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With the acceleration of urbanisation, urban areas are subject to the combined effects of the accumulation of various natural factors, such as changes in temperature leading to the thermal expansion or contraction of surface materials (rock, soil, etc.) and changes in precipitation and humidity leading to an increase in the self-weight of soil due to the infiltration of water along the cracks or pores in the ground. Therefore, the subsidence of urban areas has now become a serious geological disaster phenomenon. However, the use of traditional neural network prediction models has limitations when examining the causal relationships between time series surface deformation data and multiple influencing factors and when applying multiple influencing factors for predictive analyses. To this end, Sentinel-1A data from March 2017 to February 2023 were used as the data source in this paper, based on time series deformation data acquired using the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technique. A sparrow search algorithm–convolutional neural network–long short-term memory (SSA-CNN-LSTM) neural network prediction model was built. The six factors of temperature, humidity, precipitation, and ground temperature at three different depths below the surface (5 cm, 10 cm, and 15 cm) were taken as the input of the model, and the surface deformation data were taken as the output of the neural network model. The correlation between the spatial and temporal evolution characteristics of the ground subsidence in urban areas and various influencing factors was analysed using grey correlation analysis, which proved that these six factors contribute to some extent to the deformation of the urban surface. The main urban area of Hohhot City, Inner Mongolia Autonomous Region, was used as the study area. In order to verify the efficacy of this neural network prediction model, the prediction effects of the multilayer perceptron (MLP), backpropagation (BP), and SSA-CNN-LSTM models were compared and analysed, with the values of the correlation coefficients of the feature points of A1, B1, and C1 being in the range of 0.92, 0.83, and 0.93, respectively. The results show that compared with the traditional MLP and BP neural network models, the SSA-CNN-LSTM model achieves a higher performance in predicting time series surface deformation data in urban areas, which provides new ideas and methods for this area of research. [ABSTRACT FROM AUTHOR]

Accumulation landslides are prone to occur during the continuous infiltration of heavy rainfall, which seriously threatens the lives and property safety of local residents. In this paper, based on the Green-Ampt (GA) infiltration model, a new slope rainfall infiltration function is derived by combining the effect of air resistance and lateral seepage of saturated zone. Considering that when the soil layer continues to infiltrate after the saturation zone is formed, the air involvement cannot be discharged in time, which delays the infiltration process. Therefore, the influence of air resistance factor in soil pores is added. According to the infiltration characteristics of finite long slope, the lateral seepage of saturated zone is introduced, which makes up for the deficiency that GA model is only applicable to infinite long slope. Finally, based on the seepage characteristics of the previous analysis, the overall shear strength criterion is used to evaluate the stability of the slope. The results show that the safety factor decreases slowly with the increase of size and is inversely correlated with the slope angle and initial moisture content. The time of infiltration at the same depth increases with the increase of size and slope angle, and is inversely correlated with the initial moisture content, but is less affected by rainfall intensity. By comparing with the results of experimental data and other methods, the results of the proposed method are more consistent with the experimental results than other methods. [ABSTRACT FROM AUTHOR]

The mitigation rate (Rj) was evaluated for Ra-226 in cultivated soil in twelve fields in Vietnam. For the collected soils, the Rj values were between 0.1 and 0.58 Bq kg−2 y−1 with an average value of 0.28 Bq kg−2 y−1. The influence of the physicochemical properties of soil and cultivation characteristics on the rate of Ra-226 was considered. A strong correlation was found between the soil-to-plant factors (TF) and the uptake rates of plants (Ru) (Pearson coefficient |p|> 0.6). The leaching rate (Rℓ) in the surface soil correlates with some physical–chemical properties of soil such as the partition coefficient of Ra-226 in soil (Kd), infiltration rate of water (Rw), and activity concentration of Ra-226 in soil water (Cw) (|p|> 0.6). [ABSTRACT FROM AUTHOR]

Amidst intensifying global agricultural water demand, optimizing management practices and understanding the role of soil amendments, particularly biochar (BC), in modulating soil water dynamics are critical. Here, we review the potential impacts of BC on soil water dynamics, elucidate mechanistic underpinnings, and identify critical research gaps and prospective avenues. In general, BC modifies soil structure, hydraulic properties, surface albedo, and heat fluxes, which influence soil water storage, energy balance, and irrigation paradigms. Depending on soil texture and BC properties, BC demonstrates a greater reduction in bulk density and saturated hydraulic conductivity in coarse-textured soils compared to fine-textured soils. BC application generally increases water holding capacity (WHC) while exhibiting no consistent impact on soil water infiltration. Increased WHC of soils results from increased porosity, surface area, and soil aggregation. Increased porosity arises from a confluence of factors, encompassing new pores formation, reorganization of pores, increased soil aggregation, dilution effects of BC, reduced soil compaction, and biotic interactions, including increased population of burrowing invertebrates. BC tends to increase plant-available water in coarser soils, attributed to its hydrophilic nature, augmented specific surface area, and enhanced overall porosity. However, BC may induce soil water repellency, contingent upon variables such as feedstock composition, pyrolysis temperature, and specific soil attributes. While BC exhibits transformative potential in enhancing soil hydraulic properties, scalability concerns and economic viability pose challenges to its widespread agricultural application. Overall, BC offers promising avenues for sustainable water management. However, it is imperative to explore large-scale applications and conduct long-term field studies across different management, climate, and soil types to fully understand how different types of BC impact soil water dynamics. Highlights: Biochar generally improves soil water retention in coarse-textured soils. In coarse-textured soils, biochar increases porosity and PAW but decreases bulk density and Ksat. The effects of biochar on infiltration rates vary depending on soil types, as well as biochar particle size, production temperature, and depth of placement. Further studies on the mechanisms governing water retention in biochar-amended soils are warranted. Long-term studies encompassing various soil and biochar types are necessary. [ABSTRACT FROM AUTHOR]

The construction and investigation of dual-functional coordination polymers (CPs) with proton conduction and luminescence sensing is of great significance in clean energy and agricultural monitoring fields. In this work, an Mn-based coordination polymer (Mn-CP), namely, [Mn0.5(HL)] (H2L = HOOCC6H4C6H4CH2PO(OH)OCH3), was hydrothermally synthesized. Mn-CP has a one-dimensional (1D) chain structure, in which uncoordinated –COOH groups can serve as potential sites for fluorescence sensing. Moreover, Mn-CP shows good water and pH stabilities, offering the feasibility for proton conduction and sensing applications. Mn-CP displays comparatively high proton conductivity of 1.07 × 10−4 S cm−1 at 368 K and 95% relative humidity (RH), which is promising for proton conduction materials. Moreover, it can serve as a repeatable, highly selective, and visualized fluorescence sensor for detecting oxytetracycline (OTC). More importantly, Mn-CP reveals an amazing quantitative sensing of OTC in actual samples such as seawater, aquaculture freshwater, soil infiltration solutions, and tap water. This work proves the excellent application potential of dual-functional CPs in the field of clean energy and environmental protection, especially for the fluorescence detection of antibiotics in aquaculture systems. [ABSTRACT FROM AUTHOR]

We combined datasets from multiple research projects and remote sensing technologies to evaluate conservation conditions at La Fortaleza de Kuelap, a pre-Hispanic site in Peru that suffered significant damage under heavy seasonal rains in April 2022. To identify the causes of the collapse and where the monument is at further risk, we modeled surface hydrology using a DTM derived from drone LiDAR data, reconstructed a history of collapses, and calculated the volume of the most recent by fusing terrestrial LiDAR and photogrammetric datasets. In addition, we examined subsurface water accumulation with electrical resistivity, reconstructed the stratification of the monument with seismic refraction, and analyzed vegetation loss and ground moisture accumulation using satellite imagery. Our results point to rainwater infiltration as the most significant source of risk for La Fortaleza's perimeter walls. Combined with other adverse natural conditions and contemporary conservation interventions, this led to the 2022 collapse. Specialists need to consider these factors when tasked with conserving monuments located in comparable high-altitude perhumid environments. This integration of analytical results demonstrates how multi-scalar and multi-instrumental approaches provide comprehensive and timely assessments of conservation needs. [ABSTRACT FROM AUTHOR]

