulta imprescindible definir los métodos para obtener las expresiones matemáticas representativas de las curvas características de las bombas, a partir de los gráficos y/o datos proporcionados por el fabricante, ya que estos no brindan esta información de forma analítica. Se presentan las tres técnicas más empleadas para realizar el proceso de matematización de las curvas características para su posterior digitalización.

El objetivo de la investigación es exponer los cambios en la gestión de la cuenca hidrográfica para el uso sostenible de los recursos naturales teniendo en cuenta el desarrollo del territorio. Se caracteriza la misma en cuanto a localización, población, producción y conservación para comprender los resultados y lograr un uso eficiente de los recursos naturales teniendo en cuenta las problemáticas ambientales identificadas. Se acerca a sus funciones, al proceso de gestión de las aguas y se plasman los resultados en la transformación como parte del Programa Integral de Desarrollo e implementación de la legislación ambiental del país enfocado al desarrollo utilizando herramientas técnicas y administrativas. Se propone dar seguimiento a la gestión para mitigar los efectos del cambio climático, lograr adaptación y contribuir al desarrollo sostenible en la región.

ABSTRACT The temporal distribution of design rainfall hyetographs can be obtained through various procedures. One such method involves using temporal distribution curves to disaggregate a rainfall value of longer duration into chronological values within shorter time intervals. This is demonstrated by SCS distribution curves for durations of 6 and 24 hours and the well-known Huff curves. Another approach involves deriving temporal distribution using design hyetograph calculation methods, such as the Chicago and alternating block methods, based on Intensity-Duration-Frequency (IDF) equations. This paper aims to combine these approaches and develop universal equations capable of accurately fitting smooth rainfall time distribution curves. The advantage is the replacement of tables, like SCS and Huff, with analytical equations, enhancing usability in spreadsheets. Furthermore, these universal equations can determine the temporal rainfall distribution using an IDF equation or fitting a specified design hyetograph like Euler type II. Four numerical examples are provided.

ABSTRACT The Chicago Method is one of the most common methods to determine design rainfall hyetographs for urban drainage infrastructures. Among the advantages of the method is that it is easy to apply and is based on traditional IDF equations. Nevertheless, applications to other IDF equation models presents some limitations. The aim of the present study was to adapt and apply the Chicago hyetograph method with intense rainfall equations of the LnLn type. Equations to estimate rainfall intensity before and after peak duration were presented. In addition, equations to obtain accumulated rainfall before and after peak rainfall volumes were adapted. With this information, we were able to obtain rainfall blocks for each interval of the hyetograph. The method was applied to determine the hyetograph based on the intense rainfall equation for the town of Piracicaba, São Paulo, Brazil. The equations presented here can be implemented on electronic spreadsheets or in programming routines, hence allowing Engineering professionals to apply the most adequate methods to local data.

ABSTRACT We evaluated the water quality conditions and their relationships with the land cover/use throughout the entire Ipanema Stream Watershed (ISW), also considering temporal differences. Thirteen water quality variables were evaluated in fourteen sampling stations located in rural, peri-urban, and urban zones in both dry and rainy seasons from 2015 to 2018. A PCA was performed to detect which variables explain most of the data variability and to detect spatial and/or temporal trends in ISW water quality. The four PCs explained 74% of the data variability, but strong relationships with environmental variables were only observed in the two main components. PC1 was related to nutrients, alkalinity, BOD, electrical conductivity, DO, and pH, while PC2 was related to total suspended solids (TSS) and chlorophyll-a. A spatial pattern related to sampling stations and land uses was observed, but no temporal pattern was identified. Ammoniacal-N and TSS were most important variables (loading values >│0.75│), and showed higher values in urban zone probably due to inadequate sewage discharge. Ipanema Stream did not show a self-purification capacity, and the high TSS concentrations in rural mainstream ask for riparian zone restoration. These management actions for water quality improvement would even contribute to the recovery of Doce River.

La tempête Alex a touché la France le 1–2 octobre 2020 et provoqué les 23 octobre un épisode méditerranéen exceptionnel sur les Alpes-Maritimes. L’épisode a généré des crues torrentielles d’une magnitude sans précédent depuis plusieurs siècles sur les vallées de la Roya et de la Vésubie avec des évolutions morphologiques majeures et un bilan humain et matériel lourd. A la demande de la Direction des Territoires et de la Mer des Alpes-Maritimes, un retour d’expérience technique a été réalisé afin de comprendre et caractériser les phénomènes associés à cet évènement. Ce retour d’expérience a également été mis à profit, au fur et à mesure des besoins, pour accompagner les services de l’Etat et les collectivités gemapiennes en matière de réduction des risques et de reconstruction des vallées. L’ampleur de l’évènement a nécessité d’adapter rapidement les outils et les méthodologies. L’acquisition d’une topographie haute résolution, l’organisation d’une vaste campagne de terrain, l’élaboration de formulaires spécifiques pour les relevés de terrain via une application mobile accessible à tous, ainsi que la collaboration de l’ensemble des acteurs du territoire ont permis de construire une base de données riche pour relever les différents défis posés par un tel évènement.

La méthode des Analogues est une adaptation statistique des prévisions météorologiques à l’échelle synoptique. Son principe peut s’énoncer clairement : à situations météorologiques semblables, les effets seront comparables. Les Services de Prévision des Crues (SPC) Alpes du Nord et Loire-Allier-Cher-Indre disposent, au sein de leur système de prévision, d’outils opérationnels directement issus des travaux de recherche : l’arrivée de cette approche dans la sphère du prévisionniste est la conclusion d’une riche histoire débutée à la fin des années 1960, ponctuées de nombreuses améliorations grâce à l’arrivée des réanalyses météorologiques, la définition de critères de similarité et de performance pertinents dans le contexte de la prévision probabiliste. Le réseau Vigicrues mène un projet visant à étendre la méthode à la France métropolitaine et à mettre en place une suite logicielle unique. Cela nécessite notamment de réduire le nombre de modèles d’analogie par la répartition des mailles SAFRAN en 30 groupes, de déterminer de nouveaux paramétrages optimaux, et d’adapter la suite logicielle AtmoSwing aux pratiques et aux contraintes opérationnelles des SPC. Ces prévisions sont complémentaires à la prévision d’ensemble Arome (PEARO) et leur arrivée ouvre de nouvelles perspectives de développement par le réseau Vigicrues.

