基于开花期地域差异的中稻高温热害天气指数保险设计

高温热害是湖北省中稻单产的主要限制因子,高温热害天气指数保险的设计与推广,对于转移农业气象灾害风险,降低农民损失具有重大意义。在开顶式生长室(open-top chamber,OTC)的控制下,以中稻品种"广两优香66"为试材,模拟开花灌浆期高温热害,建立了高温热害减产模型,并用大田调查资料作对比,筛选最优投保集中时段。基于10个试点县(市)1981-2016年每年7月16日-8月31日日最高气温观测资料,采用Weibull分布模型,构建分时段的高温热害风险分布模型。综合减产率模型和概率分布模型,厘定了不同免赔率下,以县(市)为单位的,多个投保时期的中稻高温热害天气指数保险的纯费率,为被保险人提供多种投保方案。结果表明:中稻开花灌浆期高温热害保险的最优投保时间为开花始期后20d,开花始期为7月下旬时费率最高,随着开花期的延迟,费率逐渐降低。纯费率的区域差异较大,咸安、赤壁、浠水、麻城等热害高风险区费率较高,襄阳、随州等低风险区费率较低。

Weather Index Insurance Design of Middle-Season Rice Heat Damage Based on Regional Difference of Flowering Stage

Under the control of open top chamber (OTC),rice "Guangliangyouxiang 66" was tested to simulate heat damage during heading and early grain filling periods.The relationship model of heat damage and yield reduction was established,and its accuracy was verified by field investigation data.Based on the historical observation data of the highest temperature of each day between July 16th and August 31st from 1981 to 2016,the Weibull model was used to establish the heat damage risk distribution model of the pilot counties.Subsequently,according to these two models,a variety of pure premium rate scheme of the pilot counties was determined in different deductible excess and insurance period,for providing various choices.The results showed that,20 days after initial flowering period was the optimal insurance period length of heat damage insurance about heading and early grain filling periods.The pure premium rate achieved the lowest value when flowering in late July,and decreased gradually with flowering delay.Between different regions,pure premium rate fluctuated greatly,in which,the high value regions of pure premium rates are in the mountainous regions of southeast of Hubei province such as Xian'an,Chibi,Xishui and Macheng,and the humpy ground in northern Hubei,such as Xiangyang and Suizhou,were divided into low risk area.