Sunken green space is one of the urban rainwater collection facilities, which belongs to Low Impact Development (LID) techniques. It plays a key role in the construction of sponge city, and the amount of runoff collection is usually affected by the area of the sunken green space, the infiltration rate of the soil, and the annual runoff collection rate. To determine the minimum soil infiltration rate of sunken green space considering the annual runoff collection ratio of sponge cities, this paper selects a residential district in Hefei city, China, as the case study. Based on 45 years of precipitation data, the designed rainfall corresponding to annual runoff collection ratios of 75%, 80% and 85% is 21.3 mm, 23.4 mm and 27.5 mm, respectively. The characteristics of rainfall infiltration in sunken green space are analyzed by using the water balance model and runoff yield and conflux model. The results reveal that the soil infiltration rate is 1.16×10−4 cm/s~3.88×10−3 cm/s when the sunken depth is 0.1 m~0.3 m and that the ratio of green space area is 5%~25%. The runoff collection of the reconstructed sunken green space is 2.87 times and 1.98 times that of the nonsunken green space and the nonreconstructed sunken green space, respectively. That is to say, under the comprehensive performance of the sunken depth, sunken green space area, the steady soil infiltration rater of the reconstructed sunken green space cannot be less than the value obtained in this paper. Otherwise, the requirements of annual total runoff reduction ratio of the sponge city cannot be met. Therefore, this study provides references for realizing the ratio of annual runoff collection and sponge city construction in similar urban areas. It can also be applied to optimal selection of sunken green space in some sponge city projects. [ABSTRACT FROM AUTHOR]

Soil infiltration properties (SIPs) are crucial soil hydraulic parameters for hydrological and erosion models as they regulate the movement of water and nutrients within the soil. Tillage practice can significantly impact the hydrological and erosional processes of sloping farmland by changing SIPs through altering soil structure. Nevertheless, knowledge regarding the effects of short‐term conservation tillage on SIPs is unclear, which greatly limits the management of soil and water resources of sloping farmland. This study aimed to clarify the potential impact and underlying mechanisms of short‐term implementation of conservation tillage on SIPs under three typical tillage management types: conventional downslope tillage (DT), conservation contour tillage (CT), and no‐tillage (NT) in the black soil region of Northeast China. SIPs of initial infiltration rate (IIR), steady infiltration (SIR), and hydraulic conductivity (Ks) were determined by a field disc infiltration experiment under pressure heads (h) of −3, −1.5, and 0 cm. The results revealed that short‐term implementation of conservation tillage management degraded SIPs, with a significant difference observed between DT and NT. In comparison to DT, the mean SIPs of IIR, SIR, and Ks of CT decreased by 27.5%, 31.2%, and 28.6%, and the corresponding reduced values of NT were 54.1%, 65.0%, and 65.5%, respectively. SIPs were significantly correlated with soil texture, bulk density (BD), capillary porosity (CP), total porosity (TP), field capacity (FC), saturated water content (SSWC), and organic matter content (SOM). Among these influencing factors, the variations in SIPs among different tillage management and soil layers were primarily influenced by differences in clay and gravel contents, FC, and SSWC and SSWC played the most critical role. These results highlight the substantial impacts and clarify the mechanisms of short‐term conservation tillage on SIPs, which is helpful for understanding the potential effect of short‐term conservation tillage management on hydrology and erosional processes, thereby improving the sustainable utilization of arable land. [ABSTRACT FROM AUTHOR]

Soil water infiltration is an important component of the hydrological cycle, and it is best evaluated when the raindrop impacts the ground surface. For this reason, it is affected by changes in land use and land cover and by the characteristics and physical–hydric properties of the soil. This study aimed to evaluate soil water infiltration in areas occupied by annual crops (soybean and corn) and pastures in two watersheds of the Teles Pires River-MT, using simulated rainfall, physical models, and principal component analysis. Infiltration rates were evaluated based on simulated rainfall with an average intensity of 75 mm h−1, with four repetitions per region (upper, middle, and lower) of the hydrographic sub-basins of the Caiabi and Renato rivers, and soil use with cover, without cover, and disturbed. Soil tillage provided higher water infiltration rates into the soil, especially in pasture areas in the two hydrographic sub-basins. There were significant adjustments to the mathematical models based on the infiltration rate data for all land use and land cover conditions. The soil attributes that most interfered with the infiltration rate were microporosity, bulk density, and total porosity in the crop areas of the middle Caiabi and microporosity, clay content, total porosity, and silt content in the areas farming at the source of the Renato River. The Horton and Philip models presented the best adjustments in the hydrographic sub-basins of the Caiabi and Renato Rivers, which are recommended for estimating the water infiltration rate into the soil in different uses, coverages, and regions. [ABSTRACT FROM AUTHOR]

This paper aims to provide a framework for simulating the formation process of melt-driven debris flow for use in the risk assessment of hazard. According to field research, the formation process of melt-driven debris flows consists of three stages including snow melting, soil infiltration, and runoff/debris flow propagation. From this point of view, an integrated model of melt-driven debris flows is developed, coupling three corresponding physical models through some common variables while considering the effects of temperature variations and entrainment. For the evaluation of the erosion rate of loose materials while considering the presence of fine particles, a relationship between critical shear stress and surface fine-particle proportion is introduced. This integrated model is employed to retrospectively analyze the formation process of the 2010 melt-driven debris flows in the Tianmo catchment, China. The numerical results show that the melt-driven debris flow formation process is effectively described by reproducing the behaviors at each stage based on the proposed model. Furthermore, the hourly temperature variation and sediment characteristics (e.g., coarse particle size and initial soil moisture content) are discussed in detail as factors affecting runoff and entrainment. [ABSTRACT FROM AUTHOR]

Using pulsed management in drip irrigation systems has become popular as a technique that improves soil water distribution patterns and increases water productivity (WP). Pulsed irrigation consists of on–off cycles, which continue until applying the entire irrigation depth. A two-growing season field experiment was conducted to examine the combined effects of pulsed drip irrigation and its off-time duration on the silage maize yield and WP in Varamin, Iran using a randomized complete block with a split-plot design and three replications. The pulsed management included four levels, applying the irrigation volume in one, two, three, and four pulses (P1, P2, P3, and P4) and off-time duration consisting of one and three, times the on-time duration in a pulse (T1, T3). The results indicated that the interaction of the various treatments on the yield, yield components, and WP of the silage maize was significant (P < 0.01). Increasing off-time duration from T1 to T3 resulted in a 6.5% increase in plant height and stem diameter, a 13.9% increase in 1000-grain weight, and an 11.6% average increase in crop yield and WP over two growing seasons in P4 treatment. Investigating soil water content in the crop root zone demonstrated that increasing the number of pulses and off-time duration and, thus, increasing the time for the infiltration process and soil moisture redistribution improved water distribution in the soil profile, crop yield, and WP. Therefore, with similar soil texture and a high discharge rate of emitters, it is recommended to increase the number of pulses and off-time duration to enhance water redistribution in the soil. [ABSTRACT FROM AUTHOR]

Soil structure is a key attribute of soil quality and health that significantly impacts water infiltration. Structure can be significantly altered by natural or anthropogenic drivers including soil management practices and can in turn impact soil infiltration. Those changes in soil structure are often complex to quantify and can lead to conflicting impacts on water infiltration into soils. Here, we present a narrative systematic review (SR) of the impacts of soil structure on water infiltration. Based on inclusion and exclusion criteria, as well as defined methods for literature search and data extraction, our systematic review led to a total of 153 papers divided into two sets: experimental (131) and theoretical (22) papers. That implied a significant number of in-situ and field experiments that were conducted to assess the impacts of soil structure on water infiltration under the influence of different land uses and soil practices. Analysis of the metadata extracted from the collected papers revealed significant impacts of soil structure on water infiltration. Those effects were further attributed to land use and management, where we demonstrate the impact of three unique categories: soil amendments, crop management and tillage. Furthermore, significant correlations were established between infiltration rate and soil structural properties, with R2 values ranging from 0.51 to 0.80 and for saturated hydraulic conductivity and soil structural properties, with R2 values ranging from 0.21 to 0.78. Finally, our review highlighted the significant absence of and the need for theoretical frameworks studying the impacts of soil structure on water infiltration.

