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In this study we aimed to assess the role of wild red deer, along with other ungulates such as roe deer and wild boar, in the soil's physical properties, namely soil penetration resistance and depth (used as a proxy for soil compaction), hydraulic conductivity (a proxy for water infiltration), and the proportion of soil stable aggregates. Results showed that, at the density level found in our study area, red deer have a neutral effect at the soil level, not causing significant soil compaction or significantly influencing measured soil functions. [ABSTRACT FROM AUTHOR]

Within hilly agricultural landscapes, topography induces lateral transfers of runoff water, so-called interplot hydrological connectivity. Runoff water from upstream plots can infiltrate downstream plots, thus influencing the water content in the root zone that drives crop functioning. The impact of runoff on crop functioning can be crucial for optimizing agricultural landscape management strategies. However, to our knowledge, no study has specifically focused on the impact on crop yield. The current study aims to comprehensively investigate the impact of runoff on crop functioning in the context of Mediterranean rainfed annual crops. To quantify this impact, we conduct a numerical experiment using the AquaCrop model and consider two hydrologically connected plots. The experiment explores a range of upstream and downstream agro-pedo-climatic conditions: crop type, soil texture and depth, climate forcing, and the area of the upstream plot. The experiment relies on data collected over the last 25 years in OMERE, an environment research observatory in northeastern Tunisia, and data from literature. A key finding in the results is that water supply through hydrological connectivity can enhance annual crop production under semiarid and subhumid climate conditions. Specifically, the results show that the downstream infiltration of upstream runoff has a positive impact on crop functioning in a moderate number of situations, ranging from 16% (wheat) to 33% (faba bean) as the average across above ground biomass and yield. Positive impact is mostly found for higher soil available water capacity and under semiarid and dry subhumid climate conditions, with a significant impact of rainfall intra-annual distribution in relation to crop phenology. These research needs to be expanded by considering both a wider range of crops and future climate conditions. [ABSTRACT FROM AUTHOR]

This study addresses the critical role of shaft friction of pile in the interaction with expansive soil under varying moisture content. A simplified estimation method is proposed, capturing the non-linear correlation between the interface relative displacement between the soil and pile and unit skin friction and during water infiltration. The approach integrates soil-pile displacement, interface shear strength parameters, and soil matric suction fluctuations. Tests on Nanyang expansive soil include a laboratory model with water infiltration, constant volume swelling, direct shear for interface shear strength, and a filter paper method for SWCC determination. Initial water content of 21% shows an increases swelling pressure more than 24% and 27%. Increasing soil water content reduces soil matric suction. Due to lower soil matric suction, cohesion, friction, and soil interface shear strength decreased. After the passage of the infiltration duration (specifically, 200 hours), ground heave peaks at 10.7 mm, potentially affecting pile axial forces. As matric suction diminishes, the pile's shaft friction reduces, transferring more weight to the pile base, leading to settlements. Experimental data validate the proposed shaft friction estimation method. The approach aligns with previous studies and laboratory models, providing a comprehensive understanding of soil-pile interaction in changing moisture conditions. [ABSTRACT FROM AUTHOR]

Loess is the main material for subgrade construction in Northwest China, and water infiltration is an important influencing factor of loess subgrade disease. This work carried out infiltration tests on loess in different areas and with different compaction levels using a self-designed soil column device. In addition, the infiltration of loess subgrade was simulated using Hydrus-1D software based on the Van-Genuchten (VG) model, and compared and analyzed with the indoor test results to verify the accuracy of numerical calculations. Finally, with the help of scanning electron microscope (SEM), the reasons for the differences in loess infiltration in different regions were investigated at the microscopic level. The experimental results showed that the compaction of loess subgrade was negatively correlated with the rate of infiltration and the advance speed of the wetting front, and the Kostiakov infiltration model was more suitable for this study than the Philip infiltration model. The simulation showed that the numerical calculation results fitted well with the experimental results, and the infiltration time of water in the subgrade was positively correlated with the height of the subgrade. SEM indicated that the bonding of clay particles in loess reduced its pore area and face porosity. Among them, the sum of the area of mesopores and small pores in Xi'an loess was larger, and the surface porosity was 6.03%, which was 35.5% more than that of Lanzhou loess. The relevant research results can provide valuable references for the construction design of subgrade in loess areas. [ABSTRACT FROM AUTHOR]

Time-lapse ground-penetrating radar (GPR) surveys, combined with automated infiltration experiments, provide a non-invasive approach for investigating the distribution of infiltrated water within the soil medium and creating three-dimensional images of the wetting bulb. This study developed and validated an experimental protocol aimed at quantifying and visualizing water distribution fluxes in layered soils under both unsaturated and saturated conditions. The 3D images of the wetting bulb significantly enhanced the interpretation of infiltration data, enabling a detailed analysis of water movement through the layered system. We used the infiltrometer data and the Beerkan Estimation of Soil Transfer parameters (BEST) method to determine soil capacitive indicators and evaluate the physical quality of the upper soil layer. The field survey involved conducting time-lapse GPR surveys alongside infiltration experiments between GPR repetitions. These experiments included both tension and ponding tests, designed to sequentially activate the soil matrix and the full pore network. The results showed that the soil under study exhibited significant soil aeration and macroporosity (represented by AC and pMAC), while indicators related to microporosity (such as PAWC and RFC) were notably low. The RFC value of 0.55 m3 m−3 indicated the soil's limited capacity to retain water relative to its total pore volume. The PAWC value of 0.10 m3 m−3 indicated a scarcity of micropores ranging from 0.2 to 30 μm in diameter, which typically hold water accessible to plant roots within the total porosity. The saturated soil hydraulic conductivity, Ks, values ranged from 192.2 to 1031.0 mm h−1, with a mean of 424.4 mm h−1, which was 7.9 times higher than the corresponding unsaturated hydraulic conductivity measured at a pressure head of h = −30 mm (K−30). The results indicated that the upper soil layer supports root proliferation and effectively drains excess water to the underlying limestone layer. However, this layer has limited capacity to store and supply water to plant roots and acts as a restrictive barrier, promoting non-uniform downward water movement, as revealed by the 3D GPR images. The observed difference in hydraulic conductivity between the two layers suggests that surface ponding and overland flow are generated through a saturation excess mechanism. Water percolating through the soil can accumulate above the limestone layer, creating a shallow perched water table. During extreme rainfall events, this water table may rise, leading to the complete saturation of the soil profile. [ABSTRACT FROM AUTHOR]

