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Groundwater aquifers worldwide experience unsustainable depletion, compounded by population growth, economic development, and climate forcing. Managed aquifer recharge provides one tool to alleviate flood risk and replenish groundwater. However, concerns grow that intentional flooding of farmland for groundwater recharge, a practice known as Ag-MAR, may increase the leaching of pesticides and other chemicals into groundwater. This study employs a physically based unsaturated flow model to determine the fate and transport of residues of four pesticide in three vadose zone profiles characterized by differing fractions of sand (41 %, 61 %, and 84 %) in California's Central Valley. Here, we show that the complex heterogeneity of alternating coarse and fine-grain hydrogeologic units controls the transit times of pesticides and their adsorption and degradation rates. Unsaturated zones that contain a higher fraction of sand are more prone to support preferential flow, higher recharge rates (+8 %), and faster (42 %) water flow and pesticide transport, more flooding-induced pesticide leaching (about 22 %), as well as more salt leaching correlating with increased risks of groundwater contamination. Interestingly, considering preferential flow predicted higher degradation and retention rates despite shorter travel times, attributed to the trapping of pesticides in immobile zones where they degrade more effectively. The findings underscore the importance of considering soil texture and structure in Ag-MAR practices to minimize environmental risks while enhancing groundwater recharge. The study also highlights that selecting less mobile pesticides can reduce leaching risks in sandy areas.

Highlights: Time dependent deposition of two Azospirillum brasilense strains in sand quantified. Three inclusions regimes examined: surface, subsurface and premixed. For surface and subsurface the bacteria accumulated near the point source and remained stagnant in the premixed. The attachment/detachment numerical model found adequate to describe the time dependent deposition profiles of the bacteria. Azospirillum brasilense strains Sp7 and Cd are commonly employed plant growth-promoting bacteria (PGPB) that produce phytohormones and fix nitrogen. The two basic methods of PGPB soil inoculation are direct mixing with the soil and irrigation with liquid inoculants. The integration of drip irrigation with delivering plant growth-promoting bacteria in desert areas with sandy soil is becoming more common. With the drip irrigation system, the mobility of PGPB in the sandy soil determines the range of root zone inoculation. Therefore, we examined the transport and fate of PGPB under transient water flow conditions in a 30-cm high segmented sand column with three sand-inoculation regimes: (1) surface irrigation, (2) subsurface irrigation, and (3) sand premixing. The water, bromide, and bacterial distribution in the sand profile was measured at 2 and 48 h after irrigation. The measured data were described using the attachment/detachment numerical model using the HYDRUS 2/3D code. Results showed that even though A. brasilense Sp7 and Cd exhibit similar hydrophilicities and zeta potentials, their deposition in the sand profile differs. Strain Cd consists of smaller cells that undergo less adsorption and less straining than strain Sp7, and the former's vertical movement therefore reaches greater depths under surface- and subsurface-inoculation regimes. Nevertheless, most of the PGPB accumulated near the water source. In the sand-premixing inoculation regime, the bacteria barely moved at all. Overall, when the target root zone was deep, subsurface-irrigation inoculation worked better than the other two inoculation regimes, because it was more likely to deliver large amounts of PGPB to the root zone. Furthermore, the first-order attachment model optimized two parameters (first-order attachment coefficient and die-off rate) and well simulated the bacterial vertical movement in the surface- and subsurface-inoculation regimes (R2 > 0.91). [ABSTRACT FROM AUTHOR]

Low Impact Development (LID) measures have proven to be effective in reducing the runoff volume and the peak of runoff at small spatial scales. Assessment of the hydrological impacts of LID measures at river basin scales is currently limited by the absence of adequate physically-based process models that can simulate LID processes at such scales. In this study, an attempt has been made to develop LID modules to simulate the water balance and hydrological processes based on the Multi-Layer Green-Ampt (MLGA) infiltration method, which is an advancement to the existing LID modeling techniques. The performance of the MLGA-based LID modules was benchmarked with the process-intensive numerical tool HYDRUS 1D for about 5000 soil samples across the soil textural classes. The results indicated that the MLGA-based model simulates the hydrological processes in close agreement with HYDRUS for soils with moderate-to-high hydraulic conductivity values, which are amenable for LID implementation. [ABSTRACT FROM AUTHOR]

Background and Objectives Water shortage and the need for its optimal use in arid and semi-arid regions, including Iran, has led water officials and farmers to use modern irrigation systems, such as drip irrigation with the aim of making optimal use of water resources. Drip irrigation has been welcomed in most parts of the world due to its high efficiency and the possibility of irrigation in different environmental conditions. The most important reason for the superiority of drip irrigation over other irrigation methods is the controllable amount of water for each plant. Drip irrigation is a method in which water is poured out of the net at low pressure through an orifice or device called an emitter and dripped into the bottom of the plant. This irrigation system, like other methods, requires accurate knowledge of the parameters affecting it to achieve the desired efficiency. One of the most important parameters for the irrigation system is the distribution of moisture in the soil and in fact the shape of the moist bulb. Therefore, knowledge of how to distribute water in the soil is essential for the proper design and management of subsurface drip irrigation systems. Since testing is very difficult and time consuming to detect the shape of moisture distribution in the soil, the use of numerical and analytical simulation can be an effective and efficient way to design these systems. Methodology In order to determine the progress of the moisture front in drip irrigation, first the soil texture type and physical properties of the soil were determined. It should be noted that the emitter flow rate was measured and adjusted in volume at the beginning of the test to minimize the difference between the emitter flows along the three side tubes. Evaluation experiments were performed with three outflows of 2, 4 and 6 liters per hour. With the start of the system, the progress of the moisture front at different times was measured by digging a trench using a scale. Numerical simulation of moisture front progress was performed using HYDRUS model based on Richard equation and analytical simulation was performed using Moment Analysis. HYDRUS software was used to numerically simulate the progress of the moisture front. The simulation range was considered to be 100 cm by 100 cm on the two-dimensional plane. In these simulations, 3956 nodes are used to represent the entire simulation range and also, relevant equations were used to calculate the two-dimensional spatial Moment of the wetting pattern . Findings The simulations show that the initial volumetric moisture content is 0.11 and the saturation volumetric moisture content is 0.380 and the water dispersion rate increases over time on the x and z axes. With increasing flow, the maximum dispersion is in the x-axis, which occurs in flow of 6 liters per hour. The result for flow of 6 liters per hour based on the data used is slightly higher than the desired value. The reason why the value of M00 in the flow rate of 6 liters per hour is higher than expected, is that in the simulation flow rate of 6 liters per hour change in the size of the inlet diameter and the amount of flux changes the amount of water entering the soil and moistens a large volume of soil. Due to the different amount of moisture applied to the area at different times, the value of 𝑧𝑐, 𝜎𝑥 2, 𝜎𝑧 2 is different and has caused a change in the size of the oval in different flows. The increase in the size of the ovals indicates the high dispersion of water in that area. The results showed that the Moment analysis was able to express the position of the center of mass of water distributed in the soil with correlation coefficient of 0.986 in linear mode and 0.982 in logarithmic mode. By comparing the values of diameter and depth obtained from the HYDRUS and the drawn ovals, it can be concluded that both methods provide close results. The accuracy of the Moment analysis method in simulating different types of moisture patterns resulting from drip irrigation under different flows with the use of different volumes of water is similar to the HYDRUS model and therefore it is possible to use this feature to predict the pattern of moisture from a certain flow using a specific volume of water . Conclusion In this study, the accuracy of Moment analysis in simulating various moisture patterns resulting from drip irrigation under different flows with the use of different volumes of water was investigated and the possibility of using this feature to predict the pattern of moisture from a given flow using a specific volume of water checked. In order to investigate the Moment of the amount of water distributed in the soil by subsurface drip irrigation, simulation was performed by two-dimensional HYDRUS software for three discharges of 2, 4 and 6 liters per hour with an inlet water volume of 12 liters. Then, using the results of simulation of moisture distribution range by a programming language including MATLAB software, and by calculating the Moments, it was determined that the Moments are able to express the position of the center of mass of water distributed in the soil and how it is distributed relative to x and z axes. The increase in the size of the ovals indicates that more water is distributed in that area. Comparing the diameters and depths of the moisture front between the simulated HYDRUS model and the Moment analysis model, it was found that the Moment analysis is an efficient way to study the distribution of water moisture by drip irrigation and this method can be used as an alternative input to estimate parameters. [ABSTRACT FROM AUTHOR]