An hourly hydrological forecasting model (GRP), used for flood forecasting in France, has been enhanced by developing a semi-distributed version (GRPS). This new model addresses some limitations of the original lumped approach by integrating flow observations from upstream stations to improve downstream flood predictions. A comparison of GRP and GRPS was conducted on a large set of flood events in nested catchments in France. Results indicate that GRPS slightly outperforms GRP up to the lead time of the last upstream flow observations reaching the downstream station, though performance gains vary widely across events. Event classification identified detrimental interactions between data assimilation methods and river routing model errors. A sensitivity test suggested that enhancing both the propagation model and the assimilation scheme could reduce poor performance at short lead times for some events. The study also demonstrated that upstream forecast quality significantly impacts downstream forecast accuracy. Overall, the findings confirm the benefits of incorporating multiple flow observations into a semi-distributed model and suggest several avenues for further improvement.

ABSTRACT Inadequate urban planning has contributed to the sediment production in Urban Hydrographic Micro-basins (UHMs). The present study aims to develop and apply the Sediment Production Susceptibility Index (SPSI) in UHMs from Campo Grande – Mato Grosso do Sul (MS), Brazil, based on the Analysis Hierarchical Process (AHP) and Geographic Information System (GIS) aggregation. The indicators selected for the composition of the SPSI are Soil Class (49%), Average Slope (22%), Vegetation Cover (13%), and Unpaved Streets (16%). It is essentially to jointly analyze indicators from both spheres (natural and anthropogenic) to obtain greater reliability in studies related to sedimentation in urban areas. UHMs undergoing urbanization are more susceptible to sediment production than UHMs that are already densely occupied. SPSI can assist public managers in the urban and environmental planning and in the adoption of preventive measures against the silting of water bodies and obstruction of drainage systems.

ABSTRACT Accuracy in river flows forecasts is crucial for Hydrology, but is challenged by fluviometric data quality. This study investigates the impact of different missing data imputation methods on the Seasonal Autoregressive Integrated Moving Average (SARIMA) model performance. SARIMA (1,1,1)(0,1,1)12 was selected using semi-automated criteria, such as lowest AIC, significant parameters (p-value < 0.05) and residuals adequacy. This model was then compared with reconstructed series using different imputation methods such as Mean (AM), Median (M), Spline and Stinemann Interpolations, Regional Weighting (RW), Multiple Linear Regression (MLR), Multiple Imputation (MI) and Maximum Likelihood (ML). The data were analyzed considering scenarios of 5, 20 and 40% missing data, following random and block patterns, using data from the Doce River, in Southeast Brazil. Results obtained by the performance indicators and, their respective relative differences, indicated that, univariate (AM and M) and multivariate (PW and RLM) methods limited the model's performance, while univariate Spline and Stine and multivariate IM and ML methods didn't present significant limitations, except Spline for the block pattern. It is concluded that, future predictions accuracy depends, not only on a well-trained and validated model, but also on the appropriate use of missing data imputation methods.

Abstract This paper presents an analysis of the challenges associated with discoloration risk management and the impact of hydraulic transients on water quality within distribution systems. Focusing on the Metropolitan Region of Curitiba, Paraná, Brazil, the study employs a comprehensive methodology that combines the Characteristic Method for simulating hydraulic transients and real-time monitoring of water quality parameters, such as turbidity and chlorine levels. A framework for managing discoloration risk is proposed, highlighting strategies for identifying potential causes, assessing risk severity, developing prevention and mitigation strategies, and implementing continuous improvement processes. The experimental section details the impact of hydraulic transient events on water quality, with significant findings indicating a direct correlation between flow dynamics and water quality degradation, particularly in terms of increased turbidity and decreased chlorine levels during pump deactivation. The study contributes valuable insights into effective water distribution system management, emphasizing the importance of advanced monitoring and risk management techniques to maintain high-quality water standards.

ABSTRACT This study introduces an integrated model for water resources planning and management that accounts for both the quantity and quality of water in watersheds and reservoirs. Therefore, it provides a comprehensive approach for better understanding and assessing water systems. The model facilitates analyses of the spatial and temporal dynamics of hydrological processes, pollutant transport, and the behavior of rivers and reservoirs. The study evaluated pollutant load transport in the Upper Paranapanema Basin by applying the Soil Moisture Accounting Procedure (SMAP) model, Muskingum method, Streeter-Phelps buildup/washoff model, and zero-dimensional (0D) models to estimate inflows to the Jurumirim reservoir. A Python-based public library was developed to model all hydrological processes. The model calibration yielded a NSE, KGE, PBIAS and RMSE result of 0.746, 0.778, 6.5% and 73.3 m 3 s − 1, respectively. Indicating a robust simulation that attests to the versatility and reliability of the proposed approach. The methodology outlined in this research enables comprehensive water quality simulation at basin scale, thereby serving as a tool for understanding water quantity and quality dynamics and support decision-making regarding water resource planning and management.

La Cellule de Veille Hydrologique (CVH) de La Réunion assure la surveillance de 17 cours d’eau sur ce territoire montagneux sous climat tropical. Du fait des spécificités hydrométéorologiques de l’île et de la jeunesse de la CVH, la cellule n’affiche pas encore pour le grand public une vigilance crues à 24 h mais émet, depuis 2015 via le site www.vigicruesreunion.re, des vigilances “à réaction ou avec une faible anticipation”, qui s’apparentent à de la surveillance. Une stratégie de passage à la prévision a été mise en place depuis 2020 avec des résultats opérationnels déjà présents. Cette stratégie repose sur le croisement des résultats issus d’abaques et de deux modèles hydrologiques développés par INRAE (GRP et SMASH) alimentés par les lames d’eau observées (ANTILOPE) et prévues (AROMEOI). Les scores de performance des outils de prévision hydrologique sont jugés satisfaisants avec des perspectives qui laissent espérer le passage à une vigilance à 24 h à moyen terme.

Depuis 2014, le réseau Vigicrues a mis en place des outils et des méthodes pour estimer et expertiser l’incertitude associée à la prévision des crues. Les incertitudes liées à la modélisation hydrologique sont estimées par le logiciel OTAMIN, qui analyse statistiquement les écarts entre les observations et les débits simulés par les modèles à l’issue de leur calage. Un logiciel permettant l’expertise de scénarios hydrologiques avec incertitudes, l’EAO, a également été développé. Ces outils ont rendu possible la diffusion de prévisions expertisées assorties d’un intervalle d’incertitude (10–90%) dès 2017. Le projet stratégique du réseau Vigicrues prévoit de renforcer le service rendu sur les secteurs à fort enjeu. L’objectif est de publier des prévisions quantitatives assorties d’incertitudes à 24 heures d’échéance et avec un pas de temps suffisamment fin pour représenter la dynamique de la crue, y compris sur des cours d’eau à réaction rapide. Pour réaliser cet objectif, des évolutions sont nécessaires sur les outils et les pratiques opérationnelles, notamment par la construction de chaines de prévision forcées par des modèles d’ensemble météorologiques, l’amélioration de la quantification des autres sources d’incertitude et une réflexion sur le rôle du prévisionniste et la communication des incertitudes.