Heavy rainfall is the main factor inducing the failure of loess slopes. However, the failure mechanism and mode of terraced loess slopes under heavy rainfall have not been well investigated and understood. This paper presents the experimental study on the deformation and failure of terraced loess slopes with different gradients under extreme rainfall conditions. The deformation and failure processes of the slope and the migration of the wetting front within the slope during rainfall were captured by the digital cameras installed on the top and side of the test box. In addition, the mechanical and hydrological responses of the slope, including earth pressure, water content, pore water pressure, and matric suction, were monitored and analyzed under rainfall infiltration and erosion. The experimental study shows that the deformation and failure of terraced loess slopes under heavy rainfall conditions exhibit the characteristic of progressive erosion damage. In general, the steeper the slope, the more severe the deformation and failure, and the shorter the time required for erosion failure. The data obtained from sensors embedded in the slope can reflect the mechanical and hydraulic characteristics of the slope in response to rainfall. The earth pressure and pore water pressure in the slope exhibit a fluctuating pattern with continued rainfall. The failure mode of terraced loess slopes under extreme rainfall can be summarized into five stages: erosion of slope surface and formation of small gullies and cracks, expansion of gullies and cracks along the slope surface, widening and deepening of gullies, local collapse and flow-slip of the slope, and large-scale collapse of the slope. The findings can provide preliminary data references for researchers to better understand the failure characteristics of terraced loess slopes under extreme rainfall and to further validate the results of numerical simulations and analytical solutions. [ABSTRACT FROM AUTHOR]

This paper introduces a methodology devised for thermographic inspection of concrete technical condition inside concrete dams. Water infiltration into a dam accelerates the processes of concrete degradation, so temperature fields provide important information about the dynamics of these processes. As a result of the thermal imaging survey of the observation gallery at a historic hydraulic structure, a formalized pattern of the temperature field inside the dam was acquired and the locations of temperature anomalies associated with infiltration were identified. At the leakage points, the water temperature differed from the concrete temperature by 1.0–2.9 °C, indicating different rates of water flow through the water wall and the gallery ceiling. The temperature of the gallery areas with increased infiltration was 1–2 °C higher than the 12.7 °C selected as the reference temperature. When recording the temperature fields, the optical axis of the thermal imager was directed along the gallery, and not perpendicular to the surfaces under study, as in construction thermography. To this end, a methodological approach was devised to eliminate distortions of the resulting thermograms caused by the curvature of the gallery and other factors. To remove images of extraneous thermal radiation sources from the thermograms and accurately identify the area under study, a method of shielding a part of the image using special masks was used. The comparative thermography method made it possible to eliminate difficulties in determining the emissivity of the gallery concrete surface. The proposed method of comparative thermography made it possible to compare the intensity of filtration processes in the dam body and to link the current state of the hydraulic structure with the history of its restoration. In general, the thermographic method makes it possible to supplement existing primary natural control with a formalized pattern of temperature field inside the dam. [ABSTRACT FROM AUTHOR]

In order to compare the influence of different soil types and stratification on water infiltration capacity, two main types of soil in the desert steppe, sierozem (S) and aeolian sandy soil (A), were selected, and infiltration simulation tests were conducted on homogeneous soil and layered soil (layer thickness 5, 10, and 20 cm), respectively. The results show that during the whole experiment, there was a small difference between S5A95 (aeolian sandy soil 95 cm thick was covered with sierozem 5 cm thick) and S10A90 (aeolian sandy soil 90 cm thick was covered with sierozem 10 cm thick) in the wetting front process, infiltration rate and cumulative infiltration, but there was a significant difference between S5A95 and S20A80 (aeolian sandy soil 80 cm thick was covered with sierozem 20 cm thick). In the initial infiltration stage, there was no significant difference between A5S95 (sierozem 95 cm thick was covered with aeolian sandy soil 5 cm thick) and A10S90 (sierozem 90 cm thick was covered with aeolian sandy soil 10 cm thick). However, with the increase of infiltration time, the wetting front process, A5S95, A10S90 and A20S80 had significant differences in terms of wetting front process, infiltration rate and cumulative infiltration. The infiltration capacity of A was significantly higher than that of S. Combined with linear Ä2 value and model parameters, the three infiltration models were comprehensively compared, and the fitting process and results of the general empirical model for the infiltration process of homogeneous soil and layered soil showed good results. Three models were used to simulate the water infiltration process of layered soil with different textures, and the order of the effect is as follows; general empirical model > Kostiakov model > Philip model. Soil type and layer thickness had a great influence on water infiltration process. When sierozem was covered with aeolian sandy soil 20 cm thick, the infiltration capacity was the best. As aeolian sandy soil was covered with sierozem 10 cm thick, the infiltration effect was the worst. Therefore, once coarse graying occurs on the surface of sierozem (the thickness of sand is more than 20 cm) or when the content of fine particles overlying aeolian sandy soil (the thickness of silt and clay soil is more than 10 cm) during ecological restoration is high, the soil hydrological characteristics will change significantly, which may lead to changes in vegetation types and even ecosystem structure. [ABSTRACT FROM AUTHOR]

Collapse earth fissure is a common type of disaster in loess regions, where water infiltration is one of the primary factors that contributes to surface ruptures and uneven settlement. However, the research on the cracking behavior of collapsible loess under the action of water infiltration has been mainly qualitative, and there is a lack of quantitative analysis methods. In this study, through field survey, trench exploration, drilling and geotechnical engineering tests, we found that collapsible loess in Xibai Village subjected to an increased water content due to canal leakage presents a deformation and cracking failure mode similar to that of cantilever beam structure. Then, based on a simplified cantilever beam model and theory, a formula for predicting the location of initial cracks in collapsible loess caused by canal water leakage was derived using the material mechanics analysis method. The accuracy of the prediction was verified by comparing it with the results of field immersion tests, and the error was within 30%. In addition, considering the continuous expansion of the wetting zone, the theoretical formula for the location of fissure rupture propagation in collapsible loess in different seepage stages was then derived. This study provides a dependable analytical approach for estimating the extent and impact of earth fissures caused by the canal water leakage in collapsible loess areas, which can help to improve the security and stability of infrastructures in such areas. [ABSTRACT FROM AUTHOR]