In order to realize the coordinated development of coal resources exploitation and ecological protection in arid climate area, this paper selects Xilin Hot steppe mining area as the main research region, analyzing the variation features of soil water content (SWC) in horizontal and vertical directions through ECH2O-5TM water content sensors. Based on the geotechnical test of the soil samples, a profile model of lithology was developed to find out the effects of humus thickness on SWC by Hydrus. The results showed that in the horizontal direction, the SWC was higher around the waste dump and Xilin river, but lower in the steppe and mining areas. In the vertical direction, the SWC presented a descending-ascending-descending distribution ranging from 5 to 70 cm depth, among which the maximum SWC reaching 0.043 m3/m3 at depth of 52 cm. Affected by the rainfall infiltration, the average SWC decreased successively in rainy season, normal season and dry season. Compared with the steppe area, the SWC of the waste dump was rose higher after soil reconstruction. Humus exhibited superior water-holding capacity, and the humus with a thickness of 40 cm can meet the SWC requirements of herbage in the research region. The research findings can better clarify the variation regularities of SWC affected by the soil reconstruction in steppe mining area, which lay fundamental theory and reference case for the conservation of soil water and vegetation protection in arid climate. [ABSTRACT FROM AUTHOR]

In order to study the influence of fissure morphology on soil moisture-content changes under different fissure types, this study established HYDRUS 2.0 numerical models of stepped fissures and planar fissures with different fissure widths and depths based on the experimental condition parameters obtained from physical simulation tests. Then, we simulated the spatial and temporal variation rules of soil moisture around the fissures. The results showed a high level of agreement between the HYDRUS numerical simulations and actual measurements, indicating that the model accurately reflects the movement of soil moisture near fissures. The study found that ground fissures affected the spatial distribution of soil moisture, leading to an increased rate of moisture loss in the deep soil near the fissure walls. Moreover, larger fissures had greater horizontal and vertical effects on soil moisture. The soil moisture content is lower closer to the fissure walls. As the soil depth increased, the influence of the fissures gradually diminished. For planar fissure with a depth of 50 cm, the soil moisture content was 30.6%, 17.8%, and 8.4% lower at depths of 10, 30, and 50 cm, respectively, compared to a fissure with a depth of 10 cm. For a stepped fissure with a depth of 50 cm, the soil moisture content was 29.2%, 20.9%, and 13.9% lower at depths of 10, 30, and 50 cm, respectively, compared to a fissure with a depth of 10 cm. Under the same conditions of fissure width and depth, stepped fissures exhibit faster moisture loss, and the larger the fissure, the more significant the additional moisture loss compared to planar fissures. [ABSTRACT FROM AUTHOR]

Daniel Laroche,1,2,* Ayobami Adebayo,3,* Chester Ng2,* 1Department of Ophthalmology, Icahn School of Medicine at Mount Sinai and New York Eye and Ear Infirmary of Mount Sinai, New York, NY, USA; 2Advanced Eyecare of New York, New York, NY, USA; 3Albert Einstein College of Medicine, Bronx, NY, USA*These authors contributed equally to this workCorrespondence: Daniel Laroche, Advanced Eyecare of New York, 49 West 127th Street, New York, NY, 10027, USA, Email dlarochemd@aol.comBackground: The Hydrus Microstent has been shown to be efficacious in the treatment of Open-angle Glaucoma. We previously reported 1-year results of the Hydrus Microstent in Black and Afro-Latino patients.Objective: Here we report two-year results of the Hydrus Microstent in Black and Afro-Latino patients with mild to moderate open-angle glaucoma.Design: This was a retrospective, nonrandomized study that was carried out at two private practices in Harlem, NY and Queens, NY.Methods: This study consisted of Black and Afro Latino patients who had a Hydrus Microstent implanted for the treatment of glaucoma. The evaluated parameters were intraocular pressure (IOP), reductions in the number of medications, mean deviation on visual field test and visual acuity. We excluded persons with advanced glaucoma and incomplete data. We included those with mild to moderate glaucoma and had complete two-year follow-up data.Results: The study consisted of 86 patients and 86 eyes. The mean age was 69. The mean pre-op IOP was 14.1 on 2.17 medications. At two years the mean IOP was 14 (p = 0.651) on 0.42 medications (p = 0.000003); 88% of patients were medication free (p = 0.651), The MD on the visual field changed little from − 5.73 preoperatively to − 5.21 at two years. There were 3 intraocular pressure spikes and 1 case of hyphema that were treated and had complete resolution. No patients required secondary surgery.Conclusion: Our results show that at two years the Hydrus Microstent can maintain low intraocular pressures, reduce medication burden and, in aggregate, experienced little change in visual field Mean Deviation in Black and Afro Latino patients with mild to moderate glaucoma.Keywords: hydrus, microstent, glaucoma, Afro–Latino, cataract

Low impact development (LID) practices are rarely implemented on slopes due to concerns about their poor hydrological performance and the potential impact on slope stability. Implementing LIDs on slopes, involving alterations to surface topography and subsurface hydrology (specifically, the formation of a groundwater mound), can pose challenges in maintaining slope stability. However, sloping areas often require LIDs for sustainable development. It is imperative to supplement the conventional design standard to address these challenges. Before proposing specific solutions, the impact of LIDs on slope stability should be understood first. This includes quantifying the extent of changes in slope stability before and after LID implementation, as well as identifying the key factors that influence stability. To address these, we developed a numerical model in HYDRUS‐2D to simulate the hydrological and geotechnical processes of slopes implemented with a two‐stepped bioretention cell (BC) system. The numerical model was calibrated and validated using monitoring data from a stepped BC in Cincinnati, Ohio, USA. Simulation scenarios encompassed three generic slope angles (15°, 20°, and 25°) with and without BCs, two initial groundwater table positions and two inflow volumes. The hydrological process was characterized by the evolution of the groundwater mound, and the geotechnical process was quantified using the factor of safety (FoS). Our findings indicated slope cutting and filling was likely to enhance stability with an increase in the FoS of 0.1. However, the formation of groundwater mounds, resulting from exfiltration, led to an approximate 0.1–0.2 reduction in the FoS, depending on the inflow volume. The subsequent groundwater mound evolution had no further impact on stability. Ultimately, the FoS was slightly reduced by around 0–0.1 due to the combined effect of cutting and filling operations and groundwater mounds. It was generally safe to implement LIDs on 15° slopes. For steeper slopes, special design considerations are necessary, such as reducing the drainage area to strike a balance between hydrological performance and slope safety. [ABSTRACT FROM AUTHOR]

Introduction and GoalThe aquifer recharge rate is one of the most difficult items to measure in GW resource evaluation. The techniques used in quantifying recharge are categorized in three main groups: unsaturated zone, saturated zone and surface water techniques. The saturated zone method is devided into physical methods (including Darcy's law and tracers), numerical modeling (the purpose of this research), groundwater level fluctuations, and water balance.Materials and methods Hydres and LitchW models were used to simulate soil moisture movement to simulate aquifer recharge in this study. The models were then calibrated by optimizing the water flow factors of the aquifer layers in the Gareh Bygon with the inverse solution method. The water characteristics of the unsaturated soil layer in three wells with an approximate depth of 30 m in one of the floodwater spreading basins were measured by field and laboratory methods. The soil moisture measuring device, TDR, was calibrated for the stony soils of the research area The sensors are then placed in holes with insulated walls from the surface to the depth.walls of oneof the wells Amount of soil-water contents were continuously measured from Sep. 2010 to Sep. 2020. The height of floodwater inundation and rainfall were also recorded. Recharge through unsaturated layers was assessed based on the soil water balance method as the observed data set.Results and discusionValidation flow simulation results from the of Hydrus and LEACHW models with observed measurements. The results showed that the Hydrus and LEACHW model very accurately estimated the water flow after the flood event (R2 and RMSE equal to 0.994 and 45.3 cm respectively in Hydrus model and 0.993 and 37.11 cm in LEACHW, respectively). In addition, the results of the Hydrus model were closer to measurements. The discharge ratio (the amount of infiltration divided by the amount of flood + precipitation) in the three methods of soil water balance, the Hydrus model and the LEACHW model were 47, 44 and 52 respectively, with an average of 48 for all flood events and 75, 71 and 92 with an average of 80% for large flood events. In the event of precipitation without flooding, practically all precipitation was spent on evaporation-transpiration, and for this reason, the size of the average infiltration ratio decreased in all events.Conclusion and recommendationValidation simulated flow results with Hydrus and LEACHW were compared with the observed measurements, demonstrating that these models accurately estimated the water flow after the flood event. In addition, , the results of the Hydrus model were closer to measurements. The mean data of the LEACHW and Hydrus models were overestimated by approximately 5 units less than 1 unit respectively. In simulations of water movement in soil using models such as Hydrus, a certain amount of water conductivity for the entire vertical column of the soil profile commonly considered. The results of this research showed how unrealistic such an assumption is. Therefore, in multi-layer soils, special attention should be given to the difference between layers and the use of water conductivity estimation equations. For the researched area, one-dimensional Hydrus model was recalibrated and its validation results were completely acceptable. This model can be used in three-dimensional mode for larger areas as a tool for applying different scenarios to manage the floodwater spreading system and increase their efficiency.

