Comparison of Rainfall Energy and Soil Erosion Parameters from a Rainfall Simulator and Natural Rainfall

A rainfall simulator is an ideal tool for infiltration, soil erosion and other related research areas for replicating the process and characteristics of natural rainfall. The present paper describes the design of a comprehensive rainfall simulator. In this study a laboratory scale rainfall simulator is developed, which is particularly meant for the assessment of soil erosion at plot scale by considering various soil grain types, soil slope angles and surface exposures under different rainfall conditions. The Rainfall characteristics including the rainfall intensity and its spatial uniformity raindrop size and kinetic energy confirm that natural rainfall conditions are simulated with sufficient accuracy. The comparative measurement was carried out in a laboratory using rainfall simulator fabricated of 4 feet length and 2.5 feet width, where the applied slope angle is 3% with 39 mm/hr rainfall intensity. The runoff and soil loss for different samples were assessed by conducting number of trials. From the results it was found that the soil tilled and keeping it as a bare plot is more prone to runoff compared to soil without tilled and straw mulching has helped to reduce the runoff by 57% as compared to soil without mulching.

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Set-up and calibration of a portable small scale rainfall simulator for assessing soil erosion processes at interrill scale

Cuadernos de Investigación Geográfica ◽

10.18172/cig.3129 ◽

2017 ◽

Vol 43 (1) ◽

pp. 63 ◽

Cited By ~ 3

Author(s):

J. J. Zemke

Keyword(s):

Soil Erosion ◽

Kinetic Energy ◽

Rainfall Intensity ◽

Small Scale ◽

Rainfall Erosivity ◽

Fall Velocity ◽

Rainfall Simulator ◽

Spatial Homogeneity ◽

Erosion Processes ◽

Natural Rainfall

A portable rainfall simulator was built for assessing runoff and soil erosion processes at interrill scale. Within this study, requirements and constraints of the rainfall simulator are identified and discussed. The focus lies on the calibration of the simulator with regard to spatial rainfall homogeneity, rainfall intensity, drop size, drop fall velocity and rainfall kinetic energy. These parameters were obtained using different methods including a Laser Precipitation Monitor. A detailed presentation of the operational characteristics is given. The presented rainfall simulator setup featured a rainfall intensity of 45.4 mm·h-1 with a spatial homogeneity of 80.4% based on a plot area of 0.64 m². Because of the comparatively low drop height (2 m), the diameter-dependent terminal fall velocity (1.87 m·s-1) was lower than benchmark values for natural rainfall. This conditioned also a reduced rainfall kinetic energy (4.6 J·m-2·mm-1) compared to natural rainfall with same intensity. These shortfalls, a common phenomenon concerning portable rainfall simulators, represented the best possible trade-off between all relevant rainfall parameters obtained with the given simulator setup. Field experiments proved that the rainfall erosivity was constant and replicable.

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Estimating storm erosion with a rainfall simulator

Canadian Journal of Soil Science ◽

10.4141/s96-079 ◽

1997 ◽

Vol 77 (4) ◽

pp. 669-676 ◽

Cited By ~ 18

Author(s):

S. C. Nolan ◽

L. J. P. van Vliet ◽

T. W. Goddard ◽

T. K. Flesch

Keyword(s):

Soil Loss ◽

Conventional Tillage ◽

Reduced Tillage ◽

Natural Soil ◽

Rainfall Erosivity ◽

Slope Length ◽

Rainfall Simulator ◽

Rainfall Events ◽

Plot Size ◽

Natural Rainfall

Interpreting soil loss from rainfall simulators is complicated by the uncertain relationship between simulated and natural rainstorms. Our objective was to develop and test a method for estimating soil loss from natural rainfall using a portable rainfall simulator (1 m2 plot size). Soil loss from 12 rainstorms was measured on 144-m2 plots with barley residue in conventional tillage (CT), reduced tillage (RT) and zero tillage (ZT) conditions. A corresponding "simulated" soil loss was calculated by matching the simulator erosivity to each storm's erosivity. High (140 mm h−1) and low (60 mm h−1) simulation intensities were examined. The best agreement between simulated and natural soil loss occurred using the low intensity, after making three adjustments. The first was to compensate for the 38% lower kinetic energy of the simulator compared with natural rain. The second was for the smaller slope length of the simulator plot. The third was to begin calculating simulator erosivity only after runoff began. After these adjustments, the simulated soil loss over all storms was 99% of the natural soil loss for CT, 112% for RT and 95% for ZT. Our results show that rainfall simulators can successfully estimate soil loss from natural rainfall events. Key words: Natural rainfall events, simulated rainfall, erosivity, tillage