Karst ecosystems offer a wealth of ecosystem services, but their protection is increasingly challenging due to degradation and land-use conversion, including limestone mining. This study investigates the water provision service derived from karst ecosystems threatened by limestone mining in the Watuputih groundwater basin, Central Java, Indonesia. Water supply was quantified by measuring water discharge rates from major springs around the basin. Water usage was quantified for household consumption, agriculture, and recreation. This study also measured water infiltration rates in mining and non-mining areas to indicate the effects of limestone mining to hydrological processes. This study identified three primary springs around the basin: Sumber Seribu spring, Brubulan spring, and Kalutan spring, with discharge rates of 1080 L per second, 85 L per second, and 0.76 L per second, respectively. A local water company extracts water from Sumber Seribu spring at a rate of 80 L per second to supply approximately 57,600 individuals. The water supply from the three springs can irrigate approximately 1594 ha of rice fields. Water from Sumber Seribu spring also supports recreational activities in Sumber Semen recreation park, attracting an average of 19,173 visitors per year. This study revealed a complete impairment of soil's water infiltration capacity in limestone mining areas. These findings underscore the pressing need to safeguard the Watuputih groundwater basin and to mitigate the detrimental effects of limestone mining on hydrological processes. This involves designating the Watuputih karst ecosystem as a protected area, implementing Payment for Ecosystem Services (PES) programs, and restoring degraded post-mining sites.

Groundwater extracted from coal seams may be a resource for irrigation of land in areas with low rainfall, but the effect of this water on soil properties needs to be established. A lysimeter study was conducted using intact soil cores (0.75 m diameter, 1.4 m deep) of four different soil types (Sodic Vertisol, Calcic Solonetz, Haplic Solonetz and Xanthic Lixisol) from southern Queensland, Australia, to study changes in soil physical and chemical properties under accelerated rates of irrigation with coal seam (CS) water (electrical conductivity (ECw) of 3 dS/m, pH of 8.8, and a sodium adsorption ratio (SAR) of 100). Cores were also alternately irrigated with deionised water to simulate rainfall, and either lucerne (Medicago sativa L) or Rhodes grass (Chloris gayana Kunth.) where grown in the lysimeters. The soil surface was treated with stoichiometric rates of elemental sulfur (1.4 t/ha) and gypsum (2.5 t/ha) prior to every 450 mm CS water irrigation to minimise changes in SAR and pH. Three of the soils (Vertisol, both Solonetz) had low leaching fractions (≤ 0.1 %) due to their clay texture and were initially saline in the subsoil (ECse 1.4–4.4 dS/m). Irrigation with CS water resulted in a gradual increase in salt content (EC) and SAR throughout the soil profile, but pH was not increased due to surface-applied elemental sulfur. The Lixisol had a higher hydraulic conductivity and leaching fraction (6.7 %) due to is loamy texture – in this soil, accumulated salts could be leached and no increase in salinity or pH were measured. Despite an increase in SAR for this loamy soil, no structural degradation was observed, and it could be sustainably irrigated with up to 3200 mm CS water (with cumulative irrigation volume of 5400 mm). Hence, leaching fractions rather than soil chemistry are good indicators to identify soils suitable for irrigation with CS water that is saline, alkaline, and sodic.

Field monitoring was conducted to investigate and quantify the long-term effects of peanut shell biochar on soil-grass interaction over three years. Three 10 m × 5 m grassed plots were constructed in completely decomposed granitic soil. Two of them were amended, respectively, with 5% and 10% biochar contents (m3/m3) for grass growth, while the third was without biochar amendment. During the three-year monitoring, plant characteristics, saturated water permeability (ks) of grassed soil and soil suction were measured. The monitored results show that the grass leaf area index (LAI) and root length density (RLD) with biochar amendment were improved by 38% and 200%, respectively. In the grassed plot without biochar, a threshold RLD existed with a value of 1.7 cm/cm3, beyond which ks raised pronouncedly. The threshold RLD increased by 52% when biochar content increased from 0% to 10%. This implies that biochar may restrict the increase in ks of grassed soil due to the rise in the threshold RLD. The presence of biochar and grass can retain over 100% higher suction after heavy rainfalls, while 54% lower peak suction under evapotranspiration (ET) compared with the non-amended plot. Biochar can alleviate the negative effects on hydraulic properties caused by plant growth and reduce ET-induced excessive water loss. A 5% peanut shell biochar content is recommended for the long-term management of vegetated earthen infrastructures.

Extreme rainfall significantly threatens the safety of the landfill cover system, especially under humid climates. This study aims to provide design recommendations for a sustainable landfill cover system consisting of a low-permeability soil layer underlying a two-layer capillary barrier for humid climates. First, the numerical back-analysis was conducted for verification against a series of flume model tests. Then, a parametric study was performed to investigate the effects of inclination angle, particle size and layer thickness on the lateral diversion length (DL) of the three-layer cover system under the 100-year return period rainfall of humid climates. The results show that the water lateral DL of the cover system can be greatly enhanced by increasing the inclination angle from 3° to 18°. Moreover, the bottom layer of the cover system with a coarser d10 was more susceptible to the impact of the heavy rainfall, while this can be alleviated by increasing the thickness of the bottom layer. A dimensionless number, defined as the ratio of thickness and d10 of the bottom layer, is proposed for designing lateral diversion of the three-layer cover system under humid climates. To preserve the maximum DL, it is suggested that the proposed dimensionless number should be larger than 95 and 110 for the design of rainfall events with 50-year and 100-year return periods for humid climates, respectively.

