scholarly journals Mass Exchange of Water and Soil on the Soil Surface in the Rainfall Splash Erosion

2021 ◽  
Vol 9 ◽  
Author(s):  
Sun Sanxiang ◽  
Zhang Yunxia ◽  
Lei Pengshui
Keyword(s):  
Kinetic Energy ◽  
Mass Exchange ◽  
Soil Surface ◽  
Terminal Velocity ◽  
Erosion Process ◽  
Liquid Drops ◽  
Splash Erosion ◽  
The Impact ◽  
The Relationship ◽  
Soil Interface

This research aims to unfold the mass exchange mechanism of water and soil on the soil surface in the rainfall splash erosion process. We regard the rainfall splash erosion process as a collision process between the raindrop and the soil particle on the soil interface. This recognition allows us to incorporate research approaches from the spring vibrator model, which has been developed for simulating the impact of liquid drops on solid surface. We further argue that because a same set of factors determine the splash amount and infiltration amount and it is relatively simpler to observe the infiltration amount, an investigation into the relationship between the splash amount and infiltration amount would be able to provide a new channel for quantifying the splash erosion. This recognition leads us to examining the relationship between single raindrop, rainfall kinetic energy and splash erosion from both theoretical and empirical angles, with an emphasis on the relationship between the infiltration amount and the splash erosion. Such an investigation would add value to the collective effort to establish mass exchange law in water-soil interface during rainfall splash erosion. It is found that during the rainfall splash process, the splash erosion is proportional to the rainfall kinetic energy; and has a linear relation to the infiltration amount, with the rainfall intensity as one of important parameters and the slope depending on the unit conversation of the infiltration amount and the splash erosion. If the units of two items are same, the slope is the ratio of the soil and water density, and the splash erosion velocity of the rainfall is half of the rainfall terminal velocity. The single raindrop kinetic energy and the splash erosion have a quadratic parabola relation, and the splash velocity is about 1/3 of single raindrop terminal velocity.

scholarly journals Experimental Setup for Splash Erosion Monitoring—Study of Silty Loam Splash Characteristics

2019 ◽  
Vol 12 (1) ◽  
pp. 157 ◽  
Author(s):  
David Zumr ◽  
Danilo Vítor Mützenberg ◽  
Martin Neumann ◽  
Jakub Jeřábek ◽  
Tomáš Laburda ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Soil Surface ◽  
Outer Diameter ◽  
Rainfall Simulator ◽  
Soil Particles ◽  
Splash Erosion ◽  
Laboratory Setup ◽  
Before And After ◽  
Silty Loam ◽  
Raindrop Splash

An experimental laboratory setup was developed and evaluated in order to investigate detachment of soil particles by raindrop splash impact. The soil under investigation was a silty loam Cambisol, which is typical for agricultural fields in Central Europe. The setup consisted of a rainfall simulator and soil samples packed into splash cups (a plastic cylinder with a surface area of 78.5 cm2) positioned in the center of sediment collectors with an outer diameter of 45 cm. A laboratory rainfall simulator was used to simulate rainfall with a prescribed intensity and kinetic energy. Photographs of the soil’s surface before and after the experiments were taken to create digital models of relief and to calculate changes in surface roughness and the rate of soil compaction. The corresponding amount of splashed soil ranged between 10 and 1500 g m−2 h−1. We observed a linear relationship between the rainfall kinetic energy and the amount of the detached soil particles. The threshold kinetic energy necessary to initiate the detachment process was 354 J m−2 h−1. No significant relationship between rainfall kinetic energy and splashed sediment particle-size distribution was observed. The splash erosion process exhibited high variability within each repetition, suggesting a sensitivity of the process to the actual soil surface microtopography.

scholarly journals Atmospheric teleconnection patterns and eddy kinetic energy content: wavelet analysis

2004 ◽  
Vol 11 (3) ◽  
pp. 295-301 ◽  
Author(s):  
V. N. Khokhlov ◽  
A. V. Glushkov ◽  
I. A. Tsenenko
Keyword(s):  
Kinetic Energy ◽  
North Atlantic ◽  
Energy Content ◽  
Southern Oscillation ◽  
Eddy Kinetic Energy ◽  
The North ◽  
The North Atlantic ◽  
The Impact ◽  
The Relationship

