The effect of aggregate size on the infiltration behaviour of a slaking soil and its relevance to ponded irrigation

Soil Research ◽  
1979 ◽  
Vol 17 (1) ◽  
pp. 65 ◽  
Author(s):  
N Collis-George ◽  
RSB Greene
Keyword(s):  
Surface Soil ◽  
Aggregate Size ◽  
Surface Region ◽  
Infiltration Rate ◽  
Optical Microscope ◽  
Wetting Front ◽  
Cumulative Infiltration ◽  
Front Advance ◽  
Soil Wetting ◽  
Independent Confirmation

The depth and degree to which columns of aggregates of different sizes of a structurally unstable red-brown earth surface soil slaked when water was ponded on the surface were studied. The slaking affected the subsequent infiltration into the soil. Wetting front advance and cumulative infiltration data indicated that the depth of the zone of slaking increased as the aggregate size increased. However, the effectiveness of the slaked layer in reducing the infiltration rate depended not only on the depth of slaking, but also on the extent to which the different aggregates had slaked into microaggregates and to what extent the microaggregates filled the interaggregate pores, if any. Examination of vertical sections of the slaked surface region using an optical microscope provided independent confirmation of the phenomenon of slaking in the various aggregate sizes.

Simulating transient infiltration in unsaturated soils

1998 ◽  
Vol 35 (6) ◽  
pp. 1093-1100 ◽  
Author(s):  
J R McDougall ◽  
I C Pyrah
Keyword(s):  
Hydraulic Conductivity ◽  
Unsaturated Soils ◽  
Flow Model ◽  
Unsaturated Flow ◽  
Surface Region ◽  
Infiltration Rate ◽  
Soil Suction ◽  
Wetting Front ◽  
Near Surface ◽  
Unsaturated Hydraulic Conductivity

Transient responses to various infiltration events have been examined using an unsaturated flow model. Numerical simulations reveal a range of infiltration patterns which can be related to the ratio of infiltration rate to unsaturated hydraulic conductivity. A high value of this ratio reflects a prevailing hydraulic conductivity which cannot readily redistribute the newly infiltrated moisture. Moisture accumulates in the near-surface region before advancing down through the soil as a distinct wetting front. In contrast, low values of the ratio of rainfall to unsaturated hydraulic conductivity show minimal moisture accumulation, as the relatively small volumes of infiltrating moisture are readily redistributed through the soil profile.Key words: numerical modelling, infiltration, unsaturated soil, soil suction, groundwater.

One-Dimensional Vertical Infiltration Characteristics of Red Loam

2014 ◽  
Vol 644-650 ◽  
pp. 5383-5386
Author(s):  
Shen Kai Huang ◽  
Peng Fei Gu ◽  
Xin Yu Zhao ◽  
Qing Bao Pei ◽  
Jin Long Gao
Keyword(s):  
Bulk Density ◽  
Soil Column ◽  
Infiltration Rate ◽  
Experimental Results ◽  
Water Infiltration ◽  
One Dimension ◽  
Column Experiments ◽  
Wetting Front ◽  
One Dimensional ◽  
Cumulative Infiltration

Using a soil column experiments to analyze the influence of different density of one dimension vertical infiltration of water infiltration rate, cumulative infiltration and wetting front. The experimental results showed that the bulk density of the infiltration rate, cumulative infiltration and wetting front has a significant impact. Infiltration rate, cumulative infiltration and wetting front were decreased with increasing density in the same period of infiltration. The greater the soil bulk capacity, the larger the infiltration decrease ration μ and η, respectively compared to the based accumulative infiltration and the based wetting front depth.

scholarly journals Cumulative infiltration and infiltration rate prediction using optimized deep learning algorithms: A study in Western Iran

2021 ◽  
Vol 35 ◽  
pp. 100825
Author(s):  
Mahdi Panahi ◽  
Khabat Khosravi ◽  
Sajjad Ahmad ◽  
Somayeh Panahi ◽  
Salim Heddam ◽  
...  
Keyword(s):  
Deep Learning ◽  
Learning Algorithms ◽  
Infiltration Rate ◽  
Western Iran ◽  
Rate Prediction ◽  
Cumulative Infiltration

Using time compression approximation to determine actual infiltration rate from variable rainfall events

2017 ◽  
Vol 50 (1) ◽  
pp. 155-165 ◽  
Author(s):  
Yanyan Cheng ◽  
Guotao Cui ◽  
Jianting Zhu
Keyword(s):  
Infiltration Rate ◽  
Maximum Error ◽  
Richards Equation ◽  
Rainfall Time Series ◽  
Rainfall Events ◽  
Practical Applications ◽  
Time Compression ◽  
Cumulative Infiltration ◽  
Rainfall Patterns ◽  
Numerical Solver

