浙江省茶树高温热害风险区划

根据浙江省各县市区气象站1973—2017年气象资料,结合茶树高温热害等级指标,采用线性倾向率和Mann-kendall法分析了浙江省茶树高温热害等级的时间变化特征。Mann-kendall法分析结果显示,浙江省茶树高温热害影响按年度可分为1973—1987年、1988—2002年和2003—2017年3个时间阶段。通过信息扩散理论计算各阶段茶树遭受高温热害概率,t检验表明2003—2017年茶树遭受高温热害概率显著高于1973—1987年和1988—2002年2个阶段。进一步依据2003—2017年茶树各高温热害等级出现概率构建得到茶树高温热害风险值,并利用该风险值将浙江省分为低风险区、较低风险区、中等风险区、较高风险区和高风险区,其中18个沿海县市区和庆元、泰顺、开化3个山区县为低风险区,遂昌等5个山区县和临海等9个临近海洋或太湖的县市区为较低风险区,丽水等13个位于浙江省中间位置且地形多为平原或处于盆地中部的县市区为高风险区,嵊州等14个靠近高风险区的县市区为较高风险区,淳安等10个县市区为中等风险区。该区划结果较真实地反映浙江省目前和将来一定时期茶树高温热害风险,对浙江省茶树生产中做好高温热害防御工作具有指导作用。

Heat Stress Risk Regionalization of Tea Plant in Zhejiang Province

Based on the climate data of meteorological stations from 1973 to 2017 in Zhejiang Province and the heat stress index of tea plant, temporal variability of heat hurting grade of tea plant was analyzed with line trend rate and Mann-kendall method. Based on Mann-kendall method, the heat injure of tea plant in Zhejiang Province was divided into three periods: 1973—1983, 1988—2002 and 2003—2017. The probabilities of heat stress to tea plant in each period were calculated with information diffusion theory. The result of t-test showed that the probability of heat hurt to tea plant in 2003—2017 was larger than in the periods of 1973—1987 and 1988—2002. Risk value of heat injure of tea plant was calculated by using probabilities of each heat hurting grade of tea plant in 2003—2017. Based on risk values, Zhejiang province could be divided into five regions: low risk, relatively low risk, moderate risk, relatively high risk and high risk areas. Among these areas, the risk values of 18 coastal counties as well as Qingyuan, Taishun and Kaihua were low. The risk values of 5 mountain counties, such as Suichang and 9 counties near the sea or Taihu were relatively low. The risk values of 13 counties in the middle of Zhejiang Province and on a plain or in the middle of the basin such as Lishui were high. The high risk area included 14 counties such as Shengzhou. The moderate risk area contained 10 counties. It could reflect the risk of heat injure of tea plant in Zhejiang Province at present and in a certain period in the future. The results provided a basis for the defense of heat stress to tea plant in Zhejiang.