Characteristics of one-hour short-time heavy precipitation over southwestern Guizhou in the summer during 2006-2015

Based on the hourly precipitation data during 2006－2015, the characteristics of short-time precipitation and the relation between storm and short-time precipitation were investigated. The results are as follows. (1) The spatial distribution of short-time strong rainfall showed an "east and north more southwest less" pattern; (2) In recent 10 years precipitation fluctuated: peaked in 2007 followed by a rapid fell, and maintained a relatively stable trend during 2009－2015, with a lowest value in 2011; (3) Main time period of summer precipitation is in the night, accounting for 79.1%, and concentrated from 20:00 to 04:00, with peak from 23:00 to 01:00; (4)The spatial distribution of short-time strong rainfall is multi-modal, i.e., the first characteristic vector field is uniform throughout the whole area, the second characteristic vector is characterized by the north-south reverse variation, and the third characteristic vector field is characterized by northeast-southwest of reverse variation; (5) Short-time precipitation occurring in June accounts for 69.5%, and that occurring in May accounts for 30.5%; (6) The space similarity coefficient between short-time heavy rain and heavy rain was 0.9. There were 125 times of short-term heavy rain accompanied with 169 stand heavy rain weather conditions, and 239 times of short-time strong rainfall caused 229 times of storm events. Heavy rain days and the short-time strong rainfall frequency has a correlation coefficient of 0.64. Rainstorm scale and the biggest hour rainfall level has a correlation coefficient of 0.53. Both passed the reliability test of the 0.05.