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Summary: The first year in a tree's life is characterized by distinct morphological changes, requiring constant adjustments of the hydraulic system. Despite their importance for the natural regeneration of forests and future vegetation composition, little has been known about the hydraulics of tree seedlings.At different times across the first growing season, we analysed xylem area‐specific (Kshoot_Axyl) and leaf area‐specific (Kshoot_L) shoot hydraulic conductance, as well as embolism resistance of three temperate conifer trees, two angiosperm trees and one angiosperm shrub, and related findings to cell osmotic parameters and xylem anatomical traits.Over the first 10 wk after germination, Kshoot_Axyl and Kshoot_L sharply decreased, then remained stable until the end of the growing season. Embolism resistance was remarkably low in the youngest stages but, coupled with an increase in cell wall reinforcement, significantly increased towards autumn. Contemporaneously, water potential at turgor loss and osmotic potential at saturation decreased.Independent of lineage, species and growth form, the transition from primary to secondary xylem resulted in a less efficient but increasingly more embolism‐resistant hydraulic system, enabling stable water supply under increasing risk for low water potentials. [ABSTRACT FROM AUTHOR]

Summary: Both mistletoes and their hosts are challenged by increasing drought, highlighting the necessity of understanding their comparative hydraulic properties. The high transpiration of mistletoes requires efficient water transport, while high xylem tensions demand strong embolism resistance, representing a hydraulic paradox.This study, conducted across four environments with different aridity indices in Yunnan, China, examined the xylem traits of 119 mistletoe–host species pairs.Mistletoes showed lower water use efficiency, indicating a more aggressive water use. They also showed lower hydraulic efficiency (lower vessel diameter and theoretical hydraulic conductivity) but higher safety (lower vulnerability index and higher conduit wall reinforcement, vessel grouping index, and wood density) compared with their hosts, supporting the trade‐off between efficiency and safety. Environmental variation across sites significantly affected xylem trait comparisons between mistletoes and hosts. Additionally, the xylem traits of mistletoes were strongly influenced by host water supply efficiency. The overall xylem trait relationships in mistletoes and hosts were different.These findings stress the impact of host and site on the hydraulic traits of mistletoes, and suggest that mistletoes may achieve high transpiration by maintaining high stomatal conductance under low water potentials. This study illuminates the distinctive adaptation strategies of mistletoes due to their parasitic lifestyle. [ABSTRACT FROM AUTHOR]

Summary Grasses are exceptionally productive, yet their hydraulic adaptation is paradoxical. Among C3 grasses, a high photosynthetic rate (Aarea) may depend on higher vein density (Dv) and hydraulic conductance (Kleaf). However, the higher Dv of C4 grasses suggests a hydraulic surplus, given their reduced need for high Kleaf resulting from lower stomatal conductance (gs). Combining hydraulic and photosynthetic physiological data for diverse common garden C3 and C4 species with data for 332 species from the published literature, and mechanistic modeling, we validated a framework for linkages of photosynthesis with hydraulic transport, anatomy, and adaptation to aridity. C3 and C4 grasses had similar Kleaf in our common garden, but C4 grasses had higher Kleaf than C3 species in our meta‐analysis. Variation in Kleaf depended on outside‐xylem pathways. C4 grasses have high Kleaf : gs, which modeling shows is essential to achieve their photosynthetic advantage. Across C3 grasses, higher Aarea was associated with higher Kleaf, and adaptation to aridity, whereas for C4 species, adaptation to aridity was associated with higher Kleaf : gs. These associations are consistent with adaptation for stress avoidance. Hydraulic traits are a critical element of evolutionary and ecological success in C3 and C4 grasses and are crucial avenues for crop design and ecological forecasting. [ABSTRACT FROM AUTHOR]

Summary The anatomical reorganization required for C4 photosynthesis should also impact plant hydraulics. Most C4 plants possess large bundle sheath cells and high vein density, which should also lead to higher leaf capacitance and hydraulic conductance (Kleaf). Paradoxically, the C4 pathway reduces water demand and increases water use efficiency, creating a potential mismatch between supply capacity and demand in C4 plant water relations. Here, we use phylogenetic analyses, physiological measurements, and models to examine the reorganization of hydraulics in closely related C4 and C3 grasses. The evolution of C4 disrupts the expected positive correlation between maximal assimilation rate (Amax) and Kleaf, decoupling a canonical relationship between hydraulics and photosynthesis generally observed in vascular plants. Evolutionarily young C4 lineages have higher Kleaf, capacitance, turgor loss point, and lower stomatal conductance than their C3 relatives. By contrast, species from older C4 lineages show decreased Kleaf and capacitance. The decline of Kleaf through the evolution of C4 lineages was likely controlled by the reduction in outside‐xylem hydraulic conductance, for example the reorganization of leaf intercellular airspace. These results indicate that, over time, C4 plants have evolved to optimize hydraulic investments while maintaining the anatomical requirements for the C4 carbon‐concentrating mechanism. [ABSTRACT FROM AUTHOR]

This study assessed the ability of experimental materials consisting of dicalcium silicate (DCS) and tricalcium silicate (TCS) with nanosized particles to form intratubular crystals under phosphate-buffered saline (PBS) and the effect on dentin permeability reduction. By isolating the cervical part of the extracted premolars, 195 specimens were obtained. Two experimental materials (DCS/TCS and TCS) were applied to the dentin surface by brushing and stored in PBS (n = 65). Another 65 specimens were not treated. Each group was randomly divided into five subgroups based on the PBS immersion period (1, 15, 30, 60, and 90 days, n = 10). The dentin permeability was measured, and the hydraulic conductance, Lp (%), was calculated. After acid challenge with 1 M acetic acid, Lp (%) was remeasured. Data were analyzed using two-way analysis of variance and Fisher's least significant difference test (α = 0.05). Three specimens of each subgroup were longitudinally sectioned and examined using scanning electron microscopy and a field emission-electron probe micro analyzer. The Lp (%) of the experimental groups gradually decreased over time (P < 0.05). The hydroxyapatite-like crystals that grew were observed and found to have a Ca/P ratio similar to that of hydroxyapatite. The crystals remained after the acid challenge, and the Lp (%) was not significantly different from that before acid treatment. Intratubular crystals formed from the experimental materials consisted of DCS and TCS and were resistant to acid. These crystals significantly reduced dentin permeability. [ABSTRACT FROM AUTHOR]

