Fabrication and study of laboratory scale rainfall simulator for soil erosion assessment

2021 ◽  
Vol 8 (2) ◽  
pp. 139-142
Author(s):  
SRIVALLI CHERAKU ◽  
P SWATHI ◽  
Y SUSHMITHA ◽  
D PRANEETHA ◽  
CH RADHA SRIVALLI
Keyword(s):  
Soil Erosion ◽  
Rainfall Intensity ◽  
Slope Angle ◽  
Laboratory Scale ◽  
Rainfall Simulator ◽  
Research Areas ◽  
Natural Rainfall ◽  
Spatial Uniformity ◽  
Ideal Tool ◽  
Raindrop Size

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.  

scholarly journals A Rainfall Simulator Used for Testing of Hydrological Performances of Micro-Detention Permeable Pavement

2018 ◽  
Vol 7 (3.18) ◽  
pp. 44 ◽  
Author(s):  
Norazlina Bateni ◽  
Sai Hin Lai ◽  
Frederik Josep Putuhena ◽  
Darrien Yau Seng Mah ◽  
Md Abdul Mannan
Keyword(s):  
Rainfall Intensity ◽  
Drainage System ◽  
Rainfall Simulator ◽  
Rainfall Characteristics ◽  
Permeable Pavement ◽  
Natural Rainfall ◽  
Spatial Uniformity ◽  
Free Drainage ◽  
Coefficient Of Uniformity ◽  
Raindrop Size

A rainfall simulator for laboratory experimentation is developed to test hydrological performances of micro-detention pond permeable pavement, MDPP. Rainfall characteristics consisting of rainfall intensity, spatial uniformity, raindrop size, and raindrop velocity show that natural rainfall is simulated with sufficient accuracy. The rainfall simulator used pressure nozzles to spray water for rainfall intensity from 40 to 220mm/hr. Uniformity distribution test gives coefficient of uniformity of 95% over an area of 1m2. The raindrops falling at velocity ranging from 0.5 to 15m/s with drop sizes diameter between 2 to 5mm. Free drainage system below the rainfall simulator is accompanied with outlet tanks attached with ultrasonic sensor devices to record the outflow data. During the experiments, the outflow received is 98% in average. Experiment results in typical runoff hydrograph and percolation rate of the MDPP system. This shows the ability of the rainfall simulator to obtain initial hydrology data to aid in the design of the MDPP prototype.  

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

2017 ◽  
Vol 43 (1) ◽  
pp. 63 ◽  
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.

scholarly journals Research on the Fine-Scale Spatial Uniformity of Natural Rainfall and Rainfall from a Rainfall Simulator with a Rotary Platform (RSRP)

Atmosphere ◽  
2017 ◽  
Vol 8 (12) ◽  
pp. 113
Author(s):  
Bo Liu ◽  
Xiaolei Wang ◽  
Lihua Shi ◽  
Xichuan Liu ◽  
Zhaojing Kang ◽  
...  
Keyword(s):  
Fine Scale ◽  
Rainfall Simulator ◽  
Natural Rainfall ◽  
Spatial Uniformity ◽  
Rotary Platform

Development of a Mobile Rainfall Simulator

2013 ◽  
Vol 321-324 ◽  
pp. 118-122
Author(s):  
Zhen Jiang Si ◽  
Yan Meng ◽  
Yan Huang
Keyword(s):  
Soil Erosion ◽  
Rainfall Intensity ◽  
Rainfall Simulation ◽  
Effective Rainfall ◽  
Rainfall Simulator ◽  
Control Operation ◽  
Outdoor Experiment ◽  
Integration Mode ◽  
Stable Performance ◽  
Indoor And Outdoor

in order to solve the rainfall simulator single control operation currently used in the experiment of soil erosion. A mobile rainfall simulator was designed. The device adopts a rainfall simulator and Longmen mobile support integration mode, which is controllable and mobile and easy to move. The results show that the equipment is advanced in technology, stable performance, flexible movement, rainfall uniformity high, effective rainfall area is 1.5×4.5m with rainfall intensity ranging from 9.5 to 100mm/h. and to a greater extent meets the needs of rainfall simulation. This rainfall simulator can be used in indoor and outdoor experiment of soil erosion in different slope, which improves the efficiency of utilization of rainfall simulator.