In areas with shallow saline groundwater, soil salts inevitably accumulate in the root zone during the growth period due to irrigation and upward movement of salts from the groundwater. In Northern China, autumn irrigation (AIR) with large amounts of water is commonly employed post-harvest to mitigate soil salt stress on crop growth in the subsequent year. Optimizing the total irrigation depth during both crop-growth and non-growth periods is challenging because of the movement of soil salts, which is influenced by their two-dimensional distribution around drippers and the impact of the winter freeze-thaw cycles, significantly affecting water flow and solute transport during winter. In this study, the HYDRUS-1D and HYDRUS-2D models were integrated and calibrated using experimental data collected from 2021 to 2023 in China's Ordos south bank irrigation area. This model integration was conducted to assess soil water and salt dynamics during the non-growth and corn-growth periods under different irrigation strategies: a) AIR with high (AH) and low (AL) irrigation depths, and b) drip irrigation (DIR) with high (DH), medium (DM), and low (DL) irrigation depths. The results indicated that HYDRUS effectively modeled the electrical conductivity of the saturation paste extract (ECe) across different irrigation strategies, yielding an average coefficient of determination (R2) and the root mean square errors (RMSE) of 0.87 and 0.53 dS m−1, respectively. Generally, ECe increased during the growth period with DIR and decreased during the non-growth period with AIR. For the 0–40 cm soil layer, ECe decreased by 5.7 % and 12 % for every 100 mm increase in the AIR and DIR depths, respectively. Compared with the AHDM and AHDL treatments, reducing an AIR depth and increasing a DIR depth resulted in lower ECe in the 0–40 cm layer during the growth period and higher crop yield (CY) and irrigation water productivity (WPI). Specifically, the average ECe in the 0–40 cm layer decreased by 4.8 % during the growth period in the ALDH treatment compared to the AHDM treatment, and CY and WPI increased by 7.2 % and 10.3 %, respectively. Additionally, the irrigation strategy was the most effective in reducing ECe when AIR accounted for 35 % of the total irrigation. This study suggested that combining low AIR and high DIR could enhance water and field productivity.

This study presents the field performance of a five-layer composite cover to mitigate acid mine drainage in legacy sulfide tailings in northern Ontario, Canada. Installed in 2008, this cover comprised sand, clay, geosynthetic clay liner, sand, and waste rock layers. To evaluate the effectiveness of the cover in reducing water and oxygen ingress, groundwater and vadose zone hydrological characterization, stable water isotope analysis, pore-gas measurements, oxygen flux calculations, and variably saturated flow modeling were conducted. The results indicate that the clay layer stayed nearly saturated in the spring, fall, and winter, but temporary desiccation occurred during the summer. Compared to uncovered tailings, the cover significantly lowered diffusive oxygen flux. In the summer, fall, and winter, the capillary barrier effect of the cover functioned effectively and inhibited percolation. Atmospheric pore-gas oxygen concentrations at one out of the three monitoring locations indicate potential cover imperfections that enabled oxygen transport into the tailings. In the spring and early summer, snowmelt infiltration resulted in percolation that compromised the capillary barrier effect, as well as lateral drainage. The resulting increase in water saturation in the cover limited oxygen transport. Despite potential cover imperfections, this composite cover reduced oxygen and water ingress a decade after installation. [ABSTRACT FROM AUTHOR]

In order to ensure sustainability in the agricultural sector and to meet global food needs, a particularly important challenge for our time is to investigate the possibility of increasing agricultural production in areas with extreme hyper-arid environments. Warming air temperatures and sandy soils significantly influence tree root water uptake (RWU) dynamics, making accurate estimation of RWU depth distribution and magnitude crucial for effective resource management, particularly in the context of precision irrigation within agroecosystems. This study employed two non-invasive techniques, namely HYDRUS 1D and electrical resistivity tomography (ERT), to simulate RWU under controlled experimental conditions and under an extreme hyper-arid environment. The results revealed that the highest RWU rates occurred during the morning (08:00–11:00). RWU activity predominantly concentrated in the upper soil profile (0–30 cm), and the soil water content in this area was notably lower compared to the deeper soil layers. With increasing temperature, there was a tendency for the RWU zone to shift to lower depths within the soil profile. The findings of this study could have important implications for farmers, providing valuable insights to implement irrigation water management strategies. [ABSTRACT FROM AUTHOR]

To determine the intraocular pressure (IOP) reduction of various trabecular procedures (a form of minimally invasive glaucoma surgery [MIGS]) combined with cataract surgery compared with cataract surgery alone, to compare the safety of the various trabecular procedures, and to highlight patient characteristics that may favor one trabecular procedure over another. A search of English-language peer-reviewed literature in the PubMed database was initially conducted in February 2021 and updated in April 2023. This yielded 279 articles. Twenty studies met initial inclusion and exclusion criteria and were assessed for quality by the panel methodologist. Of these, 10 were rated level I, 3 were rated level II, and 7 were rated level III. Only the 10 level I randomized controlled trials (RCTs) were included in this assessment, and all were subject to potential industry-sponsorship bias. The current analysis focuses on the amount of IOP reduction (in studies that involved medication washout) and on IOP reduction with concurrent medication reduction (in studies that did not involve medication washout). Based on studies that performed a medication washout, adding a trabecular procedure to cataract surgery provided an additional 1.6 to 2.3 mmHg IOP reduction in subjects with hypertensive, mild to moderate open-angle glaucoma (OAG) at 2 years over cataract surgery alone, which itself provided approximately 5.4 to 7.6 mmHg IOP reduction. In other words, adding a trabecular procedure provided an additional 3.8% to 8.9% IOP reduction over cataract surgery alone, which itself provided 21% to 28% IOP reduction. There was no clear benefit of one trabecular procedure over another. Patient-specific considerations that can guide procedure selection include uveitis predisposition, bleeding risk, metal allergy, and narrowing of Schlemm's canal. There are no level I data on the efficacy of trabecular procedures in subjects with pretreatment IOP of 21 mmHg or less. Trabecular procedures combined with cataract surgery provide an additional mild IOP reduction over cataract surgery alone in hypertensive OAG subjects. Additional research should standardize outcome definitions, avoid industry sponsorship bias, and study the efficacy of these procedures in normotensive OAG. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article. [ABSTRACT FROM AUTHOR]

In order to study the influence of fissure morphology on soil moisture-content changes under different fissure types, this study established HYDRUS 2.0 numerical models of stepped fissures and planar fissures with different fissure widths and depths based on the experimental condition parameters obtained from physical simulation tests. Then, we simulated the spatial and temporal variation rules of soil moisture around the fissures. The results showed a high level of agreement between the HYDRUS numerical simulations and actual measurements, indicating that the model accurately reflects the movement of soil moisture near fissures. The study found that ground fissures affected the spatial distribution of soil moisture, leading to an increased rate of moisture loss in the deep soil near the fissure walls. Moreover, larger fissures had greater horizontal and vertical effects on soil moisture. The soil moisture content is lower closer to the fissure walls. As the soil depth increased, the influence of the fissures gradually diminished. For planar fissure with a depth of 50 cm, the soil moisture content was 30.6%, 17.8%, and 8.4% lower at depths of 10, 30, and 50 cm, respectively, compared to a fissure with a depth of 10 cm. For a stepped fissure with a depth of 50 cm, the soil moisture content was 29.2%, 20.9%, and 13.9% lower at depths of 10, 30, and 50 cm, respectively, compared to a fissure with a depth of 10 cm. Under the same conditions of fissure width and depth, stepped fissures exhibit faster moisture loss, and the larger the fissure, the more significant the additional moisture loss compared to planar fissures.

Alternate wetting and drying (AWD) irrigation practice requires an appropriate threshold value for which, maximum water savings and minimum water and nutrient loss can be achieved without affecting the grain yield significantly. Determining the appropriate AWD threshold value experimentally is a challenging task. Mathematical models with optimization can be substitute tools for determining appropriate AWD threshold value. In this study, field studies were carried out using the non-weighing lysimeters with three levels of irrigation treatment (no soil water stress: NS, mild soil water stress/400 cm: MS and severe soil water stress/750 cm: SS) along with three levels of nitrogen application rate (high nitrogen: HN/150 kg/ha; medium nitrogen: MN/120 kg N/ha; low nitrogen: LN/60 kg N/ha). Each treatment was replicated three times. The field experimental data were used to determine the crop production function and simulate water flow and nutrient transport with the help of the Hydrus-1D model. Finally, the simulated results were optimized with the help of Design Expert software and appropriate irrigation (ponding water depth, soil matric potential head) and nutrient management (nutrient application rate) practice determined. The simulated results indicate that, the change in ponding water depth, soil matric potential head and nutrient application rates affect the water flow, nutrient transport and grain yield significantly. Overall, the 4.5 cm ponding water depth with the recommended dose of fertilizer (N: P: K-120: 50:60 kg/ha) and soil matric potential head of 400 cm was considered as an appropriate irrigation and nutrient management practice, which resulted a maximum grain yield of 5 t/ha and net profit of approx. Rs.20595. [ABSTRACT FROM AUTHOR]

