贵德县梨树花期冻害特征及冻害年型预测

为了探讨果树花期冻害年型预报技术方法，以期为决策部门和生产一线的广大果农提供优质气象服务。利用青海省贵德县1961—2010年4月平均气温、平均最低气温和极端最低气温资料，分析了贵德县近50年来4月平均气温、平均最低气温和极端最低气温的变化趋势，同时利用4月梨树花期期间日最低气温，将贵德县梨树花期冻害年型划分为严重冻害(Td≤-4.0℃)、中等冻害(Td≤-2.0℃)、轻度冻害(Td≤0.0℃)、正常年型(Td≤2.0℃)4个状态。在逐年状态分型的基础上，运用马尔科夫链转移概率模式计算了各种状态下的转移概率矩阵，建立了贵德县梨树花期冻害年型的马尔科夫链预测模型，得出2011—2015年处于“严重冻害”的概率较大。根据检验，2011、2013年预测值与实况相符。

Characteristics and Annual Type Prediction for Pear Florescence Frost Damage in Guide County

In order to examine the technical methods of flowering-year forecast of freeze injury of fruit trees, so as to improve high quality meteorological services for policymakers and the production line of our farmers.Based on the data of mean temperature, average minimum temperature and extreme minimum temperature in April from 1961 to 2010 in Guide County, Qinghai Province, the author analyzed the trends of mean temperature, average minimum temperature and extreme minimum temperature in April in the past 50 years.At the same time, by using the data of extreme minimum temperature in April, annual type division index of frost damage in pear florescence in Guide County was proposed： serious frost damage （Td≤-4.0℃）, moderate frost damage （Td≤-2.0℃）, light frost damage （Td≤0.0℃）, and normal frost damage （Td≤2.0℃）. On the basis of the yearly state classification, the author calculated transition probability matrix under various condition by using Markov Chain transition probability Model, then the Markov Chain Prediction Model for florescence frost damage in Guide County was established, and the prediction showed that serious frost damage would be a significant probability from 2011 to 2015. According to the test, the prediction of 2011 and 2013 was consistent with the actual situation.