scholarly journals A laboratory experimental system for infiltration studies

2016 ◽  
Vol 48 (3) ◽  
pp. 741-748 ◽  
Author(s):  
Renato Morbidelli ◽  
Carla Saltalippi ◽  
Alessia Flammini ◽  
Marco Cifrodelli ◽  
Corrado Corradini
Keyword(s):  
Conceptual Model ◽  
Slope Angle ◽  
Experimental System ◽  
Soil Surface ◽  
Laboratory System ◽  
Infiltration Process ◽  
Artificial Rainfall ◽  
Surface Gradient ◽  
Loam Soil ◽  
Gradient Effects

The investigation of a few hydrological processes under natural conditions can be distorted by their interactions. In this context, a laboratory system that allows a few mechanisms of the infiltration process to be studied univocally is presented. The core component of the system is a physical model consisting of a soil tank with slope angle, γ, adjustable from 1 ° to 15 °. A generator of artificial rainfall can produce rainfall rates up to 50 mm h−1. Surface runoff and deep flow, Qd, are continuously monitored. An overall analysis of three previous investigations performed by the physical system and directed to clarify the infiltration process is also briefly reported. These investigations, that concerned the validation of a local conceptual model for erratic rainfalls, the role of run-on and the effects of sloping soil surfaces, were all carried out by using different configurations of the system. Great slope effects in bare soils were observed. For example, under steady conditions, a ratio Qd(γ = 1°) / Qd(γ = 10°) equal to about 4 was observed in a loam soil. Finally, on the basis of the acquired knowledge, further investigations to be realized with the same basic elements are proposed to derive a conceptual model that describes the soil surface gradient effects.

scholarly journals Effect of tillage, slope, and rainfall on soil surface microtopography quantified by geostatistical and fractal indices during sheet erosion

2020 ◽  
Vol 12 (1) ◽  
pp. 232-241
Author(s):  
Na Ta ◽  
Chutian Zhang ◽  
Hongru Ding ◽  
Qingfeng Zhang
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Soil Surface ◽  
Rainfall Events ◽  
Tillage Practices ◽  
Surface Microtopography ◽  
Artificial Rainfall ◽  
Soil Surface Roughness ◽  
The Difference ◽  
Sheet Erosion

AbstractTillage and slope will influence soil surface roughness that changes during rainfall events. This study tests this effect under controlled conditions quantified by geostatistical and fractal indices. When four commonly adopted tillage practices, namely, artificial backhoe (AB), artificial digging (AD), contour tillage (CT), and linear slope (CK), were prepared on soil surfaces at 2 × 1 × 0.5 m soil pans at 5°, 10°, or 20° slope gradients, artificial rainfall with an intensity of 60 or 90 mm h−1 was applied to it. Measurements of the difference in elevation points of the surface profiles were taken before rainfall and after rainfall events for sheet erosion. Tillage practices had a relationship with fractal indices that the surface treated with CT exhibited the biggest fractal dimension D value, followed by the surfaces AD, AB, and CK. Surfaces under a stronger rainfall tended to have a greater D value. Tillage treatments affected anisotropy differently and the surface CT had the strongest effect on anisotropy, followed by the surfaces AD, AB, and CK. A steeper surface would have less effect on anisotropy. Since the surface CT had the strongest effect on spatial variability or the weakest spatial autocorrelation, it had the smallest effect on runoff and sediment yield. Therefore, tillage CT could make a better tillage practice of conserving water and soil. Simultaneously, changes in semivariogram and fractal parameters for surface roughness were examined and evaluated. Fractal parameter – crossover length l – is more sensitive than fractal dimension D to rainfall action to describe vertical differences in soil surface roughness evolution.

scholarly journals Non-isolated load sharing direct current system operation with use of the auctioneering diodes

2019 ◽  
Vol 28 ◽  
pp. 01037 ◽  
Author(s):  
Maciej Kozak
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Heat Dissipation ◽  
Current System ◽  
Electrical Power ◽  
Experimental System ◽  
Laboratory System ◽  
Simulation Studies ◽  
Power Distribution System ◽  
Electrical Systems

The paper presents the background and results of numerical simulation and experimental research of a system using auctioneering diodes used to distribute the electrical power between two power converters connected with intermediate circuits in parallel, direct connection. Presented non-isolated power distribution system which utilizes blocking diodes placed in DC branches are used in the selected ship's electrical systems, however, they create problems related to control and handling ground faults. Another issue occurring during the operation of this type of systems is increased heat dissipation while diodes switching. Selected problems related to the operation of experimental system have been identified by means of simulation studies and experiments carried out in a 11 kVA laboratory system and the theoretical basis along with results are provided in the article.

