摘要
基于1961-2007年36站的逐日降水资料,分析新疆北部地区春、夏季干旱的区域性和持续性特征。结果表明:新疆北部春、夏季干旱发生较为频繁,尤其在北疆西北部地区,春旱平均3 a一遇,夏旱为4～5 a一遇。季节间的连旱概率较低,不足10%,主要以月际间的连旱为主,其中2个月的持续干旱次数占干旱总次数的20%左右。进一步的分析表明,春夏之交的5～6月,是2个月连续干旱发生次数相对频繁的时期,北疆西北部地区此类连续干旱事件最多。伊犁河谷、北天山地区和北疆北部春旱较夏旱频繁,春旱以北疆北部发生最多;夏旱3个区域发生频次相似,但北天山地区大旱发生频数较高。3个区域的春、夏季干旱程度均呈减弱趋势,春旱在20世纪90年代中后期、夏旱在80年代中后期处在一个较低的发生期。
As a kind of climate disaster, drought causes big economic loss, especially the big agricultural loss, it is meanwhile known to be such a complex natural hazard and also much more severe than any other natural extreme events. As the most frequent and serious meteorological disaster in Xinjiang, drought is characterized by vast disaster area and long duration. Therefore, it attracts more and more attention of meteorologists to study drought. Precipitation in north Xinjiang, 200 mm approximately, is much higher than that in south Xinjiang （about 50 mm）, and utilization of the unified criteria to estimate the distribution of drought in these two distinguish regions is undoubtedly improper, so this paper focuses mainly on the variation of drought features in north Xinjiang （ excluding the Tianshan Mountains）. The previous researches focused mostly on seasonal change of drought, but few studies focused upon its regional and continual features. Complex topography induced dominantly the significant climatic difference between different regions and different seasons in north Xinjiang. Therefore, it is an issue worthy to lucubrate that how to analyze qualitatively the spatial features and time response of drought distribution. In this paper, the features of regional and continuous drought over the Junggar Basin in north Xinjiang in spring and summer were analyzed based on the daily precipitation data observed by 36 meteorological stations in Xinjiang during the period of 1961 - 2007. The results revealed that the extreme drought occurred most frequently in the basin, especially in northwest Xinjiang, where spring drought occurred every 3 years, but summer one occurred every 4 - 5 years. The probability of inter-seasonal draught occurrence was lower （ 〈 10% ）, while the occurrence of inter-monthly continual draught was much more common, and the occurring frequency of 2-month continual draught was approximately 20% of the total. The analyzed results showed that the continual draught occurred most frequently in
出处
《干旱区研究》
CSCD
北大核心
2012年第3期472-478,共7页
Arid Zone Research
基金
公益性行业(气象)科研专项(GYHY201006012)
中央级科研院所基本科研业务费专项(IDM200804)联合资助
关键词
干旱
降水
区域性
持续性
新疆北部
drought
precipitation
regionality
continuity
north Xinjiang
