THE CHARACTERISTICS OF THUNDERSTORM FREQUENCY VARIATION AND THEIR POSSIBLE RELATION WITH THE ADJUSTMENTOF CROP DISTRIBUTION IN THE LEIZHOU PENINSULA

In order to research possible influences of the adjustment of plant distribution on thedevelopment frequency of thunderstorms over the Leizhou Peninsula, mathematic statistic methods,including correlation analyses, 11 kinds of fitting models and all-variable regression methods, were usedfor analyses and research. The results show that the average trend of the number of annual thunderstormdays is descending obviously, and there are thunderstorms in all seasons, in which warm post-middaythunderstorms have taken up the most part, and high frequency is found from May to September, and thestarting and ending dates of thunderstorms have a great annual discrepancy. The vegetation structure hasbeen improved along with the reduction of rice fields and the area increment of sugarcane and fruitsplanting, which results in the decrease of the number of thunderstorm days; the change in thecharacteristics of winter spare fields, which is caused by the planting of vegetables, limits the formation ofthunderstorms in early winter and late spring. Meanwhile, the area adjustment of peanut planting has littleinfluence on the variation of thunderstorm days. The adjustment of principal crop distribution, such as rice,sugarcane, fruits and vegetables, may have obvious influence on the formation of thunderstorms, andsugarcane has the largest effect, followed in turn by rice, vegetables and fruits, and the adjustment of cropdistribution has little influence on the starting and ending dates of thunderstorms.