辽西北春玉米旱灾灾损风险区划

Risk assessment and divisions of loss caused by drought for spring maize in Northwestern Liaoning

开展干旱风险区划研究,对实现抗旱减灾及粮食稳产增产至关重要。以辽西北为研究区域,以作物水分亏缺指数(CWDI)为干旱表征指标,利用该区1965—2019年逐日气象数据及多年玉米种植资料,通过数理统计和通径分析方法揭示研究区玉米干旱时空演变及对各气象因子的响应特征,在此基础上构建干旱灾损指数进行旱灾风险区划,结果表明:(1)近54年春玉米抽穗—成熟期CWDI值以2.2/10 a的速率上升,其他生育阶段呈下降趋势,空间上干旱频率由辽西向辽北递减;(2)相对湿度和降水量与CWDI指数呈明显负相关,其他气象因子呈正相关,其中气温和相对湿度对其直接影响最大;(3)辽西北分四个灾损风险区,且风险程度由辽北向辽西递增。研究结果可为优化春玉米农田管理和防灾减灾提供一定参考。

The research on divisions of drought risk is vital to reducing drought disasters and increasing grain yield. In this paper, crop water deficit index(CWDI) was used as a drought index in the northwestern Liaoning province. Based on the daily meteorological data from1965-2019 and the data of maize planting over years, the spatial and temporal evolution of maize drought and the response characteristics of meteorological factors were revealed by mathematical statistics and path analysis. And the drought risk regionalization was carried out by constructing the drought disaster loss model. The results showed that:(1) In the past 54 years, the CWDI of spring maize during the heading-maturation period increased at a rate of2.2/10 a, and the other growth stages showed a downward trend. And the spatial distribution of drought frequency of spring maize in the study area gradually increased from north to west.(2) Relative humidity and precipitation are negatively correlated with CWDI, while other meteorological factors are positively correlated;among which temperature and relative humidity have direct influence on it.(3) Northwestern Liaoning is divided into four disaster risk areas, and the degree of drought disaster risk shows an increasing trend from north to west.The research results can provide some reference for spring maize field management and disaster prevention and mitigation.