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Article

Effect of Median Soil–Particle Size Ratio on Water Storage Capacity of Capillary Barrier

by
Honghua Liu
1,2,3,
Jie Dong
1,2,3,
Qiang Liu
4,*,
Lin Geng
1,2,3,
Zhongsheng Wang
1,2,3 and
Chong Sun
5
1
Key Laboratory of Geological Safety of Coastal Urban Underground Space, Ministry of Natural Resources, Qingdao 266100, China
2
Qingdao Geo-Engineering Surveying Institute (Qingdao Geological Exploration Development Bureau), Qingdao 266101, China
3
Qingdao Key Laboratory of Groundwater Resources Protection and Rehabilitation, Qingdao 266100, China
4
College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China
5
College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
*
Author to whom correspondence should be addressed.
Water 2024, 16(13), 1774; https://doi.org/10.3390/w16131774
Submission received: 18 March 2024 / Revised: 4 June 2024 / Accepted: 18 June 2024 / Published: 22 June 2024
(This article belongs to the Topic Advances in Environmental Hydraulics)
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Abstract

:
Capillary barriers are widely used as a cover system to enhance the upper-soil-layer water storage capacity and reduce water infiltrate into the lower soil layer. In this paper, the effects of the median soil–particle size ratio on the water storage capacity of capillary barriers were studied using a series of indoor one-dimensional soil column infiltration tests. The results show that the water storage capacity rises with an increase in the median soil–particle size ratio until it exceeds 10. The variation in the total water storage capacity is related to not only the median soil–particle size ratio but also the particle size of coarse-grained soil or fine-grained soil. When the fine-grained soil-layer particle size is constant, the total water storage first increases, then decreases, and finally remains constant after increasing the median soil–particle size ratio. In contrast, when the coarse-grained soil layer particle size is constant, the relationship between the capillary barrier’s total water storage and median soil–particle size ratio can be defined as a power function. Using the capillary barrier can increase coarse-grained sand by 90% in water storage capacity and can only increase fine-grained sand by 7% in water storage capacity. The breakthrough time increases with the increase in the median soil–particle size ratio. The presence of the coarse and fine-grained soil layer interface in the capillary barrier can affect the fine-grained soil layer infiltration rate.

1. Introduction

The capillary barrier is a soil system composed of a fine-grained soil layer covered by a coarse-grained soil layer. Because of the difference in the permeability between the coarse-grained and fine-grained layers under the same matric suction condition, the capillary barrier not only cuts off the water moving downward into the coarse-grained soil layer at the top surface of the coarse-grained soil layers but also the capillary water moving upward into the fine-grained layer at the bottom surface of the coarse-grained soil layers. Because the capillary barrier has these functions, it has been used in several different fields, including as the cover in landfill and nuclear waste treatment plants instead of the traditional compacted clay gap [1,2,3,4,5], as the enhanced agricultural layer in an arid area to improve the root-zone water content [6,7,8], as a protection layer from rainfall in slope engineering [9,10], and as an obstruction layer to stop salted water from flowing upward into cultivated soil [11,12].
Several factors, such as the shape of the interface [13], the thickness of fine- and coarse-grained soil layers [14,15,16,17,18,19], the particle size of each soil layers [20], the slope [21,22,23], the rainfall intensity [24], the gradation [25], the temperature difference [26], the compaction [27], the organic [28], and the structure [29,30,31,32], affect the water storage capacity, lateral diversion, and breakthrough time, which will impact the performance of capillary barriers in practice. Among these factors, the particle sizes of two layers are important indicators for the preliminary evaluation of the capillary barrier. Smesrud et al. [33] used numerical simulations and found that 90% of seepage water laterally divert when the median soil–particle size ratio exceeds 5. Apambilla et al. [34] found that when the median soil–particle size ratio exceeds 8, the capillary barrier can effectively prevent the groundwater from rising. The mechanism of the influence of the mean ratio of soil–particle size on the prevention of infiltration is not clear. Moreover, the effect of the mean ratio of soil-particle size on the water storage capacity needs to be discussed further.
In order to obtain the effect of the median soil–particle size ratio on the water storage capacity and the breakthrough time, a series of indoor 1D ponding infiltration tests were conducted. Quartz sands of different grain sizes were used as the materials for the fine-grained layer and the coarse-grained layer. The results show that the water storage capacity increases with the decrease in the grain size of the fine-grained layer. However, when the grain size of the fine-grained layer is constant, the water storage capacity no longer increases with the median soil–particle size ratio, which exceeds by 10 times. The breakthrough time is mainly determined by the size of the fine-grained layer, when the diameter of the particles of the fine-grained layer is smaller than 0.075 mm, the breakthrough time linearly increases with the median soil–particle size ratio; otherwise, the breakthrough time remains almost same.