Abstract. In this paper, we employ a non-decimated wavelet decomposition to analyse long-term variations of the teleconnection pattern monthly indices (the North Atlantic Oscillation and the Southern Oscillation) and the relationship of these variations with eddy kinetic energy contents (KE) in the atmosphere of mid-latitudes and tropics. Major advantage of using this tool is to isolate short- and long-term components of fluctuations. Such analysis allows revealing basic periodic behaviours for the North Atlantic Oscillations (NAO) indices such as the 4-8-year and the natural change of dominant phase. The main results can be posed as follows. First, if the phases of North Atlantic and Southern Oscillations vary synchronously with the 4-8-year period then the relationship between the variations of the NAO indices and the KE contents is the most appreciable. Second, if the NAO phase tends to abrupt changes then the impact of these variations on the eddy kinetic energy contents in both mid-latitudes and tropics is more significant than for the durational dominance of certain phase.

scholarly journals Towards Mapping of Soil Crust Using Multispectral Imaging

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1850
Author(s):  
Giacomo Crucil ◽  
Kristof Van Oost
Keyword(s):  
Kinetic Energy ◽  
Multispectral Imaging ◽  
Soil Surface ◽  
Surface Dynamics ◽  
Soil Crusting ◽  
Standard Normal Variate ◽  
Digital Elevation ◽  
Standard Normal ◽  
Clear Identification ◽  
The Relationship

Soil crusts and surface roughness are properties which are highly dynamic in both space and time that change in response to biotic processes, meteorological conditions and farming operations. These factors, however, are difficult to quantify and are usually described using simplified expert-based classes. This hampers a clear identification of the controlling factors and their relation to soil erosion and sediment generation processes. The availability of new small portable multispectral cameras offers the potential to study soil surface dynamics at a high spatial and temporal resolution. The objective of this study was to analyse the relationship between soil crusting, represented by cumulative rainfall kinetic energy, and soil surface reflectance, as derived from vis-NIR multispectral imaging. We designed a series of rainfall-soil surface experiments to disentangle the effects of soil crusting on spectral reflectance factors from those related to surface micro-scale roughness. Partial least squared regression (PLSR) models were developed to predict both kinetic energy and roughness from multispectral images. We evaluated different roughness removal methods which were based on the transformation of reflectance through standard normal variate (SNV) and roughness thresholding using high resolution digital elevation models. Furthermore, we assigned the light scattering effect related to roughness in the multispectral spatial domain by calculating the inter-quantile range of the reflectance values in a kernel. Our experiments and workflow demonstrate that it is possible to model crust development, using rainfall kinetic energy as a proxy, from vis-NIR based multispectral imaging.

Numerical Simulation of Hypervelocity Impact on Mesh Bumper Causing Fragmentation and Ejection

2012 ◽  
Vol 525-526 ◽  
pp. 401-404
Author(s):  
Gong Shun Guan ◽  
Rui Tao Niu
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Impact Angle ◽  
Hypervelocity Impact ◽  
Impact Position ◽  
Debris Cloud ◽  
Combination Mode ◽  
The Impact ◽  
The Relationship ◽  
Aluminum Mesh

In order to study the fragmentation of projectile and ejection of debris clouds caused by hypervelocity impacting mesh bumper, simulation of aluminum sphere projectile hypervelocity normal impacting aluminum mesh bumper was practiced with SPH arithmetic of LS-DYNA soft. The diameter of projectile was 4mm. Impact velocities of aluminum spheres were varied between 2.2km/s and 6.2km/s. The impact angle was 0°. The relationship between the debris clouds characteristic of projectile and the impact position on aluminum mesh bumper was studied. The effect on fragmentation of projectile from different combination mode of aluminum mesh bumper was analyzed. The results showed that the morphologies of the debris cloud varied with the impact position when a projectile impacted the mesh bumper. The debris clouds as palpus was found, and some local kinetic energy concentrated appeared in the debris clouds. Debris clouds distribution was more uniform when projectile impacted wire across point on the mesh bumper. Debris clouds had more diffuse area and less residual kinetic energy when mesh bumper was combined with interleaving mode. Mesh bumper combined with interleaving mode was helpful in enhancing the protection performance of shields.