Tubular occlusion is an effective method to treat dentin hypersensitivity. This study aimed to determine the effect of a modified methyl methacrylate-p-styrene sulfonic acid copolymer-based gel desensitizer on dentin permeability and tubule occlusion in extracted human premolars. Hydraulic conductance (HC) measurement (n = 50) and scanning electron microscopy (SEM; n = 64) were performed. Tooth specimens were divided into 6 groups and treated with: G1, distilled water for 30 s; G2, distilled water for 5 min; G3, gel desensitizer for 30 s; G4, gel desensitizer for 5 min; G5, 3% potassium oxalate for 30 s; G6, 3% potassium oxalate for 5 min. HC of dentin were measured before and after 30 s-etching with 35% phosphoric acid, at 0, 30, 60 min after group treatment and after 5-min acid challenge with 6% citric acid. The degree of tubule occlusion and the penetration depth of each agent were also determined. ANOVA and multiple comparison tests were used for data analysis. G3, G4, G5 and G6 significantly decreased in HC after group treatment every observation period, compared to after acid-etching (P < 0.001), and had 100% degree of tubule occlusion with penetration depth about 7.62, 7.94, 8.59 and 8.66 μm, respectively. However, G6 showed the greatest reduction in HC (P < 0.05). Gel desensitizer treatment, for only 30 s, could reduce dentin permeability and completely occlude the dentinal tubules, even though after acid challenge. However, 5-min treatment with potassium oxalate showed the greatest decrease in dentin permeability. [ABSTRACT FROM AUTHOR]

The article "Investigating the Functional and Architectural Diversity of Leaf Venation Networks" explores the diverse leaf venation network architectures in plants and the potential trade-offs among various leaf functions. A team of students led by Dr. Matos collected samples from the University of California Botanical Garden to study 31 functional and architectural leaf venation traits across 122 species. The dataset generated is being used to identify trade-offs in venation architecture-function and understand the evolutionary processes behind the diversity of networks. [Extracted from the article]

Background: Underground research laboratories (URLs) provide a window on the deep biosphere and enable investigation of potential microbial impacts on nuclear waste, CO2 and H2 stored in the subsurface. We carried out the first multi-year study of groundwater microbiomes sampled from defined intervals between 140 and 400 m below the surface of the Horonobe and Mizunami URLs, Japan. Results: We reconstructed draft genomes for > 90% of all organisms detected over a four year period. The Horonobe and Mizunami microbiomes are dissimilar, likely because the Mizunami URL is hosted in granitic rock and the Horonobe URL in sedimentary rock. Despite this, hydrogen metabolism, rubisco-based CO2 fixation, reduction of nitrogen compounds and sulfate reduction are well represented functions in microbiomes from both URLs, although methane metabolism is more prevalent at the organic- and CO2-rich Horonobe URL. High fluid flow zones and proximity to subsurface tunnels select for candidate phyla radiation bacteria in the Mizunami URL. We detected near-identical genotypes for approximately one third of all genomically defined organisms at multiple depths within the Horonobe URL. This cannot be explained by inactivity, as in situ growth was detected for some bacteria, albeit at slow rates. Given the current low hydraulic conductivity and groundwater compositional heterogeneity, ongoing inter-site strain dispersal seems unlikely. Alternatively, the Horonobe URL microbiome homogeneity may be explained by higher groundwater mobility during the last glacial period. Genotypically-defined species closely related to those detected in the URLs were identified in three other subsurface environments in the USA. Thus, dispersal rates between widely separated underground sites may be fast enough relative to mutation rates to have precluded substantial divergence in species composition. Species overlaps between subsurface locations on different continents constrain expectations regarding the scale of global subsurface biodiversity. Conclusions: Our analyses reveal microbiome stability in the sedimentary rocks and surprising microbial community compositional and genotypic overlap over sites separated by hundreds of meters of rock, potentially explained by dispersal via slow groundwater flow or during a prior hydrological regime. Overall, microbiome and geochemical stability over the study period has important implications for underground storage applications. [ABSTRACT FROM AUTHOR]

Girdling is a crucial technique for promoting the close-to-nature transformation of plantation forests in Hainan Tropical Rainforest National Park (HNNP). It has shown effectiveness in aspects such as community structure and biodiversity restoration. However, its impacts on ecological functions like eco-hydrology still require further in-depth investigation. This study analyzes the impact of girdling on the eco-hydrological indices of three plantations—Acacia mangium, Pinus caribaea, and Cunninghamia lanceolata—through field investigations and laboratory tests. The data was evaluated using a game theory combination weighting-cloud model. The results show that the eco-hydrological indicators of leaf litter in A. mangium increased by 5.77% while those of P. caribaea and C. lanceolata decreased by 11.86% and 5.29%, respectively. Soil bulk density decreased slightly across all plantations while total porosity increased, with A. mangium showing the highest increase of 20.31%. Organic carbon content increased by 76.81% in A. mangium and 7.24% in C. lanceolata, whereas it decreased in P. caribaea. Saturated hydraulic conductivity increased by 33.32% in P. caribaea and 20.91% in A. mangium but decreased in C. lanceolata. Based on the cloud model, the eco-hydrological function of A. mangium improved from 'medium' to 'good', while that of P. caribaea and C. lanceolata declined towards the 'poor' level. In summary, during the process of close-to-nature transformation of tropical rainforests, girdling is an effective method to enhance the ecohydrological functions of broadleaf planted forests. However, for coniferous species, the ecohydrological functions of the planted forests weaken in the short term following the transformation. [ABSTRACT FROM AUTHOR]

Most previous investigations for consolidation-induced solute transport models have been limited to one-dimensional studies in unsaturated porous media and lack systematic parameter sensitivity analysis. This study addresses these gaps by analyzing the effects of hydraulic conductivity (K), shear modulus (G), saturation ( S r ), Poisson's ratio (ν), partitioning coefficient ( K d ), and anisotropy ratio ( K x K z and K y K z ) on pore water pressure, soil deformation, and solute transport. The findings reveal that higher K d values significantly hinder solute migration through enhanced adsorption and reduced vertical transport to deeper layers, while increasing anisotropy ratios primarily enhance horizontal migration, with their effects diminishing beyond a threshold. Additionally, a higher K accelerates pressure dissipation and solute movement, while a lower G increases soil deformation and speeds up solute migration. Saturation has a minor effect on solute concentration, with slight increases under higher S r . The Poisson ratio significantly impacts the transport of the solute, with smaller ν accelerating and larger ν slowing migration. These insights offer valuable theoretical support for optimizing models in unsaturated porous media. [ABSTRACT FROM AUTHOR]