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The influence of different roll erosion control products to the particle size distribution of the soil sediment eroded on artificial slopes

10.5194/egusphere-egu21-9417 ◽

2021 ◽

Author(s):

Romana Kubínová ◽

Petr Kavka ◽

Martin Neumann ◽

Jan-František Kubát

Keyword(s):

Particle Size ◽

Soil Erosion ◽

Particle Size Distribution ◽

Size Distribution ◽

Soil Aggregates ◽

Erosion Control ◽

Initial Condition ◽

Rill Erosion ◽

Rainfall Simulator ◽

Soil Sediment

In this contribution the particle size distributions of the soil sediment obtained from soil erosion experiments were analysed. All the tests were done on arable topsoil&#8217;s, separately the size distribution of the soil aggregates and individual soil particles were evaluated. Soil erosion was initiated under the controlled conditions. CTU Prague laboratory rainfall simulator and field laboratory in Jirkov were used for this research. The rainfall was artificially generated with use of a nozzle type rainfall simulator. The sediment transported due to the surface runoff and rill erosion was collected from the discharge of the inclined soil erosion plots (slopes 20 &#8211; 34&#176;, slope length 4 m). During each experiment, eight samples were collected. Four samples were collected during the first experimental rainfall. For the next ten days, the container was kept aside the rainfall. Afterwards, the raining with the rainfall simulator on plot (which now had different initial condition compared to the plot during the first experimental rainfall as the plot already contained erosion rills from the previous episode) has been resumed and another four samples were collected. Experimental plots were vertically divided into two parts. On one part was an eel and on the second part were different types of rolled erosion control products (RECPs) &#8211; Enkamat 7010, and 7020, Biomac-C, coir fibres K700 and K400, jute, Macmat 8.1, mulch, hay, nonwoven, fortrac 3D and triangle. The influence of RECPs to the particle size distribution was investigated. Laser diffraction has been selected as a method to determine particle size distribution and device Mastersizer 3000 was used. By the comparison of the particle size distribution, of more than five hundred samples, the different response to the soil erosion mechanism and the influence of external factors (slope of the experimental plot, initial condition and presence of RECPs) on the particle size distribution and soil aggregates content in eroded sediment were investigated. It has been found that both the particle size and aggregates size distribution of the eroded sediment changes considerably in time. This research is funded by the TH02030428 - &#8222;Design of technical measures for slopes stabilization and soil erosion prevention&#8221; and by the International CTU grant SGS20/156/OHK1/3T/11.

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Comparison between sprinkler irrigation and natural rainfall based on droplet diameter

Spanish Journal of Agricultural Research ◽

10.5424/sjar/2016141-8076 ◽

2016 ◽

Vol 14 (1) ◽

pp. e1201 ◽

Cited By ~ 8

Author(s):

MaoSheng Ge ◽

Pute Wu ◽

Delan Zhu ◽

Daniel P. Ames

Keyword(s):

Soil Erosion ◽

Kinetic Energy ◽

Droplet Diameter ◽

Vertical Component ◽

Radial Distance ◽

Sprinkler Irrigation ◽

Application Rate ◽

Horizontal Component ◽

Natural Rainfall ◽

Actual Field

An indoor experiment was conducted to analyze the movement characteristics of different sized droplets and their influence on water application rate distribution and kinetic energy distribution. Radial droplets emitted from a Nelson D3000 sprinkler nozzle under 66.3, 84.8, and 103.3 kPa were measured in terms of droplet velocity, landing angle, and droplet kinetic energy and results were compared to natural rainfall characteristics. Results indicate that sprinkler irrigation droplet landing velocity for all sizes of droplets is not related to nozzle pressure and the values of landing velocity are very close to that of natural rainfall. The velocity horizontal component increases with radial distance while the velocity vertical component decreases with radial distance. Additionally, landing angle of all droplet sizes decreases with radial distance. The kinetic energy is decomposed into vertical component and horizontal component due to the oblique angles of droplet impact on the surface soil, and this may aggravate soil erosion. Therefore the actual oblique angle of impact should be considered in actual field conditions and measures should be taken for remediation of soil erosion if necessary.

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