scholarly journals A Preliminary Study on Translational Kinetic Energy Absorption Using Coconut-Fiber (Coir) Sheets as a Potential Impact-Worthy Constituent in Advanced Aerospace Material

2011 ◽  
Vol 471-472 ◽  
pp. 1028-1033 ◽  
Author(s):  
Nuraishah Bazilah Affandi ◽  
Azmin Shakrine Mohd. Rafie ◽  
Shahnor Basri ◽  
Fairuz Izzuddin Romli ◽  
Dayang Laila Abang Abdul Majid ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Energy Absorption ◽  
Natural Fiber ◽  
Small Mass ◽  
Aerospace Material ◽  
Gas Gun ◽  
Preliminary Study ◽  
The Impact ◽  
The Relationship ◽  
Steel Projectiles

Known as “coir”, the fibrous husk of the coconut fruit has potential for integration as a constituent in impact-resisting aerospace materials. As a preliminary study, kinetic energy absorption of this natural fiber is studied prior to further testing, for instance; a non-ballistic surface impacted at high velocity by a small mass is the equivalent mock-up to runway debris. The purpose of this study is to find the relationship between the thickness of the fiber with the kinetic energy absorption. Fabricated fiber panels measuring 10×10×t cm with various thickness are subjected to mild steel projectiles launched by a light gas gun at a constant pressure. The velocity of the projectiles is set to be consistent with the velocity range of typical transport-category aircraft. The impact response of the panels aids in predicting the required amendments where plies of coir sheets are increased to which perforation is impossible. The relationship established from the experimental results is then used to predict the amount of layers required for total translational kinetic energy absorption.

scholarly journals Refinements in the Treatment of Ice Particle Terminal Velocities, Highlighting Aggregates

2005 ◽  
Vol 62 (5) ◽  
pp. 1637-1644 ◽  
Author(s):  
David L. Mitchell ◽  
Andrew J. Heymsfield
Keyword(s):  
Doppler Radar ◽  
Terminal Velocity ◽  
Current Theory ◽  
Cloud Base ◽  
Ice Crystal ◽  
Rigid Spheres ◽  
Liquid Drops ◽  
Accurate Treatment ◽  
Radar Measurements ◽  
The Relationship

Abstract Recent work on the terminal velocity of ice crystal aggregates suggests that their “Re–X” relationship may not be well predicted by current theory. This study examines possible reasons for this departure from theory, and develops a new Re–X relationship appropriate for ice crystal aggregates. The methodology of Khvorostyanov and Curry was applied to this new relationship to formulate power-law expressions for all ice particle types. Fall speed differences between the Khvorostyanov and Curry approach and the approach described here were as large as 50% for aggregates and 30% for single crystals. This was primarily due to the following: 1) surface roughness coefficients used in the former were appropriate for rigid spheres and liquid drops but not for ice crystals and 2) the relationship between Reynolds number Re and Best number X at high Re is better described for aggregates by adding a second term to the Re–X governing equation, as done in this work. The corrections and improvements described here may be critical to the calculation of snowfall rates, to the modeling of the aggregation process, and for interpreting Doppler radar measurements during snowfall events. Since most of the size distribution mass is generally associated with aggregates below cloud base, an accurate treatment of aggregate fall speeds is needed for determining snowfall rates.

Impact Resistance of Automobile Tires

1968 ◽  
Vol 41 (4) ◽  
pp. 1051-1064
Author(s):  
E. W. Lothrop
Keyword(s):  
Kinetic Energy ◽  
High Speed ◽  
Impact Resistance ◽  
Test Machine ◽  
Test Results ◽  
Laboratory Test Results ◽  
Breaking Energy ◽  
The Impact ◽  
The Relationship ◽  
Automobile Tires

