1965~2024年新疆地区极端降水变化特征分析

Analysis of Extreme Precipitation Changes in Xinjiang Region from 1965 to 2024

摘要: 基于国家气象科学数据中心CHM_PRE数据集1965~2024年逐日降水资料，选取ETCCDI定义的8个极端降水指数，采用Mann-Kendall检验、Sen斜率估计法和Hurst指数等方法，系统分析了新疆地区极端降水事件的时空变化特征及其未来趋势。结果表明：(1) 新疆极端降水空间分布呈“北疆 > 南疆、山区 > 盆地”格局，天山山区、伊犁河谷及北疆西部为极端降水高值区，1995~2024年天山以南地区出现大范围降水增加；(2) 1965~2024年间，新疆地区PRCPTOT、Rx1day、Rx5day、SDII、R10、R20和CWD均呈上升趋势，CDD呈下降趋势，其中PRCPTOT上升趋势最为显著(5.27 mm/10a)，CDD下降趋势显著(−0.233 d/10a)；(3) 分时段对比显示，1995~2024年期间各极端降水指数变化幅度与显著性均远超1965~1994年，表明天山北坡、伊犁河谷及南疆西部为极端降水变化最显著的核心区域；(4) Hurst指数分析表明，R10、CWD和PRCPTOT的H值分别为0.66、0.86和0.71，预示未来新疆地区降水天数上升趋势将持续，整体呈现湿润化趋势，但CDD的H值为0.74，表明部分地区干旱化情况趋势将持续。(5) 2020~2024年极端降水呈现增速加快、幅度增大的突变式增强特征，南疆西部成为新增显著增湿区，对长期趋势形成显著强化与局部调整。本研究可为新疆地区水资源管理与灾害防治提供科学依据。

Abstract: Based on the daily precipitation data of the CHM_PRE dataset from 1965 to 2024 provided by the National Meteorological Science Data Center, eight extreme precipitation indices defined by ETCCDI were selected. Using methods such as the Mann-Kendall test, Sen slope estimation method, and Hurst index, a systematic analysis was conducted on the temporal and spatial variation characteristics and future trends of extreme precipitation events in Xinjiang. The results show: (1) The spatial distribution of extreme precipitation in Xinjiang follows the pattern of “North Xinjiang > South Xinjiang, mountainous areas > basins”, with the Tianshan mountainous area, the Ili River valley, and the western part of North Xinjiang being the high-value areas of extreme precipitation, and a large-scale increase in precipitation appeared south of the Tianshan Mountains from 1995 to 2024; (2) From 1965 to 2024, PRCPTOT, Rx1day, Rx5day, SDII, R10, R20, and CWD all showed an upward trend. Among them, the upward trend of PRCPTOT was the most significant (5.27 mm/10a), and the downward trend of CDD was significant (−0.233 d/10a); (3) Comparisons by time periods indicate that the changes and significance of each extreme precipitation index during 1995~2024 exceeded those from 1965~1994, suggesting that the northern slope of Tianshan Mountains, the Ili River valley, and the western part of South Xinjiang are the core areas with the most significant changes in extreme precipitation; (4) The H values of R10, CWD, and PRCPTOT are 0.66, 0.86, and 0.71 respectively, indicating that the upward trends of moderate rain days, consecutive wet days, and total precipitation will continue in the future, showing a trend of wetting. but the H value of CDD is 0.74, indicates that the trend of drought in some marginal areas will continue. (5) Extreme precipitation from 2020 to 2024 showed a sudden enhancement with accelerated growth rate and increased amplitude, and the western part of South Xinjiang became a new significant humidification area, which significantly strengthened and locally adjusted the long-term trend. This study can provide scientific basis for water resource management and disaster prevention in Xinjiang.