Analysis of Characteristics of Hail Disaster and a Typical Hail Suppression Process in Qujing City

Based on the data of hail disaster in Qujing City and the detection data of the new generation of Doppler weather radar, the spatial and temporal distribution characteristics of hail disaster and hail suppression operations in Qujing City were analyzed statistically, and the hail suppression operations of a typical cell case was analyzed. The results showed that the number of hail days and hail frequency showed an increasing trend in Qujing City from 2017 to 2022, and the number of artificial hail suppression operations increased accordingly. Hail disaster occurred most frequently in Xuanwei City. Through the analysis of hail suppression operations of a typical cell case, it is found that the operations were timely, and the location was reasonable. The ammunition used was sufficient, and the overall effect of the hail suppression operations was good.

Risk Assessment of Hail Disaster on Cotton——A Case Study in Anhui Province

[Objective] The aim was to reveal the pattern of hail disaster risk for cotton in Anhui Province. [Method] Based on database of risk evaluation on hail disaster for cotton in Anhui Province, statistical inference and comprehensive indices measurement were made use of for extraction of disastrous index of hail （H） and loss rate of cotton （L）. Hail vulnerability curves in four stages （seedling, bud, boll and boll opening stages） of cotton were fitted by Matlab and SPSS software. Risk evaluation on hail disaster of cotton in Anhui Province was conducted and the related map was drawn on basis of yearly model of loss rate （by hail disaster）, as follows： Sa=n∑i=1Si-a∏i=1Si=1-（1-Si） [Result] In Anhui Province, high risk area by hail concentrates in northeast regions and mountainous regions in west of Anhui, and lower risk area is distributed in middle and down streams of Yangtze River and mountainous area in south of Anhui. [Conclusion] The research explored evaluation methods on hail risks based on the limited information, and could provide references for risk evaluation on hail disaster in other regions.

Climatic Characteristics of Hail Disaster and Division of Defense Region in Guizhou Province

[Objective] The aim was to study the climatic characteristics of hail disaster from 1984 to 2006 in Guizhou Province,China.[Method] Through statistical analysis,the climatic characteristics and disaster characteristics of hail from 1984 to 2006 in Guizhou Province were annalyzed and compared with previous results,then the classification standards of hail disaster were established,finally the defense zoning map of hail disaster in Guizhou Province was made.[Result] According to the statistical analysis on the historical data of hail disaster from 1984 to 2006,the frequency hail was 1 243 times in Guizhou in 23 years,that is,annual average frequency reached 54 times;annual average hailing days were 0.1-2.7 d in Guizhou Province,and the average frequency of hail was 3.8 times during each hail process;the frequency of hail was below 30 times in 52% of years and 30-80 times in 35% of years among 23 years.Hail could appear in the whole year,and 74% of hails occurred in spring,while winter had the fewest times.The results above were basically consistent with those of previous studies.Hail disaster mainly resulted in casualties and direct economic loss,and was divided into four grades according to direct economic loss,namely Grade I(extremely severe hail disaster),Grade II(severe hail disaster),Grade III(comparatively severe hail disaster) and Grade IV(medium hail disaster).The defense zoning map of hail disaster in Guizhou Province was made based on the frequency of hail and severe hail disaster,that is,the defense region at Grade I mainly distributed in Liupanshui City(in western Guizhou) and southern Guizhou;the defense region at Grade II was in the west,south and northeast of Guizhou Province,while the rest was at Grade III.[Conclusion] The study was of reference value for the defense of hail disaster in Guizhou Province.