宁夏中南部地区干旱变化趋势分析

Variation Tendency of Drought in Central and Southern Areas of Ningxia,China

采用国家最新发布的综合气象干旱指数,详细分析了宁夏中南部地区干旱发生频率、日数和强度的变化趋势。发现宁夏中南部地区春、夏季干旱变化趋势基本相似,而与秋季干旱变化趋势基本相反。20世纪60年代至80、90年代,宁夏中南部地区春、夏季干旱总体呈弱减轻趋势,而秋季干旱呈非常显著的加剧趋势,80、90年代秋季干旱强度较60年代增强了两倍多;进入21世纪以来,春、夏季干旱显著加剧,中部干旱带春、夏季干旱、南部山区夏季干旱强度较20世纪90年代平均增加了约1～2倍,而秋季干旱出现了明显减弱的新趋势。随着春、夏季干旱加剧,对农林牧业、生态环境、人畜饮水的影响越来越严重,旱灾造成的损失也在不断增大,应引起高度重视。最后提出了应对干旱加剧的措施建议。

Based on Arid Comprehensive Index released recently by China Meteorological Administration, the variation tendency of frequency, days and intensity of seasonal drought in central and southern areas of Ningxia Hui Autonomous Region were analyzed in detail. The inter-annual and inter-decadal variation tend- encies of spring drought and summer drought in central and southern areas of Ningxia are basically similar, and the tendencies are in opposite to variation tendency of autumn drought. From 1960s to 1980s--1990s, the spring drought and summer drought abated generally, while the autumn drought distinctly intensified, and the autumn drought intensity in 1980s-1990s intensified more than two times that in 1960s. Since 2000, spring drought and summer drought intensified notably, and they intensified by more than one time in the first ten years of the 21 century than in 1990s in most part of central and southern areas of Ningxia. At the same time, the autumn drought appeared new trend of distinct weakening. The intensification of spring drought and summer drought since 2000 has serious impact on farm, forestry, animal husbandry, ecological environment, and water supply for people and livestock. Some suggestions for reducing losses of drought are proposed in the paper.