Examination of the Penetration of Enteric Viruses in Soils under Simulated Conditions in the Laboratory

1985 ◽  
Vol 17 (10) ◽  
pp. 197-199 ◽  
Author(s):  
P. H. Jørgensen
Keyword(s):  
Sewage Sludge ◽  
Unsaturated Soil ◽  
Sandy Loam ◽  
Soil Column ◽  
Enteric Viruses ◽  
Soil Surface ◽  
Coxsackievirus B3 ◽  
Soil Columns ◽  
Sand Column ◽  
Loam Soil

In two different unsaturated soil columns percolated with artificial rainwater under simulated aerated conditions, transport of coxsackievirus B3 and adenovirus 1 below 3.5 cm under the soil surface could not be demonstrated. The viruses were applied to the columns as seeded sewage sludge. Under saturated conditions transport of water-suspended coxsackievirus B3 was faster in a soil column with sandy loam soil than in a diluvial sand column.

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.

Study on the Measurement Method of Soil Surface Roughness

2011 ◽  
Vol 383-390 ◽  
pp. 5357-5362
Author(s):  
Zi Cheng Zheng ◽  
Shu Qin He
Keyword(s):  
Surface Roughness ◽  
Laser Scanner ◽  
Soil Surface ◽  
Poor Correlation ◽  
Roller Chain ◽  
Soil And Water Loss ◽  
Artificial Rainfall ◽  
Soil Surface Roughness ◽  
Slope Farmland

Based on the determination method of the comprehensive domestic and international surface roughness, by the method of indoor artificial rainfall, the determination of soil surface roughness had been studied from the measurement accuracy, time-consuming and resolution. The results showed that the laser scanner method was the best to determine the surface roughness, followed by pin meter method, the roller chain meter method, and the ruler was the worst. The results of determination had the better correlation between the laser scanner method and the roller chain meter method before rainfall, however they had poor correlation after rainfall. They had the better correlation between the laser scanner method and pin meter method both before rainfall and after rainfall. And on this basis, the relationships were established among the different methods. The results provide theory basis for the further study on soil surface roughness. At the same time, it would serve for harnessing soil and water loss of the slope farmland in Loess Plateau.

scholarly journals Experimental study on soil erosion under different soil composition using rainfall simulator

2019 ◽  
Vol 65 (No. 4) ◽  
pp. 181-188 ◽  
Author(s):  
Akihiro Hamanaka ◽  
Takashi Sasaoka ◽  
Hideki Shimada ◽  
Shinji Matsumoto
Keyword(s):  
Soil Erosion ◽  
Cover Crops ◽  
Slope Angle ◽  
Soil Composition ◽  
Effective Measure ◽  
Rehabilitation Process ◽  
Tropical Regions ◽  
Artificial Rainfall ◽  
Prevention Method ◽  
Negative Impacts

Soil erosion is one of the major environmental problems in open-cut mines in tropical regions. It causes negative impacts including the removal of nutrient-rich topsoil, destroys aquatic habitat, dam and pond siltation, clogs river by deposition of sediment, and causes water pollution in the rehabilitation process. Soil texture is an important factor to affect soil erosion. In this study, artificial rainfall experiment in the laboratory scale was conducted to clarify the mechanism of soil erosion under the different soil composition and to discuss the methods for minimizing soil erosion. The obtained results showed that the soil seal generated due to the presence of fine particle under high rainfall intensity is the main contributor to accelerate the soil erosion. Additionally, the surface coverage by the cover crops is the most effective measure to reduce soil erosion because both the coarse and fine contents runoff can be minimized while arranging of the slope angle is effective for reducing the runoff of coarse contents and the soil compaction is effective to reduce that of fine contents. Soil erosion can be minimized by selecting prevention method considering the type of soil because the prevention effect on soil erosion is different depending on the type of soil.

Subsurface Application and Shallow Incorporation of Herbicides on Cotton

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 494-498 ◽  
Author(s):  
A. F. Wiese ◽  
E. B. Hudspeth
Keyword(s):  
Gossypium Hirsutum ◽  
Weed Control ◽  
Sandy Loam ◽  
Soil Surface ◽  
Sandy Loam Soil ◽  
Soil Types ◽  
Loam Soil

