Abstract:

 In order to improve the rationale for determining the premium rate for weather index insurance for tea frost damage in Anhui province. In this paper, authors refined and revised the meteorological index for tea frost damage in Huangshan based on historical disaster data. The ANUSPLIN interpolation software was used to establish the spatial interpolation model of the meteorological indices. Based on historical meteorological data from Huangshan, a refined risk assessment of tea frost damage in Huangshan was conducted with the help of a geographic information system. Taking Huangshan Maofeng tea as the research object, the risk assessment results and tea economic output were comprehensively considered to determine the insurance district and insurance period of tea frost damage, and the weather index trigger value and premium rate during some period were also designed considering daily tea frost risk and actual needs of agricultural insurance operation, and the insurance pure premium rates of tea frost damage at different periods and altitudes were calculated. The results showed as follows: the extreme minimum temperature (T_d) 3°C was used as the threshold value of tea frost damage index, according to the interval of 1℃, the tea frost damage index were divided into 2℃<T_d≤3℃, 1℃<T_d≤2℃, 0<T_d≤1℃, −1℃<T_d≤0, −2℃<T_d≤−1℃, −3℃<T_d≤−2℃ and T_d≤−3℃ 7 disaster grades, the corresponding average loss rates of tea buds were 5%, 15%, 25%, 35%, 50%, 70% and 90% respectively. The distribution of frost damage risk in Huangshan had an obvious regional characteristics, with higher the altitudes having a higher risk of frost damage, and the time series showing a decreasing trend with time. The insurance region of the weather index of tea frost damage of Huangshan Maofeng was 400−1000m above sea level, and the insurable period was from March 16 to April 15, when the extreme minimum temperature reached 2℃ to trigger the compensation. The insurance pure premium rates at 400−500m, 500−600m, 600−700m, 700−800m, 800−900m and 900−1000m above sea level were 1.4%, 1.9%, 2.7%, 3.7%, 4.9% and 6.4% respectively. The insurance pure premium rates for the four periods of coverage from March 16 to March 30, March 21 to April 4, March 26 to April 9, March 31 to April 15 were 1.2%−5.0%, 0.9%−3.8%, 0.6%−2.2% and 0.3%−1.5% respectively. The insurance-only premium rate for tea frost damage in Huangshan Maofeng shows an increasing trend with altitude and a decreasing trend with time delay. 

Key words: Tea plant, Frost damage, Weather index, Risk degree, Pure premium rate