Introduction: This study compared outcomes of the iStent inject trabecular micro-bypass system versus the Hydrus Microstent in patients with primary open-angle glaucoma (POAG). Methods: Forty subjects (80 eyes) with POAG were included in this single-center, retrospective, contralateral-eye analysis. All patients underwent phacoemulsification with either iStent inject or Hydrus implantation in one eye and the other device in the contralateral eye, with ≥ 3-month follow-up. In 58 eyes (27 iStent inject, 31 Hydrus) the surgery also included ab interno canaloplasty (ABiC). Twelve-month outcomes included intraocular pressure (IOP), medications, and adverse events. Subgroup analyses were completed for iStent inject versus Hydrus, and with versus without ABiC. Results: At 12 months versus baseline, mean IOP reduced from 16.8 ± 3.7 to 13.6 ± 2.9 (p = 0.003) in iStent inject eyes, and from 18.1 ± 4.5 to 14.9 ± 3.2 mmHg (p = 0.003) in Hydrus eyes (between-group IOP reduction p = 0.582). Mean number of glaucoma medications reduced from 1.23 ± 0.97 to 0.30 ± 0.76 (p < 0.001) in iStent inject eyes and from 1.20 ± 1.02 to 0.39 ± 0.72 (p = 0.001) in Hydrus eyes (between-group medication reduction p = 0.943). At 12 months, 82.6% of iStent inject eyes and 73.9% of Hydrus eyes were medication-free versus 20.0% preoperatively in both groups (p < 0.0001 both groups). There were no statistically significant IOP or medication differences between iStent inject and Hydrus pre- or postoperatively, both in the overall cohort and in the with/without ABiC subgroups. Outcomes also were similar between eyes with/without ABiC in the overall cohort and in the iStent inject/Hydrus subgroups. There were no adverse events in the iStent inject group; two eyes in the Hydrus group had device-related complications requiring five additional surgeries (one Hydrus repositioning, one Hydrus exchange, one Hydrus removal, two goniotomies). Conclusion: In this contralateral-eye comparison of iStent inject versus Hydrus, the groups had similar IOP and medication outcomes, regardless of stratification by ABiC completion. Eyes receiving Hydrus had more complications and subsequent surgeries. Plain Language Summary: The present study contributes some of the first real-world data comparing iStent inject versus Hydrus Microstent implantation in combination with cataract surgery in opposite eyes (right or left) of the same patient (i.e., contralateral-eye study). The report also includes subgroup analyses of eyes with versus without ab interno canaloplasty (ABiC). There were no significant between-group differences in mean intraocular pressure or medication burden preoperatively or postoperatively for iStent inject versus Hydrus. The intraocular pressure and medication reductions versus the groups' respective baselines were statistically similar as well. Finally, results remained similar for iStent inject versus Hydrus regardless of whether ABiC was completed, and were also similar when comparing eyes with ABiC versus without ABiC. In eyes receiving Hydrus, there was a greater incidence of complications and need for further surgery. [ABSTRACT FROM AUTHOR]

The spatiotemporal pattern of root water uptake (RWU) depends on multiple factors, such as plant root biomass, soil water availability, and prevailing weather conditions at the site. The water uptake reduction due to the nonuniformity in soil water contents is often mitigated through compensated root water uptake (CRWU) and hydraulic redistribution (HR). Although previous studies have often considered these two processes independently due to the simplicity and feasibility of analyzing them separately, CRWU and HR can coexist in field conditions. Therefore, this work demonstrates the importance of considering CRWU and HR simultaneously in estimating daily transpiration and RWU distribution for nonuniform soil moisture conditions. For that, we have implemented the mechanistic RWU models developed by de Jong van Lier et al. (denoted below as the DJ model), Couvreur (CR), and Nimah and Hanks (NH) (see the references in the main text) into the widely-used HYDRUS-1D model, in addition to the previously available Jarvis (JF) and Feddes (FD) models. The performance of these models was then compared for varying soil water contents and boundary conditions using experimental data and hypothetical modeling scenarios. Our analysis has shown that these models are beneficial in estimating RWU with varying degrees of accuracy. The DJ and CR models are effective in simultaneously simulating CRWU and HR. NH and JF models can simulate CRWU but cannot simulate HR satisfactorily. Implementing these models into the HYDRUS platform for simultaneously considering CRWU and HR will significantly improve the accuracy of RWU predictions.

Abstract Introduction This study compared outcomes of the iStent inject trabecular micro-bypass system versus the Hydrus Microstent in patients with primary open-angle glaucoma (POAG). Methods Forty subjects (80 eyes) with POAG were included in this single-center, retrospective, contralateral-eye analysis. All patients underwent phacoemulsification with either iStent inject or Hydrus implantation in one eye and the other device in the contralateral eye, with ≥ 3-month follow-up. In 58 eyes (27 iStent inject, 31 Hydrus) the surgery also included ab interno canaloplasty (ABiC). Twelve-month outcomes included intraocular pressure (IOP), medications, and adverse events. Subgroup analyses were completed for iStent inject versus Hydrus, and with versus without ABiC. Results At 12 months versus baseline, mean IOP reduced from 16.8 ± 3.7 to 13.6 ± 2.9 (p = 0.003) in iStent inject eyes, and from 18.1 ± 4.5 to 14.9 ± 3.2 mmHg (p = 0.003) in Hydrus eyes (between-group IOP reduction p = 0.582). Mean number of glaucoma medications reduced from 1.23 ± 0.97 to 0.30 ± 0.76 (p

The conceptual hydrological model represented by the ABCD model is one of the main methods to quantify and analyze the hydrological cycle processes. However, few studies have examined the physical basis of the variables and parameters of the ABCD model and quantified the relationship between parameters in the conceptual hydrological model and traditional soil hydraulic parameters. In this study, we select the Taigemiao mining area in the Ordos basin as the research site. The HYDRUS-1D software is used to construct the soil-plant-atmosphere continuum (SPAC) model at a site scale for obtaining the “real” actual evapotranspiration during the non-freezing period. The actual evapotranspiration obtained from the SPAC model is considered as the objective function of the ABCD model for calibrating the ABCD model. The soil water storage and soil water leakage simulated by the ABCD model are compared with the results of the SPAC model. The relationships between the parameters of a and b in the ABCD model and the traditional soil hydraulic parameters are analyzed through a large number of scenario simulations. The results show that the ABCD model can better simulate the site-scale monthly actual evapotranspiration and soil water leakage during the non-freezing period. It is indicated that parameter a in the ABCD model has a strong linear correlation with the saturated water content, residual water content and curve shape parameters, while it shows a negative logarithmic relation to the saturated coefficient of permeability. It is also found that parameter b has a strong linear correlation with the saturated water content and curve shape parameter n, while the logarithmic relationships is revealed between parameter b and the saturated coefficient of permeability and curve shape parameter α. This study can improve the understanding of the physical basis of variables and parameters in conceptual hydrological models, and expands the application of hydrological models to hydrogeology.

Low-Impact Developments (LIDs), like green roofs and bioretention cells, are vital for managing stormwater and reducing pollution. Amidst climate change, assessing both current and future LID systems is crucial. This study utilizes variably saturated flow modeling with the HYDRUS software (version 4.17) to analyze ten locations in Ontario, Canada, focusing on Toronto. Historical and projected climate data are used in flow modeling to assess long-term impacts. Future predicted storms, representing extreme precipitation events, derived from a regional climate model, were also used in the flow modeling. This enabled a comprehensive evaluation of LID performance under an evolving climate. A robust methodology is developed to analyze LID designs, exploring parameters like water inflow volumes, peak intensity, time delays, runoff dynamics, and ponding patterns. The findings indicate potential declines in LID performance attributed to rising water volumes, resulting in notable changes in infiltration for green roofs (100%) and bioretention facilities (50%) compared to historical conditions. Future climate predicted storms indicate reduced peak reductions and shorter time delays for green roofs, posing risks of flooding and erosion. Anticipated extreme precipitation is projected to increase ponding depths in bioretention facilities, resulting in untreated stormwater overflow and prolonged ponding times exceeding baseline conditions by up to 13 h at numerous Ontario locations.

