The effect of kinetic energy of excess rainfall on soil loss from non-vegetated plots

Soil Research ◽  
1983 ◽  
Vol 21 (4) ◽  
pp. 445 ◽  
Author(s):  
PIA Kinnell
Keyword(s):  
Kinetic Energy ◽  
Soil Loss ◽  
Rainfall Intensity ◽  
Acceptance Rate ◽  
Slope Gradient ◽  
The Difference ◽  
Bare Fallow ◽  
Runoff And Soil Loss ◽  
Sheet Erosion

Data obtained from three 0.01 ha runoff and soil-loss plots, established with a bare fallow treatment on a yellow podzolic (Albaqualf) soil and slope gradient of 4.2%, were analysed in terms of the kinetic energy of raindrops and the efficiency of the use of that energy in generating soil loss. The results indicate that the difference between rainfall intensity and the average infiltration (acceptance) rate of the soil during an event can be used to estimate variations in the efficiency of use of rainfall energy in generating sheet erosion.

scholarly journals Effects of land use, slope gradient, and soil and water conservation structures on runoff and soil loss in semi-arid Northern Ethiopia

2013 ◽  
Vol 34 (3) ◽  
pp. 236-259 ◽  
Author(s):  
Gebeyehu Taye ◽  
Jean Poesen ◽  
Bas Van Wesemael ◽  
Matthias Vanmaercke ◽  
Daniel Teka ◽  
...  
Keyword(s):  
Land Use ◽  
Water Conservation ◽  
Soil Loss ◽  
Soil And Water Conservation ◽  
Northern Ethiopia ◽  
Slope Gradient ◽  
Runoff And Soil Loss ◽  
Effects Of Land Use ◽  
Semi Arid ◽  
Soil And Water

Quantitative Evaluation of the Relationship Between Slope Gradient and Infiltration Capacity Based on a Rainfall Experiment Using Pit Sand

2020 ◽  
Vol 15 (6) ◽  
pp. 745-753
Author(s):  
Toru Danjo ◽  
◽  
Tomohiro Ishizawa
Keyword(s):  
Surface Layer ◽  
Slope Stability ◽  
Soil Loss ◽  
Rainfall Intensity ◽  
Horizontal Distance ◽  
Slope Gradient ◽  
Slope Surface ◽  
Infiltration Capacity ◽  
Tank Model ◽  
The Relationship

The infiltration of rainfall into a slope surface may affect slope stability; thus, it is important to understand the amount of rainfall infiltration (hereafter referred to as the “infiltration capacity”) for a slope surface layer when evaluating slope stability. This research focuses on slope gradient, a factor affecting the infiltration capacity, and performs two types of water-spraying experiments using pit sand under the same conditions but with different slope gradients. In the first experiment, the surface flow rate and soil loss were measured using an earth-tank model with a horizontal distance of 0.5 m, depth of 0.1 m, and width of 0.2 m to form slope gradients of 2°, 20°, and 40° to clarify the effect of slope gradient on the infiltration capacity. In the second experiment, a water-spraying experiment that closely simulated natural rainfall was performed at a large-scale rainfall facility owned by the National Research Institute for Earth Science and Disaster Resilience (NIED), Japan. This experiment used an earth-tank model with a horizontal distance of 1.21 m, depth of 0.5 m, and width of 0.5 m to form slope gradients of 2°, 10°, 20°, 30°, and 40° with the aim of proposing a quantitative evaluation method for the relationship between the slope gradient and infiltration capacity. The results showed that the soil loss and infiltration capacity increased as the slope gradient increased in the case of the pit sand used in the experiments. This was confirmed to be due to the fact that an increased gradient allowed grains with diameters of <50 μm in the slope surface layer to flow out easily, thereby increasing the infiltration capacity. In addition, the relationship between the rainfall intensity and infiltration capacity revealed that the infiltration capacity varied depending on the rainfall intensity and slope gradient, which is unlike the relationship for constant values such as the permeability coefficient. Moreover, the research findings indicated a strong, positive linear relationship (R2 = 0.98) between the slope gradient and fitting factor Ic. Therefore, the relationship between rainfall intensity and the infiltration capacity could be expressed using the fitting factor Ic. This suggests the possibility of quantitatively evaluating the relationships between rainfall intensity, the infiltration slope gradient, and the infiltration capacity.