2. Materials and Methods

2.1. Materials and Equipment

The physical properties of quartz sand used in the test are shown in Table 1. The maximum compaction density was determined using a proctor test [35] [ASTM D7263-2009 (R2018)], the specific gravity of different soil separates was determined using the pycnometer method [36] [ASTM D854-2014], and the saturated permeability coefficient was determined using the constant/variable head permeability coefficient method.
As shown in Figure 1, the soil column of the infiltration experiments is made of acrylic transparent tubes with a 1 cm thick wall and 14.4 cm internal diameter. The cylinders are 50 cm high and easy to combine and install. Five holes with a 40 cm diameter were located at 5 cm, 15 cm, 25 cm, 35 cm, and 45 cm heights of the acrylic cylinder wall. SM150T moisture meter (Delta-T Devices Ltd., Cambridge, UK) was adopted, with the measurement range of 0–0.7 m3·m−3 and accuracy of ± 0.03 m3·m−3. The datalogger (GP2, Delta-T Devices Ltd., Cambridge, UK) was used to automatically collect and record the readings of the moisture meter. The Mariotte bottle was used as the water source to provide a constant 5 cm water head at the top of the soil column, and a weighing device was set under the Mariotte bottle to record the infiltration water quantity. The soil column was connected to a percolation collector at the bottom using a water outlet, and the percolation collector was set on an electronic balance to record the mass of seepage water.
To ensure a uniform sand distribution, a consistent compaction effort was given at each layer with a thickness of 5 cm, and a measured mass of quartz sand was densified with a rubber hammer to achieve maximum compaction density. The maximum compaction density is listed in Table 1.
The capillary barrier was tested using two soil layers. The coarse-grained soil layer had a thickness of 10 cm, while the fine-grained soil layer was 40 cm thicker than the coarse-grained soil layer. A non-woven geotextile was placed between the fine- and coarse-grained soil layers to prevent the fine-grained soil layer particles from entering the coarse-grained soil layer.

2.2. Experiment

In this paper, the median particle size (D50) is an index that evaluates the difference in particle sizes between the coarse- and fine-grained soil layers; the screened quartz sand is used in the experiment to prevent the influence of the gradation of natural sand. The quartz sand is screened from well-continuous graded quartz sand; therefore, the median particle size can be approximated to the logarithmic average of the minimum and maximum particle sizes of screened quartz sand. Table 2 show the 21 infiltration experiments and specific configurations.
The experiment XLC1–XLC5′s coarse-grained soil-layer particle size is 2–5 mm, and XLC6–XLC9 is 1–2 mm, the fine-grained soil-layer quartz-sand particle size decrease led to the increase in the median soil–particle size ratio. The fine-grained soil-layer particle size of CLC1–CLC5 and CLC6–CLC10 are 0.1–0.25 mm and 0.075–0.1 mm, respectively. The coarse-grained soil-layer quartz-sand particle size increase led to the increase in the median soil–particle size ratio. JZT1–JZT6 are homogeneous soil columns.
In order to verify the influence of non-woven geotextile on the hydraulic properties of the soil column, infiltration experiments of 20 cm homogeneous quartz sand were carried out. The quartz-sand particle size is 0.1–0.25 mm, non-woven geotextile is set at 10 cm of the soil column in the experiment group, and no non-woven geotextile is in the control group. The 5 cm water head was applied on the soil column. Then, we monitored the outflow time from the bottom of the column and recorded the water storage of the soil column. The results show that the infiltration rate and final water storage capacity of the soil column with or without non-woven geotextile are basically the same as those shown in Figure 2. Therefore, using non-woven geotextile in the partition layer does not affect the test results.
Stormont and Morris [37] defined the water held in the fine-grained soil layer before it flows into the coarse-grained soil layer as the water storage capacity of the capillary barrier. In this paper, the water storage capacity and breakthrough time are the two main factors used to judge the capillary barrier’s effectiveness. We use the following methods to determine the water storage capacity and the breakthrough time. The total water storage capacity was defined as the total volume per unit area of water that is stored in both the fine-grained soil layer and the coarse-grained soil layer. It was calculated by the difference between the record of the two electronic balances after testing, of which one was used to weigh the variation in the Mariotte bottle, representing the water quantity of the infiltration, and the other one was used to weigh the mass of the outflow. The water storage of the coarse-grained soil layer was measured by drying the coarse-grained soil after the test by disassembling the columns. The water storage capacity (of the fine-grained soil layer) was calculated by the difference between the total water storage capacity and the water storage of the coarse-grained soil layer.
In the experiment, the moisture meter of the coarse-grained soil layer is arranged in the middle of coarse layer, and the thickness of the coarse-grained soil layer is only 10 cm. The coarse-grained soil layer used in the experiment is coarser than 0.25–0.5 mm, the saturated hydraulic conductivity is large, as shown in Table 1, and the sensing range of SM150T is 35 mm. When the wetting front reaches 15 mm below the interface [38], the SM150T can record the water content. The maximum lag is less than 40 s at 0.25–0.5 mm quartz sand as the coarse-grained soil layer. Therefore, the time of the moisture content monitored using the moisture meter in the coarse-grained soil layer is regarded as the approximate breakthrough time.

