1950～2000年甘肃农作物受旱面积与厄尔尼诺和拉尼娜的关系

Relationship between the Decadal Change of Drought Crop Area in Gansu and El Nino and La Nina from 1950 to 2000

对1950～2000年甘肃省农作物受旱面积的年代际变化与同期厄尔尼诺和拉尼娜事件作了对比研究,结果表明:在厄尔尼诺事件年甘肃省干旱严重,农作物受旱面积大,在拉尼娜事件年甘肃省干旱轻,农作物受旱面积小;1950～2000年甘肃省农作物受旱面积,最大出现在1995年,最小出现在1964年,而1995和1964年分别出现了厄尔尼诺和拉尼娜事件;离厄尔尼诺事件强的年份时间越近,甘肃省农作物受旱面积越大,反之,离厄尔尼诺事件强的年份时间越远,或厄尔尼诺事件弱的年份,甘肃省农作物受旱面积越小;1950～2000年甘肃省农作物受旱面积有显著增加趋势,20世纪50年代受旱面积最小,90年代受旱面积最大;50年代农作物受旱面积在100万hm2的年份没有出现,90年代受旱面积在100万hm2的年份有6年;在每个年代的初期,甘肃省干旱几率最大,对干旱预报有一定的积极意义。

The relationship between the decadal change of drought crop area in Gansu and El Nino and La Nino from 1950 to 2000 was comparatively analyzed,the results indicated that：at the year with El Nino event,the drought was very serious in Gansu,the crop area suffering from drought was enlarging,while at the La Nina year,the drought in this area was light,the crop area suffering from drought was small;during 1950-2000,the maximum crop area affected by drought in Gansu appeared in 1995,while the minimum appeared in 1964,because there were El Nino and La Nina respectively in 1995 and 1964;the closer to the year with strong El Nino events,the larger the crop area suffering from drought in Gansu,and vice versa;the crop area suffering from drought in Gansu Province during 1950-2000 showed an increasing tendency,the minimum drought crop area appeared in 1950s,while the maximum at 1990s;the drought crop area 1 million hm2 didn＇t appear in 1950s,while it showed up in 6a of 1990s;at the beginning of each decade,there was highest probability of drought in Gansu Province,which had certain positive significance in drought forecast.