基于SPI指数甘肃省河东地区干旱特征分析  

Analysis of drought characteristics based on SPI for Eastern area of the Yellow River in Gansu province

作　　者：沙莉 李施 沙莎[2] 关雨珊 

机构地区：[1]辽宁省气象装备保障中心,辽宁沈阳110166 [2]中国气象局兰州干旱气象研究所甘肃省干旱气候与减灾重点实验室中国气象局干旱气候与减灾重点实验室,甘肃兰州730020

出　　处：《气象与环境学报》2016年第5期122-130,共9页Journal of Meteorology and Environment

基　　金：中央级公益性科研院所基本科研业务费专项(2014IAE-CMA04)资助

摘　　要：本文利用1971—2014年甘肃省河东地区32个气象站的逐月降水观测资料,采用标准化降水指数SPI对河东地区的干旱特征进行了分析。结果表明:对于全年干旱来说,甘肃省河东地区存在一条由北向南延伸的干旱趋势带,干旱范围呈微弱缩小的趋势;春季和夏季河东大部地区呈变干的趋势,干旱范围分别呈扩大和缩小的趋势;秋季和冬季河东绝大部地区呈变湿的趋势,干旱范围亦呈缩小的趋势。1971—2014年河东地区年平均干旱发生率为30.0%,其中定西中北部和陇南北部、天水中北部等地区为干旱发生频率较高的地区;除冬季干旱发生率呈减小的趋势外,全年及春季、夏季、秋季干旱发生频率均呈先减小后增大的变化特征;全年干旱多发生在1991—2010年,春季和秋季干旱多发生在1991—2000年,夏季干旱多发生在1971—1980年和2000—2010年,冬季干旱多发生在1971—1980年。Using monthly precipitation data of 32 meteorological stations in the Eastern area of the Yellow River in Gansu province from 1971 to 2014,drought characteristics were analyzed based on a standardized precipitation index（ SPI）. The results show that,f or annual drought from 1971 to 2014, there is a drought tendency belt extending from the north to the south of study area. The extent of drought shows a slight downward trend. Most parts of the Eastern area of the Yellow River show a drying trend in spring and summer. The extent of drought shows an upward trend in spring and a downward trend in summer. Most parts of the Eastern area of the Yellow River show a wetting trend in autumn and winter with the extent of drought decreasing. From 1971 to 2014,occurrence frequency of drought is 30% for the Eastern area of the Yellow River. The areas with high drought occurrence frequency are in north-central of Dingxi,Lanzhou,as well as the north of Longnan city. Drought occurrence frequency in winter shows a downward trend. Compared to winter,drought occurrence frequency in a single year or spring, summer and autumn experiences a decline first,but rises latter. The SPIs of annual, spring,autumn,and winter are lower during the periods of 1991 to 2010,1991 to 2000,1991 to 2000,and 1971 to 1980, respectively. Summer SPI is lower during two periods of 1971 to 1980 and 2000 to 2010.

关 键 词：干旱 标准化降水指数 多时间尺度 

分 类 号：P429[天文地球—大气科学及气象学]