3. Results and Discussion

3.1. Influence of Median Soil–Particle Size Ratio on Water Storage Capacity of Capillary Barrier

The relationships of the water storage capacity and total water storage capacity with the median soil–particle size ratio are shown in Figure 3. In Figure 3a,b, the coarse-grained soil layer is 2–5 mm and 1–2 mm, respectively. The finer the fine-grained soil-layer particle size, the larger the median soil–particle size ratio. In Figure 3c,d, the fine-grained soil layer is 0.1–0.25 mm and 0.075–0.1 mm, respectively. The coarser the coarse-grained layer particle size, the larger the median soil–particle size ratio. The circle hollow dot is the total water storage of the capillary barrier, the square dot is the water storage of the capillary barrier, the triangle dot is soil saturation at section A-A shown in Figure 1, and section A-A is 5 cm above the fine- and coarse-grained layer interface, which is the moisture meter monitoring section closest to the interface of the capillary barrier.
It can be seen from Figure 3a,b, when the coarse-grained soil-layer particle size is constant, the total water storage capacity and water storage increase with the increased in the median soil–particle size ratio of about 10–20 times. The coarse-grained soil layer is made of 2–5 mm quartz sand, the total water storage capacity and water storage reach the maximum value at a median soil–particle size ratio of 20. When the coarse-grained soil layer is 1–2 mm, the maximum total water storage capacity and water storage were reached at a median soil–particle size ratio of 10. The rule of saturation at section A-A (Figure 1) is the same as the water storage capacity law: when the median soil–particle size ratio reaches 20 times and 10 times, respectively, the volumetric water content of quartz sand at A-A section is close to saturation.
In Figure 3c,d, with the increase in the median soil–particle size ratio, the total water storage capacity first increases, then decreases, and finally stabilizes, while the water storage capacity first increases before eventually stabilizing. When the fine-grained soil layer is 0.1–0.25 mm quartz sand, the water storage capacity and total water storage capacity reach a stable state at the median soil–particle size ratio of 10 times; when the fine-grained soil layer is 0.075–0.1 mm quartz sand, the water storage capacity and total water storage capacity of the capillary barrier reach a stable state at the median soil–particle size ratio of 20 times. The rule of saturation at profile A-A is the same as the water storage capacity law: when the median soil–particle size ratio reaches 10 and 20 times, respectively, the A-A profile is close to saturation.
In conclusion, with the increase in the median soil–particle size ratio, the capillary barrier water storage capacity increases. When the median soil–particle size ratio increases to 10–20 times, the water storage capacity reaches its maximum capacity. Because the A-A section has been fully saturated, it means the bottom of the fine-grained soil layer has been saturated. When the fine-grained soil-layer particle size is finer and the coarse-grained soil-layer particle size remains constant, the total water storage of the capillary barrier increases with the increase in the median soil–particle size ratio. When the fine-grained soil-layer particle size remains constant and the coarse-grained soil-layer particle size is coarser, with the increase in the median soil–particle size ratio, the total water storage of capillary barrier first increases, then decreases, and finally stabilizes.
The water storage capacity of capillary barriers with coarse-grained particle sizes of 2–5 mm and 1–2 mm quartz sand compared to the corresponding fine-grained soil-layer particle size of homogeneous sand is shown in Figure 4.
In general, regardless of the fine-grained soil-layer particle size, the water storage capacity of the capillary barrier that used 2–5 mm quartz sand as the coarse-grained soil layer is higher than the 1–2 mm quartz sand used as the coarse-grained soil layer. When fine-grained soil layer is made of quartz sand coarser than 0.25–0.5 mm, the capillary barrier that used 2–5 mm quartz sand as the coarse-grained soil layer increases the water storage capacity by more than 20–90% compared with the 1–2 mm quartz sand used as the coarse-grained soil layer. However, when the fine-grained soil layer is made of quartz sand finer than 0.25–0.5 mm, the coarse-grained layer that used 2–5 mm quartz sand only increases the water storage capacity by 4% than the 1–2 mm quartz sand used as the coarse-grained soil layer.
