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Based on data of daily average temperature observed during maize growing period as well as data of different growing periods of maize at 24 meteorological stations in Heilongjiang Province from 1980 to 2010,changes in risk of chilling damage to maize since 1980 were analyzed. Initially,the risk of the hazard factor was calculated by adopting the criterion of “ Comprehensive Decision System of Chilling Damage to Maize in Heilongjiang Province”. Then,choosing the planting area of maize at 75 stations as the exposure degree index,risk zones of exposure degree were concluded. Afterwards,risk zones of maize sensitivity to chilling damage were outlined based on maize yield per unit area. At last,a comprehensive evaluation model of chilling damage to maize in Heilongjiang Province was established,and Heilongjiang Province was divided into 5 grades of risk zones according to the model. The results showed that compared with the period before 1995,the risk of chilling damage to maize was severer in the west area of Songnen Plain,and previous sub-low or medium risk of chilling damage to maize in the west of Sanjiang Plain changed into subhigh or high risk since the middle 1980s.
Based on data of daily average temperature observed during maize growing period as well as data of different growing periods of maize at 24 meteorological stations in Heilongjiang Province from 1980 to 2010, changes in risk of chilling damage to maize since 1980 were analyzed. Initially, the risk of the hazard factor was calculated by adopting the criterion of “Comprehensive Decision System of Chilling Damage to Maize in Heilongjiang Province”. Then, choosing the planting area of maize at 75 stations as the exposure degree index, risk zones of exposure degree were concluded. Afterwards, risk zones of maize sensitivity to chilling damage were outlined based on maize yield per unit area. At last, a comprehensive evaluation model of chilling damage to maize was established, and heilongjiang province was divided into 5 grades of risk zones according to the model. The results showed that compared with the period before 1995, the risk of chilling damage to maize was sever er in the west area of Songnen Plain, and previous sub-low or medium risk of chilling damage to maize in the west of Sanjiang Plain changed into subhigh or high risk since the middle 1980s.