No Brasil, mais de 70% das estradas não são pavimentadas, o que favorece o impacto negativo de intempéries. Neste contexto, os sedimentos provenientes do desgaste destas vias acabam por atingir as galerias de drenagem pluvial das vias pavimentadas, o que pode ocasionar obstrução total ou parcial e consequente perda de capacidade hidráulica. O objetivo deste trabalho foi analisar o impacto do carreamento de solo de vias não pavimentadas sobre o sistema de drenagem pluvial de vias pavimentadas. O método de investigação incluiu análise experimental de campo e monitoramento pelo período de seis meses. Foi construído e instalado coletor de sedimentos no interior do bueiro, tendo sido observado o processo de deposição de sedimentos. Os materiais depositados no sistema de drenagem foram caracterizados quanto à sua granulometria. Este estudo demonstrou que o tipo de revestimento utilizado nas vias não pavimentadas analisadas é inadequado, em razão da alta taxa de erodibilidade e sedimentação, com tendência à aceleração do assoreamento de galerias. Além disso, a taxa de carreamento de solo para a galeria pluvial a partir da via não pavimentada analisada foi medida em 3,99 kg.m-2.ano-1 de solo, sendo de 4 a 20 vezes maior que em locais em que há apenas vias pavimentadas. Estimou-se que essa quantidade de solo carreado pode impactar 19 metros de galerias pluviais por ano.

Utilizing a bespoke CO2 phase transition pulse pressure experimental system, we conducted pulse pressure characterization tests across various activator masses, CO2 filling pressures, and energy discharge plate thicknesses. This approach enabled us to ascertain the pulse pressure's response characteristics and variation patterns under diverse conditions. The formula for calculating the peak supercritical CO2 pulse pressure was deduced by modeling the ultimate load calculation of the clamped circular plate, and then the time-course expression of the supercritical CO2 phase transition pulse pressure and energy was carried out by introducing the time factor and taking into account the parameters of the activator mass and the thickness of the energy discharging plate. Our findings reveal a four-stage pressure evolution in the cracking tube during initiation: a gradual increase, a rapid spike, swift attenuation, and eventual negative pressure formation. The activator mass and discharge plate thickness critically influence the peak pressure's timing and magnitude. Specifically, increased activator mass hastens peak pressure onset, while a thicker discharge plate amplifies it. The errors between calculated and experimental values for peak supercritical CO2 phase transition pressure fall within −5%–5%. Furthermore, the pressure peak and arrival time model demonstrates less than 10% error compared to experimental data, affirming its strong applicability. These insights offer theoretical guidance for controlling phase transition pressure and optimizing energy in supercritical CO2 systems.

Simulation of subsurface energy system involves multi-physical processes such as thermal, hydraulical, and mechanical (THM) processes, and requires a so-called THM coupled modeling approach. THM coupled modeling is commonly performed in geothermal energy production. However, for hydrocarbon extraction, we need to consider multiphase flow additionally. In this paper, we describe a three-dimensional numerical model of non-isothermal two-phase flow in the deformable porous medium by integrating governing equations of two-phase mixture in the porous media flow in the reservoir. To account for inter-woven impacts in subsurface conditions, we introduced a temperature-dependent fluid viscosity and a fluid density along with a strain-dependent reservoir permeability. Subsequently, we performed numerical experiments of a ten-year water flooding process employing the open-source parallelized code, OpenGeoSys. We considered different well patterns with colder water injection in realistic scenarios. Our results demonstrate that our model can simulate complex interactions of temperature, pore pressure, subsurface stress and water saturation simultaneously to evaluate the recovery performance. High temperature can promote fluid flow while cold water injection under non-isothermal conditions causes the normal stress reduction by significant thermal stress. Under different well patterns the displacement efficiency will be changed by the relative location between injection and production wells. This finding has provided the important reference for fluid flow and induced stress evolution during hydrocarbon exploitation under the environment of large reservoir depth and high temperature.

Rock abrasivity influences wear of cutting tools and consequently, performance of mechanized tunneling machines. Several methods have been proposed to evaluate rock abrasivity in recent decades, each one has its own advantages. In this paper, a new method is introduced to estimate wear of disc cutters based on rock cutting tests using scaled down discs (i.e. 54 and 72 ​mm diameter). The discs are made of H13 steel, which is a common steel type in producing real-scale discs, with hardness of 32 and 54 HRC. The small-scale linear rock cutting machine and a new abrasion test apparatus, namely University of Tehran abrasivity test machine, are utilized to perform the tests. Tip width of the worn discs is monitored and presented as the function of the accumulated test run to classify the rock abrasion. Abrasivity tests show that by increasing the uniaxial compressive strength (UCS) of the rock samples, wear rate is doubled gradually that reveals the sensitivity of the test procedure to the main parameters affecting the abrasivity of hard rocks. For the rocks with the highest UCS, the normal wear stops after performing 5 to 10 rounds of the tests, and then, deformation of the disc tip is detectable. Two abrasivity indices are defined based on the abrasivity tests results and their correlations with Cerchar Abrasivity Index (CAI) and UCS are established. Comparison of the established correlations in this study with previous investigations demonstrates the sensitivity of the indices to the parameters affecting wear of the disc cutters and repeatability of the outputs obtained from abrasivity tests using scaled down discs. Findings of this study can be used to enhance the accuracy of rock abrasivity classifications.

