基于日尺度SPEI的黄淮海平原冬小麦生育阶段干旱特征分析

Drought characteristics of winter wheat in different growth stages in the Huang-Huai-Hai Plain of China based on the daily SPEI

黄淮海平原地处燕山以南、淮河以北,包含黄河、淮河和海河冲积平原及部分丘陵山区,属于半干旱、半湿润地区,年降水量500~900 mm,是我国主要的冬小麦种植区。利用黄淮海平原49个农气站点1961—2017年日值气象数据,采用Penman-Monteith模型计算的日尺度SPEI指数,从气象干旱的角度分析了黄淮海平原近56 a冬小麦主要生育阶段干旱持续时间和干旱强度的变化,并采用R/S方法对干旱未来变化趋势进行预测。结果表明:(1)从空间分布上来看,冬小麦的营养生长期和并进期,北部干旱持续时间较短,干旱强度较小,南部干旱持续时间较长,干旱强度较大,而冬小麦生殖生长期与前两个生育期干旱分布相反。(2)从各站点变化趋势来看,在冬小麦整个生育期内干旱持续时间与干旱强度呈相反趋势。(3)从时间变化趋势上来看,1961—2017年干旱有明显减缓趋势,除个别站点外,在冬小麦的营养生长期和并进期,干旱持续时间和干旱强度自2003年起干旱有逐渐减缓趋势,在生殖生长期则从2007年起干旱有逐渐减缓趋势。(4)从未来变化趋势来看,营养生长期干旱持续时间将缩短,干旱强度将减小,并进期的干旱持续时间和干旱强度的变化将和过去56 a基本保持一致,生殖生长期干旱持续时间将有所增长,干旱强度将有所加重。本研究分析了黄淮海平原冬小麦生育阶段干旱特征,旨在认识分析和掌握冬小麦生育期干旱演变特征以及干旱发生规律,对保障粮食安全和防旱减灾提供了科学依据。

Huang-Huai-Hai Plain is located in the south of Yanshan Mountains and north of Huaihe River,including the alluvial plains of the Yellow River(Huanghe),Huaihe River and Haihe River and some hilly and mountainous areas.It belongs to semi-arid and semi-humid area with annual precipitation of 500-900 mm.It is also the main winter wheat planting area in China.Based on the daily meteorological data of 49 agriculture-meteorological stations in Huang-Huai-Hai Plain from 1961 to 2017 and the daily SPEI index calculated by Penman-Monteith model,the changes of drought duration and drought intensity in the main growth stages of winter wheat in the region in recent 56 years were analyzed from the perspective of meteorological drought,and the future trend of drought was predicted by R/S method.The results show as follows:(1) The drought duration in the north is short,the drought intensity is weak,and the drought duration in the south is long and the drought intensity is strong in the vegetative stage and the vegetative and reproductive stage of winter wheat,but in the reproductive growth period of winter wheat the drought distribution is contrary to that in the first two growth periods.(2) Analyzing the change trend of each station,we can see the duration of drought is opposite to the intensity of drought during the whole growth period of winter wheat.(3) Analyzing the change trend of each year,the drought had a significant slowdown trend from 1961 to 2017.Except for what’s indicated by a few stations,the duration and intensity of drought had a gradual slowdown trend from 2003 to 2017 in the vegetative growth period and the progressive period of winter wheat,while in the reproductive growth period,drought had a gradual slowdown trend from 2007.(4) From the perspective of future trends,the duration of drought in vegetative growth period will become shorter and the intensity of drought will become weaker.The duration and intensity of drought in advanced period will be basically consistent with those in the past 56 years.The duration of drought in reproductive growth period will become longer and the intensity of drought will become stronger.This study analyzed the drought characteristics of winter wheat in various growth stages in the Huang-Huai-Hai Plain,aiming at understanding and grasping the evolution characteristics of drought and the occurrence law of drought during the growth stages of winter wheat,providing a scientific basis for ensuring food security and drought prevention and disaster reduction.