Muddy water irrigation, an effective water-saving irrigation method, has been widely used in the Yellow River Basin in China. To investigate the effect of sand content on water infiltration and dense layer formation under one-dimensional vertical infiltration of muddy water, muddy water infiltration experiments were performed in the laboratory, and five sand contents of muddy water (S=0%, 3%, 6%, 9%, and 12%) were used. Models were established to describe the relationship between the cumulative infiltration amount [I(t)] and the infiltration duration (t); the relationship among the migration distance of the wetting front (Z), S, and t; the thickness of the sedimentary layer [H(t)]; and the relationship between S and t. The results revealed that I(t) and Z decreased significantly with the increase of sand contents, while H(t) increased significantly with the increase of sand contents. I(t) and Z were in the range of 7 cm and 20 cm for each treatment, respectively. The variation in I(t) with t fitted Kostiakov and Philip models, and the coefficients of determination were all greater than 0.99. With the increase in S, the infiltration coefficient gradually decreased, the infiltration index gradually increased, and the sorptivity gradually decreased. The particle composition of the sedimentary layer was similar to that of the argillaceous sediment, and the content of particles with a size of less than 2 mm in the sedimentary layer was lower than that of the argillaceous sediment. Compared with the original soil, the content of particles with a size of less than 0.05 mm and physical clay particles (diameter less than 0.01 mm) in the soil with an infiltration depth of 0-2 cm increased. The retention layer was from the topsoil to the infiltration depth of approximately 2 cm. This study can provide a scientific basis for further research on soil infiltration mechanisms under muddy water [ABSTRACT FROM AUTHOR]

Physical model experiments are increasingly applied in the study of the water infiltration law in loess with roots. In the past, due to differences in study objects and the limitations of measuring techniques, the infiltration law in loess with roots is rarely evaluated by using appropriate indoor physical model experimental data. In order to investigate the law of water infiltration in loess with roots, we designed a new soil column experimental device that can automatically collect data and images. By comparing the soil column experiment data of loess, we analyzed variables in root contents (the ratio of root mass to dry soil mass) and root types. Roots with diameters of 0–2 mm, 2–5 mm, and 5–10 mm are defined as type I, type II, and type III, respectively. It was found that the water infiltration rate, water-holding capacity, and saturated permeability coefficient increase with the increase in root content. In loess containing different root types, the root types were found to improve the rate of water infiltration, water-holding capacity, and saturated permeability coefficient in the soil. The root types were ranked in descending order in terms of their impact: root type II had the highest improvement, followed by root type III, and then root type I. The phenomenon of circumferential flow existed when water infiltrated loess with roots. Root content and root type would affect the radius of circumferential flow, infiltration path, and cross-section. When calculating the saturated permeability coefficient of loess with roots, ignoring the effect of circumferential flow would lead to a higher result. [ABSTRACT FROM AUTHOR]

Tabular Middle Atlas of Morocco holds the main water reservoir that serves many cities across Morocco. Dolomite and limestone are the most dominant geologic formations in this region in which water resources are contained. The recent studies conducted to evaluate the quality of this water suggest that it is very vulnerable to pollutants resulting from both anthropogenic and natural phenomenon. High and very high-resolution satellite imagery have been used in an attempt to gain a better understanding of this karstic system and suggest a strategy for its protection in order to reduce the impact of these phenomenon. Based on the surface reflectance of land cover benchmarks, the karstic system has been horizontally delineated, as well as regions with intense human activities. Using band combination in the portion of the infrared, shortwave infrared, and visible parts of the electromagnetic spectrum, we identified bare lands which have been interpreted as carbonate rocks, clay minerals, uncultivated fields, basalts rocks, and built-up areas. Other classes such as water and vegetation have been identified. Carbonate rocks have been identified as areas with a high rate of water infiltration through their fracture system. Using a Sobel operator filter, these fractures have been mapped and their results have revealed new and existing faults in two major fracture directions, NE-SW and NW-SE, where NE-SW is the preferable pathway for surface water infiltration towards the groundwater reservoir, while the NW-SE direction drains groundwater from the Cause to the basin of Saiss. Over time, the infiltration of surface water through fractures has contributed to a gradual erosion of the carbonate rocks, which in turn developed karst landforms. This karst system is vulnerable due to the flow of pollutants in areas with shallow sinkholes. Using GDEM imagery, we extracted karst depressions, and their analysis shows that they are distributed along the fracture system and many of them were located on curvilinear or linear axes along the NE-SW fracture direction. We found also dolines scattered in areas with a high intensity of fractures. This distribution has been validated by both on-the-ground measurements and very high-resolution satellite images, and depressions of different forms and shapes dominated by dolines, poljes, lapiez, and avens have been identified. We also found many water springs with a highly important water output, such as the Ain Maarrouf water spring. The aim of this study is to enhance the understanding of the hydrogeological system of TMA, to improve the existence of the fracture database in the Cause of Agourai, and to establish a new morpho-structural picture of the Ain Maarrouf water spring. [ABSTRACT FROM AUTHOR]

Species-specific tree traits substantially impact precipitation partitioning, soil infiltration, retention, and overall water management. With the changing climate, the evidence of drought-induced tree mortality is increasing, indicating the need for a shift to more resilient species. Therefore, the knowledge of tree species' effect on soil–water management is needed. We used a total of 54 stations for monitoring the soil moisture regimes of silt loam soil in Central Bohemia under three common and different tree species (spruce, larch, and beech). For the dry and warm part of the year 2022, the soil moisture in winter and early spring was significantly lowered by high canopy interception and gradually depleted by early spring transpiration of evergreen spruce, where mean values were more than 15% lower than for beech. Since March, the soil moisture under spruce was already below the limit of easily available water. In contrast, the deciduous beech and larch did not show a significant decrease until the foliage emergence in early May. The beech stands showed the highest soil moisture levels, which we attributed to a more effective water recharge mechanism induced by its structural traits. This adaptive strategy is vital as soil–water storage is critical for coping with climate change. In general, the results show a distinct advantage in the water recharge ability of deciduous trees and that the selection of tree species can distinctly affect soil moisture conditions, especially during drought periods in areas characterized by tight hydrological balance. [ABSTRACT FROM AUTHOR]

Agricultural land preparation and weed control techniques are essential farm management tools that affect the dynamics of soil water infiltration and the estimation accuracy of infiltration models. To analyse the interaction effect of tillage and weed control methods on the changes in soil physical properties and the efficacy of infiltration models, an experiment was conducted on a sandy clay loam forest ochrosol at Hodzo near Ho in Ghana. Four tillage systems (No Tillage [NT], Reduced Tillage [RT], Plough + Harrow + Ridging [PHR], and Deep Tillage + Plough + Harrow + Ridging [DPHR]) and three weed control methods (Hoeing [H], Machete [MAT] and No Weeding [NW]) were employed. The study also tested the reliability of the models (Kostiakov, Philip, and Horton) using the goodness of fit statistical criteria: Root mean squared error (RMSE), Mean absolute error (MAE), Coefficient of determination (R2), and Nash-Sutcliffe efficiency (NSE). The results show that conservation tillage systems (CsT) and conventional tillage systems (CT) with MAT weeding treatments recorded the highest moisture content across the studied soil profile, especially for NT x MAT (11.189%) which was significant (p < 0.05) in the 15–30 cm layer; the lowest were observed in the CsT and CT with H weeding interactions, especially for the DPHR x H (8.086%). Comparing the interaction effect on the soil infiltration, the highest mean infiltration rate was significant (p < 0.05) under the NT X H treatment combination whilst the lowest infiltration rate was recorded in the DPHR X H and PHR X NW treatment combinations. The efficiency of the fitting models (Kostiakov > Horton > Philip) highly prioritised the soil tillage operations and weed management under the treatments DPHR x MAT > DPHR x NW > DPHR x H > RT x MAT > PHR x NW > PHR x MAT > NT x NW > RT x MAT > PHR x H > RT x H > NT x MAT > RT x NW > NT x H in that order. The trend shows that the increase in tillage intensity and the decrease in weed management intensity induce the quality of the estimation process and vice versa. The study, therefore, identified the use of machete (MAT) with DPHR under the Kostiakov model as the efficient land management for modelling the cumulative infiltration characteristics of the sandy clay loam ochrosols of the study area. [ABSTRACT FROM AUTHOR]

To address the problems of inadequate water and fertilizer retention performance of the substrate, which results in the waste of water and fertilizer resources and then contributes to existing agricultural non-point source pollution, this study selected raw materials with different water retention performances for substrate compounding and explored their water retention performance and impact on the growth, yield and quality of strawberries. The experimental setup utilized the strawberry cultivar 'Hongyan' as the test subject and incorporated different proportions of vermicompost, coconut bran, biochar and humic acid into the organic fertilizer. A total of 12 treatment groups were formed across three gradients, involving different proportions of vermicompost with 0.05, 0.10 and 0.15 proportions of coconut bran/biochar and 0.05, 0.15 and 0.20 proportions of humic acid. To evaluate the water retention performance, uniform water and fertilizer regulations were applied. The results revealed that the treatment groups T4 (vermicompost:coconut bran = 0.5:0.1) and T5 (vermicompost:biochar = 0.5:0.1) exhibited higher water absorption multiplicity, lower water infiltration rates, and better water retention performances, but there was no significant difference between the two treatment groups. Among them, T4 could effectively improve the nutrient content of the substrate, and the substrate nitrogen-use efficiency (NUE) increased by 5.80% compared with CK2. Also, plant total nitrogen (TN) and total phosphorus (TP) uptake increased by 81.18% and 4.74%, respectively, compared with CK2, which in turn promoted the growth and development of the plant and improved the fruit yield and quality to a certain extent. Meanwhile, T4 had the highest urease and catalase activities, with sucrase activity ranking second only to T1. In contrast, T5 demonstrated greater effectiveness in improving the average fruit weight and maximum fruit weight, registering increases of 22.98% and 36.22% compared to CK2, respectively, but the effect on the total yield was less pronounced. A comprehensive evaluation of strawberry growth found that the T4 treatment was superior. In conclusion, the ratio of vermicompost and coconut bran at 0.5:0.1 improved and promoted the substrate water retention performance and strawberry growth. [ABSTRACT FROM AUTHOR]