Salt enrichment in the topsoil, owing to one-way migration of moisture from earthen sites to air environment, is an important inducement to weathering of sites and relics, such as efflorescence, recess, slice-peeling, which becomes the most important challenge to the preservation of unearthed sites and relics. Further, salt enrichments in the topsoil of undulating earthen sites are usually inhomogeneous such that it is difficult to precisely prevent the deterioration from happening of salt enrichment in the topsoil. A case study of salt enrichment at the K9901 funerary pit of Emperor Qin's Mausoleum Site Museum was conducted by soil column experiment and numerical simulation. The water and salt transport in the earthen sites were simulated and analyzed by HYDRUS software. The simulation of the salt enrichment process at the earthen sites demonstrated that the enrichment of soluble salt ions mainly occurs on the surface of rammed earth and increases annually; the salt damage at the earthen sites can be effectively delayed by taking an environmental control measure. These results provide a reference for the prevention of salt damage at earthen sites and facilitate the daily management of earthen sites. [ABSTRACT FROM AUTHOR]

Rainfed wheat production systems are usually characterized by low-fertility soils and frequent droughts, creating an unfavorable environment for sustainable crop production. In this study, we used a processed-based biophysical numerical model to evaluate the water balance and nitrogen (N) dynamics in soils under rainfed wheat cultivation at low (219 mm, Pygery) and medium rainfall (392 mm, Yeelanna) sites in south Australia over the two seasons. Estimated evapotranspiration components and N partitioning data were used to calibrate and validate the model and to compute wheat's water and N use efficiency. There was a large disparity in the estimated water balance components at the two sites. Plant water uptake accounted for 40–50% of rainfall, more at the low rainfall site. In contrast, leaching losses of up to 25% of seasonal rainfall at the medium rainfall site (Yeelanna) indicate a significant amount of water evading the root zone. The model-predicted N partitioning revealed that ammonia–nitrogen (NH4–N) contributed little to plant N nutrition, and its concentration in the soil remained below 2 ppm throughout the crop season except immediately after the NH4–N-based fertilizer application. Nitrate–nitrogen (NO3–N) contributed to most N uptake during both seasons at both locations. The N losses from the soil at the medium rainfall site (3.5–20.5 kg ha−1) were mainly attributed to NH4–N volatilization (Nv) and NO3–N leaching (NL) below the crop root zone. Water productivity (8–40 kg ha−1 mm−1) and N use efficiency (31–41 kg kg−1) showed immense variability induced by climate, water availability, and N dynamics in the soil. These results suggest that combining water balance and N modeling can help manage N applications to optimize wheat production and minimize N losses in rainfed agriculture. [ABSTRACT FROM AUTHOR]

This study aims to examine the impact of combined irrigation and fertilizer control on the summer maize yield, nitrogen use efficiency (NE), and nitrogen leaching (NL) in the Yellow River Basin. Based on the measured data from the field summer maize experiment in 2021 and 2022, a water-nitrogen movement model was constructed for 'Zhengdan 958' maize under two irrigation methods (wide furrow irrigation (G) and border irrigation (Q)), three fertilizer rates (120 kg/ha (N1), 220 kg/ha (N2), and 320 kg/ha (N3)), and three fertilizer frequencies (1 (T1), 2 (T2), and 3 (T3)), yielding 18 total treatments. Calculation of nitrogen leaching was based on water nitrogen transport modeling. The study then analyzed the factors and their combined effects. A multi-objective optimization genetic algorithm (NSGA-II) was established to evaluate maize yield, nitrogen use efficiency, and nitrogen leaching. The results indicate that the determination coefficients between simulated and measured water, nitrogen values exceeded 0.74. The rate optimized HYDRUS model effectively simulated the soil solute movement. The interaction of the irrigation method, fertilizer rate, and fertilizer application frequency did not significantly affect yield and nitrogen leaching, but did significantly impact nitrogen use efficiency (p < 0.05). Nitrogen leaching increased gradually as nitrogen application increased. The yield under wide furrow irrigation was 6.26% higher than that under border irrigation. The optimal coupling scheme of water and fertilizer was obtained using the genetic algorithm multi-objective optimization method, where the combined GN2T2 treatment was the optimal management model, the summer maize yield reached 14,077 kg/ha, nitrogen use efficiency and nitrogen leaching were reduced to 30.21 kg·kg−1 and 17.64 kg/ha, respectively. These findings can guide summer maize cultivation in the Yellow River Basin and assist in reducing nitrogen surface source pollution. [ABSTRACT FROM AUTHOR]

Future agriculture calls for increased input (e.g., water, nutrients, pesticides) use efficiency while maintaining or improving productivity, minimizing environmental impacts, and increasing profitability. Complete understanding of complex irrigation systems requires laborious, time-consuming, and expensive field investigations, which invariably involve only a limited number of treatments. On the other hand, fully calibrated process-based models, such as HYDRUS, can quickly evaluate different irrigation management strategies without the need for labor-intensive fieldwork and have become valuable research tools for predicting complex and interactive water flow and solute transport processes in and below the root zone. HYDRUS codes have been used worldwide in several hundreds of studies evaluating various types of irrigation (e.g., sprinkler, furrow, basin, and surface and subsurface drip), their scheduling (e.g., the timing of irrigation and its amount), and solute-related factors (e.g., fertigation, chemigation, salinization, and sodification). The objective of this manuscript is to review the current modeling capabilities of HYDRUS to evaluate various irrigation methods and related processes. The manuscript starts with a section describing governing flow and transport equations solved numerically by the HYDRUS codes, the corresponding initial and boundary conditions, and related factors such as soil hydraulic properties and root water and nutrient uptake. Modeling of different irrigation techniques is described in subsequent sections, followed by sections dealing with solute-related topics such as fertigation, chemigation, and salinization/sodification. Topics, including the effects of spatial variability, optimization of irrigation systems, and special irrigation methods, are covered in the later sections. The manuscript emphasizes the advantages and opportunities of HYDRUS in describing various processes in the root zone of irrigated plants that support sustainable irrigated agriculture. All the project files of the discussed examples and their descriptions are available for download at https://www.pc-progress.com/en/Default.aspx?hyd5-AdvancesInAgronomy. [ABSTRACT FROM AUTHOR]

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

Many arid and semi-arid regions of the world face challenges in maintaining the water quantity and quality needs of growing populations. A drywell is an engineered vadose zone infiltration device widely used for stormwater capture and managed aquifer recharge. To our knowledge, no prior studies have quantitatively examined virus transport from a drywell, especially in the presence of subsurface heterogeneity. Axisymmetric numerical experiments were conducted to systematically study virus fate from a drywell for various virus removal and subsurface heterogeneity scenarios under steady-state flow conditions from a constant head reservoir. Subsurface domains were homogeneous or had stochastic heterogeneity with selected standard deviation (σ) of lognormal distribution in saturated hydraulic conductivity and horizontal (X) and vertical (Z) correlation lengths. Low levels of virus concentration tailing can occur even at a separation distance of 22 m from the bottom of the drywell, and 6-log10 virus removal was not achieved when a small detachment rate (kd1=1 × 10⁻⁵ min⁻¹) is present in a homogeneous domain. Improved virus removal was achieved at a depth of 22 m in the presence of horizontal lenses (e.g., X=10 m, Z=0.1 m, σ=1) that enhanced the lateral movement and distribution of the virus. In contrast, faster downward movement of the virus with an early arrival time at a depth of 22 m occurred when considering a vertical correlation in permeability (X=1 m, Z=2 m, σ=1). Therefore, the general assumption of a 1.5-12 m separation distance to protect water quality may not be adequate in some instances, and site-specific microbial risk assessment is essential to minimize risk. Microbial water quality can potentially be improved by using an in situ soil treatment with iron oxides to increase irreversible attachment and solid-phase inactivation.

Drywells (DWs) and infiltration basins (IBs) are widely used as managed aquifer recharge (MAR) devices to capture stormwater runoff and recharge groundwater. However, no published research has compared the performance of these two engineered systems under shared conditions. Numerical experiments were conducted on an idealized 2D-axisymmetric domain using the HYDRUS (2D/3D) software to systematically study the performance of a circular IB design (diameter and area) and partially penetrating DW (38 m length with water table > 60 m). The effects of subsurface heterogeneity on infiltration, recharge, and storage from the DW and IB under constant head conditions were investigated. The mean cumulative infiltration (μI) and recharge (μR) volumes increased, and the arrival time of recharge decreased with the IB area. Values of μI were higher for a 70 m diameter IB than an DW, whereas the value of μR was higher for a DW after 1-year of a constant head simulation under selected subsurface heterogeneity conditions. A comparison between mean μI, μR, and mean vadose zone storage (μS) values for all DW and IB stochastic simulations (70 for each MAR scenario) under steady-state conditions demonstrated that five DWs can replace a 70 m diameter IB to achieve significantly higher infiltration and recharge over 20 years of operation. Additional numerical experiments were conducted to study the influence of a shallow clay layer by considering an IB, DW, and a DW integrated into an IB. The presence of such a low permeable layer delayed groundwater recharge from an IB. In contrast, a DW can penetrate tight clay layers and release water below them and facilitate rapid infiltration and recharge. The potential benefits of a DW compared to an IB include a smaller footprint, the potential for pre-treatments to remove contaminants, less evaporation, less mobilization of in-situ contaminants, and potentially lower maintenance costs. Besides, this study demonstrates that combining both IB and DW helps to get the best out of both MAR techniques.