Abstract Understanding infiltration into soils from rainfall events is important for many practical applications. The idea of time compression approximation (TCA) was proposed to simulate infiltration rate, which only requires the relationship between the potential infiltration rate (PIR) and potential cumulative infiltration (PCI). The TCA-based method can be used in any rainfall–runoff models since the PIR vs. PCI relationship can be developed independent of actual rainfall patterns. The main objective of this study is to establish guidelines on when this method can be adequately applied. The results based on the TCA are compared with those from the field observations and the Richards equation numerical solver for observed rainfall events and randomly generated rainfall patterns with prescribed temporal variabilities and hiatuses. For continuous rainfall with potential ponding, the maximum error of infiltration amount using the TCA-based method is less than 5%. The TCA-based method, in general, underestimates the total infiltration amount from variable rainfall events. Variance in rainfall time series does not significantly affect the errors of using the TCA-based method to determine the actual infiltration rate. The TCA-based method can produce reasonable results in simulating the actual infiltration rate for rainfall events with a short hiatus.

Effects of Cr+ ion implantation on the oxidation of Ni3Al

1993 ◽  
Vol 8 (4) ◽  
pp. 734-740 ◽  
Author(s):  
M. Chen ◽  
S. Patu ◽  
J.N. Shen ◽  
C.X. Shi
Keyword(s):  
Oxidation Resistance ◽  
Layer Structure ◽  
Surface Region ◽  
Optical Microscope ◽  
Al Alloy ◽  
Temperature Oxidation ◽  
Intermediate Layers ◽  
Air Interface ◽  
Before And After ◽  
High Temperature Oxidation Behavior

Ni3Al samples were implanted with different doses of 150 keV Cr+ ions to modify the surface region. The high temperature oxidation behavior was tested. The surface layer structure was investigated by AES, TEM, XRD, and optical microscope before and after the test. The experimental results show that chromium ions turn a small amount of ordered superlattice Ni3Al phase into a disordered Ni–Al–Cr phase. Also there is a bcc chromium phase in the implanted sample. Implanted Ni3Al alloy has better oxidation resistance than the unimplanted one at 900 °C. The oxide layer is of a multilayer structure after 50 h oxidation, composed of a NiO inner layer, Cr2O3, spinel NiAl2O4 intermediate layers, and an α–Al2O3 external layer at the oxide/air interface. The α-Al2O3 and Cr2O3 are independent scale-like layers. The two protective layers improve the oxidation resistance significantly. The effects of implanted elements and possible reaction mechanisms are discussed.

scholarly journals Numerical investigation of wetting front migration and soil water distribution under vertical line source irrigation with different influencing factors

2021 ◽  
Author(s):  
Yanwei Fan ◽  
Liangjun Ma ◽  
Hujun Wei ◽  
Pengcheng Zhu
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Content ◽  
Influencing Factors ◽  
Line Source ◽  
Vertical Line ◽  
Initial Water Content ◽  
Wetting Front ◽  
Simulation Results ◽  
Soil Wetting

Abstract Vertical line source irrigation (VLSI) is an underground irrigation method suitable for deep-rooted plants. Understanding the characteristics of the soil wetting body of the VLSI was the key to designing this irrigation system. On the basis of experimental verification of the reliability of the HYDRUS simulation results of VLSI under the conditions of soil texture (ST), initial water content (θi), line source buried depth (B), line source diameter (D) and line source length (L), numerical studies of the migration law of the wetting front of VLSI and the distribution characteristics of soil moisture were performed. The wetting front migration (WFM) was mainly influenced by ST, θi, D and L (P < 0.05), while B had little effect on WFM (P > 0.05). The shape of the soil wetting body changed little under different influencing factors. The water content contour was approximately ‘ellipsoidal’ around the line source. The soil moisture near the line source was close to the saturated moisture content. The moisture content around the line source gradually decreased outward, and the contour lines gradually became dense. According to the simulation results, a prediction model of multiple factors influencing the migration process of the VLSI wetting front was established. The predicted value was in good agreement with the measured value. The results of this research could provide a theoretical basis for further optimizing the combination of VLSI and irrigation elements.

scholarly journals Predicted Infiltration for Sodic/Saline Soils from Reclaimed Coastal Areas: Sensitivity to Model Parameters

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Dongdong Liu ◽  
Dongli She ◽  
Shuang’en Yu ◽  
Guangcheng Shao ◽  
Dan Chen
Keyword(s):  
Water Movement ◽  
Soil Surface ◽  
Coastal Areas ◽  
Model Parameters ◽  
Wetting Front ◽  
Sodic Soils ◽  
Infiltration Process ◽  
Infiltration Model ◽  
Soil Physical Quality ◽  
Cumulative Infiltration

