辽西朝阳地区近60年玉米生长季降水变化特征分析

利用气候倾向率、降水相对变率，划分基准年方法，研究近60年朝阳地区玉米生长季及各个发育期降水变化特征。结果表明：近60年玉米生长季降水量气候倾向率为-6.55mm /10 a，呈下降趋势。玉米各生育期降水变化趋势不同，玉米播种—苗期、成熟期的降水量呈增加趋势，气候倾向率分别为 4.2 mm/10 a和0.3 mm/10 a，拔节—孕穗期的降水量呈下降趋势，气候倾向率为-10.6 mm /10 a。不同基准年降水变化趋势差异显著，第Ⅱ基准年降水减少最明显，气候倾向率达-23.7 mm/10 a。第Ⅲ基准年降水增加最明显，气候倾向率达29.0 mm/10 a。朝阳地区玉米生长季及各个发育期降水相对变率大，降水偏少年最多，正常年最少。研究结果为该地区玉米生产良种选择、栽培方式改进及趋利避害、防灾减灾等提供气候依据。

Analysis of Precipitation Variation Characteristics of Maize Growth Season in Recent 60 Years in Chaoyang Area of Liaoning Province

The author used the method of climate inclination rate, the relative variability of precipitation and the division of base years to study the variable precipitation characteristics of each growth period and the growing season of corn in recent 60 years in Chaoyang area. The results showed that the climate inclination rate of precipitation of corn growing season in recent 60 years was -6.55 mm/10 a, presented a downward trend. The precipitation variation trend of different corn growth periods was different, the precipitation in corn planting-seedling stage and mature period showed an increasing trend, the climate inclination rates were 4.2 mm/10 a and 0.3 mm/10 a, respectively. The precipitation in jointing-booting stage presented a downward trend, the climate inclination rate was -10.6 mm/10 a. The precipitation variation trend in different base years had significant difference. The second base year precipitation decreased most obviously, climate inclination rate reached -23.7 mm/10 a. The third base year precipitation increased obviously, climate inclination rate reached 29.0 mm/10 a. The precipitation relative variability of corn growing season and each development period in Chaoyang was great, years of deficient precipitation accounted for the most, years of normal precipitation accounted for the least. The research results provided climatic evidence for variety selection, improvement of cultivation pattern as well as disaster prevention in corn production in this area.