In a 3-year study on four soil types, subsurface application just ahead of a planter with a device that removed the top from the bed, applied a band of spray, and covered the band with soil reduced weed control in cotton (Gossypium hirsutum L.) obtained with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), 2,4-bis(isopropylamino)-6-methylmercapto-s-triazine (prometryne), 3-(hexahydro-4,7-methanoindan-5-yl)-1,1-dimethylurea (norea), dimethyl-2,3,5,6-tetrachloroterephthalate (DCPA), and 1,1-dimethyl-3(α,α,α,-trifluoro-m-tolyl)urea (fluometuron) compared to applications on the soil surface. This machine improved weed control with α,α,α,-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin). Shallow incorporation, with two helical blades, after planting increased weed control with trifluralin, diuron, and DCPA by 10% or more over the surface applications. This incorporator increased weed control obtained with prometryne and norea 5%. Very shallow incorporation, with metal tines, after planting improved weed control obtained with trifluralin and DCPA 18 and 11%, respectively. Weed control with norea was increased 7%, but metal tines did not appreciably affect weed control obtained with prometryne, diuron, or fluometuron. Compared to surface applications, incorporation increased cotton injury with diuron, norea, prometryne, and fluometuron on sandy loam soil.

scholarly journals A New Conceptual Model for Slope-Infiltration

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 678 ◽  
Author(s):  
Renato Morbidelli ◽  
Corrado Corradini ◽  
Carla Saltalippi ◽  
Alessia Flammini ◽  
Jacopo Dari ◽  
...  
Keyword(s):  
Surface Water ◽  
Conceptual Model ◽  
Soil Type ◽  
Unsolved Problem ◽  
Threshold Value ◽  
Water Velocity ◽  
Water Infiltration ◽  
Infiltration Process ◽  
Wide Range ◽  
Steep Slopes

Rainfall infiltration modeling over surfaces with significant slopes is an unsolved problem. Even though water infiltration occurs over soil surfaces with noticeable gradients in most real situations, the typical mathematical models used were developed for infiltration over horizontal surfaces. In addition, recent investigations on infiltration over sloping surfaces have provided conflicting results, suggesting that our understanding of the process may still be lacking. In this study, our objective is to specifically examine if the surface water velocity that is negligible over near horizontal soil surfaces can affect the infiltration process over steep slopes. A new conceptual model representing a wide range of experimental results is proposed. The model represents water flow as an ensemble of infinitesimal “particles” characterized by specific velocities and assumes that only “particles” with velocity less than a threshold value can contribute to the infiltration process. The velocity distribution and the threshold value depend on slope and soil type, respectively. This conceptual model explains observed results and serves as a foundation for developing further experiments and refining models that offer more realistic representations of infiltration over sloping surfaces.

Ammonia volatilization from surface-applied livestock slurry as affected by slurry composition and slurry infiltration depth

2006 ◽  
Vol 144 (3) ◽  
pp. 229-235 ◽  
Author(s):  
S. G. SOMMER ◽  
L. S. JENSEN ◽  
S. B. CLAUSEN ◽  
H. T. SØGAARD
Keyword(s):  
Soil Water ◽  
Dry Matter ◽  
Sandy Loam ◽  
Soil Water Potential ◽  
Soil Surface ◽  
Pig Slurry ◽  
Fertilizer Value ◽  
Loam Soil ◽  
Water Values ◽  
Slurry Composition

Volatilization of ammonia (NH3) from slurry applied in the field is considered a risk to the environment and reduces the fertilizer value of the slurry. To reduce volatilization a better understanding of the slurry–soil interaction is needed. Therefore, the present study focuses on measuring NH3 volatilization as affected by differences in infiltration. Livestock slurries with different dry matter (DM) composition and viscosity were included in the experiments by using untreated cattle and pig slurry, pig slurry anaerobically digested in a biogas plant and pig slurry anaerobically digested and physically separated. NH3 volatilization was measured using dynamic chambers and related to infiltration of the livestock slurries in the soil by measuring chloride (Cl−) and Total Ammoniacal Nitrogen (TAN=ammonium (NH4+)+NH3) concentrations in soil at different depths from 0·5 to 6·0 cm from the soil surface. The slurries were applied to sandy and sandy-loam soils packed in boxes within the chambers. There were no significant differences in relative volatilization of NH3 from untreated cattle and pig slurries, but anaerobic digestion of pig slurry increased volatilization due to increases in pH. However, physical separation of the digested slurry reduced the volatilization compared with untreated slurry, due to increased infiltration. In general, the volatilization decreased significantly with increased infiltration. The present study shows that NH3 volatilization from applied slurry can be related to infiltration and that infiltration is related to slurry composition (i.e. DM content and particle size distribution) and soil water content. The infiltration of liquid (measured by Cl− infiltration) was affected by soil water potential, therefore, Cl− infiltrated deeper into the sandy loam soil than the sandy soil at similar gravimetric soil water values. Dry matter (DM) and large particles (>1 mm) of the slurry reduced infiltration of liquid. A high proportion of small particles (<0·025 mm) facilitated infiltration of TAN.

Sign in / Sign up

Export Citation Format

Share Document