In this paper, we have first discussed that groundwater is very important, especially as it is getting scarce. We see rain waters on the puddles but it is not going underground. That has to do with the increased saturated soil, which gives less space for water to move deeper. We studied the nonlinear problem that arises in infiltration phenomenon with External effect (Input and output). The infiltration phenomenon with External effect (Input and output) is defined by a non-linear partial differential equation, which gives the soil moisture content under suitable conditions. The moisture content was determined and was analyzed using the Differential transform method. We investigated groundwater infiltration with an external impact (Input and output) using the Differential Transform method. The analysis is also explained, as well as its numerical and graphical depiction. For this, we utilized MATLAB for that. [ABSTRACT FROM AUTHOR]

The rapid development and growth of Purwokerto requires greater groundwater resources. Research on groundwater vulnerability in Purwokerto is important in order to maintain groundwater resources, sustainability and development of the city. The approach or methods used in this research were: groundwater level measurement, geoelectric survey, and infiltration rate measurement to calculate the aquifer vulnerability index or AVI. This research uses soil infiltration rate data from the surface to a certain depth and the hydraulic conductivity of the lithologies located below the soil. The application of soil infiltration rate data and lithological hydraulic conductivity located below the soil provides a more continuous AVI level without any level voids than solely using lithological hydraulic conductivity data in the previous study. The AVI level of Purwokerto area ranges from low, moderate, high to extremely high. The level of AVI vulnerability in the lithology of the Slamet Volcano Lahar Deposits and Alluvium or its weathered soil is more varied than the lithology of the Tapak Formation and its weathered soil. This is thought to be related to variations in the composition of the components that make up each lithology which causes variations in weathering and AVI levels. [ABSTRACT FROM AUTHOR]

The infiltration rate of soil data is important in a wide range of planning, such as city planning, drainage design, landuse planning, flood prediction, flood disaster mitigation, etc. Collecting data of infiltration through in-site direct measurements is time consuming and costly. Indeed, inferring the infiltration rate using available parameters and the fittest model is needed. The model can shortcut the field measurement to get a predicted accurate infiltration rate that is worthy to support vital planning. This research aims to develop a model of infiltration rate based on initial water contents and grain size of soils. The results are three outstanding models based on the Multiple R Squared, Root Mean Square Error (RMSE), and Mean Average Error (MAE). The implication of the fittest model is reducing the cost and time to get the predicted infiltration rate. The field measurements can be skipped by sampling undisturbed soils and laboratory tests. [ABSTRACT FROM AUTHOR]

This study was undertaken in the Himalayan basin, in the river Lohawati, Uttarakhand, to study its hydro-morphological characteristics and prioritise the watersheds using geospatial tools. Advanced Spaceborne Thermal Emission and Reflection (ASTER-30 m) data and the Survey of India's topographic sheets were used to analyse the study area comprehensively. Nine watersheds were identified within the basin in order to calculate the hydro-morphological characteristics in terms of basic, shape, texture, and relief aspects. The basin was identified as being elongated, with a total drainage area of 337.48 km2. The interaction between the terrain, rock formations, and precipitation levels produced a branching structure in the areas drainage system that ranged from dendritic to sub-dendritic. The basin had been classified as a fifth-order basin, comprising a network of 500 stream segments spanning a total length of 492.41 km. In each of the watersheds, the primary streams are of the first order, followed by those of the second order, and so forth. The physiography and lithology of the basin have a significant influence on this pattern. The calculated elongation ratio, circulatory ratio, form factor, shape index, and shape factor ranged from 0.57 to 0.80, 0.35 to 0.64, 0.26 to 0.50, 1.98 to 3.89, and 0.57 to 1.77, respectively. These values indicate that watersheds are elongated, suggesting moderate lag times. The parameters, including drainage density (0.98 to 1.62), stream frequency (1.07 to 1.59), infiltration number (1.04 to 2.59), drainage texture (0.67 to 2.82), and drainage intensity (0.93 to 1.12), pointed towards the coarser drainage texture, higher infiltration, and minimal runoff characteristics of the basin. In light of the relief characteristics of the basin, a higher basin relief, relief ratio, and relative relief were observed for the watersheds, indicating the possibility of higher erosion and deforestation rates. Using the Weighted Sum Analysis (WSA) method, the computed factors were utilised to rank the watersheds based on their potential for erosion. Based on the WSA approach, watersheds were classified into high-, moderate-, and low-prioritisation zones. This further indicates that 36.14% (121.95 km2) of watersheds are in the high-priority zone, and that 48.84% (164.91 km2) and 15.00% (50.62 km2) of watersheds are in the moderate- and low-priority zones, respectively. The WSA is a practical strategy to prioritise watersheds when making appropriate decisions. [ABSTRACT FROM AUTHOR]

Moistube irrigation is an efficient method that accurately irrigates and fertilizes agricultural crops. Investigation into the mechanisms of infiltration behaviors under an adjusted working head (WKH) benefits a timely and artificially regulating moisture condition within root zones, as adapted to evapotranspiration. This study explores the laws of Moistube irrigated soil water movement under constant and adjusted working heads. Lysimeter experiments were conducted to measure Moistube irrigation cumulative infiltration, infiltration rate, and to observe wetting front area and water content distribution using digital image processing and time domain reflectometry, respectively. Treatments of constant heads (0, 1, and 2 m), increasing heads (0 to 1, 0 to 2 and 1 to 2 m) and deceasing heads (1 to 0, 2 to 0 and 2 to 1 m) were designed. The results show that (1) under constant heads, the cumulative infiltration increases linearly over time. The infiltration rate and cumulative infiltration are positively correlated with the pressure head. When WKH is increased or decreased, the infiltration rate and cumulative infiltration curves significantly change, followed by a gradual stabilization. The more the head is increased or decreased, the more evident this tendency will be. (2) When WKH is increased, the wetting front migration rate and the wetted soil moisture content marked increase; when WKH is decreased, the wetting front migration rate sharply decelerates, and the water content of the wetted soil slowly grows. They both tend to equilibrium with time. (3) By regarding the same cumulative infiltration of increased WKH and constant WKH treatments as a similar initial condition, we proposed a cumulative infiltration empirical model for Moistube irrigation under variable working head. Additionally, we treat the Moistube as a clayey porous medium and construct a HYDRUS-2D numerical model to predict the infiltration behaviors under variable WKH. The validity of the two models were well proven, with MRE and NRMSE close to 0 and NSE greater than 0.867, indicating good agreements with the experimental results. This model breaks through the limitation of constant boundary of traditional numerical model and applies variable head boundary to the boundary of the Moistube pipe, which can also effectively simulate the response mechanism of Moistube irrigation to variable WKH. The research results further confirmed the feasibility of manually adjusting the WKH to regulate the discharge of the Moistube pipe and soil moisture state. Based on the HYDRUS-2D numerical model simulation results and the root distribution and water demand of typical facility crops, the selection range of placement depth and the adjustable range of WKH of Moistube irrigation were proposed. The research results provide a theoretical reference for manual adjustment or automatic control of Moistube irrigation WKH to adapt to real-time crop water demand in agricultural production. [ABSTRACT FROM AUTHOR]