Organic-rich shales have gained significant attention in recent years due to their pivotal role in unconventional hydrocarbon production. These shale rocks undergo thermal maturation processes that alter their mechanical properties, making their study essential for subsurface operations. However, characterizing the mechanical properties of organic-rich shale is often challenging due to its multiscale nature and complex composition. This work aims to bridge that knowledge gap to fully understand the nanomechanical properties of Shale organic matter at various thermal maturation stages. This study employs PeakForce Quantitative Nanomechanical Mapping (PF-QNM) using Atomic Force Microscopy (AFM) to investigate how changes at the immature, early mature, and peak mature stages impact the mechanical properties of the Bakken Shale organic matter. PF-QNM provides reliable mechanical measurements, allowing for the quantification and qualification of shale constituents' elastic modulus (E). We also accounted for the effect of probe type and further analyzed the impact of probe wear on the nanomechanical properties of shale organic matter. In immature shale, the average elastic modulus of organic matter is approximately 6 ​GPa, whereas in early mature and peak mature shale, it decreases to 5.5 ​GPa and 3.8 ​GPa, respectively. Results reveal a mechanical degradation with increasing thermal maturation, as evidenced by a reduction in Young's modulus (E). Specifically, the immature shale exhibits an 8% reduction in E, while the early mature and peak mature shales experience more substantial reductions of 31% and 37%, respectively. This phenomenon could be attributed to the surface probing of low-modulus materials like bitumen generated during heating. The findings underscore the potential of AFM PF-QNM for assessing the nanomechanical characteristics of complex and heterogeneous rocks like shales. However, it also highlights the need for standardized measurement practices, considering the diverse components in these rocks and their different elastic moduli.

The ROP (rate of penetration) within the horizontal section of shale gas wells in the Luzhou oil field is low, seriously delaying the exploration and development process. It is proved that reducing mud density mitigates the bottom-hole differential pressure (ΔP) and increases the ROP during overbalanced drilling. However, wellbore collapse may occur when wellbore pressure is excessively low. It is urgent to ascertain the optimal equilibrium point between improving ROP and maintaining wellbore stability. The safe mud weight window and the lower limit of mud density in the horizontal section of the Luzhou block are predicted using the piecewise fitting method based on conventional logging data. Then, the accuracy of the collapse pressure prediction was verified using the distinct element method (DEM), and the effect of wellbore pressure, in-situ stress, rock cohesion, and natural fracture density on borehole collapse was investigated. Finally, a fitting model of ΔP and ROP of the horizontal section in the Luzhou block is established to predict ROP promotion potential after mud density reduction. The field application of this approach, demonstrated in 8 horizontal wells in the Luzhou block, effectively validates the efficiency of reducing mud density for ROP improvement. This study provides a useful method for simultaneously improving ROP and maintaining wellbore stability and offers significant insights for petroleum engineers in the design of drilling parameters.

Viscoelastic plastic solutions for tunnel excavation in strain-softening rock mass and tunnel-rock interaction are proposed based on the Mohr-Coulomb and the Generalized Zhang-Zhu (GZZ) strength criterion considering stress path. The solutions are verified by numerical simulations, results show that the theoretical solutions are close to the simulated data. The evolutions of rock stresses, strains, displacements and support pressure were investigated and the influences of residual strength parameter, support stiffness, support timing, initial support pressure and viscosity coefficient on the rock deformation and the support pressure are discussed by proposed solution. It is found that strain-softening results in large deformation and high support pressure, with stiffer support and a larger viscosity coefficient contributing to even greater support pressure. Ductile support is recommended at the first stage to release the energy and reduce the support pressure by allowing a relatively large deformation. The support pressure, especially the additional support pressure at the second stage will be much smaller if a higher initial support pressure is applied at the first stage. This can not only control the displacement rate of surrounding rock and improve the tunnel stability at the first stage by exerting sufficient support pressure immediately after tunnel excavation, but also greatly reduce the pressure acted on permanent support and improve the structure stability at the second stage. Therefore, to avoid the instability of support structure, ductile support, which could not only deform continuously but also provide sufficient high support pressure, is recommended at the first stage.

Rockburst is a phenomenon where sudden, catastrophic failure of the rock mass occurs in underground deep regions or areas with high tectonic stress during the excavation process. Rockburst disasters endanger the safety of people's lives and property, national energy security, and social interests, so it is very important to accurately predict rockburst. Traditional rockburst prediction has not been able to find an effective prediction method, and the study of the rockburst mechanism is facing a dilemma. With the development of artificial intelligence (AI) techniques in recent years, more and more experts and scholars have begun to introduce AI techniques into the study of the rockburst mechanism. In previous research, several scholars have attempted to summarize the application of AI techniques in rockburst prediction. However, these studies either are not specifically focused on reviews of the application of AI techniques in rockburst prediction, or they do not provide a comprehensive overview. Drawing on the advantages of extensive interdisciplinary research and a deep understanding of AI techniques, this paper conducts a comprehensive review of rockburst prediction methods leveraging AI techniques. Firstly, pertinent definitions of rockburst and its associated hazards are introduced. Subsequently, the applications of both traditional prediction methods and those rooted in AI techniques for rockburst prediction are summarized, with emphasis placed on the respective advantages and disadvantages of each approach. Finally, the strengths and weaknesses of prediction methods leveraging AI are summarized, alongside forecasting future research trends to address existing challenges, while simultaneously proposing directions for improvement to advance the field and meet emerging demands effectively.

Fracture initiation has been a challenging issue for fracturing deep and tight gas reservoirs, which generally requires a high breakdown pressure for hydraulic fracturing treatment. In this situation, fluid injections frequently have to terminate at the very beginning. Toward predicting and solving this issue, a novel fracturing system for deep and tight sandstone gas reservoirs was developed. The key components of the fracturing system and some criterion will be introduced, which can be used to optimize the ideal perforation locations along the landing part and select the right perforation strategy accordingly. The main components of the fracturing system include: (1) evaluating the log-based diagenetic rock typing and flow index; (2) 1D mechanical earth model; (3) calculating the breakdown pressure envelope along the well trajectory of the landing part; (4) calculating the optimal perforation directions along the landing part; (5) select the first set of perforation locations based on the log-based diagenetic rock typing and flow index; (6) narrowing down the first set of perforation locations to a second set of perforation locations based on the breakdown pressure envelope; (7) determining a perforation strategy based on breakdown pressure envelope and wellhead pressure safety limit in the second set of perforation locations. The computational framework to calculate the breakdown pressure envelope and optimal perforation directions is applicable to arbitrary well trajectory. The fracturing system has been used to provide pre-fracturing suggestions for wells landed in deep and tight sandstone reservoirs, which is very efficient for identifying locations with good rock typing and relatively low breakdown pressure. Also, it can indicate whether oriented perforation should be used further for alleviating breakdown issue. By taking these efforts and procedures, the fracturing success rate for deep and tight sandstone gas reservoirs can be improved, which has been verified in practice. Example studies from the field will be provided to demonstrate the fracturing system's performance and applicability.