Water conservation and effective irrigation management are vital for sustainable agriculture in arid regions. While organic soil amendments have been widely used to enhance water retention in sandy soils, research on the use of date palm waste-derived biochar remains limited. Thus, this study aimed to explore the innovative application of biochar produced from date palm waste, focusing on its effects on the hydrological properties of sandy soil. Biochars of varying particle sizes (0.5, 1, and 2 mm) and pyrolysis temperatures (300 °C, 450 °C, and 600 °C) were produced and their impacts were assessed under both saturated and unsaturated conditions on soil hydrological properties. The biochar was incorporated into soil columns at application rates of 0%, 1%, 3%, and 5% (w/w) within a 10 cm layer on top of 35 cm deep soil columns. The soil columns were placed vertically into water basins for saturation. Evaporation, infiltration, and saturated hydraulic conductivity were measured. The findings revealed that the application of 1%, 3%, and 5% biochar significantly increased soil water retention by 36.80%, 34.18%, and 29.66%, while cumulative evaporation decreased by 7.30%, 2.00%, and 1.35%, respectively, as compared to the control. Water retained at the end of the experiment was increased by 100.63%, 112.29%, and 101.68%, while unsaturated hydraulic conductivity decreased by 21.27%, 26.15%, and 26.17% after amending the soil with 1%, 3%, and 5% biochar, respectively, as compared to the control. The water retention ranged between 30.34 and 42.51%, 22.59 and 43.20%, and 22.48 and 38.81% for biochar produced at 300 °C, 450 °C, and 600 °C, respectively. Water infiltration rate and pore size was decreased with the increased pyrolysis temperature. Overall, the application rates of 3% and 5% with particle sizes of 1 and 0.5 mm and low pyrolysis temperature were most efficient for improving soil properties such as water retention, reducing unsaturated hydraulic conductivity, reducing the rate and volume of infiltration, and enhancing the micro-porosity reduction of sandy soils. In a nutshell, this study highlights the potential of date palm waste-derived biochar as an effective soil amendment, significantly enhancing water retention by up to 112.29% and reducing evaporation. By optimizing irrigation management in sandy soils, these findings contribute to more sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Hydraulic functionality is crucial for tree productivity and stress tolerance. According to the theory of the fast–slow economics spectrum, the adaptive strategies of different tree species diverge along a spectrum defined by coordination and trade-offs of a suite of functional traits. The fast- and slow-growing species are expected to differ in hydraulic efficiency and safety; however, there is still a lack of investigation on the mechanistic association between tree growth rate and tree hydraulic functionality. Here, in a common garden condition, we measured radial growth rate and hydraulic traits in a fast-growing (Populus alba L. × P. berolinensis Dippel) and a slow-growing tree species (Acer truncatum Bunge), which are both important tree species for afforestation in northern China. In line with the contrasts in radial growth rate and wood anatomical traits at both the tissue and pit levels between the two species, stem hydraulic conductivity of the Populus species was significantly higher than that of the Acer species, but the resistance to drought-induced xylem cavitation was the opposite. A trade-off between hydraulic efficiency and safety was observed across the sampled trees of the two species. Higher water-transport efficiency supports the greater leaf net photosynthetic carbon assimilation capacity of the Populus species and hence facilitates fast growth, while the conservative hydraulic traits of the Acer species result in a slower growth rate but enhanced drought tolerance. [ABSTRACT FROM AUTHOR]

Until now, the contribution of soils in urban spaces has been underestimated and, as a result, the services they provide have been severely undervalued in urban planning. This article aims to address this issue through a study of Chapultepec Park in Mexico City. We provide two methodological proposals for the analysis of soil ecosystem services characterized by the interaction of natural and anthropic processes: the morpho-pedological landscapes (MpL), in which we quantify soil carbon sequestration (SOC Mg ha−1) and the comparison of two methods for the analysis of hydraulic conductivity: Pedotransfer functions (PTF) and direct measurement with a double ring infiltrometer. Among the 12 MpL, we found the highest SOC content in slopes with mixed tree vegetation and Phaeozem soils. However, SOC retention decreased by 40%–50% due to sealing surfaces. For infiltration measures, despite the diversity of soils and vegetation, direct measurements values are highly homogeneous, while values calculated using PTFs better reflect the morphopedological landscape heterogeneity. In all the MpLs, the hydraulic conductivity was higher than the maximum rainfall intensity report, indicating that the soils in Chapultepec Park, despite the differences in soils and intensity of use, provide the ecosystem service of infiltration. These results would allow the establishment of a baseline for monitoring these services and provide information to decision makers and urban planners seeking to reduce the construction of gray infrastructure that seals soils and reduces their capacity to provide these ecosystem services. [ABSTRACT FROM AUTHOR]

A cementitious paste fill (CPF) ensures the long-age stability of underground cavities. Recently, superplasticizers, specifically ones that are polycarboxylate ether-based, have been incorporated to enhance CPF performance, yet their long-term effects on permeability, mechanical properties, and microstructures remain unclear. This study investigates these effects with CPF samples containing varying superplasticizer dosages (0%, 1%, 3%, 5%) that have been cured for up to 150 days. Rheological assessments (slump cone, vane shear tests), unconfined compressive strength testing, microstructural characterization (MIP, SEM), and hydraulic conductivity measurements were performed alongside XRD and thermal analyses (TAns) on high w/c (2) cement paste samples. The results showed that superplasticizer addition reduced CPF water content by 23% and yield stress by six times, aiding slurry transport. Long-term strength was enhanced by up to 2.4 times compared to the control samples, indicating improved underground stability. Superplasticizers altered the CPF samples stress–strain responses, increasing their load-bearing capacity. TG/DTG and XRD analyses revealed that hydration product development increased and porosity decreased in the presence of a superplasticizer. Hydraulic conductivity and permeability also decreased significantly. SEM and MIP analyses showed that the superplasticizer enhanced denser microstructures with fewer pores and fractures. These findings offer promising implications for designing CPFs with improved strength, durability, and environmental sustainability. [ABSTRACT FROM AUTHOR]

Soils are highly sensitive to the type of tillage practices used, as these practices influence soil properties and affect crops, the environment, and society. However, research on cassava production under different tillage systems during drought conditions in the Peruvian Amazon has not been reported. The objective of this study was to compare soil properties, cassava physiology, and yield under conservation agriculture (CA) and traditional agriculture (TA) practices, with and without mulch, in a water-scarce environment. Soil moisture, earthworm population (Ew), stomatal conductance, leaf area index, and commercial yield under CA were 5.26% (~105.2 m3 ha−1), 83%, 1.2 times, 1.14 times, and 7.3 t ha−1, respectively, higher than under TA. Hydraulic conductivity (Ks) in TA was 2.1 times higher than that in CA. However, Ks, bulk density, and Ew over time showed a gradual recovery under CA. The mulch factor only affected Ew, which was higher without mulch than with mulch. The results indicate that CA practices were superior to TA practices, improving soil properties, cassava physiology, and yield, and, therefore, offer significant benefits in resource conservation and higher production and profitability in a drought-prone environment. [ABSTRACT FROM AUTHOR]

A field study was conducted to investigate the effects of selected climate-smart agriculture practices on soil bulk density (ρ), porosity (β), hydraulic conductivity (Ksat), and nutrient dynamics in southeast Texas. Treatment combinations of two types of organic manure (chicken and dairy) with three rates (0, 224, and 448 kg N ha−1) and two levels of biochar (2500 and 5000 kg ha−1) were used in a factorial randomized block design. Bulk density and porosity measurements were conducted on undisturbed soil core samples collected from the topsoil (0–10 cm) of a field cultivated with sweet corn. Ksat was calculated from the steady-state infiltration measured using the Tension Infiltrometer (TI). The ANOVA results indicated that the manure application rates, and biochar levels significantly affected the soil properties. Compared to the control, β increased by 15% and 29% for the recommended and double recommended manure rates. Similarly, hydraulic conductivity increased by 25% in the double-recommended rate plots compared to the control. Also, we applied the concept of non-parametric elasticity to understand the sensitivity of soil physical and chemical properties to Ksat. ρ and β are critical physical properties that are highly sensitive to Ksat. Among soil nutrients, Boron showed the highest sensitivity to Ksat. Hydraulic conductivity can be enhanced by employing selected climate-smart practices and improving water management. Future directions for this study focus on scaling these findings to diverse cropping systems and soil types while integrating long-term assessments to evaluate the cumulative effects of climate-smart practices on soil health, crop productivity, and ecosystem sustainability. [ABSTRACT FROM AUTHOR]