This study was conducted to assess the influences of soil surface conditions and initial soil water content on water movement in unsaturated sodic soils of reclaimed coastal areas. Data was collected from column experiments in which two soils from a Chinese coastal area reclaimed in 2007 (Soil A, saline) and 1960 (Soil B, nonsaline) were used, with bulk densities of 1.4 or 1.5 g/cm3. A 1D-infiltration model was created using a finite difference method and its sensitivity to hydraulic related parameters was tested. The model well simulated the measured data. The results revealed that soil compaction notably affected the water retention of both soils. Model simulations showed that increasing the ponded water depth had little effect on the infiltration process, since the increases in cumulative infiltration and wetting front advancement rate were small. However, the wetting front advancement rate increased and the cumulative infiltration decreased to a greater extent whenθ0was increased. Soil physical quality was described better by theSparameter than by the saturated hydraulic conductivity since the latter was also affected by the physical chemical effects on clay swelling occurring in the presence of different levels of electrolytes in the soil solutions of the two soils.

scholarly journals Effect of Water Quality and Date Palm Biochar on Evaporation and Specific Hydrological Characteristics of Sandy Soil

Agriculture ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 300
Author(s):  
Arafat Alkhasha ◽  
Abdulrasoul Al-Omran ◽  
and Abdulaziz G. Alghamdi
Keyword(s):  
Water Quality ◽  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Date Palm ◽  
Saline Water ◽  
Sandy Soils ◽  
Infiltration Rate ◽  
Hydrological Characteristics ◽  
Arid Conditions ◽  
Cumulative Infiltration

Experiments were conducted in a soil laboratory using transparent columns (5 and 40 cm in diameter and length, respectively) to evaluate the effects of water quality (i.e., fresh or saline water) with the addition of biochar on soil moisture characteristics. Soil and biochar were gently combined and added into the top 10 cm of each column at a rate of 2%, 4%, 6%, and 8% (w/w). The results show a decrease in cumulative evaporation by 29.27%, 16.47%, 14.17%, and 14.61% with freshwater, and by 21.24%, 12.22%, 21.08%, and 12.67% with saline water for B1, B2, B3, and B4, respectively, compared with unamended soil (B1, B2, B3 and B4 represent the treatments with the biochar rate of 2, 4, 6, and 8%, respectively). Cumulative infiltration was reduced by 34.38%, 43.37%, 58.89%, and 57.07% with freshwater, and by 30.18%, 44.38%, 54.44%, and 49.11% with saline water for B1, B2, B3, and B4, respectively. The infiltration rate was reduced by 32.73%, 42.17%, 57.82%, and 56.85% with freshwater, and 42.09%, 54.6%1, 62.68%, and 58.41% with saline water for T1, T2, T3, and T4, respectively, compared with the control. The saturated hydraulic conductivity of B1 decreased significantly by 92.8% and 67.72% with fresh and saline water, respectively. Biochar, as a soil conditioner, could be used in arid conditions with fresh and saline water to enhance the hydrological properties of sandy soils.

Effects of moisture condition and freeze/thaw cycles on surface soil aggregate size distribution and stability

2012 ◽  
Vol 92 (3) ◽  
pp. 529-536 ◽  
Author(s):  
Enheng Wang ◽  
Richard M. Cruse ◽  
Xiangwei Chen ◽  
Aaron Daigh
Keyword(s):  
Water Content ◽  
Size Distribution ◽  
Surface Soil ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Moisture Condition ◽  
Freeze Thaw ◽  
Aggregate Size Distribution ◽  
Disturbed Soil

Wang, E., Cruse, R. M., Chen, X. and Daigh, A. 2012. Effects of moisture condition and freeze/thaw cycles on surface soil aggregate size distribution and stability. Can. J. Soil Sci. 92: 529–536. Freeze/thaw cycles can affect soil aggregate stability, which in turn impacts wind and water erosion. The objectives of this laboratory study were: (1) to determine the effect of variable freeze/thaw cycles and soil water conditions on aggregate size distribution and stability; and (2) to evaluate differences in aggregate size distribution and stability between disturbed soil and undisturbed soil cores as affected by freeze/thaw cycles and soil water conditions. Surface soil was collected before freezing in late fall of 2009. Aggregates isolated from disturbed soil or intact soil cores were subjected to a factorial combination of 3 gravimetric water content treatments: 0.15 m3 m−3, 0.23 m3 m−3 or 0.30 m3 m−3, and 3 freeze/thaw treatments: 0, 3, or 9 cycles. A freeze/thaw cycle involved soil freezing at –10∘C for 24 h, followed by thawing at 5∘C for 24 h. Most aggregate size classes were affected significantly (P<0.05) by freeze/thaw cycles except for wet-sieved aggregates >5 mm. Dry-sieved aggregates were relatively more sensitive to the freeze/thaw treatment than wet-sieved aggregates. The mean weight diameter (MWD) of dry-sieved aggregates was significantly (P<0.05) greater at 0.30 m3 m−3 than 0.15 m3 m−3 water content, but the opposite trend was observed for MWD of wet aggregates and aggregate stability. There was a significant (P<0.05) response of the MWD in dry-sieved aggregates to the interactive freeze/thaw×water content effect that differed for aggregates obtained from disturbed soil and those in the undisturbed soil core, but not for the MWD of wet-sieved aggregates and aggregate stability.

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