A Numerical Infiltration Model in Civil Engineering and its Comparison with Geo-Seep Software

2013 ◽  
Vol 859 ◽  
pp. 257-260
Author(s):  
Dong Fang Tian ◽  
Xiao Yu Ling
Keyword(s):  
Rainfall Intensity ◽  
Influence Factor ◽  
Slope Gradient ◽  
Slope Surface ◽  
Infiltration Capacity ◽  
Infiltration Model ◽  
Calculation Results ◽  
The Difference ◽  
Difference Calculation ◽  
Manning Roughness

A numerical couple model of infiltration and runoff is presented which could simulate infiltration more accurately in theory. While a usually tool to solve infiltration problem is Geo-Seep software which contained in Geo-Slope package. In this paper, the difference of infiltration capacity between two above methods are researched. A numerical orthogonal test considering saturated conductivity (Ks), rainfall intensity (R), slope gradient (S) and Manning roughness of slope surface (n) is adopted to explore the difference. Calculation results show that the maximum difference reaches 38.25% and the biggest influence factor is Ks.

scholarly journals Simulation of Rainfall Intensity and Slope Gradient to Determination the Soil Runoff Coefficient at Microplot Scale

2020 ◽  
Vol 10 (1) ◽  
pp. 12-17
Author(s):  
Dawod Rasooli Keya ◽  
Tariq H. Karim
Keyword(s):  
Soil Loss ◽  
Rainfall Intensity ◽  
Low Cost ◽  
Silty Clay ◽  
Runoff Coefficient ◽  
Slope Gradient ◽  
Erosion Processes ◽  
High Repeatability ◽  
Runoff And Sedimentation ◽  
Rain Simulator

Simulating rainfall is one of the valuable methods of measuring hydrological data and soil erosion processes. Rapid evaluation, high repeatability, and low cost are the reasons of using rain simulators. In this study, a rain simulator was constructed in dimensions of 3.0 × 3.0 × 3.0 m and it was protected on three sides by a plastic cover. An inclined table was used to create slopping surfaces of 5, 10, and 15%. Microplots were used in the dimensions of 0.2 × 0.4 × 1.0 m to collect and measure direct runoff in a bucket outside the device. Nozzles were calibrated to produce two different rainfall intensities 10 and 20 mmh−1 using sprinkler Model 5B at 8 and 12 psi, respectively. Furthermore, three different soil types, namely, clay loam (CL), silty clay (SC) loam, and SC were examined. In general, it was observed that with increasing the rainfall intensity and slope, the rate of runoff and sedimentation increase. SC soil at 15% slop offered the highest performance under the intensity of 20 mmh−1. SC and the CL soils produced the highest and lowest runoff coefficients, respectively. The CL soil produced the highest soil loss (1 kgm2 at 15% and I = 20 mmh−1). Further, it was concluded that a significant change (an average increase of 53%) in soil loss can be achieved as the rainfall intensity increased from 10 to 20 mmh−1.

scholarly journals Considering the relationship of slope and soil loss on skid trails in the north of Iran (a case study)

2013 ◽  
Vol 59 (No. 9) ◽  
pp. 339-344 ◽  
Author(s):  
M. Akbarimehr ◽  
H. Jalilvand
Keyword(s):  
Soil Loss ◽  
Rainfall Intensity ◽  
Forest Harvesting ◽  
Slope Gradient ◽  
Slope Length ◽  
The North ◽  
North Of Iran ◽  
Relationship Of ◽  
The Relationship