Enhancing integrated crop–livestock systems (ICLSs) to improve land-use efficiency is a critical goal. Understanding the ICLS impacts on lowland soils is key to sustainable agricultural practices. Our objective was to test whether adopting ICLSs in lowlands improves soil structure, pore connectivity, and water and air permeability. This study was conducted in a long-term field trial, consisting of the following production systems with flood-irrigation rice: rice–fallow–rice, under conventional tillage and absence of grazing (RFR-ct); rice-grazed ryegrass–rice, under no-tillage and grazing (RGrR-nt); rice-grazed ryegrass–soybean-grazed ryegrass–rice, under no-tillage and grazing (RGrS/RGrR-nt); and a grazed pasture-consortium (winter) and succession field (summer), with no-till rice every 4 years (P4R-nt). Core samples were collected after grazing (October 2018), harvesting (March 2019), and grazing (October 2019). We analyzed soil air permeability, saturated hydraulic conductivity, pore connectivity by computed tomography. Soil tillage in a semi-direct system generated discontinuous porosity. Systems with intense trampling or less surface protection are affected by shearing on topsoil, reducing pore continuity. ICLSs are mainly composed of ryegrass–rice mitigated the harmful effects of trampling, and improved soil structure and functioning. Systems without soil tillage exhibited higher pore connectivity and pores with vertical orientation. Finally, soil tillage is not required to improve structural quality in ICLSs. [ABSTRACT FROM AUTHOR]

Introduction Water scarcity and the need for optimal water utilization in arid and semi-arid regions, including Iran, have encouraged water authorities and farmers to adapt modern irrigation systems likedrip irrigation, to make optimal use of water resources. The most important advantage of drip irrigation over other irrigation methods is its ability to control the amount of water applied to each plant. New irrigation methods focus on plant irrigation and not on land irrigation. In arid and semi-arid regions, a drip irrigation system is used to use water optimally and prevent wastage and evaporation. Factors such as soil texture, type of cultivated plant, amount of available water, distance of drippers and laterals, the wetted surface, and the dimensions of the moisture bulb under the soil surface are involved in the design of the drip irrigation system. Due to the variety of soil textures in the earth, the movement of water under the soil surface is different in all kinds of textures, therefore, knowing exactly how water moves in the soil and how the moisture bulb is distributed under the soil surface is of particular importance. The purpose of this study is to investigate the movement of moisture bulbs, check their dimensions under the soil surface in different soil textures and flow rates, and evaluate the capability of the Moment analysis method to simulate this process under various conditions. Materials and Methods To simulate the moisture bulb in different soil textures, detailed information on the physical properties of the soil, including the percentage of particles that make up the soil texture, bulk and real density, porosity, and saturated hydraulic conductivity, is required. In this research, the simulation of the moisture front in different soil texture was conducted using Rosetta software, which defines 12 types of soil textures. In these tests, the source of soil power was considered as surface and point. The total feeding volume of each type of soil texture is 24 L, and this volume was used with different flow rates of two, four, six, and eight L s-1. To numerically simulate the progress of the moisture front, Hydrus software was used. Then the analytical simulation of the moisture front was done using the equations of the Moment analysis method. In this study, an ellipse was drawn to represent the moisture bulb simulated by Hydrus software at different times for the applied flow rates. Coefficient k was used to draw the ellipse, and its appropriate value was determined by minimizing the difference between the model and Hydrus results. Results and Discussion To calculate the moments, the first step is to obtain the values of M00 According to the applied flow rates of two, four, six, and eight L s-1 and the amount of volume intended to feed all types of soil texture, i.e., 24 L, the duration of irrigation is 12, 6, 4, and 3 hr, respectively. The comparison of moisture distribution over all periods and soil textures showed acceptable results, and the distributed subsurface moisture values were similar. In the study of clay texture, with time from the start of irrigation, the difference in the total amount of distributed moisture increased, and the reason for this result is the decrease in the permeability of the clay due to the filling of fine pores. The results indicated that σx2 values changed with the increase in irrigation duration. The highest variance was found in sandy clay with a flow rate of 8 L s-1 (1503.3 cm² ), while the lowest variance was observed in clay texture with a flow rate of 4 L s-1 (368.6 cm² ). By increasing the amount of applied discharge, σz2 increases and the slope of this increase is different in each soil texture, according to the characteristics of that texture. Also, the effect of irrigation duration on the value of σz2 is evident. In other words, the longer the duration of irrigation, the more the amount of variance changes. Conclusion In this research, the accuracy of the Moment analysis method in predicting moisture distribution from drip irrigation was evaluated using results from Hydrus and Moment analysis. The Hydrus results demonstrated that the moisture bulb expanded over time in both the horizontal and vertical directions. The results also indicated higher flow rates increased the horizontal expansion of the moisture bulb, while the duration of irrigation affected both horizontal and depth expansions. Using the moment analysis method, the center of mass of water distribution in the soil and the changes in the moisture front along the x and z axes were determined. By examining and comparing the dimensions of the moisture front resulting from Hydrus and ovals, it was observed that there is a suitable compatibility between the two methods. Therefore, the Moment analysis method can be relied upon to estimate the dimensions of the moisture bulb in drip irrigation. It also provides an efficient and accurate approach to reducing the time and cost of field experiments. [ABSTRACT FROM AUTHOR]

In-stream restoration structures, such as woody weirs, are intended to enhance hyporheic exchange, thus altering temperature dynamics in restored reaches. However, the relative effects of various in-stream structure types and streambed settings (i.e. the size, spacing, number and sediment hydraulic conductivity) remain poorly understood. Here, we conducted a field experiment with a channel-spanning weir in a stream to study its impact on hyporheic exchange and streambed and surface water temperatures. We subsequently applied numerical models to explore the effects of height, spacing and number of weirs and sediment permeability on hyporheic exchange and thermal distribution characteristics. Based on the field experiments and numerical models, the results showed that the addition of a weir enhanced hyporheic exchange and produced a characteristic temperature heterogeneity pattern in sediment that varied with height, spacing, number of weirs and sediment permeability. The spatial extent and rate of hyporheic exchange and temperature heterogeneity near the weir primarily increased with weir height and sediment permeability. With increasing spacing, the exchange flux and thermally heterogenous area increased, but the exchange intensity decreased, and the sediment temperature readily stabilized. With increasing number of weirs, the exchange flux first decreased and then increased, and the region exhibiting temperature heterogeneity increased. The interaction between the introduction of in-stream structures introduction and streambed settings must be understood to improve vertical connectivity in rivers, increase the thermal heterogeneity in the hyporheic zone and create localized but potentially valuable thermal refuge areas. [ABSTRACT FROM AUTHOR]

