近40a三穗县四季变化特征分析

Analysis of Seasonal Variation Characteristics in Sansui County over the Past 40 Years

摘要: 利用三穗国家基准气候站1986~2025年逐日平均气温资料，依据气象行业标准《气候季节划分》(GB/T 42074-2022)，系统分析了三穗县四季起始日期、季节长度及季节平均气温的变化特征，并采用M-K趋势检验法对各季节长度进行突变检测与趋势显著性检验。结果表明：1) 近40年三穗县春季平均长度83天，较常年偏短1天，但极端性增强；夏季平均长度约104天，较常年偏长7天，2015年后夏季长度呈显著上升突变，主要是受入秋推迟影响；秋季平均长度69天，较常年偏短2天；冬季平均长度109天，较常年偏短4天。2) M-K检验显示，仅夏季长度通过显著性检验，突变点为2015年；春季、秋季、冬季趋势不显著，但存在明显的年代际波动。3) 各季节气温均呈上升趋势，夏季增温最显著，秋季和冬季近5年屡创高温纪录，表明三穗县气候正经历以夏季为主导的全面暖化过程，且近十年变暖速率加快。研究结果可为三穗县农业布局、防灾减灾及气候适应策略提供科学参考。

Abstract: Based on the daily mean temperature data recorded at the Sansui National Reference Climatological Station from 1986 to 2025, and in accordance with the meteorological industry standard Climate Season Division (GB/T 42074-2022), this study systematically analyzes the variation characteristics of the start dates, lengths, and mean temperatures of the four seasons in Sansui County. The Mann-Kendall (M-K) trend test is employed to detect abrupt changes and test the significance of trends in seasonal lengths. The results indicate that: 1) Over the past 40 years, the mean spring length in Sansui County is 83 days, which is 1 day shorter than the climatological normal, yet with increased extremity; the mean summer length is approximately 104 days, 7 days longer than the normal, and has exhibited a significant upward abrupt change since 2015, mainly influenced by a delayed autumn onset; the mean autumn length is 69 days, 2 days shorter than the normal; and the mean winter length is 109 days, 4 days shorter than the normal. 2) The M-K test reveals that only the summer length passes the significance test, with the abrupt change point identified in 2015; the trends for spring, autumn, and winter are not statistically significant, although they show pronounced interdecadal fluctuations. 3) Seasonal mean temperatures all display upward trends, with summer warming being the most prominent; autumn and winter have repeatedly set high-temperature records in the recent five years, suggesting that Sansui County is undergoing an overall warming process dominated by summer, accompanied by an accelerated warming rate over the last decade. These findings can serve as a scientific reference for agricultural planning, disaster prevention and mitigation, and climate adaptation strategies in Sansui County.