Brackish water has been increasingly used worldwide for irrigation to relieve crop water stress. However, crop yield reductions inevitably occur under uncontrolled irrigation with saline waters, especially in areas with shallow and saline groundwater. It is essential to quantify the movement of soil water and salts in a soil-plant system and to optimize irrigation patterns with brackish water to alleviate the harm of salt stress on crop growth. Therefore, a two-year cornfield experiment was carried out during 2020–2021 to evaluate differences in soil water and salt movement under different irrigation regimes: a) brackish water irrigation with high (HB), medium (MB), and low (LB) irrigation depths, and b) freshwater irrigation with medium irrigation depths (MF). Moreover, the HYDRUS (2D/3D) model was used to evaluate soil water contents (SWC), electrical conductivities of the saturation paste extract (ECe), and fluxes, distributions, and mass balances of soil water and salts for the HB, MB, LB, and MF regimes. Meanwhile, oxygen isotope (18O) was used to calibrate and verify the simulation accuracy of the HYDRUS (2D/3D) model by determining the proportion of water and salt sources in a soil-plant system.The results showed that HYDRUS (2D/3D) could precisely capture SWC and ECe under different irrigation treatments, with the root mean square error (RMSE) of 0.004–0.017 cm3 cm−3 and 0.023–0.372 dS m−1 for SWC and ECe, respectively. The highest differences in SWCs and ECe in plots under brackish water and freshwater irrigations occurred in the 0–20 cm soil layer. The stress areas in the soil profile due to water and salt stresses under MB decreased and increased by 1.8 cm2 and 2010.0 cm2, respectively, compared with MF, accounting for 0.04% and 40.2% of the root zone. However, average root water uptake (RWU) in both years under MB decreased by 1.9% compared to MF. Additionally, RWU showed a nonlinear relationship with irrigation depth when brackish water was used for irrigation. The highest RWU occurred under MB, where the average RWU in both years increased by 7.7% and 12.4% compared with HB and LB, respectively. Therefore, the MB treatment could be recommended to increase crop yield and alleviate the freshwater shortage in agricultural production. Moreover, the findings of this study improve our understanding of the mechanisms of soil water and salt movement and groundwater contributions in a system under brackish water irrigation with different irrigation depths.

The perfect design of open drains requires understanding the effect of the different design parameters on groundwater table. The paper objective is to perform sensitivity analysis to show the effect of the drainage flow rate, the distance between the bed of the open drain and the bottom impervious layer, the drain bed width, the spacing between drains, and the soil type (design parameters) on the maximum height of groundwater table above the open drain bed. HYDRUS software, Dupuit equation, and artificial neural networks (ANNs) are used. Comparison is performed between HYDRUS and Dupuit equation for simulating water flow in unconfined aquifer between two water ways. The predicted groundwater table using HYDRUS is above the other one from Dupuit equation. ANNs were used to predict the maximum height of groundwater table from its design parameters. MATLAB code is written to simply use the previous ANNs to find the best drain design.

Contemporary research on pesticides/fungicides as potential sources of groundwater contamination, including their migration pathways, especially in the Western Bengal basin (WBB), is scarce. The present research intends to study the vulnerability of groundwater towards pollution from metalaxyl. Metalaxyl is a fungicide added anthropogenically to the sandy soil of WBB for the cultivation of crops like tomatoes, potatoes and mustard. The study explores the mechanics of metalaxyl adsorption in soil and its migration to the associated groundwater system. Chemical analyses show high concentrations of metalaxyl within groundwater (472.9 μg/L, maximum amount) from the study area (Nadia district of WBB). The groundwater ubiquity score of metalaxyl (4.6) depicts that it is very much prone to leach through the sandy soils of WBB to the underlying groundwater system. The results of column leaching experiments and their congruence to the findings of numerical modelling study using HYDRUS software confirm the fact. The adsorptive resilience of the studied soils towards metalaxyl is insignificant (soils of North Chandmari (S1) =0.1087 mg/g, Ghoragacha (S2) =0.21 mg/g, and Khaldarpara (S3) =1.771 mg/g). However, the presence of excess iron concentration may enhance the adsorptive capacity of the soil toward Metalaxyl, thereby limiting its migration toward the zone of saturation.

Ecological water conveyance is an effective measure to mitigate or reverse vegetation ecosystem degradation in arid regions, which can lead to frequent fluctuations in the groundwater table. The depth of soil water that vegetation takes up varies in response to groundwater table fluctuations in arid environments. To better characterize the root water uptake process under dynamic changes in the groundwater table in arid regions, this study proposed a new model for simulating root water uptake. The model reduces the dominant effect of root density on water uptake by introducing a correction factor and accounts for the effect of changes in the water content profile on root water uptake in arid areas. The new model was incorporated into the HYDRUS code and tested against the monitoring data of typical vegetation in the arid region of northwestern China. The results demonstrated that the soil water content simulated by the new model matched well with the observed data, which was consistent with the water uptake process under the fluctuations of the groundwater table at the study site. Compared with other models, this model can flexibly alter water uptake layers according to soil moisture conditions in arid conditions, thus providing a new method to depict the dynamic process of water uptake influenced by fluctuations in the groundwater table. [ABSTRACT FROM AUTHOR]

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

In recent years, the emergence of COVID-19 has created disastrous health effects worldwide. Doxycycline, a member of the tetracycline group, has been prescribed as a treatment companion for attending this catastrophe. Due to extensive use and high solubility, a significant amount of un-metabolized doxycycline has been found to reach water bodies within a short time, and consumption of this water may lead to the development of fatal resistance in organisms and create health problems. Therefore, it has become necessary to develop suitable technologies from a geoenvironmental point of view to remove these unwanted antibiotics from wastewater. In this context, locally obtainable silty-sandy soil was explored as a low-cost material in a constructed wetland with Chrysopogon zizanioides (vetiver sp.) for phytoremediation to mitigate doxycycline spiked wastewater. The obtained soil hydraulic conductivity was 1.63×10−7 m/s. Batch adsorption tests conducted on silty-sandy soil, vetiver leaf, and vetiver root provided maximum removal efficiencies of 90%, 72%, and 80% percent, respectively, at optimal sorbent doses of 10 g/L , 17 g/L , and 16 g/L , and contaminant concentrations of 25 mg/L , 20 mg/L , and 23 mg/L , with a 30-min time of contact. The Freundlich isotherm was the best fit, indicative of sufficient sorption capacity of all the adsorbents for doxycycline. The best match in the kinetic research was pseudo-second-order kinetics. A one dimensional vertical column test with the used soil on doxycycline revealed a 90% breakthrough in 24 h for a soil depth of 30 mm. Studies on a laboratory-scale wetland and numerically modeled yielded removal of around 92% by the selected soil and about 98% combined with Chrysopogon zizanioides for 25 mg/L of initial doxycycline concentration, which is considered quite satisfactory. Simulated results matched the laboratory tests very well. The study is expected to provide insight into remedies for similar practical problems. To explore a cost-effective method for abatement of aqueous doxycycline in the surrounding environment and groundwater, a locally accessible silty-sandy soil was selected. While investigating its suitability, it was found that this soil met current standards (10−4 to 10−5 cm/s) for hydraulic conductivity of wetland adsorbent. The selected soil also had a relatively large surface area (23.502 m2/g), and the presence of higher percentages of finer particles (50%) resulted in an outstanding adsorptive and removal capacity for doxycycline, as indicated by several test findings and validated with numerical modeling. Furthermore, as evidenced by batch experiments, the vegetative cover, primarily provided by vetiver, was also found to be an effective adsorbent. Sorption of a particular contaminant in wastewater to wetland soil is problematic due to the simultaneous presence of various compounds and other wastewater contaminants. The competition effect among these compounds is of concern in any treatment wetland, where thousands of compounds are present. Hence, further studies are required to address the competition between these compounds and their cumulative effect on the efficacy of the wetland system over a long period. This has therefore cemented the fact that silty-sandy soil is a perfect choice as bed material for wetlands. Together with vetiver, it has the potential to become a stable and environment-friendly removal system against doxycycline. However, the investigation was carried out with a spiked doxycycline solution in the laboratory, the results of which are believed to provide a basic understanding and remedial measures for this problem. Based on that, if several field studies are conducted with the studied soil using phytoremediating plants in doxycycline-laden wastewater, a real-life solution to the doxycycline problem may be obtained that is very much needed for assuage of social health problems. [ABSTRACT FROM AUTHOR]

Drywells are widely used as managed aquifer recharge devices to capture stormwater runoff and recharge groundwater, but little research has examined the role of subsurface heterogeneity in hydraulic properties on drywell recharge efficiency. Numerical experiments were therefore conducted on a 2D-axisymmetric domain using the HYDRUS (2D/3D) software to systematically study the influence of various homogenous soil types and subsurface heterogeneity on recharge from drywells under constant head conditions. The mean cumulative infiltration (μI) and recharge (μR) volumes increased with an increase in the saturated hydraulic conductivity (Ks ) for various homogeneous soils. Subsurface heterogeneity was described by generating ten stochastic realizations of soil hydraulic properties with selected standard deviation (σ), and horizontal (X) and vertical (Z) correlation lengths. After 365 days, values of μI, μR, and the radius of the recharge area increased with σ and X but decreased with Z. The value of μR was always smaller for a homogeneous than a heterogeneous domain. This indicates that recharge for a heterogeneous profile cannot be estimated with an equivalent homogeneous profile. The value of μR was always smaller than μI and correlations were highly non-linear due to vadose zone storage. Knowledge of only infiltration volume can, therefore, lead to misinterpretation of recharge efficiency, especially at earlier times. The arrival time of the wetting front at the bottom boundary (60 m) ranged from 21-317 days, with earlier times occurring for increasing σ and Z. The corresponding first arrival location can be 0.1-44 m away from the bottom releasing point of a drywell in the horizontal direction, with greater distances occurring for increasing σ and X. This knowledge is important to accurately assess drywell recharged performance, water quantity, and water quality.

