东北地区玉米不同生长阶段干旱冷害危险性评价

利用东北地区35个农业气象站1961—2010年气象资料、玉米产量资料和1981—2010年玉米生育期资料,选用合适的干旱指标和冷害指标,结合自然灾害风险理论建立了灾害危险性评价模型。基于灾害判别结果和历史灾情资料,从典型灾害年中提取不同灾种的影响差异,构成权重系数,对东北地区玉米不同生长阶段和整个生育期干旱、冷害危险性进行评价。结果表明,东北地区干旱、冷害危险性在玉米生长前期(出苗—拔节阶段)主要集中在东北地区东南部,此阶段主要以冷害为主；而在玉米生长后期(抽雄—成熟阶段),风险高值区转移到西部,此阶段以干旱为主。生长前期和生长后期对整个生长阶段危险性的贡献值分别为0.3473和0.6527。东北地区的主要气象灾害正逐渐从冷害向干旱转变,冷害发生的频次逐渐减少,而干旱发生的频次快速增多,影响的范围也迅速增大。

An assessment of the drought disaster and chilling injury hazard for maize in the various growth stages in northeast China

With the meteorological data and the maize yield data from 1961 to 2010 and the growth and development data of maize from 1961 to 2010 from the 35 agricultural stations in northeast China, a hazard assessment model was established by selecting appropriate drought indices and chilling injury indices combined with the natural hazard assessment theory. By identifying the type of hazard and using the historical hazardous data, the weight ratio are created based on the impacts from the different hazard types in typical hazardous years. The evaluation of the hazard of drought and chilling injury for the maize at the different growth periods in northeast China and the whole growing phase were made. The results showed that at the early period, the hazard mainly concentrated in the southeast of the studying area, with the chilling injury as the major disaster; while at the latter period, the hazardous area with high risk had changed to the west part, and the major disaster of this period was drought. The contributions of each period to the evaluation of the hazard of the whole stage are 0.3473 and 0.6527, respectively. The distribution of the disaster hazard in northeast China was regional: drought disaster was located in the western and northern areas while chilling injury was in the eastern and southern areas. To the whole growth and development period, the impacts caused by chilling damage were superior to those caused by drought disaster slightly. The major type of meteorological disaster was changing from chilling injury to drought, with gradually decreasing occurrence of the former disaster but increasing frequency and affecting area of the latter one.