[Objective] In order to provide a reference for revealing the infiltration law of the L1-S5 layers of the Baoji loess-paleosol profiles in the middle and late Pleistocene, the variation characteristics of water stable infiltration rate of L1-S5 loess and paleosol in Baoji Middle Late Pleistocene Series and its relationship with soil properties such as soil bulk density, initial soil water content and soil capillary porosity are explored. [Methods] The characteristics and its influencing factors of stable infiltration rate of loess and paleosol in the middle and late Pleistocene of Baoji were studied by double ring method. [Results]（1） The average stable infiltration rate（2.38 mm/min） of the loess is higher than that of the paleosol（1.55 mm/min） in the middle and late Pleistocene of the L1-S5 layers of the Baoji loess-paleosol profile, which may be related to the climate change at the time of formation and the strength of the weathering soil.（2） The infiltration experiment of loess and paleosol can be well fitted by using Kosgakov and general empirical formulas in the L1-S5 layers of the Baoji loess-paleosol profile in the middle and late Pleistocene.（3） Soil properties, such as soil bulk density, initial soil water content, saturated soil water content and so on are important factors affecting the stable infiltration rate of loess and paleosol in the L1-S5 layers of the middle and late Pleistocene of Baoji.（4） The soil stable infiltration rate（R²=0.88, NSE=0.88） of loess and paleosol in the L1-S5 layers of the Baoji loess-paleosol profile in the middle and late Pleistocene can be well simulated by using such parameters as soil bulk density, soil capillary porosity, maximum capillary water capacity, total soil porosity, soil saturated water content and soil initial water content. [Conclusion] The changes of stable water infiltration rate of loess and paleosol are mainly caused by the changes of soil bulk density, initial soil water content and capillary porosity. These soil parameters can be used to simulate the changes of stable water infiltration rate of L1-S5 loess and paleosol in the Middle Late Pleistocene in Baoji. [ABSTRACT FROM AUTHOR]

Plastic-film mulching plays an important role in farming practice and acts as a barrier to soil surface. Residual plastic film (RPF) affects the water and nutrient flow in the soil. A column experiment was conducted to observe the variation of water infiltration in the soil and wetting front under different amount and distribution of RPF. Eight kinds of RPF treatments (0, 40, 80, 160, 270, 400, 800 and 1400 kg hm−2) and two kinds of distribution treatments (average distribution and decreasing distribution layer by layer) were designed in the experiment. The results showed that RPFs had a negative impact on soil water infiltration and wetting front, especially if higher than 400 kg hm−2. The stable infiltration rate decreased 64.3% in average distribution and 71.4% in decreasing distribution layer by layer. The migration distance of the wetting front decreased by 2.51 cm in average distribution and 3.32 cm in decreasing distribution layer by layer. The Kostiakov and power function models suggest that decreasing the distribution layer by layer provides greater benefits to farming soil. This study provided a theoretical reference for actual soil water movement patterns in RPF-contaminated areas of the field. [ABSTRACT FROM AUTHOR]

The analysis of rainwater infiltration is crucial for the prevention and early detection of rainfall-induced landslides. Under the assumption of saturated-unsaturated stratification, and considering the influence of saturated layer seepage and air pressure on infiltration, a modified Green-Ampt model (SRGA model) suitable for slope rainfall infiltration is established. A corresponding slope safety factor expression is derived for the model. The results show that the SRGA is demonstrated to accurately describe dynamic expansion of the wetting layer throughout the heavy rainfall infiltration process; it is also applicable under weaker rainfall conditions. Validation against experimental data confirms the model's accuracy, with an error of approximately 21% compared to Chen-Young's model. The instability time predicted with the SRGA model during the slope stability analysis emerges approximately 7.2% earlier than measured, significantly outperforming Chen-Young's model. Air pressure and seepage force influence infiltration depth through different mechanisms. The influence of air pressure is more significant in the early control stage of soil infiltration capacity, while seepage force is more significant in the later stage. Rainfall infiltration is affected by slope length to greater extent than slope stability. The SRGA model is versatile, and can be simplified into existing models under certain conditions. The results of this work may provide theoretical support for slope control under rainfall infiltration conditions. [ABSTRACT FROM AUTHOR]

Modifications to the landscape for urban expansion directly impact the natural hydrological dynamics in Urban Hydrographic Micro-basins (UHMs). This study aims to develop the Urban Flood Susceptibility Index (UFSI) from indicators pertinent to different spheres, considering both infiltration and surface runoff of rainwater, and apply it in UHMs of a municipality in the Midwest Region of Brazil. Historical records of urban floods available in information media are used to validate the UFSI. The methodology adopted involves the Analytical Hierarchical Process linked to the Geographic Information System. UFSI is composed of the following indicators: average slope (Sa), coefficient of compactness (Kc), drainage density (Dd), demographic density (Ddem), degree of surface permeability (DSP), susceptibility to production of sediment (SPS), daily precipitation (Pd), degree of canalization of watercourses (DCW), condition of storm drains (CSD), and rainwater retention devices (RRD). Therefore, USFI simultaneously includes morphometric, environmental, land use and occupation, and urban infrastructure indicators. Pd (0.16 for both dimensions) and DSP (0.15 for surface runoff and 0.26 for infiltration) indicators are the most significant for urban flood susceptibility in both analysed dimensions. Sa (0.15) and DCW (0.14) are relevant in relation to surface runoff, while RRD (0.13) and SPS (0.09) regarding to infiltration. UFSI and historical records of each UHM obtained strong correlation (r > 0.80), evidencing reliability and validation of the index. The UFSI can assist in the formulation of guidelines for land use and occupation and to indicate UHMs that require attention from the public authority for sustainable socioeconomic development. [ABSTRACT FROM AUTHOR]

The Xiashu loess exhibits expansion when in contact with water and contraction when water is lost, making it highly susceptible to the influence of rainfall. Therefore, it is essential to investigate the infiltration behavior of rainwater in Xiashu loess slopes under various conditions. The depth of infiltration in slopes directly affects the depth of landslide failure and serves as an important indicator for studying slope infiltration characteristics; only a handful of academics have delved into its study. This article is based on on-site rainfall experiments on Xiashu loess slopes, using three main factors, rainfall intensity, rainfall duration, and slope angle, as discrimination indicators for the infiltration depth of Xiashu loess slopes. The particle swarm optimization algorithm is employed to optimize the BP neural network and establish a PSO-BP neural network prediction model. The experimental data are accurately predicted and compared with the multivariate nonlinear regression model and traditional BP neural network models. The results demonstrate that the PSO-BP neural network model exhibits a better fit and higher prediction accuracy than the other two models. This model provides a novel approach for rapidly determining the infiltration depth of Xiashu loess slopes under different rainfall conditions. The results of this study lay the foundation for the prediction of the landslide damage depth and infiltration of Xiashu loess slopes. [ABSTRACT FROM AUTHOR]

Soil erosion by water on agricultural hillslopes leads to numerous environmental problems including reservoir sedimentation, loss of agricultural land, declines in drinking water quality, and requires deep understanding of underlying physical processes for better mitigation. It is imperative to accurately predict soil erosion caused by overland flow processes so that soil conservation efforts can be undertaken proactively before large-scale sedimentation problems arise. Soil detachment is often described by the excess shear stress equation that contains two physical soil erodibility parameters, erodibility coefficient, and critical shear stress. These parameters are normally assumed to be constant but can change across varying soil texture classes as well as during surface runoff events due to changes in soil cohesion and potential dependency on soil moisture content. These changes may significantly affect soil erosion rates at the field and watershed scale. In this study, the erodibility parameters of three soil types (sandy loam, clay loam, and silty clay loam) were analyzed using a laboratory mini-Jet Erosion Test (JET) to determine the effect of soil sample infiltration and moisture condition. Results from the experiments depicted a dynamic relationship between the soil erodibility parameters and amount of infiltrated mass of water. Data analysis displayed that for soils of different texture critical shear stress exhibited local minimum with higher values for very dry and saturated soils, while erodibility coefficient tended to increase with the increase of mass of soil water. Utilizing these dynamic soil erodibility parameters did not result in a significant difference in soil erosion rates when compared to using the averaged soil erodibility parameters taken from the experiment but the range of potential erosion rates increases with the increase of applied sheer stress to soil surface. The erosion rates with the experiment-based coefficients were found to be higher than with the baseline WEPP-based coefficients. These results highlight the importance of evaluating the effect of intrastorm dependent factors during surface runoff events, such as antecedent soil moisture content, time to peak from the start of runoff, soil cohesion, etc., on soil erodibility parameters to accurately calculate erosion rates, especially for initially dry soils or during earlier stages of surface runoff when critical shear stresses were highly affected. Further assessment of such factors with JET or other laboratory and field tests is recommended. [ABSTRACT FROM AUTHOR]

