江西早稻高温逼熟气象灾害指数保险费率的厘定

以江西早稻“五优157”为试材,于2012年在早稻灌浆期利用人工气候室模拟高温逼熟的气候模式（白天35℃/夜间28℃分别持续2、4、6、8、10、12、14、16d）,建立早稻减产率与高温持续天数间的关系模型.再依据江西省11个市1960-2007年气象数据,采用Weibull分布模型模拟不同地区发生高温逼熟的概率,结合减产率模型确定免赔额为15％、30％、45％的保险纯费率.结果表明：“五优157”的减产率（y,％）与灌浆期高温持续天数（x）呈对数函数关系,即y=32.082lnx-22.681;鹰潭和赣州地区的高温逼熟发生概率较高,达87.5％,抚州、景德镇、宜春和萍乡等地区较低,均在70％以下;江西省高温逼熟气象灾害指数保险纯费率呈北高南低的趋势,鹰潭地区的纯费率最高,达4.707％,宜春地区的纯费率最低,为2.138％.研究认为在免赔额为30％时的纯费率较适宜,研究结果可为江西省早稻开展政策性气象指数保险提供科学依据.

Estimation of Premium Rates of High Temperature Disaster for Early Rice in Jiangxi

Rice cv.Wuyou 157 was grown in a climate chamber at filling stage to simulate the weather pattern of high temperature disaster.The air temperature in the climate chamber was set as 35℃ during the day and 28℃ during the night,and this day/night temperature regime lasted for 2,4,6,8,10,12,14 and 16 days,respectively.A relationship model between yield reduction rate （y） of early rice and duration of high temperature （x） was established.Based on the meteorological data of 11 cities of Jiangxi province from 1960 to 2007,the Weibull distribution model was used to calculate the probability of high temperature induced maturity,which was then combined with the yield reduction model to determine the pure premium rates for 15%,30% and 45% of deductible excess.The results showed that the relationship between yield reduction rate （y） of early rice and duration of high temperature （x） could be well described by the following logarithmic function：y （%） =32.0821nx-22.681.The probabilities of high temperature induced maturity in Yingtan and Ganzhou both reached 87.5%,which were higher than other cities in Jiangxi.However,the probabilities were below 70% in Fuzhou,Jingdezhen,Yichun and Pingxiang.The pure premium rates of high temperature induced maturity for early rice in Jiangxi province presented a descending trend from north to south,and the maximum pure premium rate was 4.707% in Yingtan and the minimum one was 2.138% in Yichun.It was considered that the deductible excess of 30% was the most appropriate for high temperature disaster of early rice in Jiangxi province.The results of this study were expected to provide a scientific basis for the implementation of policy weather index insurance for early rice in Jiangxi province.