Water infiltration is important for improved crop productivity and environmental sustainability, but the combined effects of cover crops (CCs) and tillage on cumulative infiltration and infiltration parameters are not fully understood. The objectives of this study were to evaluate the influence of CCs and tillage on cumulative water infiltration and infiltration parameters. The field was set up using a randomized complete block design with two levels of CCs (CCs vs no cover crop [NC]) and two levels of tillage (till vs no-till [NT]). The CCs used included winter wheat (Triticum aestivum) and crimson clover (Trifolium incarnatum), and the tillage included disc tillage (to a depth of 10 cm). Results showed that CCs and tillage significantly increased the Parlange and Green-Ampt model estimated sorptivity and saturated hydraulic conductivity parameters during 2022 compared with NC and NT, respectively. Additionally, KGuelph was significantly higher under CC compared with NC during both years, suggesting that CCs can increase groundwater recharge. While CC-Till management had the highest 2-h cumulative infiltration, tillage only significantly increased water infiltration during early times, and CCs increased water infiltration during the infiltration period. Conclusively, CCs can improve the ability of tillage to increase water infiltration. [ABSTRACT FROM AUTHOR]

To have the desired therapeutic effect, nanomedicines and macromolecular medications must move from the site of injection to the site of action, without having adverse effects. Transvascular transport is a critical step of this navigation, as exemplified by the Enhanced Permeability and Retention (EPR) effect in solid tumors, not found in normal organs. Numerous studies have concluded that passive, diffusion- and convection-based transport predominates over active, cellular mechanisms in this effect. However, recent work using a new approach reevaluated this principle by comparing tumors with or without fixation and concluded the opposite. Here, we address the controversy generated by this new approach by reporting evidence from experimental investigations and computer simulations that separate the contributions of active and passive transport. Our findings indicate that tissue fixation reduces passive transport as well as active transport, indicating the need for new methods to distinguish the relative contributions of passive and active transport. [ABSTRACT FROM AUTHOR]

Vacuum preloading via prefabricated horizontal drains (PHDs) is an efficient technique to accelerate the consolidation of dredged soft soils. However, this technique lacks a clear and concise theoretical solution to the PHD vacuum consolidation analysis for slurry. To address this issue, this study proposes a novel analytical solution based on a mathematical logical procedure. The governing equations are first derived based on square PHD consolidation unit cells given the assumption of equal strain, taking into account various drainage conditions at the boundaries and the horizontal and vertical spacings of PHD. A seepage direction coefficient, directly determined through PHD spacing without additional identification, is further introduced into the derived formulation to enhance the solution to be more consistent with the results of free strain consolidation analysis. Then, the proposed analytical solution is validated based on three laboratory and field tests. The proposed solution is successfully applied to estimate the consolidation behavior at a site in Aomori Prefecture, Japan, involving PHD vacuum preloading. All results demonstrate that the proposed analytical solution is applicable for the design and management of PHD vacuum preloading construction projects and practically useful for engineers. Furthermore, the influences of the large strain effect, variable hydraulic conductivity, and variable compressibility on the consolidation analysis are discussed. [ABSTRACT FROM AUTHOR]

Hydraulic conductivity (k) is a crucial parameter in hydrogeology and engineering geology, describing the rate at which water filters through porous media, i.e., soil. It can be determined directly through tests on soil samples in situ, or it can be calculated from other soil parameters using various equations and models. This study aims to compare the results of six machine learning (ML) models with those of four empirical formulas and to identify the soil parameters required for the optimal ML performance. A dataset consisting of 282 unique entries of Lithuanian soils was compiled from laboratory testing reports. Twelve features, including grain sizes and particle diameters, were used to create 4095 combinations of inputs for each ML algorithm. Prediction results were evaluated using the determination coefficient (R²) and the mean absolute error (MAE). The ML models provided more accurate predictions (R² 0.36-0.46, MAE 2.31-2.81 m/d) compared to the empirical formulas (R² 0.10-0.33, MAE 3.05-6.54 m/d). However, some ML models showed signs of overfitting. The study also revealed that each ML algorithm performs best with a customized combination of input parameters, ranging from 4 to 8, whereas the empirical formulas used in this study utilize only 1-2 parameters. [ABSTRACT FROM AUTHOR]

Few studies have investigated the performance of land surface models for semiarid Mediterranean forests. This study aims to parameterize and test the performance of the Noah-MP land surface model for an eastern Mediterranean ecosystem. To this end, we calibrated the model for root zone soil moisture and transpiration of two conifer species, Pinus brutia, and Cupressus sempervirens, in a plantation forest on the Mediterranean island of Cyprus. The study area has a long-term average annual rainfall of 315 mm. Observations from 4 sap flow and 48 soil moisture sensors, for the period from December 2020 to June 2022, were used for model parameterization. A local sensitivity analysis found that the surface infiltration (REFKDT), hydraulic conductivity (SATDK), and stomatal resistance (RSMIN) parameters had the highest impacts on the water balance components (soil evaporation, tree transpiration, surface runoff, and drainage). The model performed better during the wetter 9-month validation period (379 mm rain) than during the drier 10-month calibration period (175 mm rain). Average soil moisture in the top 60 cm of the soil profile was reasonably well captured for both species (daily Nash–Sutcliffe efficiency > 0.80 for validation). Among the three soil layers, the second layer (20–40 cm) showed better simulation performance during both periods and for both species. The model exhibited limitations with respect to simulating transpiration, particularly during the drier calibration period. The inclusion of a root distribution function in the model, along with the monitoring of soil moisture below the 60 cm soil depth in the field, could improve the accuracy of model simulations in such water-limited ecosystems. [ABSTRACT FROM AUTHOR]

Microplastic contamination in soil ecosystems is a major environmental concern in the world. The current study aims to explore the extent of microplastic pollution in unregulated village dumpsites in India, focusing on the movement of these pollutants from soil to aquatic environments. Soil samples from eight distinct sites (A to H) in six villages were analyzed for various properties, including pH, bulk density, porosity, water retention capacity, hydraulic conductivity, and particle size distribution. The attenuated total reflection–Fourier-transform infrared spectroscopy (ATR-FTIR) method was used to identify prevalent plastic types. The research classifies microplastics by their shape and color, identifying a wide range of particles such as sheets, fibers, foams, fragments, and films. The study also examines the presence and concentration of microplastics in both soil and sediment samples. It was found that PE and PP microplastics are significantly present across different size fractions. Sample A contains a variety of items in the 1–5 mm size range, mainly PE, while the 0.3–1 mm fraction is largely PP. Samples B to H are mostly composed of PE microplastics in different forms. Sample F is unique with a mix of PE, EPS, and a higher amount of red and blue foam particles in the 0.3–1 mm fraction. Microplastics were quantified using stereomicroscopy, revealing concentrations between 80 and 840 numbers per kilogram in soil and 20 to 60 numbers per kilogram in sediments. The findings emphasize the widespread nature of microplastic pollution across ecosystems and the importance of developing effective strategies for monitoring and mitigating their impact on environmental health and human well-being. [ABSTRACT FROM AUTHOR]