Geological disaster occurrences in loess regions are intrinsically linked to water infiltration in loess, with the Malan loess-paleosol interlayer structure significantly influencing the infiltration patterns of soil moisture. This research was carried out to reveal the moisture migration characteristics in loess-paleosol interlayers, and to investigate the influence of the moisture migration on the microstructure of loess, providing a theoretical basis for engineering practice and scientific research in loess areas. In this study, we focused on the loess of the South Plateau in Jingyang County, Shaanxi Province, and conducted water infiltration tests using a soil column model to investigate the soil moisture transport dynamics under loess-paleosol interlayer conditions. Subsequently, we analyzed the impact of soil moisture transport on the loess microstructure under these conditions through microstructural testing, and calculation of fractal dimension and probability entropy. The findings revealed that the permeability of the paleosol layer was low, causing transient water stagnation when the wetting front reached the loess-paleosol interface. The stagnant water at the interface of loess and paleosol under the influence of the paleosol layer will lead to the interconnection of pore structure, and the pore space will increase by 4.13% on average, and the analysis of the indexes of fractal dimension and probability entropy shows that the probability entropy of the pore direction decreases by 0.029 on average, and the fractal dimension decreases by 0.076 on average, i.e., the water-blocking effect of the paleosol layer makes the pore space of the loess at the interface increase, the pores are arranged in an orderly manner, and the pore morphology is regular. The results of the study provide scientific support for the engineering construction and eco-environmental protection in loess areas.

Non-invasive imaging methods are a useful tool in informing conservation actions for historical buildings. Electrical Resistivity Tomography (ERT) is widely used in geophysics to image the subsurface but has been seldom used for non-invasive imaging of small-scale masonry structures. Here, we propose an adaptation of the method allowing non-damaging investigation of larger-scale stone structures. We report results of an ERT survey of Prebends Bridge in Durham, a heritage masonry structure constructed in 1778. Our assessment is based on data acquired on the paved top surface of the bridge, which is subsequently modelled and inverted with the use of open-source software. Final images of the internal structure of the bridge reveal areas of lower electrical resistivity, that we interpret as representing regions of water saturation. Locations of low resistivity areas are in good agreement with the structural defects and patches of seepage observed externally. These results will help inform remediation work, to preserve this historical structure from further water damage. In future studies, time-lapse imaging may help to highlight water pathways unambiguously (through comparison of dry/wet periods), while additional electrode arrays installed on the sides/base of the structure could be used to better constrain 3D internal structure. [ABSTRACT FROM AUTHOR]

Collapsible soils are one of the problematic soils, as they exhibit good stability in dry conditions but undergo sudden and significant settlements upon water entry. The surrounding layers of collapsible soil can be either permeable or impermeable, but the existing devices for determining the collapse potential lack the ability to model the drainage conditions around the collapsible soil layer. In this study, an apparatus capable of modeling drainage conditions was constructed. A collapsible soil was made in laboratory, and its collapse potential was determined using single and double oedometer tests as well as the constructed apparatus. The results show that drainage conditions are an influential factor on the behavior of collapsible soils. The collapse potential obtained from this apparatus is lower than the collapse potential obtained from the oedometer test. The comparison of the two conditions with drainage and without drainage in two point and wide water distributions shows that in both water distributions, the collapse potential is higher in the condition with drainage than in the condition without drainage. For example, in the point distribution, the collapse potential with drainage is 27.7% higher than the without drainage, while in the wide distribution, it is 19.5%higher. [ABSTRACT FROM AUTHOR]

Though amendment using coal gasification coarse slag (CGCS) has garnered attention, the intrinsic mechanism of how CGCS, a glassy material, works to amend physicochemical properties in the soil is not yet clear. This study aimed to analyze the effects of different CGCS particle sizes on soil water infiltration and nutrient retention, and to identify the relationship between the physicochemical properties of the amended soil and the water nutrient amendment. The continuous infiltration pattern of soil water and plant growth after the amendment was measured using an indoor continuous dynamic soil column simulation experiment and a field pot experiment of CGCS with different particle sizes (0.25, 1, and 2 mm). The CGCS amendment loosened the soil, improved the pore channels, and amended the water infiltration. However, this process was negatively correlated with CGCS particle size. The Kostiakov performed better in simulating soil water infiltration of heterogeneous dump soil. The CGCS amendment had no heavy metal risk and promoted plant growth. Though amendment enhanced nutrients, in terms of soil organic matter (SOM), the presence of C must be verified by a long team of nutrient cycling if it can be transformed into accessible SOM. Therefore, CGCS amended water nutrition by amending the soil's physical structure. Soil pore adsorption improved water nutrient availability and had a positive effect on chemical properties, which promoted crop growth. The amendment effect was greatest at 0.25 mm particle size. [ABSTRACT FROM AUTHOR]

Introduction: Surface water from precipitation or irrigation is the sole contributor to groundwater replenishment in the Loess Plateau of China. The occurrence of landslides in the Loess Plateau is closely related to the infiltration process of surface water, and the frequent occurrence of landslides in the Loess Plateau in recent years has seriously affected the economic development and security of the Loess Plateau. Methods: To investigate the loess infiltration in deeper soil, the process of moisture infiltration in unsaturated loess is studied by field observation, theoretical analysis, and numerical simulation. Results and discussion: The research results indicated that the interstitial flow in loess could be divided into three different zones: the active zone, the stable zone (2-94 m), and the saturated zone (below 97 m); based on the matric suction and water content calculations, the L1 soil stable water content is 24.4%, which corresponds to the moisture sensor measurement of L1 loess 4 m and 7 m of stable zone data; the numerical simulation results show that whether the infiltration is continuous or intermittent, the infiltration law is the same. After 20 years, there will be a stable water content zone in the 1-8 m soil layer with a water content of 31%. The numerical results well confirm the theoretical calculation results. The research results explain the process of surface water infiltration into groundwater through thick loess and can provide an important reference for the prevention and control of geological disasters caused by water infiltration in loess areas. [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.)

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]

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

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

Heavy rainfall is the main factor inducing the failure of loess slopes. However, the failure mechanism and mode of terraced loess slopes under heavy rainfall have not been well investigated and understood. This paper presents the experimental study on the deformation and failure of terraced loess slopes with different gradients under extreme rainfall conditions. The deformation and failure processes of the slope and the migration of the wetting front within the slope during rainfall were captured by the digital cameras installed on the top and side of the test box. In addition, the mechanical and hydrological responses of the slope, including earth pressure, water content, pore water pressure, and matric suction, were monitored and analyzed under rainfall infiltration and erosion. The experimental study shows that the deformation and failure of terraced loess slopes under heavy rainfall conditions exhibit the characteristic of progressive erosion damage. In general, the steeper the slope, the more severe the deformation and failure, and the shorter the time required for erosion failure. The data obtained from sensors embedded in the slope can reflect the mechanical and hydraulic characteristics of the slope in response to rainfall. The earth pressure and pore water pressure in the slope exhibit a fluctuating pattern with continued rainfall. The failure mode of terraced loess slopes under extreme rainfall can be summarized into five stages: erosion of slope surface and formation of small gullies and cracks, expansion of gullies and cracks along the slope surface, widening and deepening of gullies, local collapse and flow-slip of the slope, and large-scale collapse of the slope. The findings can provide preliminary data references for researchers to better understand the failure characteristics of terraced loess slopes under extreme rainfall and to further validate the results of numerical simulations and analytical solutions.