Human urine concentrates 88% of the nitrogen and 50% of the phosphorus excreted by humans, making it a potential alternative crop fertilizer. However, knowledge gaps remain on the fate of nitrogen in situations favouring NH3 volatilization and on the availability of P from urine in soils. This study aimed at identifying the fate of nitrogen and phosphorus supplied by human urine from source separation toilets in a calcareous soil. To this end, a spinach crop was fertilized with 2 different doses of human urine (170 kgN ha−1 + 8.5 kgP ha−1 and 510 kgN ha−1 + 25.5 kgP ha−1) and compared with a synthetic fertilizer treatment (170 kgN ha−1 + 8.5 kgP ha−1) and an unfertilized control. The experiment was conducted in 4 soil tanks (50-cm depth) in greenhouse conditions, according to a randomized block scheme. We monitored soil mineral nitrogen over time and simulated nitrogen volatilization using Hydrus-1D and Visual Minteq softwares. We also monitored soil phosphorus pools, carbon, nitrogen and phosphorus (CNP) in microbial biomass, soil pH and electrical conductivity. Only an excessive input of urine affected soil pH (decreasing it by 0.2 units) and soil conductivity (increasing it by 183%). The phosphorus supplied was either taken up by the crop or remained mostly in the available P pool, as demonstrated by a net increase of the resin and bicarbonate extractable P. Ammonium seemed to be nitrified within about 10 days after application. However, both Visual Minteq and Hydrus models estimated that more than 50% of the nitrogen supplied was lost by ammonia volatilization. Overall, our results indicate that direct application of urine to a calcareous soil provides available nutrients for plant growth, but that heavy losses of volatilized nitrogen are to be expected. Our results also question whether long-term application could affect soil pH and salinity. [ABSTRACT FROM AUTHOR]

Harvesting of stormwater in the Gaza Strip is very important for the aquifer recharge since the stormwater infiltration is considered the sole replenishing source which reimburses the severe groundwater abstraction and protects the aquifer from unrecoverable deterioration. Gaza Strip experienced stormwater infiltration basins several years ago using different infiltration techniques. Waqf Basin is an existing stormwater infiltration basin located in Gaza City that used a surface natural infiltration technique, however, recently the basin was upgraded and augmented by drilling 18 boreholes (drywells) at zone 4 (western part of the basin). As a result, the basin has an improved infiltration capacity as revealed during the 2021–2022 wet season through field observation readings of water levels with a borehole infiltration capacity estimated as 111.0, 250, 316.7 m3 /d at 1.70, 3.40, 5.10 m ponded water depth, respectively. In addition, HYDRUS (2D/3D) software was used in this research to model/simulate Waqf Basin at ponded water depths 1.70, 3.40, and 5.10 m with the corresponding obtained borehole infiltration capacities as 289.0, 324.19, 250.39 m³ /d, respectively. The results emphasized that the single borehole infiltration capacity was in agreement with the field observed readings as the borehole infiltration capacity increases with the increase of basin ponded water depth. Nevertheless, the difference between HYDRUS and field observed results was attributed to the clogging effect which needs further studies in the future. Using the borehole infiltration technique is efficient when properly designed, implemented, and repaired at the end of each wet season to protect the system from permanent malfunctioning. [ABSTRACT FROM AUTHOR]

Nonadherence to glaucoma medication and poor follow-up is a global health concern. Glaucoma remains one of the largest causes of irreversible blindness worldwide. Traditional treatment guidelines suggest topical eye drop medication as first-line therapy followed by addition of supplementary medications before proceeding to more invasive glaucoma surgeries. Unfortunately, poor glaucoma self-management remains high, leading to disease progression and blindness. Recent advancements in the field of pharmacotherapies, surgeries, and behavioral approaches have taken aim at increasing support for glaucoma self-management. We review the current and emerging approaches toward glaucoma management, with the exception of bleb-based surgical approaches, to investigate if they have had an impact on adherence. Literature searches were conducted via MEDLINE (PubMed), Embase (Elsevier), Cochrane Library (Wiley), and Preprints from 1 January 2018 to 26 January 2023. The ability to offer patients a multitude of choices enables patients to tailor their glaucoma treatment to their values and lifestyle. Offering personalized patient education and coaching to support chronic glaucoma self-management would better enable patient engagement in whichever treatment path is chosen. Currently, literature regarding the impact of these new advancements on treatment engagement is lacking; this field is ripe for additional intervention and assessment. [ABSTRACT FROM AUTHOR]

Nutrient availability after fertilising agricultural soils is affected by many factors, including soil moisture conditions and physicochemical properties. Herein, the availability of potassium in soil enriched with biochar is studied, considering either saturated or unsaturated moisture conditions and questioning key ion exchange approaches, such as equilibrium exchange (E.E.) and kinetic exchange (K.E.). Potassium release is simulated from a soil–biochar mixture of 0, 0.5, 1 and 2% by coupling HYDRUS-1D and PHREEQC models. The water flow, mass transport and geochemical processes are simulated for a cultivation period that imitates agronomic and environmental conditions of a common agricultural field in Northern Greece. Potassium is released gradually during the irrigation period in the case of unsaturated flow conditions as opposed to its complete release over a few days in the case of saturated flow conditions in the soil. Regarding ion-exchange processes, the soluble amount of potassium is more readily available for transport in soil solution when using the E.E. approach compared to the K.E. approach that assumes a kinetically controlled release due to interactions occurring at the solid–solution interface. The increased proportion of biochar in soil results in a doubling of available potassium. Among the four modelling schemes, although the total mass of potassium released into soil solution is similar, there is a significant variation in release time, indicating that simplified saturated conditions may lead to unrealistic estimates of nutrient availability. Further experimental work will be valuable to decrease the uncertainty of model parameter estimation in the K.E. approach. [ABSTRACT FROM AUTHOR]

Groundwater evapotranspiration (ETg) is an important component of the hydrological cycle in water-scarce regions and is important for local ecosystems and agricultural irrigation management. However, accurate estimation of ETg is not easy due to uncertainties in climatic conditions, vegetation parameters, and the hydrological parameters of the unsaturated zone and aquifers. The current methods for calculating ETg mainly include the WTF method and the numerical groundwater model. The WTF method often requires data supplementation from the numerical unsaturated model to reduce uncertainty; in addition, it relies on point-monitoring data and cannot solve the spatial heterogeneity of ETg. The ETg calculation module of the numerical groundwater model is set up too simply and ignores the influence from the unsaturated zone and surface cover. Subsequent research breakthroughs should focus on the improvement of WTF calculation theory and the setting up of an aquifer water-table fluctuation monitoring network. The numerical groundwater model should couple the surface remote sensing data with the unsaturated zone model to improve the accuracy of ETg calculation. [ABSTRACT FROM AUTHOR]

Engineered carbon‐based nanoparticles are increasingly used for environmental, industrial, and medical purposes. Thus, understanding their interaction with and transport through materials is important. We examine the impact of nanoparticle hydrophobicity and porous medium surface area on the transport of carbon nanoparticles through sand‐packed columns under saturated and unsaturated conditions. The fluorescent carbon nanoparticles (FCNs) used in this study, synthesized from citric acid and ethanolamine, exhibit synthesis‐temperature‐dependent hydrophobicity. To quantify the impact of hydrophobicity on retention, we use FCNs synthesized at four temperatures: 190°C (FCN190), 210°C (FCN210), 230°C (FCN230), and 250°C (FCN250). Several observations are noted. First, the more hydrophobic particles (FCN230 and FCN250) attain lower outlet concentrations and mass recovery than more hydrophilic particles (FCN190 and FCN210). For instance, while 77% of the FCN190 was recovered after passing through a fine‐sand‐packed column, only 23% of the FCN250 was recovered. Second, sand surface area significantly impacts FCN recovery. A 17‐fold increase in sand surface area yields a 30% decrease in the recovery of FCN210. Third, no significant difference in the mass recovery of the FCNs was observed between the unsaturated and saturated conditions, which is attributed to the small size of the FCNs relative to the water film thickness surrounding sand grains. Fourth, the particle transport model in HYDRUS‐1D successfully simulated FCN transport, showing approximately a tenfold increase in the attachment coefficient for hydrophobic FCNs. In summary, through experiments and modeling, we show that hydrophobicity is a major factor impacting FCN transport. Key Points: The synthesis‐temperature‐dependent hydrophobicity reduces the transport of fluorescent carbon nanoparticles through sand‐packed columnsA two‐kinetic sites transport model describes the transport of fluorescent carbon nanoparticles in porous mediaFluorescent carbon nanoparticles are not trapped in the meniscus under unsaturated conditions at the tested moisture contents [ABSTRACT FROM AUTHOR]