IntroductionChickpea (Cicer arietinum L.) is a plant from the legume family, which is usually cultivated under rainfed conditions. This crop is mostly cultivated in late winter or early spring. In these conditions, there is a high probability of heavy rains (short or long term) and there is a possibility of waterlogging in early spring and during the early growing stages of chickpea. In waterlogged conditions, due to the lack or absence of oxygen in the plant roots occur anaerobic conditions and greatly reduced the amount of energy production in the roots. In this case, the root does not have the necessary energy to transport materials from the cell membrane, and plants face ionic stress, reduced hydraulic conductivity, and reduced water absorption. Reduced and disrupted root growth leads to diminished shoot growth, impaired water and nutrient absorption, and ultimately lower grain yield. In general, the extent of damage caused by oxygen deficiency depends on the plant species, variety, growth stage, soil type, and environmental conditions. Therefore, the purpose of this exfaiment was to investigate the effects of waterlogging on chickpea cultivars (Desi and Kabuli), physiological characteristics, root growth and yield. Materials and MethodsThis exfaiment was carried out as factorial based on completely randomized design (CRD) in three replications in the research farm via pot of the Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran in 2013-2014. Factors included chickpea cultivars ILC482 and Azad (from Kabuli type) and Kaka and Pirooz (from Desi type) and duration of waterlogging including no waterlogging (control), 4, 8 and 12 days at 30 days after planting (vegetative stage). Physiological traits (relative water content, membrane stability and pigments) as well as total root lenth, root dry weight, number of nodes, main root lenth and root volume in a destructive way in the pod setting stage, as well as in the ripening stage, root traits, remobilization, relative water content, membrane stability, pigments, seed protein, biological yield, seed yield, 100-seed weight and plant height were investigated. Planting was done in the first year on March 11, 2013 and in the second year on March 15, 2014. The size of plastic pots was 30 x 30 cm. 30 days after planting were applied treatments. Compound analysis of data was done with SAS software and means comparisons were faformed using the least significant difference (LSD) at the 5% level. Results and DiscussionThe results of compound analysis showed that there were significant differences between the two years in seed yield and the number of seeds fa plant. In the second year, the seed yield and the number of seeds fa plant compared to the first year increased by 16.9% and 12.1%, respectively. In the second year, the ambient temfaature was lower. At a lower temfaature, the waterlogging damage is more severe to plants. The total dry matter yield of chickpea cultivars in waterlogged conditions was significantly different and Kaka, Pirooz, ILC482 and Azad cultivars were 4.42, 3.19, 2.99 and 2.54 g.plant-1, respectively. The highest damage to seed yield in waterlogging in 12 days was related to Azad variety (71% compared to the control). In waterlogged conditions, the seed yield was in Kaka (1.51 g.plant-1), Pirooz (1.16 g.plant-1), ILC482 (0.95 g.plant-1) and Azad (0.97 g.plant-1). There was a significant difference between Kabuli type and Desi type, however, grain yield in Desi type was 28.3% higher than Kabuli type. In the pod setting stage, the Pirooz cultivar in the control treatment had the highest total root lenth with 7741 cm (in the first year) and 7432 cm (in the second year), but the lowest was in the second year at the Kaka cultivar and 12 days with 440 cm. In general, with the increase of the duration of flooding in chickpea cultivars, the total root lenth decreased significantly and between 4 days, 48.4 to 60.4 facent, 8 days to 8.8 to 70.8 facent, and 1.12 days from 81 to 89.4 facent. In all treatments, the control treatment (without waterlogging) had the highest chlorophyll a, and the amount of chlorophyll a decreased in other treatments. However, no reduction was observed in Pirooz in 4, 8 and 12-day treatment. Chlorophyll b had a different response to waterlogging levels and cultivar. Chlorophyll b was the highest in ILC482 in control treatment, while in Azad, Kaka and Pirooz treatments, chlorophyll b increased with increasing duration of waterlogging. Pigment carotenoids in ILC482 and Azad significantly decreased with increasing duration of waterlogging, but it was not significant in Kaka and Pirooz cultivars. Overall, carotenoids were less fluctuating in the desi type. ConclusionsWaterlogging in the vegetative stage even for 4 days with a decreasing effect on total root lenth, number of nitrogen fixing nodes, plant height, total dry matter, chlorophyll and carotenoids content, membrane stability index, relative leaf water content, biological yield, seed protein, the number of seeds fa plant and the weight of 100 seeds and finally caused a decrease in seed yield. Among the components of seed yield, the amount of damage was higher on the number of seeds fa plant. In general, the seed yield of ILC482 and Azad (Kabuli type) was lower than that of Kaka and Pirooz (Desi type). In the second year, due to the lower air temfaature compared to the first year, the damage to the total root lenth and total dry matter decreased. This exfaiment provides valuable results on the response mechanisms of chickpea to waterlogging stress and can help develop strategies to improve its faformance in waterlogged environments, which are expected to waterlogging increase due to climate change. However, more research is needed to investigate the response of different chickpea species to short-term and long-term waterlogging conditions. [ABSTRACT FROM AUTHOR]

Pedotransfer function (PTFs) is widely developed using machine learning algorithms (MLA) and non-linear regression (NLR). Saturated hydraulic conductivity (Ks) is obviously used to regulate water movement in the soil. The objective of the work is to evaluate the accuracy of MLA to predict Ks. Moreover, is to determine the best class of predictors that can be used to predict Ks with little estimation error. Saturated hydraulic conductivity was measured by direct method using the constant head method. In addition, Ks was predicted using PTFs developed by machine learning algorithms including Random Forest Algorithm (RFA), and Gradient Boosting Algorithm (GBA) models with three categories of soil physical predictors. Furthermore, PTFs developed by RFA, and GBA were compared with PTFs developed by NLR models using the same three categories of soil physical predictors. The three categories of soil physical predictors were the following: category-1 refers to sand, silt, and clay "SSC"; category-2 refers to category-1, in addition to bulk density "SSC+BD"; and category-3 refers to category-2, in addition to organic matter "SSC+BD+OM". The results of error analysis observed that PTFs developed by RFA were more accurate than GBA and NLR models, respectively, for Ks prediction with the three categories of soil physical predictors. Moreover, the category-3 which takes into account sand, silt, clay, bulk density, and organic matter was the best category used to predict Ks using RFA, and NLR models. PTFs developed by machine learning algorithms including RFA, and GBA models can be utilized to predict Ks with little calculation error. However, RFA was greater than GBA for calculating Ks. The efficiency of RFA was associated with the number of soil variables predictors and building classification and regression trees which is more robust than decision trees such as GBA to optimize Ks prediction. [ABSTRACT FROM AUTHOR]

