Abstract:

Based on the meteorological data of blueberry ripening period at four stations in Dandong region from 1991 to 2020, the index of continuous rain disaster was taken as the daily precipitation greater than 0.1 mm for more than 3 days and greater than 25 mm for at least 1 day during blueberry ripening period.Considering the frequency and duration, the grades of light, moderate and severe continuous rain disaster were established.The characteristics of continuous rain disaster of blueberry were analyzed by the frequency and station ratios of this disaster, and the risk probability was evaluated based on information diffusion theory.The results show that during the past 30 years, the influence of continuous rain disaster was reduced in the whole blueberry ripening period in Dandong, and the frequency of continuous rain disaster showed a decreasing trend, especially in Zhen'an District, the frequency tendency rate of continuous rain disaster was 0.23 times per decade (p < 0.01).The risk of continuous rain disaster was low in the early maturing period of 30 years, the risk probabilities of mild and moderate continuous rain disasters were less than once in 20 years (≤5%), and no severe disaster occurred.Continuous rain disasters were mainly concentrated in the late maturing period, and the probability of light disaster was more than once in 10 years (≥10%).Zhen'an District is a high risk area of continuous rain disaster, with a wide range, high frequency and heavy degree.The probabilities of mild and moderate continuous rain disasters were more than once in 10 years (≥10%).

Key words: Blueberry, Ripening period, Continuous rain, Information diffusion theory, Risk probability