Based On The Artificial Simulation Of Rainfall Device DIK-6000 Hydrological Features Research

In order to make the data obtained by artificial rainfall simulator more reliable in soil and water conservation experiments,the paper color spot method was used to analyze the relationship between rainfall parameters of DIK-6000 Artificial Rainfall Simulator under different rainfall frequency and intensity conditions,and to explore the applicability of the Rainfall Simulator.The result show that:?1?Calibration of the effective rainfall area of the rainfall device: When the rainfall frequency is the same,the rainfall area gradually approaches the effective rainfall area of 1.04 m² with the increase of rainfall intensity.When the rainfall intensity is the same,the rainfall area increases with the increase of frequency.?2?Calibration of rainfall intensity in the artificial rainfall simulation system: when the frequency is 0 hz,300 hz and 600 hz,the actual rainfall intensity is significantly different from the designed rainfall intensity.When the frequency is 900 hz,there is no significant difference between the actual rainfall intensity and the designed rainfall intensity.?3?The rainfall uniformity coefficient of the artificial rainfall simulation system varies with the rainfall intensity and frequency.Because the rainfall area is small and the error is small,the rainfall uniformity achieves a better degree.When the frequency is 0-900 hz and the rainfall intensity is 0.17-2.0 mm/min,the uniformity coefficient is between 0.99-1 and the average uniformity coefficient is 0.991.When the frequency is 900 Hz and the rainfall intensity is 0.17 mm/min,the variation coefficient is 0.69 and the uniformity coefficient is 0.99.When the rainfall intensity is 1.5 mm/min,the coefficient of variation is the smallest,but the uniformity coefficient is 0.99.?4?The parameters measured by the artificial rainfall simulation system are as follows:?1?Spot diameter: when the frequency is the same,the diameter,quality and diameter of raindrops increase with the increase of rainfall intensity;when the rainfall intensity is the same,the diameter,quality and diameter of raindrops decrease with the increase of rainfall intensity.?2?Median diameter: Within the range of test rainfall intensity,the ratio of accumulated volume Y and diameter D of Raindrops under test conditions conform to the power function distribution of Y=a D^b?a and b are constant?,which increases with the increase of rainfall intensity and decreases with the increase of frequency.?3?Spectral characteristics of raindrops: the mean diameter,maximum diameter and average diameter of raindrops increase with the increase of rainfall intensity,but the similarity is poor;but the mean diameter,maximum diameter and average diameter of raindrops decrease with the increase of frequency.?4?Raindrop diameter fitting: at frequency 0hz,the mean diameter of raindrops and rain intensity d₅₀=0.0767x²+0.2534x+2.9359;At frequency 300 hz,the mean diameter of raindrops and rain intensity d₅₀=-0.0728x²+0.2526x+2.9118;At frequency 600 hz,the mean diameter of raindropdrops and rain intensity d₅₀=-0.155x²+0.549x+2.5463;at frequency 900 hz d₅₀=-0.0113x²+0.235x+2.1069.The higher the frequency,the higher the fitting degree and the more accurate the R².?5?Within the range of experimental rainfall intensity and frequency,the kinetic energy of rainfall increases with the increase of rainfall intensity and decreases with the increase of rainfall frequency.When the frequency is 0 hz,the linear relationship E=20.815x-0.775;when the frequency is 300 hz,the linear relationship E=17.497x-0.7695;when the frequency is 600 hz,the linear relationship E=9.8552x²-33.454x+36.1525;when the frequency is 900 hz,the linear relationship E=2.9649x-0.5495.?6?The relationship between the velocity of raindrop and the kinetic energy of raindrop: the kinetic energy of raindrop is closely related to the rainfall intensity and the size of raindrop per unit area.With the increase of frequency,the variation range of the velocity and kinetic energy of raindrop is larger;with the increase of rainfall intensity,the variation range of the velocity and kinetic energy of raindrop is smaller.