ANALYSIS OF DROUGHT-FLOOD ABRUPT ALTERNATION OF TOBACCO BASED ON PRECIPITATION AND SOIL PONDING IN SIUWEN CHINA

Drought-flood abrupt alternation disaster caused by climate change results in greater difficulty in disaster relief and more serious agricultural losses. In order to identify the characteristics of drought-flood abrupt alternation in the tobacco growth period and effectively prevent and reduce the drought-flood abrupt alternation disaster, the daily precipitation data in the tobacco growth period from 1951 to 2017 in Guiyang City are used and the data of soil moisture content in the Xiuwen country Irrigation Test Base of Guizhou Irrigation Test Center are adopted. By defining continuous days without available precipitation and the cumulative available precipitation during the flood period, the characteristics of drought-flood abrupt alternation in Guiyang are comprehensively analyzed. The results are as follows: (1) it can be verified by soil moisture content data that the law of drought-flood abrupt alternation in tobacco growth period can be accurately described based on continuous days without available precipitation and the cumulative available precipitation during the flood period. (2) In the tobacco growth period, there are two or more times of drought-flood abrupt alternation with low intensity. (3) In tobacco root extension period, there is no drought-flood abrupt alternation; during the flourishing growing period of tobacco, drought-flood abrupt alternation with low intensity prevails, and the intensity and frequency of drought-flood abrupt alternation increase; in tobacco mature period, the intensity of drought-flood abrupt alternation fluctuates greatly, and the intensity and frequency of drought-flood abrupt alternation increase. The research results can provide theoretical basis for the formulation of tobacco disaster prevention and mitigation countermeasures in Guiyang China.