根据风险分析原理,利用北方各县市冬小麦近5 0年的实际单产资料和气象资料,进行冬小麦产量灾损风险评估和风险类型划分.以历年平均减产率、灾年减产率变异系数、不同减产率及其发生的概率和抗灾指数作为产量灾损风险评估指标.结果表明,产量灾损风险量化指标在北方冬麦区的分布具有明显的区域分异性和一定的连片性.在各风险评估指标的基础上构建了北方冬小麦产量灾损综合风险指数模式,提出了北方冬小麦产量灾损综合风险类型分类指标.根据分类指标将北方冬麦区划分为高、中、低3个风险类型,并进行了分类评述.分类结果表明,高风险类型主要分布在水土条件较差的陕、晋黄土高原地区和华北平原部分地区;中风险类型分布在华北平原东北部和河南南部以及太行山区;低风险类型主要分布在有灌溉条件和农业生产水平较好的华北平原的大部分地区和关中地区. According to the principle of risk analysis, the risk assessment and risk classification of winter wheat yield were carried out by using the actual yield data and meteorological data of winter wheat in the counties and cities of North China in the past 50 years.According to the historical average yield reduction, coefficient of variation of rate of decrease of annual yield, Rate and its occurrence probability and disaster resistance index as yield disaster risk assessment index.The results show that the quantitative indicators of yield disaster risk have obvious regional differentiation and some contiguity in the distribution of winter wheat in the north.In each risk assessment Based on the index, a comprehensive risk index model of winter wheat yield in North China was established, and the comprehensive risk index of winter wheat in north China was put forward. According to the classification index, North Winter wheat was divided into high, medium and low risk types The classification results showed that the high-risk types mainly distributed in the areas of Shaanxi and Shanxi loess plateau and parts of the North China Plain with poor soil and water conditions; the middle-risk types were distributed in the northeastern North China Plain and southern Henan and the Taihang Mountains; low risk The types are mainly distributed in the irrigation conditions and agricultural production better than the majority of the North China Plain Area and the Guanzhong area.