The determination of field capacity (FC), irrigation thresholds, and irrigation amounts is characterized by site-specific soil hydraulic properties (SHPs). This study, conducted in two zones (zone 1 and zone 2) delineated based on soil, topography, and historical crop yield in Alabama (USA), focused on determining zone-specific FC using negligible drainage flux qfc criterion. The HYDRUS-1D model was used to optimize zone-specific SHPs using measured soil matric potential (h). The zone-specific FCs were determined using optimized and raw SHPs at 0.01 cm/day as qfc. The results showed that the optimized FC at qfc was at −39 kPa in zone 1 and raw FC was at −15 kPa. However, in zone 2, optimized FC was at −25 kPa and raw FC was at −59 kPa. To validate that optimized values are more accurate than raw values, a relationship between accumulated crop evapotranspiration (ETc) and required irrigation amount was determined using optimized parameters (SHPs and FC) and showed a stronger correlation in both zones than using raw parameters (SHPs and FC). At flux-based FC, the optimized irrigation thresholds and amounts in zone 1 were −88 kPa and 20 mm, and raw irrigation threshold and amount were −58 kPa and 33 mm, respectively. In zone 2, the optimized irrigation thresholds and amounts were −45 kPa and 18 mm, and raw irrigation threshold and amount were −116 kPa and 14 mm, respectively. Therefore, using raw and benchmark FC can result in inefficient irrigation strategies. The proposed novel method of optimizing zone-specific FC and irrigation thresholds can help with adopting timely best irrigation management schemes in respective zones.

Food contamination is responsible for thousands of deaths worldwide every year. Plants represent the most common pathway for chemicals into the human and animal food chain. Although existing dynamic plant uptake models for chemicals are crucial for the development of reliable mitigation strategies for food pollution, they nevertheless simplify the description of physicochemical processes in soil and plants, mass transfer processes between soil and plants and in plants, and transformation in plants. To fill this scientific gap, we couple a widely used hydrological model (HYDRUS) with a multicompartment dynamic plant uptake model, which accounts for differentiated multiple metabolization pathways in plant's tissues. The developed model is validated first theoretically and then experimentally against measured data from an experiment on the translocation and transformation of carbamazepine in three vegetables. The analysis is further enriched by performing a global sensitivity analysis on the soil-plant model to identify factors driving the compound's accumulation in plants' shoots, as well as to elucidate the role and the importance of soil hydraulic properties on the plant uptake process. Results of the multilevel numerical analysis emphasize the model's flexibility and demonstrate its ability to accurately reproduce physicochemical processes involved in the dynamic plant uptake of chemicals from contaminated soils.

Riparian zones are essential to preserve water quality of rivers adjacent to large areas of irrigated agriculture. We used HYDRUS (2D/3D) to quantify the long-term (8 years) influence of crops (almonds, wine grapes and potato-carrot) irrigated with recycled water on water and solute exchange at the Gawler River interface in relation to vegetation buffer widths from 10 to 110 m. We found that under almond and annual horticulture the likely average annual water flow from the irrigated area to the river was nearly twice as much (2.1 and 1.8, respectively) that under wine grapes. The hydraulic exchange at river interface for different irrigated crops was found to be sensitive to the buffer widths. For wine grapes, almonds and annual horticulture, the average annual hydraulic balance reached an equilibrium at 20, 65 and 55 m buffer widths, respectively. Furthermore, for wine grapes, with a 20 m buffer width, the average annual load of salts became negligible. This study shows that buffer widths of 20, 60, and 40 m for irrigated wine grapes, almond, and annual horticulture, respectively, are needed to restrict the migration of salts to the river. Further refinements are possible by incorporating the influence of preferential flow paths, improved water stress response functions, and addressing the data limitations for calibration of the model for solute dynamics.

Drywells are increasingly used to capture stormwater runoff for surface infiltration and aquifer recharge, but little research has examined the role of ubiquitous subsurface heterogeneity in hydraulic properties on drywell performance. Numerical experiments were therefore conducted using the HYDRUS (2D/3D) software to systematically study the influence of subsurface heterogeneity on drywell infiltration. Subsurface heterogeneity was described deterministically by defining soil layers or lenses, or by generating stochastic realizations of soil hydraulic properties with selected variance (σ) and horizontal (X) and vertical (Z) correlation lengths. The infiltration rate increased when a high permeability layer/lens was located at the bottom of the drywell, and had larger vertical and especially horizontal dimensions. Furthermore, the average cumulative infiltration (I) for 100 stochastic realizations of a given subsurface heterogeneity increased with σ and X, but decreased with Z. This indicates that the presence of many highly permeable, laterally extending lenses provides a larger surface area for enhanced infiltration than the presence of isolated, highly permeable lenses. The ability to inversely determine soil hydraulic properties from numerical drywell infiltration results was also investigated. The hydraulic properties and the lateral extension of a highly permeable lens could be accurately determined for certain idealized situations (e.g., simple layered profiles) using constant head tests. However, variability in soil hydraulic properties could not be accurately determined for systems that exhibited more realistic stochastic heterogeneity. In this case, the heterogeneous profile could be replaced with an equivalent homogeneous profile and values of an effective isotropic saturated conductivity (Ks) and the shape parameter in the soil water retention function (α) could be inversely determined. The average value of Ks for 100 stochastic realizations showed a similar dependency to I on σ, X, and Z. Whereas, the average value of α had large confidence interval for soil heterogeneity parameters and played a secondary role in drywell infiltration. This research provides valuable insight on the selection of site, design, installation, and long-term performance of a drywell.

【Objective】 Bioretention is a method to purify water, and the aim of this paper is to study its effect on stormwater runoff. 【Method】 We took stormwater runoff in Shijiazhuang city as an example, investigating the outflow characteristics of the bioretention system in response to two rainfall patterns, constant pattern and Chicago pattern using column experiment and HYDRUS model. From the simulated results, we analyzed and discussed the sensitivities of the runoff to soil hydraulic parameters, catchment area and thickness of the planting soil layer. We also developed a model to predict the influence of rainfalls with different return periods (N) on outflow. 【Result】 Compared to constant rainfall, the Chicago rainfall pattern delayed the emergence of outlet-outflow and prolonged the ponding duration on the soil surface. The hydraulic parameters to which the runoff was sensitive include saturated soil permeability Ks, saturated soil water content θs, and the empirical parameter α in the van Genuchten formula. An increase in Ks increased the maximum outlet-drainage rate and brought forward its arrival time. Increasing θs prolonged the latent time and reduced the outflow rate and ponding duration. Increasing the parameter α resulted in an increase in outflow. Doubling the catchment area ratio increased the maximum drainage rate, the peak-reduction rate and ponding duration by 13%, 33% and 300%, respectively, whereas reducing the latent time by 16%. Change in thickness of the planting soil layer did not show a significant effect on the outflow pattern. 【Conclusion】 The bioretention system is more permeable with more than 90% of rainwater flowing through the planting soil layer. When the return period of the rainfall is no more than 5 years, there is no overflow with the peak reduction rate being 40.6%~76.5%, the latent time > 1 h and ponding time < 2 h.

Abstract Due to the high cost of the large-scale measurement of heavy metals, the use of statistical land models and techniques is one of the proper ways to study their distribution and level of pollution. The study area, is agricultural lands of south Tehran in Iran. Municipal wastewater is often used for irrigation agricultural lands under surface irrigation method. To study the distribution of heavy metals including copper, nickel, and lead, the ordinary kriging method in the GIS environment was used. In addition, one-dimensional HYDRUS modeling of water flow and heavy metals in the soil environment was simulated up to a depth of 50 cm for 210 days and the concentration of heavy metals in the depth was simulated. Distribution of lead element in soil surface with spherical model showed that its variation was in the range of 20–70 mg/kg. These values were 50–60 mg/kg for copper and 30 mg/kg for nickel. Investigation of heavy metal concentrations in soil profiles using the HYDRUS-1D model showed that the major accumulation of heavy metals occurred in the surface layer of soil at a depth of 0–15 cm that was higher than the permissible level.