Abstract Geodetic monitoring measurements (e.g., of terrain surfaces) are used to detect deformations. Terrestrial laser scanning (TLS) or unmanned aircraft systems (UAS) equipped with lightweight cameras are often utilized for land surveying, resulting in point clouds that represent the surface of the captured object. For image-based acquisition of the area of interest, point clouds must first be generated from overlapping images, for which the Structure-from-Motion (SfM) method is commonly used. To perform deformation analyses and derive changes from them, at least two temporally different measurement epochs of the same area are required. In this article, we present both point cloud- and feature-based models from TLS and SfM-based UAS point clouds. In addition, an image-based 2D approach using optical flow is applied as an example for landslide simulation to detect changes on object surfaces. To eliminate erroneous results in the analyses due to vegetation areas, the 3D data is filtered using the CANUPO algorithm. The results of this research study show, that the task of deformation detection has some challenges, depending on the use case and the methodology. The point cloud-based methods are suitable to detect pure changes between two point clouds. Also, the direction of these changes can be determined to distinguish between material uplift and downlift. In contrast, the feature-based descriptor (Fast Point Feature Histogram, FPFH) assigns pairs of points between two epochs based on similar geometry in both point clouds therewith individual movements can be detected. However, areas that have changed significantly cannot be assigned. Optical flow shows point changes in similar dimensions to the target deformations and allows deformation analysis with much less computational effort than with 3D point clouds. Considering these findings, point cloud-based method are suitable for determining surface-based information, while the feature-based and image-based methods are capable of extracting local changes.

Abstract The main objective of the current investigation is to study the dynamic behaviour of a 3-pile group with different loading direction under coupled (horizontal and rocking) excitations. To accomplish this objective, machine-induced field excitation tests are conducted on small-scale hollow steel piles. The 3-pile group is driven into the ground in a triangular arrangement with 3d spacing. Two different soil-pile setups, i.e., Pile Group-I and Pile Group-II, are created based on dynamic force directions. In the case of Pile Group-I, the forces are applied to the direction of the median of the triangle, and for Pile Group-II, the forces are applied to other directional loads. From the test results, it is found that the resonant peaks of horizontal and rocking amplitudes for Pile Group-I are lower than Pile Group-II. In the case of resonant frequencies, the values of Pile Group-I are observed to be the same or a little bit higher as compared to Pile Group-II. It is found that the dynamic soil-pile-soil interaction effect is more prominent for Pile Group-II than for Pile Group-I. For numerical investigation, the continuum approach method is utilised with the inclusion of a dynamic group interaction factor to predict the dynamic coupled responses in terms of frequency and amplitude for these two soil-pile setups. To understand the behaviour of pile groups, boundary zone parameters and variations of impedance parameters (stiffness and damping) with operating frequencies are also measured using this theoretical approach.

En esta investigación se indaga la relevancia del estado de derecho en la gobernación del agua en México. Tomando como marco de análisis esta idea toral se recurre a una metodología de encuesta y estadística descriptiva para estudiar una problemática detonada por una decisión inadecuada sobre el uso del líquido: el proyecto de instalación de una planta para la producción de cerveza en el valle de Mexicali, en Baja California. Los resultados señalan que el estado de derecho halla obstáculos para su realización, pues no se satisfacen condiciones básicas para su existencia, prevaleciendo procesos de exclusión del acceso a su goce para sectores sociales amplios; en esa tesitura, el soslayo de la legalidad debilita la institucionalidad esperada en una sociedad democrática. Revelan, asimismo, el efecto negativo que produce la racionalidad de uso dominante, máxime frente a iniciativas de crecimiento económico altamente demandantes del líquido. Para mejorar la gobernación y coadyuvar al aprovechamiento adecuado del recurso hídrico se plantea una reforma institucional por vía de una política que comprenda tres grandes acciones: (1) revisar y deslindar responsabilidades, y aplicar la ley, sobre omisiones o procedimientos irregulares de agentes encargados; (2) impulsar una renovación jurídico-administrativa que dé cabida a la pluralidad de voces y privilegie la perspectiva pública del aprovechamiento; y (3) generar un modelo educativo de acción proclive a la convergencia de intereses en torno al objetivo del mejor aprovechamiento.

La calidad de las aguas alumbradas por pozos horizontales cubiertos (galerías), asociadas o no con presas subálveas, desata un enorme interés por su apropiación en medios áridos y semiáridos donde los recursos hídricos son escasos. El objeto de estudio de este trabajo es conocer las prácticas de alumbrar y explotar las aguas de freáticos próximos a la superficie del territorio, concretamente los recursos de la circulación subsuperficial en las ramblas de Béjar, Nogalte, Vilerda y Goñar en el sector noroccidental de la depresión prelitoral murciana (sureste de España). Se trata de aprovechamientos hídricos históricos organizados como comunidades de propietarios de aguas. Son modelos de sostenibilidad en su explotación para usos del agua en abastecimientos y regadíos, que también incorporan el valor de adaptación a sucesos extremos de sequías e inundaciones. La metodología es la del análisis geográfico regional aplicado al estudio de casos (sistemas socio-hídricos) de forma diacrónica y comparada, con amplio trabajo de campo y consulta de fuentes documentales, con entrevistas a los gestores y usuarios de estos sistemas de captación y distribución del agua. Los casos estudiados ponen de manifiesto que son sistemas sostenibles de aprovechamiento de agua que facilitan el desarrollo local en medios semiáridos como el sureste ibérico.

El estudio de la seguridad hidrológica en los embalses se realiza con el llamado hidrograma de la creciente de diseño. El proceso más sencillo y aproximado para estimar tal gráfica se basa en el análisis de frecuencias bivariado (AFB) para definir su gasto máximo (Q) y volumen (V), asociados con el periodo de retorno conjunto de diseño. Las funciones Cópula (FC) se fundamentan en la dependencia entre Q y V, y definen la distribución bivariada por medio de las funciones univariadas marginales previamente adoptadas. El enfoque práctico adoptado utiliza FC de un solo parámetro de ajuste y selecciona la más adecuada a partir de la dependencia que muestra el registro conjunto de Q y V en el extremo derecho de su distribución empírica. Además, contrasta y ratifica la FC adoptada contra varias de uso común en los AFB. Lo anterior, por medio de los errores de ajuste entre las probabilidades bivariadas empíricas y teóricas. La búsqueda de las distribuciones marginales se realizó con base en el diagrama de cocientes L para adoptar las tres mejores y confrontarlas con las funciones Kappa y Wakeby de gran versatilidad. Se realizó el AFB de las 55 crecientes anuales registradas en la estación hidrométrica La Cuña de la Región Hidrológica No. 12-3 (río Santiago), México. Se definen cuatro periodos de retorno conjuntos de diseño y se detalla el cálculo de sus curvas de tipo AND. Por último, se citan varias conclusiones que destacan las ventajas del uso de las FC en los AFB de crecientes.