Eutrophication is a common problem for the dams situated within an urban or agricultural catchment with a high source of untreated plant nutrients. This can negatively affect the hydro ecosystem, recreational and other uses of water. On the other hand, such eutrophic dams could also be a rich source of nutrients for agricultural use. Thinking irrigation as an alternative means of eutrophic reservoir water management, water suitability for irrigation was investigated for Roodeplaat Dam, South Africa using physicochemical parameters recorded (1981–2017) at five sampling stations. Irrigation suitability was evaluated in terms of nutrient content, salinity, soil infiltration, and toxicity problems to irrigated plants. Plant nutrients: NH4_N, NO3_NO2_N, PO4_P, are within the normal range. But K is above the normal range for irrigation use and can cause nitrogen deficiency. The salinity of 0.44 dS/m was found within the normal range with none restriction for irrigation use. Na toxicity in terms of SAR and Cl toxicity was none for both surface and sprinkler irrigated plants. The pH value of 8.4 was within the normal range (6.5–8.4). Generally, the quality of the reservoir water was categorized under C2S1 (medium salinity and low sodium hazard). Irrigation water can cause slight to moderate soil infiltration problem. Therefore, eutrophic reservoirs can be a potential source of readily available nutrients for irrigation and, hence irrigation use can be considered as one of the remedial measures to decrease nutrient accumulation in the reservoir. The existing water conveyance system can be used to transport water to agricultural fields. [ABSTRACT FROM AUTHOR]

This research uses random forest machine learning to develop infiltration-friendly land-use scenarios, addressing the global 32% change in land use over the past six decades. The study used Sentinel-2A satellite imagery data for 2017, 2019, 2021, and 2022 as a land use baseline, predicting business as usual using cellular automata and comparing it with regional spatial planning and land capability scenarios. One hundred points of infiltration data were distributed using a random forest. Results showed that deforestation and its change into orchards, rice fields, and settlements over five years affected the infiltration. Business as usual reduces the high infiltration class to approximately 1,545 ha, while regional spatial planning and land capability cover 1,390 ha and 1,316 ha, respectively. The most infiltration-friendly land-use scenario is applicable at the sub-watershed level, with an accuracy of about 97%. The limitations of this research include not comparing extreme dry seasons and using 2022 infiltration values for all other years. [ABSTRACT FROM AUTHOR]

Purpose: Unpaved road erosion represents a key source of terrigenous sediment threatening Caribbean coral reefs, yet no empirical data existed to document this in Culebra, Puerto Rico. Here, we compared unpaved road erosion to that from undisturbed hillslopes and evaluated the effects of road grading frequency and slope on erosion. Methods: A total of 46 plot-scale rainfall simulation experiments were used to measure runoff response and erosion rates from undisturbed hillslopes and unpaved roads with varying slopes and time since grading. Rainfall rates recorded over a one-year period combined with empirically derived infiltration capacity curves and erosion rates allowed for annualizing runoff and sediment production for natural hillslopes and four road types representing different grading frequencies and slopes. Results: Infiltration rates from roads were between a tenth and a quarter of those from natural hillslopes and that lead to roads generating runoff five times more frequently than natural hillslopes annually. Road erosion rates were between 330 and 760 times greater than those from undisturbed hillslopes, depending on slope and grading. Roads represent a dominant source of sediments responsible for increasing watershed-scale erosion rates from 1.1 to 25 times above background rates. Conclusion: Unpaved roads represent a major source of the sediment that threatens the coral reefs of Culebra. Therefore, future new road building must be kept to a minimum and unpaved roads must be the focus of coral reef protection efforts. [ABSTRACT FROM AUTHOR]

Climate change brings with it phenomena such as large amounts of rainfall in short periods. Infiltration of rainwater into clayey soils is a common trigger for shallow landslides on slopes. In this way, numerous shallow landslides occur in the area of northern Croatia, and a characteristic example is the landslide "Orehovčak". To stop the sliding of the destabilized slope, it was necessary to solve the drainage of water that infiltrates the landslide body. For this purpose, detailed geotechnical investigations and monitoring were conducted. Many data were collected at the investigation site, especially soil characteristics and groundwater fluctuations. The surface soil on the slope consists of highly plastic clay, and the sliding surface was created in contact with the solid subsoil of marl, the depth of which varies positionally. The analyses confirmed that water is a slip trigger. To solve the problem, excavations and installation of deep drains were performed. The slope safety factor confirms landslide stabilization, whose calculated value after rehabilitation was Fs = 1.645. Inclinometer readings carried out after remediation show that slope slippage stopped. This confirms that the presented remediation method is very applicable to shallow landslides in northern Croatia and similar landslides around the world. [ABSTRACT FROM AUTHOR]

Clarifying the distribution and dynamics of soil moisture during the freeze–thaw process is crucial for surface ecology and is an objective requirement to investigate the mechanism of changes during the groundwater recharge process in a freeze–thaw zone. Based on the monitoring data of soil moisture and temperature in the Changbai Mountain area, the freeze–thaw process is classified into four periods. This study investigates the hydrothermal migration processes during different periods. The simultaneous heat and water model is used to simulate and analyse the infiltration of soil moisture into groundwater under five precipitation insurance rates. The results are as follows: (1) The smaller the soil depth, the stronger is the correlation between soil temperature and air temperature during the freeze–thaw process. (2) The redistribution of soil moisture before and after freeze–thaw is significantly affected by the soil texture, and soil permeability affects the recharge of soil moisture from the upper region to the lower region during the thawing period. (3) Groundwater receives vertical infiltration recharge mainly during non‐freezing and is supplied by freezing and snowmelt recharge during the stable thawing period. The percentage of soil water infiltration during the stable thawing period in the total annual infiltration increases gradually with the precipitation insurance rate. [ABSTRACT FROM AUTHOR]

The interception of rainfall by plant canopies alters the depth and spatial distribution of water arriving at the soil surface, and thus the location, volume, and depth of infiltration. Mechanisms like stemflow are known to concentrate rainfall and route it deep into the soil, yet other mechanisms of flow concentration are poorly understood. This study characterizes pour points, formed by the detachment of water flowing under a branch, using a combination of field observations in Western Australian banksia woodlands and rainfall simulation experiments on Banksia menziesii branches. We aim to establish the hydrological significance of pour points in a water‐limited woodland ecosystem, along with the features of the canopy structure and rainfall that influence pour point formation and fluxes. Pour points were common in the woodland and could be identified by visually inspecting trees. Throughfall depths at pour points were up to 15 times greater than rainfall and generally comparable to or greater than stemflow. Soil water content beneath pour points was greater than in adjacent controls, with 20%–30% of the seasonal rainfall volume infiltrated into the top 1 m of soil beneath pour points, compared to 5% in controls. Rainfall simulations showed that pour points amplified the spatial heterogeneity of throughfall, violating assumptions used to close the water balance. The simulation experiments demonstrated that pour point fluxes depend on the interaction of branch angle and foliation for a given branch architecture. Pour points can play a significant part in the water balance, depending on their density and rainfall concentration ability. Plain Language Summary: When rain hits a tree canopy, it either wets the canopy, falls off, or flows along the tree's surfaces (leaves, branches, and trunk). This interaction changes the amount and location of water arriving at the ground. The water flowing underneath branches is may eventually reach the ground by flowing along the tree trunk as stemflow. Using a combination of field observations in seasonally dry Banksia woodlands and rainfall simulation experiments on tree branches, we show that this water may, alternatively, peel off the branch and reach the ground at a "pour point." Rain gauges placed under pour points recorded 1.5–15 times the water recorded at rain gauges under the open sky. We showed that the quantity of water arriving at the pour points varies with the rain volume, and with branch properties including the upstream leaf area, angle, and shape of the branch. The changes in the distribution of water received beneath tree canopies and deeper infiltration into the soil due to pour points proved their hydrological significance. Understanding pour points represents one path toward an improved characterization of the complex processes occurring when rain hits a tree canopy. Key Points: Pour points occur when intercepted rain flowing under tree branches detach and their depths were 1.5–15 times the rainfallPour points increase spatial heterogeneity of throughfall and enhance infiltration into the soilRainfall simulation showed branch structure, foliation, and angle impose unclear controls on the volume of water received at the pour point [ABSTRACT FROM AUTHOR]

