1981—2020年沈阳地区春玉米生长季水热资源时空特征

利用沈阳地区7个气象站点逐日气象数据以及春玉米生育期数据, 对1980—2020年春玉米播种期、苗期、拔节期、抽雄期、成熟期和全育期的生长度日(GDD)、高温度日(HDD)、降水量及其气候倾斜率的时空变化特征进行了分析。结果表明: 春玉米全育期生长度日呈上升趋势, 各生育期生长度日空间分布差异不太显著, 总体上呈由北向南递增趋势, 高值主要分布在浑南区和苏家屯区, 低值分布在康平县和法库县。春玉米全育期高温度日呈递增趋势, 除康平县在成熟期高温度日呈减少趋势, 其他各地生育期高温度日均呈增加趋势, 空间上由西北向东南不断递增。沈阳地区在近40 a春玉米全生育期均呈降低趋势, 空间上由东南向西北呈递减趋势, 在苗期各地降水均呈增加趋势, 其他时期均以减少趋势为主。沈阳地区春玉米全育期热量资源呈增加趋势, 但降水量呈减少趋势, 此种趋势增大了该地区极端高温和气象干旱风险。

Spatiotemporal characteristics of heat and rainfall resources during the growth period of spring maize in Shenyang from 1981 to 2020

Based on the daily meteorological data and growth period data of spring maize from seven meteorological stations in Shenyang, the spatiotemporal change characteristics of the growing degree days (GDD), heating degree days (HDD), precipitation, and climatic tendency rate of spring maize during sowing, seeding, elongation, heading, maturation, and whole growing periods were analyzed. The results indicate that the GDD of spring maize shows an upward trend during the whole growing period. The spatial distribution difference of GDD during different growth periods is not significant, which demonstrates an ascending trend from the north to the south, with the high value mainly distributed in Hunnan and Sujiatun Districts, and the low value in Kangping and Faku counties. The HDD of spring maize during the whole growing period increases progressively. Except for Kangping, which shows a decreasing trend during the mature period, the HDD in other regions shows an increasing trend during the growing period, increasing from northwest to southeast in space. In the last 40 years, the whole growing period of spring maize in the Shenyang area shows a decreasing trend, and the spatial trend is decreasing from southeast to northwest. At the seedling stage, the precipitation in all regions shows an increasing trend, and the other periods show a decreasing trend. During the whole growing period of spring maize in Shenyang, the heat resources show increasing trends, but the precipitation shows a decreasing trend, which will increase the risk of extremely high temperature and meteorological drought in the region.