关键词: 春播期, 降水, 首场透雨, 最大无有效降水日数

Abstract: Using linear inclination estimation and accumulative anomaly analysis methods,the temporal characteristic of precipitation during the spring sowing period and its relationship with the first soaking rain and the maximum continuous days without available precipitation were analyzed.The results show that the precipitation during the spring sowing period increased slowly with a rate of 3.1 mm/10 a in Shenyang from 1960 to 2017.The precipitation during the spring sowing period increased rapidly with larger fluctuations since 2004.The increase of abnormal precipitation years induced spring drought (or flood) events occurring frequently.The first soaking rain during the spring sowing period of Shenyang delayed with a rate of-0.051 d/10 a,which usually leads to the shortage of soil water during the spring sowing period and are unfavorable for spring sowing.The maximum continuous days without available precipitation increased with a rate of 0.56 d/10 a,which had significant impacts on precipitation in April.Although the total amount of precipitation during the spring sowing period had an increasing trend,its temporal distribution was uneven.Above all,the uneven distribution of precipitation and the frequently occurrence of continuous days without available precipitation will increase drought disaster risk during the spring sowing period and the sowing date may be delayed.

Key words: Spring sowing period, Precipitation, The first soaking rain, Continuous days without available precipitation