scholarly journals Measurement and computation of kinetic energy of simulated rainfall in comparison with natural rainfall

2018 ◽  
Vol 13 (No. 4) ◽  
pp. 226-233 ◽  
Author(s):  
Petrů Jan ◽  
Kalibová Jana
Keyword(s):  
Kinetic Energy ◽  
Drop Size ◽  
Rainfall Intensity ◽  
Soil Aggregates ◽  
Meteorological Parameter ◽  
Simulated Rainfall ◽  
Fall Velocity ◽  
Rainfall Simulator ◽  
Rainfall Characteristics ◽  
Natural Rainfall

Rainfall characteristics such as total amount and rainfall intensity (I) are important inputs in calculating the kinetic energy (KE) of rainfall. Although KE is a crucial indicator of the raindrop potential to disrupt soil aggregates, it is not a routinely measured meteorological parameter. Therefore, KE is derived from easily accessible variables, such as I, in empirical laws. The present study examines whether the equations which had been derived to calculate KE of natural rainfall are suitable for the calculation of KE of simulated rainfall. During the experiment presented in this paper, the measurement of rainfall characteristics was carried out under laboratory conditions using a rainfall simulator. In total, 90 measurements were performed and evaluated to describe the rainfall intensity, drop size distribution and velocity of rain drops using the Thies laser disdrometer. The duration of each measurement of rainfall event was 5 minutes. Drop size and fall velocity were used to calculate KE and to derive a new equation of time-specific kinetic energy (KE<sub>time</sub> – I). When comparing the newly derived equation for KE of simulated rainfall with the six most commonly used equations for KE<sub>time</sub> – I of natural rainfall, KE of simulated rainfall was discovered to be underestimated. The higher the rainfall intensity, the higher the rate of underestimation. KE of natural rainfall derived from theoretical equations exceeded KE of simulated rainfall by 53–83% for I = 30 mm/h and by 119–275% for I = 60 mm/h. The underestimation of KE of simulated rainfall is probably caused by smaller drops formed by the rainfall simulator at higher intensities (94% of all drops were smaller than 1 mm), which is not typical of natural rainfall.

A multi-purpose rainfall simulator for field infiltration and erosion studies

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 599 ◽  
Author(s):  
R. J. Loch ◽  
B. G. Robotham ◽  
L. Zeller ◽  
N. Masterman ◽  
D. N. Orange ◽  
...  
Keyword(s):  
Rainfall Intensity ◽  
The Body ◽  
Effective Rainfall ◽  
Laboratory Studies ◽  
Great Flexibility ◽  
Rainfall Simulator ◽  
Plot Size ◽  
Spatial Uniformity ◽  
Coefficients Of Variation ◽  
Steep Slopes

This paper describes a rainfall simulator developed for field and laboratory studies that gives great flexibility in plot size covered, that is highly portable and able to be used on steep slopes, and that is economical in its water use. The simulator uses Veejet 80100 nozzles mounted on a manifold, with the nozzles controlled to sweep to and from across a plot width of 1.5 m. Effective rainfall intensity is controlled by the frequency with which the nozzles sweep. Spatial uniformity of rainfall on the plots is high, with coefficients of variation (CV) on the body of the plot being 8–10%. Use of the simulator for erosion and infiltration measurements is discussed.

scholarly journals Development and Calibration of a New Dripper-Based Rainfall Simulator for Large-Scale Sediment Wash-Off Studies

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 152
Author(s):  
Juan Naves ◽  
Jose Anta ◽  
Joaquín Suárez ◽  
Jerónimo Puertas
Keyword(s):  
Physical Model ◽  
Large Scale ◽  
Terminal Velocity ◽  
Final Solution ◽  
Rainfall Simulator ◽  
Natural Rainfall ◽  
Raindrop Size Distribution ◽  
Wide Range ◽  
The Mean ◽  
Raindrop Size

Rainfall simulators are useful tools for controlling the main variables that govern natural rainfall. In this study, a new drop-forming rainfall simulator, which consists of pressure-compensating dripper grids above a horizontal mesh that breaks and distributes raindrops, was developed to be applied in wash-off experiments in a large-scale physical model of 36 m2. The mesh typology and size, and its distance to drippers, were established through a calibration where rain uniformity and distributions of raindrop sizes and velocities were compared with local natural rainfall. Finally, the rain properties of the final solution were measured for the three rain intensities that the rainfall simulator is able to generate (30, 50 and 80 mm/h), obtaining almost uniform rainfalls with uniformity coefficients of 81%, 89% and 91%, respectively. This, together with the very suitable raindrop size distribution obtained, and the raindrop velocities of around 87.5% of the terminal velocity for the mean raindrop diameter, makes the proposed solution optimal for wash-off studies, where rain properties are key in the detachment of particles. In addition, the flexibility seen in controlling rain characteristics increases the value of the proposed design in that it is adaptable to a wide range of studies.

scholarly journals Measurement and computation of kinetic energy of simulated rainfall in comparison with natural rainfall.

