四种气象干旱指数在新疆区域适用性研究

利用降水量距平百分率(PA)、标准化降水蒸散指数(SPEI)、自适应帕默尔干旱指数(scPDSI)和气象干旱综合指数(MCI)四种气象干旱指数，进行变化趋势、相关性和干旱频率的分析，并与历史灾情进行对比，来研究1961—2020年新疆不同区域干旱指数适用性。结果表明，scPDSI和MCI指数显著上升，干旱程度呈减轻趋势，其干旱监测结果一致率高。PA指数变化趋势均平稳，但与其他三种干旱指数在全频域和高频域干旱监测结果一致率较好。SPEI指数在东疆和南疆东部区域显著下降，干旱程度呈加重趋势，与其它三种指数低频域干旱监测结果存在显著负相关。干旱频率分析结果显示，PA指数的特旱等级判定存在异常情况，特别是南疆和东疆。与历史灾情对比结果显示，MCI指数是对干旱灾害反映最好的。总体上，MCI指数在新疆地区的适用性要优于其它三种干旱指数。近60年来，全疆不同区域的MCI指数均呈上升趋势，各区域的干旱程度均有所减轻。空间上，新疆西北部发生干旱显著比南疆和东疆区域概率大。全疆不同区域在1962—1967年、1974—1977年、1989—1991年、1997年、2020年均发生干旱，并且主要集中在春夏两季较多，其中北疆西部和伊犁河谷区域易出现干旱灾情。

Applicability study of four meteorological drought indices in Xinjiang, China

The applicability of the drought index in different regions of Xinjiang from 1961 to 2020 was studied by analyzing the variation trend, correlation, and drought frequency of four meteorological drought indexes of the Precipitation Anomaly Percentage(PA), the Standardized Precipitation Evapotranspiration Index(SPEI), the self-calibrating Palmer Drought Severity Index(scPDSI) and meteorological drought comprehensive Index(MCI), and comparing them with historical disasters. The results showed that the scPDSI and MCI indices increased significantly, the drought degree showed a decreasing trend, and the consistency rate of the drought monitoring results was high. The variation trend of the PA index was stable, but it was in good agreement with the other three drought indices in the full-frequency domain and high-frequency domain drought monitoring results. The SPEI index decreased significantly in eastern Xinjiang and the eastern part of southern Xinjiang, and the degree of the drought was increasing, and there was a significant negative correlation with the other three indices in low-frequency domain drought monitoring results. The results of drought frequency analysis showed that there were abnormalities in the determination of PA special drought grade, especially in southern and eastern Xinjiang. Compared with the four indices and historical disasters, MCI is the best reflection of drought disasters. In general, the applicability of MCI in Xinjiang is better than the other three drought indices. In the past 60 years, MCI in different regions of Xinjiang showed an upward trend, and drought in each region was alleviated. Spatially, the probability of drought in northwestern Xinjiang is higher than that in southern and eastern Xinjiang. The probability of drought in northwest Xinjiang is higher than that in southern and eastern Xinjiang. Droughts occurred in different regions of Xinjiang in 1962-1967, 1974-1977, 1989-1991, 1997, and 2020, and mainly occurred in spring and summer. Droughts were prone to occur in the western part of northern Xinjiang and the Ili River Valley.