This is because when the particle size is coarser than 0.25–0.5 mm, the water content of the fine-grained soil layer is sensitive to the matrix potential. As shown in Figure 5, the water entry value of 2–5 mm quartz sand as the coarse-grained soil layer is −1 kPa, only 1 kPa higher than the 1–2 mm quartz sand used as the coarse-grained soil layer. When the fine-grained soil-layer soil particle size is coarser than 0.25–0.5 mm, the water storage capacity increases by more than 20% in the 1 kPa matrix suction. When the fine-grained soil layer particle size is finer than 0.25–0.5 mm, the fine-grained soil layer has been almost saturated at 1–2 mm quartz sand coarse-grained soil layer’s water entry value; the water content of the fine-grained soil layer does not substantially increase when the 2–5 mm quartz sand is used as coarse-grained soil layer. According to Figure 3a,b, when the coarse-grained soil layer remains constant, the fine-grained soil-layer particle size is coarser than 0.25–0.5 mm, regardless of whether the coarse-grained soil layer uses 2–5 mm or 1–2 mm quartz sand, the median soil–particle size ratio is lower than 10; the water storage capacity of capillary barrier that uses 2–5 mm quartz sand as the coarse-grained soil layer is far better than the 1–2 mm quartz sand used as the coarse-grained soil layer. When the fine-grained soil-layer particle size is finer than 0.25–0.5 mm, the median soil–particle size ratio is greater than 10; the water storage capacity of capillary barrier that uses the 2–5 mm quartz sand as the coarse-grained layer is slightly higher than the 1–2 mm quartz sand used as the coarse-grained soil layer. Similarly, it can be seen from Figure 3c,d that the fine-grained soil layer remains constant when the median soil–particle size ratio is lower than 10, and the water storage of capillary barrier increased with the increase in the median soil–particle size ratio; when the median soil–particle size ratio is higher than 10, the water storage of capillary barrier does not increase with the increase in the median soil-particle size ratio. Therefore, increasing the coarse-grained soil-layer particle size cannot increase the water storage capacity of the capillary barrier infinitely. When the median soil–particle size ratio is higher than 10, the water storage of the capillary barrier only slightly increases.

3.2. Effect of Median Soil-Particle Size Ratio on Breakthrough Time of Capillary Barrier

It can be seen from Figure 6a that when the coarse-grained soil-layer particle size is constant and the fine-grained soil-layer particle size decreases, the breakthrough time increases with the increase in the median soil–particle size ratio. The coarse-grained soil-layer particle size remains constant, and the water entry value is certain. With the decrease in the fine-grained soil-layer particle size, the saturated hydraulic conductivity of the fine-grained soil layer decreases, and a higher water content is required to achieve the water entry value, which leads to breakthrough time increasing with the increase in the median soil–particle size ratio. Figure 6b shows that when the fine-grained soil layer is made of 0.075–0.1 mm quartz sand, the breakthrough time increases with the increase in the median soil–particle size ratio. But, when the fine-grained soil layer used 0.1–0.25 mm quartz sand, the breakthrough time almost does not increase with the increase in the median soil–particle size ratio. As shown in Figure 6, when the coarse-grained soil-layer particle size is coarser, ranging from 0.25–0.5 mm to 2–5 mm, the water entry value range is −3.2 kPa–−0.7 kPa; 0.1–0.25 mm quartz sand is close to saturation at −4 kPa; and the water content is insensitive to the increased water entry value. So, the water entry value increase only results in a slight water storage increase when 0.1–0.25 mm quartz sand is used in the fine-grained soil layer, and the breakthrough time almost does not increase with the increase in the median soil–particle size ratio. When the fine-grained soil layer is made of 0.075–0.1 mm quartz sand, the saturated hydraulic conductivity is low. The water content at −3.2–0.7 kPa (coarse-grained soil layer’s water entry value) was not saturated, the coarse-grained soil layer used coarser quartz sand, and the fine-grained soil layer needed more water to obtain a higher water entry value. So, when the fine-grained soil layer is made of 0.075–0.1 mm quartz sand, it takes a long time to reach the corresponding breakthrough water content with the given coarser coarse-grained soil-layer particle size.