Time-lapse ground-penetrating radar (GPR) surveys, combined with automated infiltration experiments, provide a non-invasive approach for investigating the distribution of infiltrated water within the soil medium and creating three-dimensional images of the wetting bulb. This study developed and validated an experimental protocol aimed at quantifying and visualizing water distribution fluxes in layered soils under both unsaturated and saturated conditions. The 3D images of the wetting bulb significantly enhanced the interpretation of infiltration data, enabling a detailed analysis of water movement through the layered system. We used the infiltrometer data and the Beerkan Estimation of Soil Transfer parameters (BEST) method to determine soil capacitive indicators and evaluate the physical quality of the upper soil layer. The field survey involved conducting time-lapse GPR surveys alongside infiltration experiments between GPR repetitions. These experiments included both tension and ponding tests, designed to sequentially activate the soil matrix and the full pore network. The results showed that the soil under study exhibited significant soil aeration and macroporosity (represented by AC and pMAC), while indicators related to microporosity (such as PAWC and RFC) were notably low. The RFC value of 0.55 m3 m−3 indicated the soil’s limited capacity to retain water relative to its total pore volume. The PAWC value of 0.10 m3 m−3 indicated a scarcity of micropores ranging from 0.2 to 30 μm in diameter, which typically hold water accessible to plant roots within the total porosity. The saturated soil hydraulic conductivity, Ks, values ranged from 192.2 to 1031.0 mm h−1, with a mean of 424.4 mm h−1, which was 7.9 times higher than the corresponding unsaturated hydraulic conductivity measured at a pressure head of h = −30 mm (K−30). The results indicated that the upper soil layer supports root proliferation and effectively drains excess water to the underlying limestone layer. However, this layer has limited capacity to store and supply water to plant roots and acts as a restrictive barrier, promoting non-uniform downward water movement, as revealed by the 3D GPR images. The observed difference in hydraulic conductivity between the two layers suggests that surface ponding and overland flow are generated through a saturation excess mechanism. Water percolating through the soil can accumulate above the limestone layer, creating a shallow perched water table. During extreme rainfall events, this water table may rise, leading to the complete saturation of the soil profile.

[Objective] The mechanism on how bryophytes influence water infiltration in the soil surface layer following a short period of heavy precipitation was studied in order to provide data support for the use of bryophytes to control soil erosion in rocky desert areas. [Methods] We measured soil water infiltration in a laboratory study using a one-dimensional soil column covered with Hypnum plumaeforme, Anomodon viticulosus, Weisia controversa, or Bryum coronatum after a short period of 20 mm of precipitation. We used the classical Horton infiltration model and Singh’s entropy infiltration equation to simulate water infiltration, and compared the differences in soil water infiltration. [Results] ① The initial, stable, and mean infiltration rates and the cumulative infiltration amount for the bryophyte-cover treatments were all greater than observed for the bare soil treatment (p

Construction wastes such as recycled concrete have been widely reused in geotechnical engineering to reduce environmental pollution and preserve natural resources. In this study, a one-dimensional (1D) soil column test was carried out to evaluate the hydrological performance of a three-layer landfill cover system using recycled concrete aggregates (RCA) under humid climatic conditions. This three-layer system consists of a layer of fine-grained and a layer of coarse-grained recycled aggregates (i.e. FRC and CRC) overlying the bottom silt refuse soil. Numerical simulations were conducted to analyse the model test and investigate the effects of the bottom layer and climate conditions on the performance of the three-layer landfill cover system. Consistent results were obtained between the measured data and numerical predictions. The matric suctions in the vegetated cover were nearly 80% higher than the bare cover after drying for 14 days from a nearly saturated condition. Even after the simulated extreme rainfall of Hong Kong with a return period of 100 years, a higher suction was also well-retained in vegetated cover. This was due to the initial high suction induced by evapotranspiration of plants, which led to the infiltration rates into grassed cover being up to 30% lower than the bare one. The results from the numerical parametric analysis suggest a bottom soil layer with an effective particle size (d10) value of 0.02 mm and 0.2 mm to be used in the three-layer landfill cover system under humid and semi-humid climates, respectively. For semi-arid or even arid regions, a two-layer cover with capillary barrier effects (CCBE) is already sufficient for preventing water percolation as the rainfall in those areas is not heavy. [ABSTRACT FROM AUTHOR]

This paper takes the interlayer soil of heavy saline-alkali soil in Weigan River Irrigation Demonstration base in Aksu District, Xinjiang Province, China as the research object. Through field plot tests, the changes of soil water and salt under different years and winter irrigation quota of 4725 mm·ha-1 were studied. Analysis revealed that, after three rounds of irrigation, the control (CK) treatment exhibited soil moisture content 1.4%-16.2% and 2.3%-15.5% higher than that of other treatments at 60-80 cm and 0-100 cm, respectively. Among all treatments, G1 exhibited the highest desalination rate of 75.9%, followed by G6 and G3 at 51.5% and 39.4%, respectively, whereas G2 and G5 were relatively similar at 38.2% and 37.4%, respectively, and G4 showed the lowest desalination rate of 33.9%. Significant desalination effects were observed after two and three winter irrigations, particularly in the 0-20 cm soil layer where salt content decreased from 7.06-11.61 g kg-1 before irrigation in 2020 to 2.00-5.91 g kg-1 after irrigation in 2022. The desalination rate was between 76.8% and 382.5%, which improved the surface soil from the initial medium to moderate saline-alkali soil to light to moderate saline-alkali soil. The research findings that improvement measures can enhance soil water infiltration and improve soil desalination efficiency. [ABSTRACT FROM AUTHOR]