The seismic effect of well water level is complex and variable, and even if both wells are located in an area with similar tectonic and hydrogeological conditions, they exhibit slightly varying response characteristics to the same earthquake. Wells BB and RC, located about 100 km apart in the southwest of the Huayingshan fault zone in the Sichuan and Chongqing regions, exhibited obvious similarities and differences in their co-seismically response and sustained recovery characteristics during the Wenchuan Ms8.0 earthquake. Based on the dislocation theory and fluid–solid coupling theory, this study developed the seismic stress–strain model and the response model of pore pressure to seismic stress using Coulomb 3.3 and COMSOL 6.3, respectively. Simulation findings indicate that both BB and RC are located in the expansion zone, where their water levels show a co-seismic step-down. The amplitudes of BB and RC water levels are 83 cm and 81 cm, which are approximately 10 cm smaller than the actual values. The recovery times are 60 d for BB and 3 h for RC, closely resembling the actual values. Furthermore, the numerical results from different scenarios show that the recovery time of pore pressure is reduced by several times when the permeability of the confining layer overlying the observed aquifer increases by one order of magnitude or the thickness decreases, and this change is more sensitive to the permeability. It is clear that the confining condition has an important impact in the response time of sustained changes in well water levels, which may also help to explain the variations in the characteristics of sustained changes in wells BB and RC. [ABSTRACT FROM AUTHOR]

The movement of solutes in soil is crucial due to their potential to cause soil and groundwater pollution. In this study, a mathematical model based on the Advection Dispersion Equation (ADE) was developed to evaluate solutions for solute transport. This equation enabled us to attain a relationship for concentrations at different locations and times, also known as the breakthrough curve. Five columns (5 cm in diameter and 30 cm in height) of soil types were prepared to check the validity of the results. An evaluation of the calculated relations showed high accuracy in estimating the breakthrough curve and the saturated hydraulic conductivity of the soil. [ABSTRACT FROM AUTHOR]

Drought is a serious constraint on crop growth and production of important staple crops such as maize. Improved understanding of the responses of crops to drought can be incorporated into cropping system models to support crop breeding, varietal selection, and management decisions for minimizing negative impacts. We investigate the impacts of different soil types (stony and silty) and water regimes (irrigated and rainfed) on hydraulic linkages between soil and plant, as well as root : shoot growth characteristics. Our analysis is based on a comprehensive dataset measured along the soil–plant–atmosphere pathway at field scale in two growing seasons (2017 and 2018) with contrasting climatic conditions (low and high vapor pressure deficit). Roots were observed mostly in the topsoil (10–20 cm) of the stony soil, while more roots were found in the subsoil (60–80 cm) of the silty soil. The difference in root length was pronounced at silking and harvest between the soil types. Total root length was 2.5–6 times higher in the silty soil than in the stony soil with the same water treatment. At silking time, the ratios of root length to shoot biomass in the rainfed plot of the silty soil (F2P2) were 3 times higher than those in the irrigated silty soil (F2P3), while the ratio was similar for two water treatments in the stony soil. With the same water treatment, the ratios of root length to shoot biomass of silty soil were higher than for stony soil. The seasonally observed minimum leaf water potential (ψleaf) varied from around -1.5 MPa in the rainfed plot in 2017 to around -2.5 MPa in the same plot of the stony soil in 2018. In the rainfed plot, the minimum ψleaf in the stony soil was lower than in the silty soil from -2 to -1.5 MPa in 2017, respectively, while these were from -2.5 to -2 MPa in 2018, respectively. Leaf water potential, water potential gradients from soil to plant roots, plant hydraulic conductance (Ksoil_plant), stomatal conductance, transpiration, and photosynthesis were considerably modulated by the soil water content and the conductivity of the rhizosphere. When the stony soil and silt soil are compared, the higher "stress" due to the lower water availability in the stony soil resulted in fewer roots with a higher root tissue conductance in the soil with more stress. When comparing the rainfed with the irrigated plot in the silty soil, the higher stress in the rainfed soil resulted in more roots with a lower root tissue conductance in the treatment with more stress. This illustrates that the "response" to stress can be completely opposite depending on conditions or treatments that lead to the differences in stress that are compared. To respond to water deficit, maize had higher water uptake rate per unit root length and higher root segment conductance in the stony soil than in the silty soil, while the crop reduced transpired water via reduced aboveground plant size. Future improvements in soil–crop models in simulating gas exchange and crop growth should further emphasize the role of soil textures on stomatal function, dynamic root growth, and plant hydraulic system together with aboveground leaf area adjustments. [ABSTRACT FROM AUTHOR]

The accurate prediction of groundwater contamination is challenging due to uncertainties arising from the inherent heterogeneity of aquifers, inadequate site characterization, and limitations in conceptual mathematical models. These factors can result in an underestimation of contaminant concentrations. For effective contaminant prevention and control, it is important to estimate the probability of exceeding the allowed threshold for contaminant concentrations, known as the failure probability of groundwater contamination. Computing small failure probabilities using classical Monte Carlo simulation (MCS) requires computing a large number of samplers to converge to a stationary target value, which is time‐consuming. To address this, in this paper, we develop a novel approach for calculating small failure probabilities, known as subset simulation (SS) coupled with preconditioned Crank‐Nicolson Markov chain Monte Carlo (pCN‐SS), which combines subset simulation with preconditioned Crank‐Nicolson Markov chain Monte Carlo (pCN‐MCMC) to promote computational efficiency. We have tested the performance of the proposed algorithm in both a mathematical example and a numerical case study of groundwater contamination. The results demonstrate that pCN‐SS provides improved accuracy and efficiency for evaluating small failure probabilities for high‐dimensional groundwater contamination, specifically for hydraulic conductivity as a source of uncertainty. Compared to classical MCS and traditional SS, pCN‐SS requires fewer model evaluations but produces stable and accurate results. Key Points: The pCN‐SS is proposed to accurately estimate the small failure probability in high‐dimensional groundwater contaminant transport problemsThe results demonstrate that the pCN‐SS can offer both accuracy and efficiency in estimating small failure probabilitiesThe pCN‐SS surpasses traditional subset simulation in accurately estimating small failure probabilities [ABSTRACT FROM AUTHOR]

Aquifer protection is essential for securing a sustainable supply of clean water. This study integrates an artificial neural network (ANN) model, identifying non-linear connections, with multivariate linear regression (MLR) analysis to improve predictions of aquifer protective capacity and assess vulnerability. Twelve vertical electrical soundings (VES) were conducted with a maximum electrode spacing of 250 m. Aquifer parameters derived from the VES dataset were analyzed using ANN to capture complex patterns. The ANN model, trained on historical data, learned the relationship between input variables and protective capacity. MLR analysis identified influential factors affecting vulnerability. Results reveal varying aquifer depths, with Umudime being the deepest and western parts having the shallowest depths. The resistivity map shows high values around Okorobi and Uhuala and low values in eastern to northeastern parts. Hydraulic conductivity and 3D subsurface models exhibit an inverse relationship with resistivity. Transmissivity and storativity maps exhibit similar patterns. MLR outperforms ANN in predicting resistivity, transmissivity, and storability, indicating high forecasting accuracy for aquifer protective capacity. Input parameters' contribution levels follow a specific order for different aquifer properties. R2 Value 0.0869, indicating a weak correlation between the predicted and actual values in ANN model while R2 Value 0.9775 in MLR model shows a strong correlation and much better performance than the ANN model. The results of the modeling suggest that both the ANN and MLR models have shown promising effectiveness and accuracy in predicting aquifer parameters, aiding decision-makers in implementing targeted protection measures, predicting aquifer parameters, providing insights for effective management strategies. [ABSTRACT FROM AUTHOR]

