Application of an optical disdrometer to characterize simulated rainfall and measure drop-size distribution |
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Authors: | Derege Tsegaye Meshesha Atsushi Tsunekawa Nigussie Haregeweyen |
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Institution: | 1. Geospatial Data and Technology Centre, College of Agriculture and Environmental Science, Bahir dar University, Bahir Dar, Ethiopiaderemesh@yahoo.com;3. Arid Land Research Centre, Tottori University, Tottori, Japan;4. International Platform for Dryland Research and Education, Tottori University, Tottori, Japan |
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Abstract: | ABSTRACTKnowledge of rainfall characteristics such as drop-size distribution is essential for the development of erosion-mitigation strategies and models. This research used an optical disdrometer to elucidate the relationships between raindrop-size distribution, median volume drop diameter (D50), kinetic energy and radar reflectivity (dBz) of simulated rainfall of different intensities. The D50 values were higher for the simulated rain than for natural rain at almost all rainfall intensities, perhaps due to variations in rainfall types and the turbulence in natural rain that breaks up large drops. The kinetic energy ranged from 26.67 to 5955.51 J m?2 h ?1, while the median volume drop diameter (D50) was in the range 1.94–7.25 mm, for intensities between 1.5 and 202.6 mm h?1. The relationship between radar reflectivity (Z) and the intensity (R) of the simulated rain was best described by a power law function (Z = aRb), with a and b coefficients in the ranges 162–706 and 0.94–2.46, respectively, throughout the range of rainfall intensities (1.5–202.6 mm h?1). |
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Keywords: | dryland optical disdrometer raindrop size radar reflectivity rainfall simulator rainfall intensity |
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