3.3. Effect of Capillary Barrier on Infiltration Rate of Fine-Grained Soil Layer

The moisture meter can record a moving wetting front in the fine-grained soil layer with time. As shown in Figure 7a, capillary barrier has a weak effect on the infiltration rate below 15 cm in fine-grained soil layer when the fine-grained soil layer is made of 0.1–0.25 mm quartz sand. When the coarse-grained soil-layer particle size is coarser, the infiltration rate decreases slightly, and the time for the wetting front to reach the coarse- and fine-grained soil-layer interface increases slightly. It can be seen in Figure 7b that the capillary barrier has a significant effect on the infiltration rate l below 25 cm in the fine-grained soil layer, and the infiltration rate decreases significantly when the coarse-grained soil-layer particle size is coarser and the fine-grained soil layer is made of 0.075–0.1 mm quartz sand. The results show that the capillary barrier can influence the infiltration rate of the fine-grained soil layer, and the coarse-grained soil-layer particle size and fine-grained soil-layer particle size are major factors. The coarse-grained soil-layer particle size controls the infiltration rate of the fine-grained soil layer, and the fine-grained soil-layer particle size determined the range of the fine-grained soil layer affected by the capillary barrier; that is, the coarser the coarse-grained soil-layer particle size, the slower the infiltration rate of the fine-grained soil layer, and the finer the fine-grained soil-layer particle size, the greater the range of the infiltration rate of the fine-grained soil layer affected by the capillary barrier.

4. Conclusions

The ponding infiltration tests conducted on the quartz sand capillary barrier with different grain sizes show that the water storage capacity is influenced by the grain size of the fine-grained layer and the median soil–particle size ratio. When the grain size of the coarse-grained layer is constant, the water storage capacity increases with the decrease in the grain size of the fine-grained layer and is more affected by it. However, when the grain size of the fine-grained layer is constant, the water storage capacity no longer increases with the median soil–particle size ratio that exceeds 10 times.
The total water storage is related to the median soil–particle size ratio change mode. When the fine-grained soil-layer particle size remains constant and the coarse-grained soil-layer particle size is coarser, with the increase in the median soil-particle size ratio, the total water storage first increases, then decreases, and finally stabilizes. When the fine-grained soil-layer particle size is finer and the coarse-grained soil-layer particle size remains constant, the relationship between the total water storage of the capillary barrier total and the median soil–particle size ratio can be defined a power function. The capillary barrier can increase coarse-grained sand by 20–90% in field capacity compared to the corresponding homogeneous sand, but it can only increase fine-grained sand by 7% in field capacity because the field capacity of homogenous fine-grained sand is close to saturation.
The breakthrough time increases with the increase in the median soil–particle size ratio. Therefore, enlarging the median soil–particle size ratio can improve the effective time of the capillary barrier. The coarser the coarse-grained soil-layer particle, the slower the infiltration rate of the fine-grained soil layer. The finer the fine-grained soil-layer particle size, the greater the range of the infiltration rate of the fine-grained soil layer affected by the capillary barrier.
In conclusion, when using capillary barriers in engineering, the median soil–particle size ratio should greater than 10 to obtain the maximum water storage capacity and a long effective time.

Author Contributions

Conceptualization, Q.L. and C.S.; Methodology, Q.L. and C.S.; Validation, C.S.; Formal analysis, C.S.; Writing—original draft, C.S.; Supervision, J.D. and Q.L.; Project administration, H.L., Q.L., L.G. and Z.W.; Funding acquisition, Q.L. All authors have read and agreed to the published version of the manuscript.