In order to investigate the impact of herbaceous root development on soil slope stability in expansive soil areas, the research was conducted in the soil slope experimental area of Yaoshi Town, Shangzhou District, Shangluo City. Three types of herbaceous plants, namely Lolium perenne, Medicago, and Cynodon dactylon, were planted to examine their influence on slope stability. The results indicated that Lolium perenne had significantly higher root length density and root surface area density compared to Cynodon dactylon and Medicago. However, the root weight density of Cynodon dactylon was found to be highest. The roots of Lolium perenne, Cynodon dactylon, and Medicago were predominantly observed in diameter ranges of 0 < L ≤ 1.0 mm, 0 < L ≤ 2.5 mm, and 2.5 < L ≤ 3.0 mm, respectively. The roots of herbaceous plants have the ability to enhance water retention in soil, resist hydraulic erosion of slope soil, and reduce soil shrinkage and swelling. During the initial phase of herbaceous planting, there is an accelerated process of organic carbon mineralization in the soil. The roots of herbaceous plants play a crucial role in soil consolidation and slope protection. They achieve this by dispersing large clastic particles, binding small particles together, altering soil porosity, enhancing soil water retention, and reducing soil water infiltration. It was found that Lolium perenne and Medicago, which have well-developed roots, exhibited superior slope protection effects. These findings contribute to the theoretical understanding for the implementation of green ecological protection technology on soil slopes. [ABSTRACT FROM AUTHOR]

The correlation between extreme precipitation and flood magnitude is still poorly understood because of the complex mechanisms controlling flood generation. In this study, we used 50 years of precipitation and streamflow data across Iran to analyse the spatial distribution, slope, and significance of long-term trends in extreme precipitation compared to the spatial distribution of long-term trends for flood magnitude and frequency. Despite the decreasing trend of extreme precipitation in 60% of Iran’s subbasins, the flood magnitude showed an increasing trend. In particular, the number of flooding days with a return period of 25~50 years and >50 years in 2010s has increased by 1.3 and 2.2 times, respectively, compared to that in 2000s. We attributed the above contrasting relationship between extreme precipitation and flood magnitude to the influence of an increase in short-duration extreme precipitations, extensive land use and land cover change, and reduced soil infiltration due to long-term droughts. [ABSTRACT FROM AUTHOR]

Identifying locations prone to exporting nitrogen (N), also called export control points, within residential landscapes, is key to determining N mitigation strategies. Within residential landscapes, lawns have the potential to act as either a sink of N via uptake and denitrification, or a source of N via additions such as fertilizer. Lawns draining to impervious surfaces are more likely to be sources of N loading to receiving water bodies through directly connected curb and sewer flow paths. We utilized small-scale rainfall experiments to examine whether hydrobiogeochemical measurements of potential denitrification and saturated infiltration rates were predictive of N mobilization, and how potential export control points (locations within the upper quartile of N mobilization values) varied spatially and temporally on residential lawns in Baltimore, Maryland. We found potential denitrification, but not infiltration, was predictive of N mobilization in runoff and leachate, only on fertilized lawns. Potential export control points occurred more often in the late summer and fall and 85% were on fertilized lawns. Applying fertilizer shortly before a rainfall event increased the N mobilization in runoff and leachate by an order of magnitude. Suburban front yards also had more potential export control points compared to backyards, which is notable as front yards are surrounded by impervious surfaces increasing their vulnerability to transporting N to downstream ecosystems. These findings highlight the spatial and temporal variability of N mobilization on lawns. Targeting locations such as vulnerable front yards, or behaviors, such as timing of fertilizer application, may be useful N mitigation strategies. [ABSTRACT FROM AUTHOR]

Subsoiling is an essential practice in conservation tillage technology. The amount of disturbed soil at various depths resulting from subsoilers with different parameters has an important effect on soil properties (e.g., bulk density and water infiltration). The information regarding the effects of subsoiling on the characteristics of soil water infiltration is essential for the design of subsoiling tools. In this study, the effects of the wing mounting height (h) (75–155 mm) of the subsoiler on soil disturbance and soil water infiltration were modelled using HYDRUS-2D and validated using field experiments. Results showed that reducing h values resulted in larger soil disturbance area ratios, soil water infiltration rates (f(t)), distances of vertical wetting front movement (DVWs), accumulative infiltrations (AINs), and soil moisture contents at depths of 10–30 cm. The relationships among characteristics of soil water infiltration, h and time (t), were developed. The stable infiltration rates (fs) varied quadratically with h and the corresponding coefficient of determination (R2) was 0.9869. The Horton model is more suitable for describing the relationship between f(t) and t under the tested soil conditions, as compared with the Kostiakov and Philip models. According to the results of soil water content at different depths from the HYDRUS simulations and field experiments, the developed soil water infiltration model had a good accuracy, as indicated by RMSEs of <0.05, R2 values of >0.95, and mean relative errors of <12%. The Above results indicated that increasing the hardpan disturbance by optimizing wing parameters of the subsoiler could improve soil water infiltration characteristics. [ABSTRACT FROM AUTHOR]

Formation of soil horizon boundaries are commonly qualitatively described, their formation and time evolution are rarely quantified by adequate mathematical modeling. In this paper, analytical (using conformal mappings) and numerical (involving HYDRUS2D simulations) methods are employed to model 2D infiltration-induced Darcian flows within a layered fine/coarse soil substrate system featuring a wedge-shaped interface, considering both saturated and unsaturated conditions. Initial-boundary value problems to the Richards (in particular, Laplace's) partial differential equations are set in domains with geometry of interfaces more complex than in regular soil profiles. The patterns of 2D distribution of physical characteristics (streamlines, isobars, velocities, etc.) are found in two variants of such a system (loam/gravelly non-capillary material, loam/sand), with comparison of analytical and numerical models. The novelty of the results is in the analysis of concentrating streamlines with maximum water flow rates and fastest travel time of advected marked particles at the tops of the jagged interface of the soil textures and the unsaturation of the underlying coarse-dispersed substrates during pressure infiltration of water in such systems. Also, if the soil surface is subject to small infiltration fluxes, the opposite phenomenon of capillary barrier, i.e. diversion of the infiltration flux from the top of the interface of the coarse substratum, is demonstrated in HYDRUS2D simulations. Prediction of morphological variations of soil profiles with non-horizontal interfaces, which undergo time-factor controlled anthropogenic drivers, is important for theoretical soil hydrophysics and hydrological and soil/geotechnical engineering. [ABSTRACT FROM AUTHOR]

In this paper, a new approach based on the demand-capacity model is developed for hydraulic design of granular and granular-cum-geocomposite drainage layers in pavements. The demand is given by the intensity-duration curve obtained from the Intensity-Duration-Frequency curve, which is geographic location specific and corrected for climate change. The capacity curve corresponds to critical infiltration rates and critical durations for a drainage layer which is influenced by the hydraulic and geometric characteristics. The design is acceptable if the capacity curve exceeds the demand curve. The design framework is illustrated for typical geometries of highway pavements with three granular gradations and three geocomposites. Based on the developed framework, hydraulic equivalence is defined and evaluated for the drainage layers. The permissible reduction of granular layer thickness for hydraulic equivalence is evaluated if geocomposite is embedded in the subbase layer of pavements. For an optimum gradation based on hydraulic and structural characteristics, the thickness of granular layer with geocomposite could be reduced by 30% compared to the granular layer without geocomposite, which showed similar hydraulic performance. The significance of drainage layer thickness with geocomposite is shown based on the demand for storage to satisfy the drainage requirement for rainfall events of high intensities and long durations. • The key points of this paper are summarized below: • A demand-capacity model is developed for the hydraulic design of granular and geocomposite drainage layers. • The demand is given by the climate-corrected intensity-duration curve. • The capacity curve for drainage layer is influenced by the hydraulic and geometric characteristics. • The design framework is illustrated for three granular gradations and three geocomposites. [ABSTRACT FROM AUTHOR]

The structure of soils is often heterogeneous with layered strata having distinct permeabilities. An advanced mathematical and numerical coupled model of elastic wave propagation in poroelastic multi-layered soils subjected to subsoil water infiltration is proposed in this study. The coupled model was based on the introduction of an inhomogeneous functionally graded fluid-saturation of the considered soil depending on the infiltration time, which was evaluated employing Richards' equation. The time-harmonic solution was formulated in terms of the Fourier transform of Green's matrix and the surface load that excites the vibration. The convergence and efficiency of the proposed approach are demonstrated. An example of dispersion curves for partially saturated porous strata made of loam, sand, and rock at different infiltration times is provided, and it is shown that the characteristics of the surface acoustic waves change with time, which can be further used for inverse problems' solution. [ABSTRACT FROM AUTHOR]

Slurry infiltration has strong influence on the slurry pressure transfer, which is important for slurry shields. In our previous study, we have studied the filter cakes and the infiltration process. However, the filter of slurry by soil and the relation between infiltration and soil particles were untouched there. In this study, some experiments including soil-filtering tests and penetration tests with sand-added slurry are carried out to study these two important topics. The results show that the slurry is indeed filtered by the soil during infiltration and the filtration starts with the large particles. It is known that sand-added slurry can significantly accelerate the formation of filter cakes in coarse strata. The results of this study show that the size of sands in the slurry should not exceed a threshold that depends on the aperture of the soil. A slurry that contains all sand size fractions with sizes less than the threshold will achieve the most efficient clogging. The filter-clog model proposed in this paper can well describe the clogging mechanism of the slurry infiltration. [ABSTRACT FROM AUTHOR]