This study investigated the behaviour of permeable interlocking concrete pavement (PICP) in terms of water infiltration volume, surface runoff volume, and load resistance, using a specific lab apparatus, designed and manufactured as a rainfall simulator. The connecting pattern of the surface blocks is a stretcher bond pattern with a joint spacing of (5 and 10 mm) between the block pavers to be filled with a small-sized open-graded aggregate to finalise the permeable surface of joints. The adopted pattern has been examined under three rainfall intensities of (20, 40, and 60 l/min), four longitudinal slopes (0, 2, 4, and 6%), and three transverse slopes (0, 2, and 4%). The results showed that at high rainfall intensities (60 l/min), high longitudinal slopes (6%), and high transverse slopes (4%), the stretcher-bonded PICP with 5 mm spacing between the blocks infiltrates less water than the one with 10 mm. Furthermore, PICP with 5 mm spacing has higher surface runoff than PICP with 10 mm spacing at high rainfall intensities (60 l/min), high longitudinal slopes (6%), and all transverse slope percentages (0, 2, and 4%). In addition, the load resistance of stretcher-bonded PICP with 5 mm spacing between the blocks is higher than that of 10 mm at all the subjected loads in the load-deflection test. Despite the shown differences between both types of PICP, they are strongly recommended as an alternative choice for ordinary dense-graded pavement. [ABSTRACT FROM AUTHOR]

Accurate predictions of fluid flow, mass transport, and reaction rates critically impact the efficiency and reliability of subsurface exploration and sustainable use of subsurface resources. Quantitative dynamical sensing and imaging can play a pivotal role in the ability to make such predictions. Geophysical thermoacoustic technology has the potential to provide the aforementioned capabilities, since it builds upon the principle that electromagnetic and mechanical wave fields can be coupled through a thermodynamic process. In this letter, we present laboratory experiments featuring the efficacy of thermoacoustic imaging in the monitoring of preferential flow of water in porous media. Our laboratory experimental equipment can be readily packaged in a form factor that fits in a borehole, and the use of multiple acoustic transducers—which can be combined with volumetric coding techniques—has the potential to provide quasi‐real‐time imaging (0.5 Hz video rate) of regions in close proximity (a few meters) of an open field well. Plain Language Summary: Multiphysics subsurface sensing and imaging technology has the potential to provide unique insights to better understand multiphase flow and transport in porous media in 4D (time and space). Conventional high‐resolution, laboratory‐based imaging technology—such as X‐ray or MRI—require power‐hungry and often bulky equipment; the latter limits their use in open field experiments and challenges their ability to perform real‐time image reconstruction. Acoustics Doppler imaging has been used for real‐time flow velocity monitoring in biomedical applications; however, the relationship between fluid saturation in porous media and measured acoustic pressure still requires further investigation. In this letter we show how microwave‐induced thermoacoustic (TA) imaging technology can be applied to monitor water distribution in sand. In contrast to traditional acoustic imaging, the proposed TA method exhibits a dominant monotonic relationship between the degree of water saturation and the measured amplitude of the TA pressure. Our experimental results show the efficacy of TA technology for imaging 2D water distribution profiles in sand. The reconstructed TA images are in good agreement with the optical ground truth water distribution map, thus illustrating the feasibility of the proposed method for real‐world field applications in agricultural and hydrological sciences. Key Points: The increased water saturation level in sand, silt, and clay leads to a higher thermoacoustics wave amplitudeThe reconstructed thermoacoustics images match well with the optical ground truth for water‐saturated sandThermoacoustics imaging enables real‐time monitoring of water distribution in subsurface sand [ABSTRACT FROM AUTHOR]

Preferential water flow in soil significantly affects runoff, water infiltration, storage, groundwater environment, and soil stability. Plant roots positively affect preferential flow development. This study explored the relationship between the root system of Paulownia fortunei (Seem.) Hemsl. and preferential flow using dyeing tracer test and image analysis techniques. A typical red soil hilly region on the outskirts of Guilin City (Guangxi, China) was selected as the study area. A Bright Blue solution was used to visualize the pathways followed by the infiltrated water in simulated rainfall experiments, and Image Analyzer of Plants was used to analyze the root length, surface area, and volume. The results revealed significant differences in the root surface area density of coarse roots (RSAD-CR) and length index of preferential flow (LI) among soil profiles at various distances from the tree trunk. The root volume density of coarse (RVD-CR) and total roots (RVD-TR), the root length density of coarse roots (RLD-CR), and RSAD-CR were significantly correlated with the characteristics of dyeing morphology. Conversely, the root length density and root surface area density of fine (RLD-FR and RSAD-FR, respectively) and total roots (RLD-TR and RSAD-TR, respectively), and the root volume density of fine roots (RVD-FR) were not significantly correlated with the characteristic parameters of dyeing morphology. The root systems of P. fortunei were critical for enhancing soil water infiltration and developing preferential flow in red soil hilly regions. Coarse roots had a greater impact on the development of preferential flow than fine roots, and root volume had a greater influence on preferential flow development than root length and root surface area. This study contributes to a better understanding of the hydrological cycle at the plant-soil interface in red soil hilly regions.

Abstract Accurate predictions of fluid flow, mass transport, and reaction rates critically impact the efficiency and reliability of subsurface exploration and sustainable use of subsurface resources. Quantitative dynamical sensing and imaging can play a pivotal role in the ability to make such predictions. Geophysical thermoacoustic technology has the potential to provide the aforementioned capabilities, since it builds upon the principle that electromagnetic and mechanical wave fields can be coupled through a thermodynamic process. In this letter, we present laboratory experiments featuring the efficacy of thermoacoustic imaging in the monitoring of preferential flow of water in porous media. Our laboratory experimental equipment can be readily packaged in a form factor that fits in a borehole, and the use of multiple acoustic transducers—which can be combined with volumetric coding techniques—has the potential to provide quasi‐real‐time imaging (0.5 Hz video rate) of regions in close proximity (a few meters) of an open field well.

