气候变化背景下中国南方地区季节性干旱特征与适应Ⅱ.基于作物水分亏缺指数的越冬粮油作物干旱时空特征

Characteristics and adaption of seasonal drought in southern China under the background of global climate change.Ⅱ.Spatiotemporal characteristics of drought for wintering grain-and oil crops based on crop water deficit index

近年来中国南方地区的季节性干旱频繁发生,对当地越冬作物造成严重影响.本文基于中国南方地区268个气象站点1959—2009年的地面气象观测资料,以作物水分亏缺指数为指标,分析了中国南方地区越冬作物冬小麦和油菜的季节性干旱时空特征.结果表明:对于中国南方地区而言,西南、淮北和华南部分地区的越冬作物在生育阶段内易发生干旱.在长江中下游地区,冬小麦在生育中后期的干旱发生范围和强度增加,且随着生育期后移,其干旱越加严重;油菜在冬前生育阶段和生育后期的干旱发生范围和强度呈增加趋势.在西南地区,冬小麦和油菜在冬前生育期的干旱发生范围和强度均显著增加.20世纪90年代初以来,研究区域冬小麦和油菜在生育阶段中后期发生干旱的范围和强度都增加.

In recent years,seasonal drought occurs frequently in southern China,giving severe impact on the production of local wintering crops.Based on the 1959-2009 meteorological data from 268 meteorological stations in southern China,and by using crop water deficit index（CWDI） as agricultural drought index,this paper analyzed the spatiotemporal characteristics of drought for winter wheat and rapeseed.The results showed that in southern China,drought happened more frequently in Southwest China,north Huaihe basin,and parts of South China during the developmental stages of wintering crops.In the mid-lower Yangtze basin,the intensity and extent of drought increased during the mid-late developmental stages of winter wheat,and became much heavier at its later developmental stages.For rapeseed,the intensity and extent of drought increased during the developmental stage before winter and the late developmental stages.In southwest part,the intensity and extent of drought increased significantly during the developmental stage before winter for winter wheat and rapeseed.Since the early 1990s,the intensity and extent of drought in southern China increased during the mid-late developmental stages of wintering crops.