Raindrop Size Distribution Characteristics of Stratiform and Convective Precipitation during Rainy Season in Anning River Valley

Based on the observation data of raindrop size distribution (DSD) in Anning Valley from August to October 2017, the microphysical characteristics, Gamma distribution function, Z-Ifitting relationship, logarithmic concentration of precipitation particles and contribution rate of precipitation intensity of precipitation particle spectrum of stratiform cloud and convective cloud were analyzed. The results show that the DSD spectral width for stratiform precipitation is narrower than that of convective precipitation, and the raindrop concentration, precipitation intensity, liquid water content and radar reflectance of convective precipitation are significant higher than those of stratiform precipitation. The Gamma distribution function can fit the DSD well, and the curve of stratiform precipitation is smoother than that of convective precipitation. The Z-I relation of stratiform and convective precipitation are both well. The Z-I relation of stratiform precipitation and convective precipitation can be respectively written as Z=181.90I^1.54 and Z=175.59I^1.54. The raindrops with diameter less than 2 mm make the 80% precipitation intensity contribution rate of stratiform precipitation. The raindrops with diameter larger than 1mm make the 90% precipitation intensity contribution rate of convective precipitation. It shows that the precipitation particle size has a greater impact on the precipitation intensity than the particle number concentration, and the large-scale precipitation particles have a greater contribution to the precipitation intensity.