辽宁省春播期降水的时空特征及其对土壤水分的影响

The Characteristics of Spring Sowing Precipitation and its Effects on Soil Moisture in Liaoning Province

利用辽宁省53个气象站1961-2015年日降水量资料和19个农业气象观测站1981-2015月0~20 cm土壤含水量资料,应用EOF(经验正交函数)、小波分析、相关分析等统计方法对春播期降水时空分布特征及其对土壤水分的影响进行了分析。研究结果显示:(1)辽宁省春播期降水场主要有三种模态,即全局型、东西差异型和东北和西南差异型,降水场是由三种模态决定的6种表现类型,其中全省一致多、少雨年份共占58.1%。(2)辽宁春播降水呈现增多趋势,4月和5月空间变化趋势变化略有不同,且区域性变化明显;近20年极端降水事件显著增多,并存在2~3年、4年、4~5年振荡周期。(3)浅层土壤湿度与降水量相关系数通过95%显著性检验,辽东地区土壤湿度对降水的敏感性大于辽西地区。

Using EOF（Empirical Orthogonal Function）,wavelet analysis and correlation analysis,we analyzed the temporal and spatial distribution characteristics of precipitation during spring sowing and its influence on soil moisture by using the daily precipitation data of 53 meteorological stations during 1961 to 2015 and the monthly0-20 cm soil data of 19 agrometeorological stations during 1981 to 2015. The results show that there are three typical modes of precipitation in the spring sowing period in Liaoning Province,the whole region,west-east,and northwest-southeast. The precipitation field has six types determined by three typical modes,the whole region years accounted for 58. 1%. The precipitation trend is increasing,and the change of spatial trend is slightly different in April and May,and the regional change is obvious. In the past 20 years,the extreme precipitation events have increased significantly,and there are 2 ~ 3 a,4 a,4 ~ 5 a oscillation period. The correlation coefficient between soil moisture and precipitation in the shallow soil was 95% statistically significant,and the sensitivity of soil relative humidity to precipitation in Liaodong area was higher than that in western Liaoning.