El diseño hidrológico de varias obras hidráulicas o la revisión de las construidas se basa en las crecientes de diseño, que son gastos máximos del río, asociados con bajas probabilidades de excedencia o predicciones. Su estimación más confiable se realiza a través del análisis de frecuencias, proceso estadístico que consiste en representar el registro de gastos máximos anuales con una función de distribución de probabilidades (FDP) o modelo probabilístico, utilizado para realizar las predicciones buscadas. En este estudio de contraste se proponen las FDP beta-kappa y beta-Pareto, y se consideraron FDP de uso generalizado las tres siguientes: la Log-Pearson tipo III, la general de valores extremos y la logística generalizada. Por lo anterior, se expone para las dos primeras FDP un resumen de su teoría y su método de ajuste por máxima verosimilitud. Se procesan 11 registros de datos hidrológicos extremos anuales y se contrastan los ajustes con dos índices: el error estándar de ajuste y el error absoluto medio. La selección de las predicciones en los siete periodos de retorno (Tr) estudiados se basó en los valores menores de los errores de ajuste y en la búsqueda de predicciones representativas, en los Tr ≥ 500 años. Las conclusiones sugieren la inclusión de las distribuciones beta-kappa y beta-Pareto en los análisis de frecuencias debido a su versatilidad y facilidad de ajuste.

El mezcal es una bebida alcohólica elaborada en México. Esta industria produce vinazas de mezcal, que son aguas residuales complejas con alta concentración de materia orgánica (de 35 000 a 122 860 mg DQO/l), pH bajo (3.60-3.94) y compuestos recalcitrantes como fenoles (478-1460 mg ácido gálico/l) y sulfatos (308-947 mg/l), cuya disposición sin tratamiento al medio ambiente representa un peligro para cuerpos de agua y suelo. El presente estudio busca presentar y discutir el actual desarrollo tecnológico en el tratamiento de las vinazas de mezcal e identificar los sistemas con mayor potencial para su aplicación. Los tratamientos de vinaza de mezcal con las mejores eficiencias de remoción de DQO son fúngicos y anaeróbicos (80 %). La ozonización tiene potencial como pretratamiento, eliminando más del 80 % de los fenoles. Algunos sistemas híbridos pueden eliminar más del 90 % DQO. Sin embargo, estos tratamientos no incluyen el concepto de economía circular, por lo que su implementación se ve como un gasto que en ocasiones no puede ser asumido por los productores. Una opción incluye la revalorización para generar un beneficio económico para los productores. El tratamiento de biorrefinería, en el que se han obtenido diversos tipos de energía, como biohidrógeno, metano y bioelectricidad mediante la aplicación secuencial de diferentes bioprocesos, fue identificado como el tratamiento con mayor potencial.

Diversas experiencias de pequeñas unidades de riego muestran que, a partir de organizaciones sociales, normas, usos y costumbres, y arreglos consensados para la toma de decisiones han logrado acuerdos vinculantes en torno a temas de interés colectivo, tales como sistemas autogestivos del agua, en donde mediante un nivel organizativo se llevan a cabo todas las actividades del sistema de riego, como distribución del agua, mantenimiento, resolución de conflictos, monitoreo y vigilancia. El objetivo del estudio fue conocer la capacidad autogestiva de la sociedad de usuarios “Pozo Zamorano” en el manejo del agua a partir de los principios de diseño característicos de los recursos de uso común (RUC) de larga duración. Los resultados muestran que la gestión del recurso está dada por normas y reglamentos internos, sistemas de sanciones económicas que han sido establecidas de forma común por los usuarios, para permitir un buen manejo y orden dentro de la sociedad. Los puntos de diseño propuestos por Ostrom para las organizaciones administradas por los mismos usuarios están presentes en la organización de la sociedad “Pozo Zamorano” y se pueden considerar con un desempeño alto. La condición autogestiva de los socios regantes les ha permitido dar continuidad a la actividad agrícola, de la cual depende la mayoría de los habitantes de la comunidad.

Las aguas residuales hospitalarias (ARH) contienen fármacos que ocasionan efectos a la salud y el ambiente. Para este estudio se seleccionó la carbamazepina (CBZ) como contaminante modelo para evaluar la eficiencia de remoción de fármacos en un biofiltro no convencional (BF) empacado con astillas de madera (Prosopis) y roca porosa (tezontle). La electro-oxidación (EO) como pretratamiento también se evaluó. Se hizo crecer una biopelícula en el BF adaptada al ARH. Posteriormente, el ARH se enriqueció con altas concentraciones de CBZ (1 000 y 10 000 µg/l). La biomasa del BF no fue inhibida por estas concentraciones de CBZ, ya que la eficiencia de remoción de DQO (73 %) y NH4+-N (99 %) permanecieron constantes. El BF mostró una importante eliminación de CBZ por adsorción durante el arranque. La cama filtrante tuvo una capacidad de adsorción de 19.84 µg/g (Co = 10 000 µg/l). Después de la saturación del material filtrante, y operando en estado estable, el BF eliminó el 17.2 ± 7.4 % de CBZ por biotransformación, equivalente a 1 551 ± 664 µg/l de concentración. Esto es mayor que la concentración en la mayoría de los reportes para efluentes de ARH, AR municipales y AR farmacéuticas, que se encuentran entre 0.1 y 890 µg/l. Cuando se aplicó la EO como pretratamiento, la eficiencia de eliminación de CBZ aumentó a 55 ± 5.9 %. En este sistema híbrido, en la EO se biotransformó la CBZ y en el BF se removieron el nitrógeno y la DQO, y presentó desorción de CBZ.

La concentración de cloro como desinfectante suministrado a la red de distribución de agua decae con el paso del tiempo debido a su interacción con microorganismos, metales y otras sustancias presentes en el agua. Los programas de computadora, como Epanet, se utilizan para simular el comportamiento hidráulico y la calidad del agua en las redes de distribución; con su ayuda se pueden representar modificaciones físicas y operativas en un modelo numérico para conocer el nuevo comportamiento sin comprometer la calidad del servicio. La calibración del modelo de cloro como desinfectante consiste en tomar como referencia la concentración en varios puntos de la red y ajustar los coeficientes de decaimiento en el modelo hasta lograr que las concentraciones simuladas coincidan con las medidas. En el presente artículo se muestra la automatización de este proceso haciendo uso de la técnica heurística algoritmos genéticos y la Toolkit de EPANET con MATLAB (2016). El proceso de calibración se realiza en un sector de la red de distribución de la ciudad de Guanajuato, obteniendo una correlación de 0.816 con un error promedio absoluto de 0.08 mg/l entre las concentraciones modeladas y medidas; y que como resultado permitirá conocer la concentración del cloro en diversos puntos de la red, asegurándose de brindar un servicio de calidad durante el abastecimiento.

