近 60年大连市不同等级降水量与降水日数的变化特征

为了研究掌握不同等级降水量和降水日数演变规律,合理利用降水资源,更好地服务于农业生产。根据大连市1951—2010年逐日降水资料,利用线性趋势和Mann-Kendall突变检验等方法,对大连市不同等级降水量和降水日数的变化特征进行分析。结果表明：年降水量和降水日数均呈减少趋势,降水日数的减少更加显著。小雨量和大雨量（日数）显著减少,中雨量（日数）则呈增加趋势,暴雨量（日数）减少趋势不明显。降水量（日数）的季节变化明显,其中夏、秋、冬季降水量（日数）呈减少趋势,而春季降雨量（日数）呈增加趋势。降水强度春季显著增大,夏、秋季显著减小,而冬季有微弱的下降趋势。春季发生极端降水事件的概率增加,尤其是进入21世纪以来更加明显。年降水日数在1978年发生1次明显突变。

Variation Characteristics of Precipitation and Precipitation Days with Different Grades over Dalian in Recent 60 Years

In order to study and master the evolution of different grades precipitation and precipitation days for giving a better suggestion of rainwater resources management and better services for agricultural production. Variation characteristics of precipitation and precipitation days have been analyzed using trend analysis and Mann-Kendal test methods based on daily precipitation data from 1951 to 2010 in Dalian. The results showed that annual precipitation and precipitation days decreased, with the decrease of annual precipitation days being more obvious. Light and rainfall (days) showed the decreasing trend, with moderate rainfall (days) showing an increasing trend, but torrential rainfall (days) had increased faintly, which was not remarkable. The seasonal distribution of precipitation also showed significant changes. Rainfall (days) in summer, autumn and winter were reducing, and rainfall (days) in spring were increasing. Precipitation intensity showed an evident increasing trend in spring and a decreasing trend in summer and autumn, but the decline of precipitation intensity was not obvious in winter. On the other hand, it was found that extreme precipitation events would increase in spring, which had been more remarkable since the 21st century particularly. The obvious abrupt changes of annual precipitation days occurred in 1978.