Spatial-Temporal Evolution Characteristics of Drought-Flood Abrupt Alternation in Henan Province from 1961 to 2024

本研究基于1961~2024年河南省119个气象站点的降水数据，计算了旱涝急转指数(SDFAI)，系统分析了其时空演变特征及典型年份的旱涝急转规律。结果表明：(1) 河南省各站点SDFAI与区域降水集中期SDFAI的相关系数介于0.31至0.84之间，空间上呈现南北低、中部高的分布特征，表明旱涝急转现象具有显著的空间异质性；(2) 1961~2024年期间，河南省SDFAI呈微弱上升趋势，涝情风险略有增加，且旱涝急转强度表现出显著的年代际变化特征，其中2024年SDFAI达到历史峰值(8.49)；(3) 典型年份分析显示，旱转涝显著的年份(如2024年、1995年、1982年)表现为前汛期降水显著偏少、后汛期降水显著偏多，而涝转旱显著的年份(如2015年、2002年、1991年)则呈现相反特征，其中2002年5~6月降水偏多70.18%，7~8月降水偏少38.43%。研究揭示了河南省降水季节分配的极端不均匀性，为区域气候变化适应和水资源管理提供了科学依据。Based on the precipitation data from 119 meteorological stations in Henan Province during 1961~2024, the SDFAI was calculated, and its spatio-temporal evolution characteristics and the rule of SDFAI in typical years were systematically analyzed. The results showed that: (1) The correlation coefficients between SDFAI and regional precipitation concentration period in Henan Province ranged from 0.31 to 0.84, and the spatial distribution characteristics were low in north and south and high in central China, indicating significant spatial heterogeneity of abrupt transition between drought and flood; (2) During 1961~2024, the SDFAI in Henan Province showed a slight upward trend, with a slight increase in the risk of waterlogging, and the intensity of abrupt transition from drought to flood showed a significant interdecadal variation, with the SDFAI reaching a historical peak in 2024 (8.49); (3) Analysis of typical years shows that years with significant drought to flood (such as 2024, 1995, 1982) have significantly less precipitation in the pre-flood season and significantly more precipitation in the post-flood season, while years with significant flood to drought (such as 2015, 2002, 1991) have the opposite characteristics. The precipitation in May-June 2002 was 70.18% more than that in July-August 2002, and 38.43% less than that in July-August 2002. The study reveals the extreme unevenness of seasonal precipitation distribution in Henan Province, which provides scientific basis for regional climate change adaptation and water resources management.