基于多尺度SPI指数的哈巴河地区近53a的干旱分析

为了对新疆哈巴河地区开展最新的旱情研究,以期全面了解该地区干旱特征及演变规律,基于不同时间尺度下的标准化降水指数(SPI)方法,分析了哈巴河地区1962—2014年间的干旱演变特征。结果表明:(1)近53 a来,SPI指数方法在哈巴河地区有较高的适用性,不同时间尺度SPI皆可监测旱情变化,且与记载的流域实际旱情相符。(2)从SPI1,SPI3,SPI6指数过程线可以看出,哈巴河地区发生不同干旱等级事件的概率为20%左右;SPI3指数较SPI1,SPI6指数评价的旱情程度要重;SPI12呈现显著的上升趋势,长时间尺度说明地区气候在逐步变湿,有助于减轻地区干旱。(3)不同季节SPI的年际过程差异显著,其中年SPI最小值为1963年的-1.97,53 a间发生轻旱、中旱、重旱等不同等级干旱事件的年份分别为9,4,0 a。(4)四季SPI发生轻旱级别以上干旱的年份约占26%~28%,平均约11 a。(5)冬季SPI呈增加趋势,其余季节及年SPI变化趋势不明显,且夏季SPI与年SPI过程较为相似。研究结果可为区域旱情监测与预警、风险管理提供科学依据。

Drought Analysis Based on Multi-timescale Standardized Precipitation Index in Habahe Region from 1962 to 2014

The drought evolution characteristics of Habahe in Xinjiang Autonomous Region from 1962 to 2014 were analyzed based on multi-timescale standardized precipitation index (SPI).Results show that 1) the SPI index method is highly applicable to Habahe region in the past 53 years,and the SPI values of different time scales can be used for drought monitoring,which is in line with actual drought conditions.2) According to the process lines of SPI1 (time scale of one month),SPI3(time scale of three months) and SPI6(time scale of six months),the probability of different levels of drought events was around 20％.The drought condition reflected by SPI3 was more severe than those by SPI1 and SPI6.The value of SPI12 presented a significant rising trend,indicating that the regional climate is becoming wet gradually,conducive to alleviating regional drought.3) The inter-annual process of SPI value in different seasons varied significantly,among which the minimum SPI value was-1.97 in 1963.During the 53 years,slight drought event appeared for 9 years,medium drought event 4 years,and severe drought event 0 year;medium and severe droughts in four seasons took up 11 years in average,accounting for 26％-28％;in winter,the SPI value displayed rising trend,whereas in other seasons the changes were not obvious.The process of SPI value in summer was similar with that of annual SPI value.