With increasing mechanization of forest harvesting operations the impacts on soil have increased quite dramatically. The objective of this paper was to examine the relationship of slope and soil loss. This research was carried out in parcels 14 and 26 of the third district of Nav-Asalem forest in the north of Iran. Erosion plots were 75, 150 and 225 m<sup>2</sup> with two slope classes. After each rainfall event the amount of runoff was measured; then, a sample was taken to determine the weight of soil loss. The results of correlation analysis by Pearson&rsquo;s test between soil loss and slope classes, soil loss and slope length showed that there was a significant (P &lt; 0.05) and positive correlation between the mentioned factors. Also, linear regression between soil loss, slope length and slope gradient was significant. It could be concluded that studying and underlying factors that increase soil loss such as soil type, rainfall intensity, should also be taken into consideration in future. Skid trail construction and skidding should be limited to the slope of &lt; 20%; machine traffic should be restricted. The above-mentioned conclusions can be applied to proper harvesting and management of forest ecosystems.&nbsp; &nbsp;

scholarly journals Assessment of Rainfall Kinetic-Energy–Intensity Relationships

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1994 ◽  
Author(s):  
Claudio Mineo ◽  
Elena Ridolfi ◽  
Benedetta Moccia ◽  
Fabio Russo ◽  
Francesco Napolitano
Keyword(s):  
Kinetic Energy ◽  
Soil Loss ◽  
Energy Intensity ◽  
Rainfall Intensity ◽  
Central Italy ◽  
Direct Evaluation ◽  
Hydrological Variable ◽  
The Mean ◽  
Raindrop Energy ◽  
Soil Loss Equation

Raindrop-impact-induced erosion starts when detachment of soil particles from the surface results from an expenditure of raindrop energy. Hence, rain kinetic energy is a widely used indicator of the potential ability of rain to detach soil. Although it is widely recognized that knowledge of rain kinetic energy plays a fundamental role in soil erosion studies, its direct evaluation is not straightforward. Commonly, this issue is overcome through indirect estimation using another widely measured hydrological variable, namely, rainfall intensity. However, it has been challenging to establish the best expression to relate kinetic energy to rainfall intensity. In this study, first, kinetic energy values were determined from measurements of an optical disdrometer. Measured kinetic energy values were then used to assess the applicability of the rainfall intensity relationship proposed for central Italy and those used in the major equations employed to estimate the mean annual soil loss, that is, the Universal Soil Loss Equation (USLE) and its two revised versions (RUSLE and RUSLE2). Then, a new theoretical relationship was developed and its performance was compared with equations found in the literature.

Interaction Effects of Polyacrylamide Application Rate, Molecular Weight, and Slope Gradient on Runoff and Soil Loss under Sprinkler Irrigation

2014 ◽  
Vol 955-959 ◽  
pp. 3489-3498
Author(s):  
Fa Hu Li ◽  
Ai Ping Wang ◽  
L. S. Wu
Keyword(s):  
Molecular Weight ◽  
Soil Loss ◽  
Sprinkler Irrigation ◽  
Interaction Effects ◽  
Application Rate ◽  
Control Treatment ◽  
Slope Gradient ◽  
Runoff Volume ◽  
Total Runoff ◽  
Runoff And Soil Loss

Runoff and soil loss affect both farmland productivity and environmental quality. This study tested the interaction effects among polyacrylamide (PAM) application rate, PAM molecular weight, and slope gradient on runoff and soil loss under simulated sprinkler irrigation in laboratory. Experimental treatments consisted of four PAM application rates of 0 (control), 0.5, 1.0, and 2.0 g m-2, two PAM molecular weights of 12 and 18 Mg mol-1, and three slope gradients of 5o, 15o, and 25o. Results indicated that compared with the control treatment, PAM application generally decreased total runoff volume but increased soil loss. Total runoff volume and soil loss increased with the increased PAM application rate. Under control treatment, total runoff volume increased with the increased slope gradient. However, total runoff volume was similar for different slope gradients when PAM application rates were 0.5 and 1.0 g m-2, but it decreased with the increased slope gradient when PAM application rate was 2.0 g m-2. Total soil loss increased with the increase of slope gradient under experimental conditions. Polyacrylamide molecular weight did not affect total runoff volume but did soil loss significantly atP< 0.001, and a high PAM molecular weight resulted in less soil loss than a low one did. Statistical analysis demonstrated that there existed a significant interaction effect atP< 0.001 between PAM application rate and soil slope gradient on runoff volume and soil loss. The interaction effects between PAM molecular weight and slope gradient or among PAM application rate, PAM molecular weight, and slope gradient on soil loss were also significant atP< 0.01. A PAM application rate less than 2 g m-2is suggested to control water and soil loss on sloped lands under sprinkler irrigation.

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