En esta investigación se lleva a cabo un análisis de la evolución histórica del derecho de aguas de Perú y se discuten los resultados obtenidos por el Tribunal Nacional de Resolución de Controversias Hídricas (TNRCH) de la Autoridad Nacional del Agua (ANA) durante el periodo 2014-2020. En Perú, el derecho de aguas ha evolucionado desde los tiempos coloniales. En 2008 se inició un importante cambio en la gestión de los recursos hídricos, creando la ANA y promulgando la Ley de Recursos Hídricos en 2009; en esta última se contempla la creación del TNRCH, órgano colegiado que resuelve en segunda y última instancia administrativa. En este trabajo se dan los resultados de dicho órgano colegiado. Se espera que el aporte coadyuve a mejor el desempeño de la institución en la solución de las controversias hídricas incrementando la predictibilidad.

El presente trabajo, como estudio de caso, expone problemáticas situadas de carácter hídrico en la localidad Kilómetro 30, ubicada en la zona rural del municipio de Acapulco, Guerrero, México. Más que pretender proponer soluciones a partir de agendas ambientales estandarizadas internacionales, este documento resalta las relaciones de poder y formas de gobierno que emergen ante escenarios críticos de abastecimiento de agua, así como la asimetría en la gobernanza de dicho recurso. Se tiene como objetivo analizar las prácticas de gestión de agua para uso doméstico bajo la óptica de un enfoque sociocultural de las relaciones sociedad-Estado Para ello, se emplea metodología cualitativa, que involucra al mismo tiempo observaciones de tipo etnográfico y entrevistas a profundidad que siguen el modelo de mapeo de actores involucrados en políticas ambientales: actores institucionalizados estatales, institucionalizados no estatales y no institucionalizados. Se concluye que las prácticas como acciones, discursos, reglas y recursos que se ponen en juego en el marco de relaciones históricas de violencia política y social se encuentran en el punto marginal entre lo legal y lo ilegal, moviéndose libremente entre ambas dimensiones mientras esto permita la sobrevivencia en condiciones socioambientales hostiles.

Soil water repellency (SWR) is a phenomenon that prevents the spontaneous wetting of numerous forest soils. It is a moisture-dependent characteristic, which disappears when soil moisture reaches near saturation. The heat generated during forest fires affects soil characteristics including SWR. The possibility of heat influencing moisture-dependent repellency (MDR) is not well understood. The present study aimed to investigate the effects of different heating temperatures (HT) and exposure durations (ED) on MDR using water-repellent Japanese Cedar (CED) and Japanese Cypress (CYP) forest soils. Soil samples collected from 0–5 cm depth were exposed to heat separately at 50, 100, and 150 °C (HT) for 1 h and 2 h durations (ED). The MDR of heated and non-heated soils was determined using the water drop penetration time (WDPT) test in a drying process. During the drying process of the tested soils, SWR appeared and then increased with drying to reach an extreme level (WDPT ≥3600 s) that persisted for a range of decreasing moisture contents, and declined to be non-repellent again (WDPT = 0 s). The critical moisture content at which soils become water-repellent with drying (CMC), the highest and the lowest moisture contents when soils showed maximum SWR (HMCmax and LMCmax, respectively), and the integrated area below the MDR curve (SWR) decreased with increasing HT in both CED and CYP soils. The moisture content at which soils become non-repellent again during drying, MCNR, was independent of the type of soil and heat treatment. The range of moisture contents between HMCmax and LMCmax, where soils show maximum SWR during drying, decreased with increasing HT, from 50 to 150 °C in CED and from 100–150 °C in CYP. The SWR showed strong positive linear correlations with CMC and HMCmax. The heat generated during wildfires can alter the MDR and all the related repellency parameters of water-repellent forest soils. SWR prevails over a narrower range of moisture contents in heated soil compared with non-heated soils. Further investigations with higher temperature levels using different soil types would be important for a comprehensive understanding of the heat impacts on MDR.

In this paper, the scour downstream of a trapezoidal Piano key weir (PKW) is investigated under free and submerged flow conditions. For this purpose, an experimental model was used in a laboratory channel with a length of 10 m, width of 0.75 m, and height of 0.8 m at various discharges and tailwater depths. The results showed an increase and decrease in the maximum scour depth with an increase in the discharge and submergence ratio, respectively. In addition, increasing the particle Froude number enhanced the geometric features of the scour hole downstream of the PKW. The rate of bed changes slowed down over time. The average values of maximum scour depth, the distance of the maximum scour depth from the weir toe, maximum scour hole length and weir toe scour depth increased in the free flow compared to the submerged flow. The scour hole volume and scour hole area in the submerged flow were less compared to the free flow. The average maximum level of the sedimentary ridge in the free flow is less than the submerged flow. New equations for calculating the geometric characteristics of the scour hole downstream of the trapezoidal PKW are presented with acceptable accuracy.

The dams and banks of small water reservoirs face significant erosion from wind-generated oscillatory waves. Proper design of structure height is crucial to protect such banks against erosion, considering the maximum characteristics of wind waves. Long-term measurements at the Hulín reservoir revealed that the wave spectrum aligns best with the Bretschneider type. This spectrum serves as a basis for simulating oscillatory waves and their impact on shore protection structure design. Empirical models were evaluated using wind and wave data from Hulín reservoir in the Czech Republic. The measured wind speeds attained a maximum of 8 m/s, and wave heights reached up to 15 cm. The Bretschneider (SMB) empirical formula provided the most accurate estimation of wave height (Hm0), with an average underestimate of RMSE = 0.038 m. On the other hand, Wilson revisited (WIL rev.) performed less effectively, with an average RMSE = 0.304 m. For wave period (T) estimation, Bretschneider (SMB) yielded the best results, with an average RMSE = 0.062 s. Conversely, Wilson revisited (WIL rev.) showed poorer performance, with an average underestimate of RMSE = 2.196 s. The discrepancy between the empirical formulas and measured values, particularly in underestimating Hm0, can be attributed to inaccurate determination of fetch length and wind speed.