The existence of macropores acutely enhances the capacity of soil to conduct water, gas, and chemicals. The capacity of macropores to transport water extremely depends on their spatial characteristics. However, the effect of the horizontal spatial distribution of macropores (especially the position characteristics of macropores) on water infiltration is still ambiguous. Therefore, this study utilizes the approach of numerical simulation to investigate the general pattern of the effects of horizontal spatial distribution characteristics of macropores (such as number, pore size and position) on water infiltration. Given the limitations on the ability to characterize the macropore position from the existing spatial characteristic parameters of macropores, two new statistical parameters (spatial dispersion, γ , and spatial deviation, γ * ) are established to characterize the position relationships among macropores and between the macropores and the observation area, respectively. The results show that the larger the macropore number and the more uniformly macropores are distributed, the greater the soil permeability and the preferential flow degree, while the pore size hardly affects the water transport. Additionally, comparison between number and position effects reveals that the macropore number is the dominant factor when the macropore number is relatively small, but this relationship will reverse when the macropore number is relatively large. This study provides a novel meals to investigate the effect of macropore position on water infiltration, and emphasizes that besides the macroporosity, number and position are also significant for quantifying soil permeability. [ABSTRACT FROM AUTHOR]

Unbound granular materials (UGMs) have advantages in their water storage and drainage capabilities in permeable pavement, which is a benefit for urban sustainable development. The plastic strain of UGM is a crucial mechanical property that affects its design and construction. During its service life, repeated load only, repeated load after infiltration, and simultaneous action with load and infiltration are the three inevitable working conditions that will impact plastic strain, especially dynamic water infiltration. How these working conditions influence plastic strain needs to be focused on and solved. This study conducted laboratory tests to investigate plastic strain considering factors such as loading strength and repetitions, as well as infiltration number and duration. The results showed that the plastic strain and plastic strain rate exhibited similar variations during the repeated load only test and repeated load after infiltration test. The plastic strain changed significantly with different infiltration numbers but had relatively small variations in terms of the plastic strain rate. Longer infiltration duration led to greater plastic strain. With the simultaneous action, the plastic strain presented different variation to the other two conditions. The first and second infiltrations had a more obvious influence on the plastic strain when infiltration was applied. Calculation models were established to predict the effects of loading strength and repetitions as well as infiltration number and duration on plastic strains. For the repeated load only test, an error of 4.6% was observed. In terms of the infiltration number and duration, the errors were found to be 18.5% and 8.5%, respectively. The power function and Sigmoidal Logistic model were used to establish calculation models under the simultaneous action test with a maximum error of 11.5% ranging from 100 to 60,000 repetitions. The proposed calculation models can characterize plastic strain under the three working conditions very well, which can help in the design and construction of fully permeable pavement. [ABSTRACT FROM AUTHOR]

Jakarta City is one of the largest cities in Indonesia, experiencing urban areas development generally intensive and unsustainable. This development impacts directly or indirectly on landscape degradation. Kalijodo is one of the important public open spaces (POS) constructed in the Jakarta Capital Special Region to facilitate different social functions and ecosystem services. This paper aims to describe the non-ideal condition of the Kalijodo area as a POS and to strengthen its functions towards a Public Green Open Space (PGOS). The Kalijodo POS had actually 47.91 % vegetated and 52.09 % of non-vegetated land cover and this area cannot be categorized as PGOS due to its vegetated land cover under a minimum threshold of 75 %. This condition is closely related to other aspects and parameters which indicate that Kalijodo POS has low water absorption ability, low water storage capacity, high average air temperature, high Thermal Humidity Index (THI), and low potential for economic benefits. The ecohydrology principles were taken into consideration for understanding, assessment, and identification of possible efforts to achieve the PGOS level. Several possible actions would be suggested for improvement consisting of increasing vegetated land cover, replacing pavement hardeners, introducing bio pores, constructing water ponds and wetlands, increasing public participation, and adjusting appropriate government policy and regulations. These efforts will probably have positive impacts on average air temperature reduction, increasing water absorption ability and potential economic gain, entering THI to a comfort zone and positive people's perception, as well as increasing people attendance. [ABSTRACT FROM AUTHOR]

In an anchor support system, once the soil strength is improved by grouting with a geotextile, the pull-out force of anchors increases. To investigate the improvement of surrounding soils due to the grouting with a geotextile, a series of filtration and penetration tests under various parameters such as different initial degrees of compaction, water content and soil types were conducted via a self-developed device. In addition, microscopic tests were then carried out to obtain the soil's structure before and after grouting. The main conclusions are as follows: (1) The strength of surrounding soils is improved by grouting with a geotextile through the compaction effect and the slurry infiltration, while its strengthening effect gradually declines with the increase in the initial degree of compaction. (2) As the initial water content increases, the strengthening effect derived from the compaction effect and the cohesive substances infiltration decreases, while this improved efficiency of the soil strength declines due to the water infiltration during grouting. (3) Although the effect of grouting with a geotextile on different soils is obviously different due to the different efficiency of slurry (i.e., water and cohesive substances) infiltration, it can improve the soil strength regardless of soil type, especially for sandy soils. (4) Under the filtration of geotextile, a hardened layer is formed at the grout–soil interface due to the accumulation of cohesive substances, which is beneficial to the performance improvement in applications such as the capsule-type anchor. [ABSTRACT FROM AUTHOR]

Prescribed fires are one of the most effective tools to reduce the risk of wildfires but this treatment may negatively affect the hydrological and erosive response of soil, with noticeable increases in surface runoff and soil erosion. Many studies have been published on this matter but there is no consensus in the literature on the magnitude and duration of these effects since the relevant hydrological conditions are site‐specific. Moreover, the relationship between post‐fire hydrology and its main environmental drivers has been little explored. This study has carried out a bibliographic review and a meta‐analysis of the changes resulting from prescribed fire applications (water infiltration, soil water repellency (SWR), surface runoff and soil erosion) using a database of 85 case studies from 41 academic papers that have been published over the last 23 years. The effects of annual precipitation, soil slope, burn severity, fire application season, post‐fire ground cover, and vegetation type on those changes have also been statistically explored. The bibliographic review has revealed that previous case studies have not been equally distributed across the globe but concentrated in only a few countries, mainly the United States and Spain. The meta‐analysis has revealed that (i) water infiltration generally decreases and SWR appears with noticeable increases in surface runoff and soil erosion immediately after the prescribed fire, while the pre‐fire values progressively recover over time; (ii) the window of disturbance in burned soils may last a few months (with some exceptions); (iii) annual precipitation and soil slope significantly influence water infiltration and surface runoff, but not soil erosion, in both the short‐term and medium‐term; (iv) moderate‐to‐high levels of soil burn severity severely enhance surface runoff and soil erosion, and noticeably reduce water infiltration in the short‐term; (v) the level of ground cover burning is important for reducing the runoff rates, but it plays a minor role in water infiltration and soil erosion rates;and (vi) the prescribed fire applied in spring results in lower increases in short‐term runoff and erosion, while fire applications in summer and in shrublands produce the highest increases in soil loss. The following practical recommendations arise from this study: (i) research should be better distributed across all environmental contexts on a global scale; (ii) post‐fire management actions should be immediately implemented after the prescribed fire application; (iii) prescribed fire should be carried out in spring and the soil burn severity should be kept low during burning; (iv) the monitoring studies should be prolonged at least for some years (more than two or three) after prescribed fire; (iv) the catchment‐scale investigations, although more difficult and expensive, should be encouraged (avoiding, however, areas to sparsely burnt in the context of the whole catchment); (v) the monitored variables should also include the most important physical, chemical and biological properties of soil, the cover and structure of regenerating vegetation, as well as the water quality parameters; (vi) the effects of repeated applications of prescribed fire should be experimentally assessed; and (vii) guidelines for standardized and appropriate measurements and analytical methods in experimental activities should be set up. These indications support the use of land managers in the monitoring of the hydrological impacts of the prescribed fire and in the choice of sites where post‐fire management actions must be implemented. The last recommendation of this study is the creation of an experimental database supporting the bibliographic review and the meta‐analysis, which is made available to other researchers and land managers, to create a public, easily‐accessible and comprehensive tool for future research needs and professional use. [ABSTRACT FROM AUTHOR]

