1951-2014年辽宁省气象干旱时空特征分析

Spatial and temporal characteristics of meteorological drought in Liaoning Province from 1951 to 2014

利用辽宁省56个国家气象观测站1951-2014年逐日降水量和气温资料,依据当前气象干旱监测业务中使用的气象干旱综合监测指数(MCI),使用国家标准《气象干旱等级》中对干旱事件的定义,分析讨论了1951-2014年辽宁省气象干旱事件的时空分布特征和变化规律。结果表明:1)辽宁省近64年来气象干旱事件出现的频率高、影响范围广,特别是2000年后气象干旱范围呈急剧上升趋势;春旱和秋旱影响范围增长速率最大,春旱的影响范围最广;2)辽宁省气象干旱的发生频率分布有很强的地域特征,辽西地区是气象干旱高发区;3)四个季节都有可能发生气象干旱,其中春旱发生频率最高,夏旱次之,秋旱发生频率相对较小;4)辽宁省出现的气象干旱事件强度(持续时间)呈现全省普遍偏大(偏长)或者普遍偏小(偏短)的一致特征,辽中地区是易发生强干旱并持续的敏感区。

In this paper,we discussed the spatial and temporal distribution characteristics of drought events in Liaoning Province from 1951 to 2014 by defining drought events in Liaoning Province referring to the meteorological drought grades of national standards. Also,the data of daily precipitation and the average cooling condition of fifty six meteorological stations in Liaoning Province was used,and the integrated monitoring index of meteorological drought（ MCI） was used as the basis,too. The results showed that：（ 1） the frequency of nearly 64 years of meteorological drought events of Liaoning Province was high and its range was wide,the growth rate of spring drought and autumn drought was the largest and the affected area of spring drought was the most wide.（ 2） The distribution of frequency for the meteorological drought in Liaoning Province had a strong regional characteristics,meteorological drought was more likely to occur in western Liaoning.（ 3） Meteorological drought happened in four seasons,among which,spring drought occurred most frequently while frequency of autumn drought was relatively small.（ 4） Meteorological drought events of Liaoning Provincial presented consistent features,whose intensity（ duration） was generally too large（ or rather long） or generally small（ or shorter）,and the central region was a sensitive area where strong drought occurred and sustained easily.