辽宁玉米典型复合农业气象灾害影响损失评估

Maize Loss Assessment of Typical Multiple Agrometeorological Disasters in Liaoning Province,China

全球极端天气气候事件频发背景下,复合农业气象灾害发生频率和强度可能增大。为实现复合农业气象灾害对玉米生长过程影响的定量评估,基于多个单一指标综合识别的玉米复合农业气象灾害历史实况和净初级生产力(NPP),评估1987—2013年辽宁玉米复合农业气象灾害影响损失。结果表明:1987—2013年辽宁玉米生长季,有22年受到多发育期干旱影响,其平均气象NPP损失率为7.1%,有12年受干旱+低温冷害复合影响,其平均气象NPP损失率为3.5%,多发育期干旱灾害对辽宁玉米造成的影响高于干旱+低温冷害;通过对典型年和典型站点辽宁玉米复合农业气象灾害影响损失的分析,均发现玉米拔节期之前遭受灾害的影响可能在生长季中后期有所缓解,而拔节期之后遭受的严重灾害难以恢复;复合灾害影响损失率主要与灾害发生时段和程度有关;对辽宁玉米生产力影响最大的复合灾害是多发育期干旱,造成的损失普遍高于单发育期干旱;干旱+低温冷害复合造成的损失普遍高于单一冷害但低于单一干旱,干旱+低温冷害和单一冷害造成的影响均较小。由于复合农业气象灾害对玉米生长过程的影响机理复杂,多个单一指标无法直接判别复合灾害造成的叠加影响,而利用气象NPP损失指标,能够直接判别灾害损失程度,可为复合农业气象灾害监测预警和评估提供手段。

Under the background of frequent global extreme weather events,the occurrence frequency and intensity of Multiple Agrometeorological Disaster(MAD)may increase.To quantitatively evaluate the effect of MAD on maize growth and development,the loss effect of MAD on maize were evaluated in Liaoning province from 1987 to 2013,based on the historical MAD occurrence identified by multiple single indicators and actual net primary productivity(NPP).The results showed that there were 22 years affected by drought in multiple periods(M1-D)of maize in Liaoning province from 1987 to 2013 with an average NPP loss rate of 7.1%,and there were 12 years affected by drought and cold damage(M2-DC)with an average NPP loss rate of 3.5%.The effect of M1-D on maize in Liaoning province was higher than that of M2-DC.After an analysis of MAD effect losses in typical years and typical stations in Liaoning province,it was found that the maize encountered disasters before the jointing stage was expected to be alleviated in the middle and late growing season,but the maize encountered severe disaster after the jointing stage was difficult to be recovered.The loss rate of MAD was mainly related to the time and disaster grade.The M1-D was the greatest influence on maize productivity in Liaoning province,which caused more losses than drought in single growth period.The losses caused by M2-DC were generally higher than that single cold damage but lower than single drought.The effects of M2-DC and single cold damage were smaller.Because of the complex mechanism of MAD on the maize growth process,multiple single indices cannot directly identify the effects of MAD,but it can directly evaluate the disaster loss by using meteorological NPP loss index.This study can provide a means for monitoring,early warning and evaluating MAD.