In geotechnical engineering, understanding the relationship between soil permeability and deformation is essential, particularly for applications like earth dams, where compaction‐induced permeability reduction is crucial for performance optimization. In unsaturated soils, soil moisture content significantly impacts hydraulic conductivity. Traditionally, changes in unsaturated hydraulic conductivity have been linked to soil void ratios. However, a pore network modeling perspective reveals the significance of structural parameters, such as pore and throat size distribution and pore coordination number. This study introduces a pore network model to estimate unsaturated hydraulic conductivity based on void ratio‐dependent soil‐water retention curves. It examines how soil deformation at varying stress levels affects structural parameters and the water phase continuity. The model shows strong potential in predicting unsaturated hydraulic conductivity across different stress levels, aligning well with experimental data and established equations. Notably, the aspect ratio and coordination number parameters are most affected by stress levels. The study also presents relationships to describe changes in pore network structural parameters with soil void ratio, which can be used to predict soil‐water retention curves and unsaturated hydraulic conductivity at various stress levels. [ABSTRACT FROM AUTHOR]

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Characterization of near (field) saturated hydraulic conductivity (Kfs) of the soil environment is among the crucial components of hydrological modeling frameworks. Since the associated laboratory/field experiments are time-consuming and labor-intensive, pedotransfer functions (PTFs) that rely on statistical predictors are usually integrated with the existing measurements to predict Kfs in other areas of the field. In this study some of the most appropriate machine learning approaches, including variants of artificial neural networks (ANNs) were used for predicting Kfs by some easily measurable soil attributes. The analyses were performed using 100 measurements in Bajgah Agricultural Experimental Station. First, physico-chemical inputs as bulk density (BD), initial water content (Wi), saturated water content (Ws), mean weight diameter (MWD), and geometric mean diameter (GMD) of aggregates, pH, electrical conductivity (EC), and calcium carbonate equivalent (CCE) were measured. Then, radial basis functions (RBFNNs), multilayer perceptron (MLPNNs), hybrid genetic algorithm (GA-NNs), and particle swarm optimization (PSO-NNs) neural networks were utilized to develop PTFs and compared their accuracy with the traditional regression model (MLR) using statistical indices. The statistical assessment indicated that PSO-NNs with the lowest RMSE and MAPE as well as the highest correlation coefficient (R) value provided the most accurate and robust prediction of Kfs. The prediction models ranked as PSO-NNs (R = 0.958; RMSE = 0.343; MAPE = 9.47), GA-NNs (R = 0.949; RMSE = 0.404; MAPE = 11.83), MLPNNs (R = 0.933; RMSE = 0.426; MAPE = 12.13), RBFNNs (R = 0.926; RMSE = 0.452; MAPE = 14.30), and MLR (R = 0.675; RMSE = 0.685; MAPE = 22.54) in terms of their performances for the test data set. Results revealed that all NN models particularly PSO-NNs were efficient in prediction of Kfs. However, further evaluations may be recommended for other soil conditions and input variables to quantify their potential uncertainties and wider potential and versatility before they are used in other geographical locations/soil conditions. [ABSTRACT FROM AUTHOR]

There is limited information regarding the adaptation of anatomical features and growth ring formation to ecological site conditions in Costa Rican mangrove trees. We used the methods and principles of ecological anatomy to explore the relationship between wood properties (e.g., ring formation, anatomical characteristics) and ecological factors for six mangrove tree species growing in three sites in the Gulf of Nicoya in Costa Rica. We found that variations of ecological conditions affected the growth ring formation of Avicennia bicolor, Avicennia germinans, Pelliciera rhizophorae and two species of Rhizophora but not Laguncularia racemosa. Site conditions affected the anatomical features of the mangrove tree species. Ray dimensions (height and width) were the factors most affected, which were followed by the frequency, diameter, and length of vessels. The fiber dimensions, green density, specific gravity, and carbon content were also affected by the site conditions. The plasticity in ray (increasing of ray dimension) and vessel elements (multiple vessels) facilitate efficient hydraulic conductivity amidst negative growth conditions and physiological restrictions for mangrove trees. We hypothesize that soil salinity, freshwater inputs and intertidal flooding influence these changes. Laguncularia racemosa presented the most changes in anatomical features across the different sites, followed by Pelliciera rhizophorae, with identical changes between Avicennia and Rhizophora spp. Finally, site salinity and wave energy affected the highest number of anatomical changes in mangrove tree species, including 38 changes in the wood structures in site 1. [ABSTRACT FROM AUTHOR]

Composite geomembrane cut-off walls (CGCW) have been widely used for the remediation of polluted sites, especially where the environmental conditions are complex. Accurate predictions of the GMB hole leakage and CGCW performance are essential for engineering design and cost control. This paper establishes empirical equations to predict the leakages through the CGCWs based on the numerical models. Additionally, an analytical solution for contaminant migration through the CGCW is proposed considering the effects of GMB holes. The accuracy of the established equations and analytical solution is verified by the numerical models. The key effects of the GMB thickness (TG), head loss (HG), cut-off wall hydraulic conductivity (kG), hole radius (rG) and shape on the leakage and CGCW performance are investigated. The results show that compared with other hole shapes, the leakage through the circular hole is lowest. This is mainly because the shape factor for the circular hole is 1.15–1.3 times lower than that for other shapes of holes with the same area. Additionally, the effects of the hole geometric properties and head loss on the CGCW performance can be more significant when the cut-off wall hydraulic coefficient is small. For example, the breakthrough time differences between the cases with rG = 0.005 m and 0.05 m are 0.8 and 5.0 years when kG = 10−10 and 10−9 m/s, respectively. This is because the impermeability of the CGCW is good when kG is small. This will weaken the impacts of the hole geometric properties on the leakage. The proposed empirical equations and analytical solution can provide effective suggestions for the design of the CGCW in different GMB hole cases. [ABSTRACT FROM AUTHOR]

Rainfall infiltration affects permafrost-related slope stability by changing the pore water pressure in soil. In this study, the infiltration responses under rainfall conditions were elucidated. The instantaneous profile method and filter paper method were used to obtain the soil–water characteristic curve (SWCC) and hydraulic conductivity function (HCF). During the rainfall infiltration test, the vertical patters of volumetric moisture contents, total hydraulic head or suction and wetting front were recorded. Advancing displacement and rate of the wetting front, the cumulative infiltration, the instantaneous infiltration rate, and the average infiltration rate were determined to comprehensively assess the rainfall infiltration process, along with SWCC and HCF. Additionally, the effects of dry density and runoff on the one-dimensional vertical infiltration process of soil columns were evaluated. The results showed that the variation curve of wetting front displacement versus time obeys a power function relationship. In addition, the infiltration rate–time relationship curve and the unsaturated permeability curve could be roughly divided into three stages, and the SWCC and HCF calculated by volumetric moisture content are more sensitive to changes in dry density than to changes in runoff or hydraulic head height. [ABSTRACT FROM AUTHOR]