Changes in hydrological processes and water resources required to sustain vegetation for ecological restoration of landfill covers and post mining sites in arid environments pose challenges in the context of extended droughts. Knowledge of actual threshold and wilting suction values based on tree morphological feature or plant age is essential for understanding the variation of root water uptake with drought stress and numerically predict the pore water pressure profile in root zone. The objective of this study is to quantify the transpiration reduction function (TRF; in terms of stomatal conductance (SC) and xylem sap flow (SF)) of Schefflera arboricola, considering the effects of tree morphology. Continuous drought condition was applied on the plant quantified with leaf area index (LAI) values at 0.5, 2 and 3.5, wherein each LAI represent tree age. The soil matric suction (ψ) and volumetric water content were measured by embedded sensors in the root zone. Based on the TRF obtained from SC values, a unique threshold suction (ψNTRt) ranging from 30 to 50 kPa was identified. Beyond this ψNTRt, measured leaf abscisic acid concentration increased up to 35 ng/mL, indicating the start of water stress avoidance mechanism. It is evident that ψNTRt is independent of tree morphological parameter- leaf area to root length ratio (LA/RL). On the contrary, a threshold suction (ψSAPt), depending on LA/RL ratio, can be determined, indicating the start of xylem cavitation. This ψSAPt values ranging from 80 to 500 kPa depending on the LA/RL value, imply that the plant could significantly resist xylem embolization at higher LA/RL. In contrast, the plant with low LA/RL values have less tolerance of drought stress and hence low survivability. The results from this research study can be vital for devising and predicting plant available water in water scarce arid environments by a flux-based approach which is dependent on the tree age.

The present study used three machine learning models, including Least Square Support Vector Regression (LSSVR) and two non-parametric models, namely, Quantile Regression Forest (QRF) and Gaussian Process Regression (GPR), to quantify uncertainty and precisely predict the side weir discharge coefficient (Cd) in rectangular channels. So, 15 input structures were examined to develop the models. The results revealed that the machine learning models used in the study offered better accuracy compared to the classical equations. While the LSSVR and QRF models provided a good prediction performance, the GPR slightly outperformed them. The best input structure that was developed included all four dimensionless parameters. Sensitivity analysis was conducted to identify the effective parameters. To evaluate the uncertainty in the predictions, the LSSVR, QRF, and GPR were used to generate prediction intervals (PI), which quantify the uncertainty coupled with point prediction. Among the implemented models, the GPR and LSSVR models provided more reliable results based on PI width and the percentage of observed data covered by PI. According to point prediction and uncertainty analysis, it was concluded that the GPR model had a lower uncertainty and could be successfully used to predict Cd.

Water is one of the key ecological factors that has a great impact to development and productivity of lowland species such as Quercus robur. This paper deals with water regime influence to site conditions of these species and how actually changeable soil moisture affects Q. robur. Studied area includes a protective embankment built on the river bank in order to eliminate flooding effect, which means that all needs for water these associations provide from rainfalls and groundwater. Water regime was monitored during two critical years (extremely dry and extremely wet) on four soil types – Planosol, Fluvisol and Gleysol that belong to hydromorphic (three experimental plots) and Chernozem which belongs to automorphic soils (three experimental plots), respectively. It was studied the distribution of rainfalls and groundwater during the growing seasons and how it affects total and available water amount in the soil. The main focus should be given to available water, because it is located in capillary pores and plants can utilize it. Bearing in mind rainfalls makes just 15–20% of the total water amount in the soil it is much more significant to evaluate its proportion in available water. Based on obtained results, we can deduce that much more suitable site conditions for Q. robur are present on hydromorphic soils due to much greater proportion of groundwater.

This study investigates the performance of two lumped hydrological models, BILAN and GR2M, in simulating runoff across six catchments in the Gambia River Basin (Senegal) over a 30-year period employing a 7-year sliding window under different climatic conditions. The results revealed differences in overall performance and variable sensitivity of the models to hydrological conditions and calibration period lengths, stemming from their different structure and complexity. In particular, the BILAN model, which is based on a more complex set of parameters, showed better overall results in simulating dry conditions, while the GR2M model had superior performance in wet conditions. The study emphasized the importance of the length of the calibration period on model performance and on the reduction of uncertainty in the results. Extended calibration periods for both models narrowed the range of the Kling-Gupta Efficiency (KGE) values and reduced the loss of performance during the parameter transfer from calibration to validation. For the BILAN model, a longer calibration period also significantly reduced the variability of performance metric values. Conversely, for the GR2M model, the variability rate did not decrease with the length of the calibration periods. Testing both models under variable conditions underscored the crucial role of comprehending model structure, hydrological sensitivity, and calibration strategy effects on simulation accuracy and uncertainty for reliable results.

Hydraulic transport pipelines in the dredging, mining and deep sea mining are designed using steady-state methods. However, these methods cannot predict density wave formation. Density waves form a risk for pipeline blockages, therefore there is a need to understand and preferably be able to model the process. The density waves studied in this research are caused by a stationary sediment deposit in the pipeline. This article explores the development of a new transient design model, based on 1-dimensional-two-layer Driftflux CFD. The two layers model the exchange of sediment between the turbulent suspension, and a stationary bed layer, and can therefore model density wave amplification. An empirical erosion-sedimentation closure relationship is applied to model the sediment exchange between the two layers, and is calibrated using experiments. The final model is also validated against a second experiment, specifically for density wave amplification. The experiments and the model show good agreement on the erosion of a stationary bed layer and the growth rate of a density wave and the amplitude of the density wave.

In winter, the water transfer channel of the Middle Route of South-to-North Water Transfer Project (MR-StNWTP) in China always encounters ice problems. The preciously simulation and prediction of water temperature is essential for analyzing the ice condition, which is important for the safety control of the water transfer channel in winter. Due to the difference of specific heat between water and air, when the air temperature rises and falls dramatically, the range of change of water temperature is relatively small and has a lag, which often affects the accuracy of simulation and prediction of water temperature based on air temperature. In the present study, a new approach for simulating and predicting water temperature in water transfer channels in winter has been proposed. By coupling the neural network theory to equations describing water temperature, a model has been developed for predicting water temperature. The temperature data of prototype observations in winter are preprocessed through the wavelet decomposition and noise reduction. Then, the wavelet soft threshold denoising method is used to eliminate the fluctuation of certain temperature data of prototype observations, and the corresponding water temperature is calculated afterward. Compared to calculation results using both general neural network and multiple regression approaches, the calculation results using the proposed model agree well with those of prototype measurements and can effectively improve the accuracy of prediction of water temperature.