Funding

The financial support is provided by the Shandong Provincial Natural Science Foundation (ZR2021MD021) and the Key Laboratory of Geological Safety of Coastal Urban Underground Space, Ministry of Natural Resources (BHKF2021Z05).

Data Availability Statement

The data presented in this study are available on request from the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 1. Setup of the 1D ponding infiltration test.
Figure 1. Setup of the 1D ponding infiltration test.
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Figure 2. Effect of non-woven geotextile on hydraulic properties of soil column. (a) Detection time of water at different positions. (b) water storage capacity with and without geotexile.
Figure 2. Effect of non-woven geotextile on hydraulic properties of soil column. (a) Detection time of water at different positions. (b) water storage capacity with and without geotexile.
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Figure 3. Variation curve of median soil–particle size ratio and water storage capacity of capillary barrier.
Figure 3. Variation curve of median soil–particle size ratio and water storage capacity of capillary barrier.
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Figure 4. The effect of capillary barrier on increased water storage capacity compared with homogeneous soil.
Figure 4. The effect of capillary barrier on increased water storage capacity compared with homogeneous soil.
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Figure 5. Wetting soil–water characteristic curve.
Figure 5. Wetting soil–water characteristic curve.
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Figure 6. The effect of median soil–particle size ratio on breakthrough time of capillary barrier. (a) different partical size of coarse-grained soil layer. (b) different partical size of fine-grained soil layer.
Figure 6. The effect of median soil–particle size ratio on breakthrough time of capillary barrier. (a) different partical size of coarse-grained soil layer. (b) different partical size of fine-grained soil layer.
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Figure 7. Relationship between wetting front and infiltration time.
Figure 7. Relationship between wetting front and infiltration time.
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Table 1. Basic physical properties of quartz sand.
Table 1. Basic physical properties of quartz sand.
Sand Diameter (mm)Specific GravityMaximum Compaction Density (g/cm3)Saturated Hydraulic Conductivity (cm/s)Porosity
<0.0752.801.662.11 × 10−40.408
0.075–0.12.771.563.16 × 10−30.439
0.1–0.252.881.574.39 × 10−30.454
0.25–0.52.681.574.11 × 10−20.416
0.5–12.641.571.69 × 10−10.408
1–22.631.563.61 × 10−10.406
2–52.641.651.430.378
Table 2. Scheme of ponding infiltration experiments.
Table 2. Scheme of ponding infiltration experiments.
NumberCoarse Quartz Sand Grade/mmFine Quartz Sand Grade/mmMedian Soil-Particle Size Ratio
XLC12–51–22.24
XLC20.5–14.45
XLC30.25–0.59.03
XLC40.1–0.2519.75
XLC50.075–0.136.7
XLC61–20.5–12
XLC70.25–0.53.99
XLC80.1–0.258.95
XLC90.075–0.116.25
CLC10.25–0.50.1–0.252.19
CLC20.5–14.44
CLC31–28.81
CLC42–519.75
CLC55–1044.75
CLC60.1–0.250.075–0.11.78
CLC70.25–0.54.02
CLC80.5–18.16
CLC91–216.20
CLC102–536.70
JZT12–52–51
JZT21–21–2
JZT30.5–10.5–1
JZT40.25–0.50.25–0.5
JZT50.1–0.250.1–0.25
JZT60.075–0.10.075–0.1
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Liu, H.; Dong, J.; Liu, Q.; Geng, L.; Wang, Z.; Sun, C. Effect of Median Soil–Particle Size Ratio on Water Storage Capacity of Capillary Barrier. Water 2024, 16, 1774. https://doi.org/10.3390/w16131774

AMA Style

Liu H, Dong J, Liu Q, Geng L, Wang Z, Sun C. Effect of Median Soil–Particle Size Ratio on Water Storage Capacity of Capillary Barrier. Water. 2024; 16(13):1774. https://doi.org/10.3390/w16131774

Chicago/Turabian Style

Liu, Honghua, Jie Dong, Qiang Liu, Lin Geng, Zhongsheng Wang, and Chong Sun. 2024. "Effect of Median Soil–Particle Size Ratio on Water Storage Capacity of Capillary Barrier" Water 16, no. 13: 1774. https://doi.org/10.3390/w16131774

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