Abstract: In order to solve the problem that the forest and fruit agricultural insurance products can not meet the meteorological disaster risk of industrial dispersion due to the serious lack of table grape agricultural insurance loss data, this essay is based on the meteorological data such as precipitation and sunshine of Wafangdian meteorological station around the Bohai Sea and the grape yield data from 1998 to 2019. According to the correlation between continuous cloudy and rainy index(Lu) constructed by sunshine hours and grape yield reduction rate(K), the key disaster causing factors and critical values in the critical period of grape growth and development were determined. Using the regression model established by Lu and K and the method of information diffusion theory, the risk probability is calculated, the insurance premium rate is determined, and the continuous overcast and rainy disaster index insurance products in the critical period of the growth and development of Wafangdian table grapes are designed. The results showed that: (1) continuous rain disaster was the main meteorological disaster affecting the growth, development and yield of table grapes in Wafangdian area. Lu was significantly correlated with K, and the regression model was K=2.93Lu+4.19. (2) Lu of table grapes in Wafangdian area is defined as the cumulative number of rainy days (daily precipitation≥0.1mm, and precipitation≥25mm for at least one day) for three or more consecutive days from April 1 to June 30, during which no rainfall is allowed for one day and sunshine hours≤2h per day. (3) According to ADF test, Lu and K series are stable, which can be used as the basis for designing weather index insurance. The corresponding relationship between the disaster level of continuous rain and yield reduction rate of table grapes in Wafangdian area is: 12.98%≤K<18.84%(3≤Lu<5), 18.84%≤K<24.7%(5≤Lu<7), 24.7%≤K<30.56%(7≤Lu<9), 30.56%≤K<39.35%(9≤Lu<12), K≥39.35%(Lu≥12). (4) Based on the application of information diffusion theory and continuous overcast and rainy disaster index series, the net insurance premium rate is 19.01%. The determination of gross insurance premium rate also depends on the value of safety factor, operating cost coefficient and profit margin. For specific compensation, the grape continuous cloudy and rainy index 3d is taken as the starting point, and the projection pursuit statistical method is used for hierarchical compensation when Lu≥3d.

Key words: Bohai rim, Grape, Continuous rain, Weather index insurance