Purpose: Soil water and nutrients are easily lost from tailings in rare earth mining areas, resulting in slow plant restoration and limited remediation effects. The present study was conducted to explore the remediation effect of superabsorbent polymers (SAPs) incorporated with organic and inorganic fertilizers on the retention capacity of soil water and nutrients in rare earth mining areas. Materials and methods: In this experiment, five treatments were established: the control (CK), 0.4% SAPs (S), a mixture of 8% organic fertilizer, 0.2% urea, and 1% minerals (F), and mixtures of F with 0.2% SAPs (FS1) and 0.4% SAPs (FS2). The processes of water infiltration, wetting front migration, and water leaching, the pH value and total nitrogen (TN), total phosphorus (TP), and total potassium (TK) contents in the leachate and the water content, pH value, and bulk density (BD) in the soil column were measured. Results and discussion: The results showed that all amendments significantly reduced soil infiltration and the migration of the wetting front, with decrease rates of 46.39–58.76% and 31.43–54.29%, respectively. Among them, the greatest significant delay in water infiltration in the initial period was observed in the FS1 treatment. A similar effect was found in the leaching process after 50 or 80 days of incubation, after which the leachate volume was reduced by 10.11–23.61% for the FS1 treatment. The soil water content also significantly improved, and greater effects were found in the F, FS1, and FS2 treatments, where the contents increased by 0.49–29.61%. Fertilizer addition increased soluble soil nutrients, resulting in increased TN, TP, and TK contents and a decrease in the pH value of the leachate. Nutrient loss and acidification were alleviated in the FS1 and FS2 treatments due to mixing with SAPs, with reductions of 2.00–34.21% and 2.27–6.82%, respectively. In addition, adding SAPs (in the S, FS1, and FS2 treatments) alleviated soil compaction and decreased the BD. Conclusion: Our findings indicated that SAPs incorporated with organic and inorganic fertilizers could increase soil fertility and enhance the soil retention capacity of soils for water and nutrients, thus providing a promising reference for the positive phytoremediation effects of this method. [ABSTRACT FROM AUTHOR]

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In this study, Fluvisol from the area of Stari Beĉej (Serbia) was investigated with the aim of evaluating selected chemical and physical indicators of soil quality affter its long-term use in crop production. Ten bulk soil samples (soil depth: 0-210 cm) were collected to analyze soil chemical properties (humus, CaCO3, pH, P2O5, K2O), texture (six samples, soil depth: 0-130 cm), dry-stable aggregate distribution and stability of soil aggregates (four samples, soil depth: 0-80 cm). Additional undisturbed core samples (100 cm3 volume) were also collected to determine soil bulk density, total porosity, field air capacity, and field water capacity. Water infiltration capacity was also measured in the field using a double ring infiltrometer. The results indicated that the soil had a two-layer profile and a silty loam texture (with a physical clay content of 41-42% and a colloidal clay content of 27-28%). The humus horizon has quite favorable chemical properties up to a depth of 60 cm, and at a depth of 60-80 cm it is alkalized under the influence of saline groundwater. From an agronomic point of view, the structure of this soil is favorable. The results of determining the stabillity soil aggregates show that the soil structure in the Ahp and Ah horizons at depth (0-40 cm) with a content of 41% of water-stable aggregates < 0.25 mm is significantly worse (less favorable) than in the surface part of the AhBca horizon (40-60 cm) with a content of ~58% of waterstable aggregates < 0.25 mm. The main physical properties are not particularly favorable in the Ah and AhBca horizons to a depth of 80 cm. The Ah horizon is very compact (bulk density: 1.33-1.38 g/cm3 ), and the air-filled porosity is very low (less than 5%) and small (5-10%) at all depths up to 80 cm, and it is lowest in the surface 0-20 cm layer, only 3.8%. Infiltration capacity is low. The reserves of soil moisture available for plant growth in the soil layer 0-100 cm are very good (> 160 mm water depth). In summary, the results of this study show that perennial tillage can lead to a loss of soil productivity and serious soil degradation.

Preferential flow is the most common form of water loss occurring at the interface between rock and soil (hereinafter referred to as "rock–soil interface") in karst areas, and it is also one of the important factors causing soil water leakage into the underground. Therefore, it is of great significance to cut off the pathway of soil water loss through control of preferential flow. In this experiment, rock film mulching (RFM) was used to control the preferential flow at the rock–soil interface, and its influence on the soil water infiltration pattern and soil water content was analyzed by simulating rainfall, dye tracer tests, and digging soil profiles. The results show that: (1) the RFM can significantly control the soil water loss at the rock–soil interface, (2) so that the water intercepted by the above-ground rocks changed from longitudinal infiltration to transverse diffusion, more water moved into the surrounding soil patches, and (3) the soil water content was significantly increased. These results indicate that the RFM has an important blocking effect on preferential flow at the rock–soil interface, which has important guiding significance for reducing soil water erosion in karst areas. [ABSTRACT FROM AUTHOR]