The risk division on climate and economic loss of maize chilling damage in Northeast China
东北地区玉米低温冷害气候和经济损失风险分区

The thermal condition,occurring frequency,risk index and climatic risk probability of the maize chilling damage in Northeast China were analyzed,and the synthetic climatic risk index and model were developed.Northeast China was divided into five climatic risk areas(highest,higher,moderate,lower and lowest)using synthetic climatic risk index.The risk evaluation model of climate-economic loss of the chilling damage was developed using synthetic climatic risk index,considering the maize's output and proportion of planting area.On this basis,Northeast China was divided into five typical damage areas of economic loss risk,including the highest,higher,moderate,lower and lowest one.Then the authors put forward relevant measures to reduce the damage risk in different areas.The difference in damage risk is obvious in different areas.The northern and eastern parts of Northeast China are the highest climatic risk areas,and southwestern Jilin and most parts of Liaoning are the lower ones.The central part of Northeast China,the northern part of Heilongjiang and eastern Jilin are the highest risk areas on economic loss,western Jilin and northeastern Liaoning are moderate,the central and eastern parts of Liaoning are lower,and southern Liaoning is the lowest one even without risk.Though the climate becomes warm,the supply-demand relation of thermal condition of maize production is still tense as a result of the increasing proportions of maize production(especially the late-ripe species).Therefore,the chilling damage risk is still high in most parts of Northeast China,and we should positively control the chilling damage under the condition of climatic change.The main measure to reduce the damage risk firstly is to improve the planting structure,adjust the maize variety proportion in different areas;and secondly is to use the cultivating technique of resisting the damage for promoting the resistibility.