Wang Jing, Yang Xiao-Guang, Li Yong, Liu Zhi-Juan, Zhang Xiao-Yu
College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Ying Yong Sheng Tai Xue Bao. 2011 Jun;22(6):1511-22.
Based on the 1959-2007 daily precipitation data and 1983-2007 spring maize phenologyical data, the thresholds of extreme precipitation at different places in Sanjiang Plain of Heilongjiang Province were calculated by percentile method, and, in combining with the indices involving the frequency and intensity of extreme precipitation, longest consecutive wet (dry) days, and contribution rate of extreme precipitation, the annual change characteristics of extreme precipitation, quantitative change of different grade precipitation, and distribution characteristics of extreme precipitation at each growth stage of spring maize were analyzed. In 1959-2007, the annual precipitation in Sanjiang Plain showed a slight decreasing trend, and the decreasing amplitude of precipitation days was much larger than that of precipitation. Accordingly, the annual distribution of precipitation tended to be more concentrated. The frequency and intensity of extreme precipitation declined, and the annual fluctuation of the frequency was bigger than that of the intensity. There was a slight decrease in the proportion of annual extreme precipitation to annual precipitation, but the decreasing tendency was not significant. The annual light rain days had a significant decreasing trend, but the annual moderate and heavy rain days didn't have. During spring maize growth season, the distribution ratio of extreme precipitation from high to low was reproductive growth stage, coexistence stage of vegetative growth and reproductive growth, vegetative growth stage, and premergence stage. There was a significant decrease in the proportion of the precipitation during spring maize growth season to annual precipitation, resulting in an increasing risk of precipitation scarcity during the growth season. The longest consecutive dry days during spring maize growth season showed a significant increasing trend, with the increment averaged 1.1 d x (10a)(-1), while the longest consecutive wet days showed a significant decreasing trend, with the decrement averaged 0.5 d x (10a)(-1). Under natural precipitation, the spring maize drought risk in the study region increased.
基于1959 - 2007年的日降水数据以及1983 - 2007年春玉米物候期数据，采用百分位数法计算黑龙江省三江平原不同地点的极端降水阈值，并结合极端降水频率、强度、最长连续湿（干）日数以及极端降水贡献率等指标，分析了极端降水的年变化特征、不同等级降水量的定量变化以及春玉米各生育阶段极端降水的分布特征。1959 - 2007年，三江平原年降水量呈微弱下降趋势，降水日数下降幅度远大于降水量下降幅度，降水年分布趋于更加集中。极端降水频率和强度下降，频率的年际波动大于强度。年极端降水量占年降水量的比例略有下降，但下降趋势不显著。年小雨日数有显著下降趋势，而年中雨和大雨日数无显著变化。在春玉米生长季，极端降水分布比例从高到低依次为生殖生长阶段、营养生长与生殖生长并存阶段、营养生长阶段和出苗前阶段。春玉米生长季降水量占年降水量的比例显著下降，导致生长季降水短缺风险增加。春玉米生长季最长连续干日数呈显著增加趋势，增量平均为1.1 d×(10a)^(-1)，而最长连续湿日数呈显著下降趋势，减量平均为0.5 d×(10a)^(-1)。在自然降水条件下，研究区域春玉米干旱风险增加。