2018 ◽  
Author(s):  
Petrů Jan ◽  
Kalibová Jana
Keyword(s):  
Kinetic Energy ◽  
Drop Size ◽  
Rainfall Intensity ◽  
Soil Aggregates ◽  
Meteorological Parameter ◽  
Simulated Rainfall ◽  
Fall Velocity ◽  
Rainfall Simulator ◽  
Rainfall Characteristics ◽  
Natural Rainfall

Rainfall characteristics such as total amount and rainfall intensity (I) are important inputs in calculating the kinetic energy (KE) of rainfall. Although KE is a crucial indicator of the raindrop potential to disrupt soil aggregates, it is not a routinely measured meteorological parameter. Therefore, KE is derived from easily accessible variables, such as I, in empirical laws. The present study examines whether the equations which had been derived to calculate KE of natural rainfall are suitable for the calculation of KE of simulated rainfall. During the experiment presented in this paper, the measurement of rainfall characteristics was carried out under laboratory conditions using a rainfall simulator. In total, 90 measurements were performed and evaluated to describe the rainfall intensity, drop size distribution and velocity of rain drops using the Thies laser disdrometer. The duration of each measurement of rainfall event was 5 minutes. Drop size and fall velocity were used to calculate KE and to derive a new equation of time-specific kinetic energy (KE<sub>time</sub> – I). When comparing the newly derived equation for KE of simulated rainfall with the six most commonly used equations for KE<sub>time</sub> – I of natural rainfall, KE of simulated rainfall was discovered to be underestimated. The higher the rainfall intensity, the higher the rate of underestimation. KE of natural rainfall derived from theoretical equations exceeded KE of simulated rainfall by 53–83% for I = 30 mm/h and by 119–275% for I = 60 mm/h. The underestimation of KE of simulated rainfall is probably caused by smaller drops formed by the rainfall simulator at higher intensities (94% of all drops were smaller than 1 mm), which is not typical of natural rainfall.  

Use of laboratory-scale rill and interill erodibility measurements for the prediction of hillslope-scale erosion on rehabilitated coal mine soils and overburdens

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 285 ◽  
Author(s):  
G. J. Sheridan ◽  
H. B. So ◽  
R. J. Loch ◽  
C. Pocknee ◽  
C. M. Walker
Keyword(s):  
Soil Erosion ◽  
Field Measurements ◽  
Strong Relationship ◽  
Laboratory Scale ◽  
Rainfall Simulation ◽  
Combined Processes ◽  
Sediment Delivery ◽  
Natural Rainfall ◽  
The Cost ◽  
Hillslope Scale

Prediction of hillslope-scale soil erosion traditionally involves extensive data collection from field plots under natural rainfall, or from field rainfall simulation programs. Recognising the high costs and inconvenience associated with field-based studies, a method was developed and tested for predicting hillslope-scale soil erosion from laboratory-scale measurements of erodibility. A laboratory tilting flume and rainfall simulator were used to determine rill and interill erodibility coefficients for 32 soils and overburdens from Queensland open-cut coal mines. Predicted sediment delivery rates based on laboratory determinations of erodibility were tested against field measurements of erosion from 12-m-long plots under simulated rainfall at 100 mm/h on slopes ranging from 5% to 30%. Regression analysis demonstrated a strong relationship between predicted and measured sediment delivery rates, giving an r2 value of up to 0.74, depending on the particular modeling approach used. These results demonstrate that soil losses due to the combined processes of rill and interill erosion at the hillslope scale can successfully be predicted from laboratory-scale measurements of erodibility, provided a suitable methodology and modelling approach is adopted. The success of this approach will greatly reduce the cost and effort required for prediction of hillslope scale soil erosion.

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