Abstract The construction and operation of a high speed plunger test machine to determine the impact energy required to produce failure of automobile tires are described. The equipment has been designed to operate over an energy range of 1500 to 15,000 in. lb at preselected velocities between 40 and 100 mph and at preselected temperatures between 75 and 300° F. These ranges are adequate to permit the testing of passenger tires over a range of conditions simulating those encountered in high speed driving. The test machine consists of a pneumatic gun for propelling the plunger at an inflated tire, mounted in a temperature controlled cabinet, and photoelectric devices for measuring plunger velocity. In a test the kinetic energy of the plunger is increased in increments, until failure occurs. The minimum kinetic energy required to cause failure of the tire fabric is taken as a measure of the carcass breaking energy. Data on rayon and nylon cord tires indicate that the breaking energy of a tire is dependent on both speed and temperature and that the relationship between energy, speed, and temperature depends on the cord-reinforcing material in the tire. As a result it is impossible to predict the relative impact resistance of tires under use conditions on the basis of laboratory test results obtained with the standard static plunger test, in which the plunger penetrates the tire at 2 in./min at room temperature.

scholarly journals Experimental Investigation of the Crater Caused by Hypervelocity Rod Projectile Impacting on Rocks

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yanyu Qiu ◽  
Songlin Yue ◽  
Mingyang Wang ◽  
Gan Li ◽  
Yihao Cheng ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Impact Crater ◽  
Energy Scale ◽  
Small Scale ◽  
Essential Difference ◽  
Impact Cratering ◽  
Dimensionless Analysis ◽  
Gas Gun ◽  
The Impact ◽  
The Relationship

To investigate the cratering effects of hypervelocity rod projectile impacting on rocks, a two-stage light gas gun was used to carry out 10 groups of small-scale experiments, whose velocity ranges from 1.5 km/s to 4.1 km/s. After each experiment, the morphology and size of the hypervelocity impacting crater were accurately obtained by using a device for image scanning. According to the morphology of the final crater, the impact crater can be divided into crushing area, spallation area, and radial crack area. Based on the experimental results of steel projectile vertical impacting on granite targets, the relationship between the depth and the diameter of the crater is analyzed, i.e., h/D≈0.1∼0.2; it shows that the depth of the crater is much smaller than the diameter of the crater, and the crater seems to be a shallow dish. The relation between the kinetic energy of the projectile and the size of the crater was discussed. With the increase of the projectile kinetic energy, it is uncertain whether the depth of the crater increases, but the volume of the crater will increase. Lastly, dimensionless analysis of the impact crater was carried out. Specifically, the limitations of point source solutions to hypervelocity rod projectile impact cratering have been proved, and there is no essential difference to calculate the final crater by using the energy scale or the momentum scale.

scholarly journals Rainfall Parameters Affecting Splash Erosion under Natural Conditions

2020 ◽  
Vol 10 (12) ◽  
pp. 4103 ◽  
Author(s):  
Nives Zambon ◽  
Lisbeth Lolk Johannsen ◽  
Peter Strauss ◽  
Tomas Dostal ◽  
David Zumr ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Kinetic Energy ◽  
Linear Function ◽  
Rain Gauge ◽  
Total Kinetic Energy ◽  
Rainfall Erosivity ◽  
Erosion Process ◽  
Good Tool ◽  
Splash Erosion ◽  
Natural Rainfall

The interaction between rainfall erosivity parameters and splash erosion is crucial for describing the soil erosion process; however, it is rarely investigated under natural rainfall conditions. In this study, we conducted splash erosion experiments under natural rainfall on three sites in Central Europe. The main goal was to obtain the relationship between splash erosion of the bare soil in seedbed condition and commonly used rainfall erosivity parameters (kinetic energy, intensity, and rainfall erosivity (EI30)). All sites were equipped with a rain gauge and an optical laser disdrometer where the splash erosion was measured, with modified Morgan splash cups. In order to investigate which parameter best describes the splash erosion process for all sites, a regression analysis was performed. In total, 80 splash erosion events were evaluated. Splash erosion can be described as a linear function of total kinetic energy and a non-linear function of EI30. However, the use of the total kinetic energy led to underestimation of the splash erosion rates for highly intensive rainfalls. Therefore, better results were obtained when using average rainfall intensity as the splash erosion predictor or the kinetic energy divided by the rainfall duration. Minor differences between the replicates during splash erosion measurements indicate that the modified Morgan splash cup provides a good tool for soil erosion assessment.

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