Unconventional water resources (e.g., saline water, etc.) for irrigation as a promising supplementary water source can alleviate the freshwater shortage in the agriculture of red soil areas in Southern China. It should be noted that the presence of soluble salt in this water source may have detrimental influences on soil water infiltration and crop growth. Understanding the effect of unconventional water irrigation (UWI) on water infiltration in red soil is important. Previous studies have shown that the salinity of UWI can alter soil hydraulic properties to change soil water movement in saline soils. However, the underlying mechanism and factors of water infiltration in red soil under UWI with different salinity levels remain limited. Therefore, a laboratory experiment (one-dimensional vertical infiltration experiment and centrifuge method) was conducted to evaluate the effect of UWI with different salinity levels [0 (the distilled water, CK), 1 (S1), 2 (S2), 3 (S3), 5 (S5), and 10 (S10) g L−1] on the soil water infiltration process, soil water characteristic curve (SWCC), soil water constants estimated using the SWCC, saturated and unsaturated hydraulic conductivity (KS and K) as well as the soil chemistry of soil profile [pH, electrical conductivity (EC), and Na+ and Cl− contents]. The primary factors of soil water infiltration were identified using stepwise regression and path analysis methods. The results showed that UWI salinity decreased water infiltration by 1.53–7.99% at the end of infiltration in red soil, following the order of CK > S1 > S5 > S2 > S3 > S10. Moreover, UWI could enhance soil water availability with an increase of 8.55–12.68% in available water capacity. In contrast, lower KS and K were observed in S1–S10, and there was a negative linear relationship between irrigation salinity and KS. UWI also produced the EC, Na+, and Cl− accumulations in the soil profile. As the salinity level of UWI increased, the accumulations aggravated. Soil acidification was found in S1–S5, while soil alkalization was observed in S10. Additionally, α, PWP, and KS were the primary factors influencing the water infiltration of red soil. This study can help optimize the soil infiltration model under UWI and establish a foundation for unconventional water management in the red soil regions of Southern China and other similar regions. In addition, the undisturbed red soil under agricultural unconventional water irrigation and the long-term effect of unconventional water application should be considered. [ABSTRACT FROM AUTHOR]

In order to study the effect of a plastic membrane and geotextile cloth mulching on soil moisture and crop growth in the loess–hilly region, a one-year continuous field monitoring experiment was carried out in Ansai District, City of Yan'an, Shaanxi Province, China. The experimentation included three treatments: plastic membrane and geotextile cloth mulching on the ridge (MB), geotextile cloth mulching on the ridge (DB), and bare soil ridge (CK). Soil moisture and water potential sensors were installed to monitor the changes in soil moisture content and water potential at 5, 15, and 30 cm below the furrow surface and meteorological data above the soil surface, and the growth traits, yield, and quality of maize were analyzed. The results showed the following: (1) The soil water-storage capacity of the three treatments dropped to a minimum in the filling stage and gradually recovered in the mature stage. The average water-storage capacity for the MB treatment was 35.5% higher than that for the DB treatment and 85.1% higher than that for the CK treatment, significant throughout the whole growth period. (2) For four types of rainfall events, namely, light, medium, heavy, and storm rainfall, significant responses were observed at 5 cm below the ground for three treatments, and the fastest response was in MB due to its best rain-collection effect. A significant response was also observed at 15 and 30 cm below the surface of the furrow during medium, heavy, and storm rainfall, while no significant difference in response time was found between the three treatments due to the restriction of the soil infiltration capacity. (3) The differences between the three treatments in the agronomic traits of maize, except for plant height and stem thickness, were insignificant (p < 0.05). The seed moisture content and yield for the MB treatment were the highest, with values of 40.33% and 8366 kg/hm2, respectively, followed closely by the DB treatment, with values of 38.61% and 7780 kg/hm2, respectively, and the smallest values were observed in the CK treatment, with values of 35.80% and 6897 kg/hm2, respectively. Compared with those for the CK treatment, the average starch content and the average lipid content for the mulching treatments (MB, DB) decreased by 13.40% and 17.11%, respectively, while the average protein content of maize increased by 7.86%. Overall, a plastic membrane and geotextile cloth mulching could significantly increase soil moisture and spring maize yield due to their better rain-collection effect. [ABSTRACT FROM AUTHOR]

Investigating the impact of vegetation restoration on changes in runoff generation patterns is essential for understanding watershed hydrology and soil erosion processes in a changing environment. This study examined the influence of vegetation restoration to the runoff generation patterns in a typical small watershed in the gullied rolling loess area through stratified in-situ double-ring infiltration tests and the analysis of the measured flood process before and after vegetation restoration. The results show that a) vegetation restoration has significantly enhanced soil infiltration capacity, resulting in varying degrees of increase in the infiltration rate at different depths (0-60 cm). Vegetation restoration has increased the difference in infiltration capacity between the surface soil and the 10 cm layer. b) Soil infiltration capacity increases significantly with a decrease in soil bulk density and an increase in porosity. Vegetation restoration can affect soil infiltration and runoff generation processes by reducing soil bulk density and increasing porosity. c) After vegetation restoration, the peak flow, runoff depth, runoff coefficient and surface runoff ratio of storm events in the small watershed are decreased, while subsurface runoff is increased. The runoff generation pattern is shifted from excessive infiltration to saturated runoff. These findings indicate that vegetation restoration has an impact on the runoff generation patterns and provide a scientific basis for further studying soil hydrological processes in the Loess Plateau. [ABSTRACT FROM AUTHOR]

Vegetative trapping of heavy rainfall is an important mechanism for mitigating frequent rain-induced flood disasters in the context of global warming. To investigate the role of natural vegetation in trapping heavy rainfall following the widespread implementation of the "the Grain for Green" project in the Loess Hilly and Gully area, an automatic soil moisture monitoring system was employed to continuously monitor the soil moisture content in the top 10 m on one shrub-covered slope and three herbaceous slopes during six heavy rainfall events occurring in the Fangta watershed of the Ansai District, Shaanxi Province, from 2019 to 2022. The results showed that the maximum infiltration depth of the herbaceous slopes was approximately 200 cm during the heavy rainfall events, while for the shrub-covered slope, it was only 100 cm. Furthermore, the shrub-covered slope exhibited superior rainfall interception compared to the herbaceous slopes. The trapping efficianncy of the herbaceous slopes improved with each successive year of "Grain for Green" project implementation. Additionally, natural shrub-covered slopes displayed a trapping efficiency of up to 60.8% during low-intensity, short-duration rainfall events, and 40.8% during high-intensity, long-duration rainfall events. Therefore, it is advisable to strategically conserve and allocate shrub-herbaceous ecosystems within the Loess Hilly and Gully area to enhance the storage and mitigation capacity of vegetation and soil in response to heavy rainfall. [ABSTRACT FROM AUTHOR]

A field trial was conducted in Tianjin to assess the impact of "three-compartment septic tank (SPT) + soil wastewater infiltration system (SWIS)" on vegetable crop soil, determine the SPT effluent quality, and establish the consumer safety of vegetables grown above the SWIS. The effluent total nitrogen (TN), total phosphorus (TP), ammonium-N (NH4+-N), chemical oxygen demand (COD), and 5-d biochemical oxygen demand (BOD5) levels all varied largely every month. The average COD failed to meet the criteria of the Standard for Irrigation Water Quality (No. GB5084-2021) but significantly influenced bacterial community distribution. Hierarchical clustering disclosed seasonal variation in SPT effluent. SWIS treatment of rural black-grey water significantly affected both the vegetable soil TN and TP content, and it promoted microbial community diversity and richness in deep soil. The treatment also increased the relative abundances of the beneficial bacterial genera Thiobacillus and Arthrobacter by more than 320% and decreased the relative abundance of the pathogenic bacterial genus Streptomyces in vegetable soil by more than 20.33%. The faecal coliform levels and ascaris egg mortality rates in the vegetable crop soils lay within published human health and safety thresholds both before and after SWIS treatment. All vegetable crops grown above the SWIS were fit for human consumption. The VC level in the vegetables planted in experimental households were higher than those for the vegetables planted in ordinary households. The present work provides reasonable theoretical and empirical bases for optimising the "SPT + SWIS" process and SPT discharge standards in rural areas. [ABSTRACT FROM AUTHOR]