中国山丘区极端降雨演变的时空分异特征

Spatiotemporal differentiation characteristics of extreme precipitation evolution in China's mountainous areas

  • 摘要: 山丘区极端降雨是诱发山洪、滑坡、泥石流等灾害的主要驱动因子,厘清其演变规律对完善山区防灾减灾体系具有重要意义。基于中国山丘区(平均坡度≥2°)800个气象站点1971—2024年小时降雨观测数据,以各站点降雨序列(>1 mm)的95%分位数作为极端降雨识别阈值,采用Mann-Kendall检验和Theil-Sen斜率估计方法,系统分析了中国山丘区极端降雨量级和频次的演变规律。结果表明:①从全国尺度看,山丘区极端降雨量级和频次呈增加趋势,平均每10 a增加0.6 mm和0.3次;②就空间分布格局而言,华东和西北地区增加最为突出,东北和华中地区次之,华南和西南地区增加较小,华北地区频次变化不明显;③基于30 a滑动窗口分析揭示的不同区域极端降雨趋势发展规律,预判未来东北、华北和西北地区极端降雨量级和频次呈加速增加态势,其中西北地区增速最为突出,华东地区增加趋于放缓,华南和华中地区可能趋于稳定甚至下降,西南地区波动性增加。研究揭示了中国山丘区极端降雨演变规律的时空分异格局,可为区域极端降雨灾害风险防控提供科学依据。

     

    Abstract: Extreme precipitation in mountainous areas is the primary driver of flash floods, landslides, and debris flows. Understanding the evolutionary patterns of extreme precipitation is therefore crucial for enhancing disaster prevention and mitigation systems in these areas. Using hourly precipitation records from 800 meteorological stations located in China's mountainous regions (average slope ≥ 2°) from 1971 to 2024, this study defined extreme precipitation at each station as values above the 95th percentile of precipitation events exceeding 1 mm. The Mann-Kendall test and Theil-Sen slope estimation were then applied to systematically analyze the temporal trends in both the magnitude and frequency of extreme precipitation across China's mountainous areas. The results indicate the following: ① At the national scale, both the magnitude and frequency of extreme precipitation in mountainous areas have shown increasing trends, with average decadal increases of 0.6 mm and 0.3 events, respectively; ② In terms of spatial distribution, the most pronounced increases occurred in East China and Northwest China, followed by Northeast China and Central China, whereas South China and Southwest China exhibited relatively smaller increases, and North China showed negligible changes in frequency; ③ A 30-year sliding window analysis revealed distinct regional developmental patterns of extreme precipitation trends. Projections suggest that Northeast China, North China, and Northwest China will experience accelerated increases in both magnitude and frequency, with Northwest China showing the most pronounced growth. East China is expected to follow a decelerating upward trend, while South China and Central China may stabilize or even decline, and Southwest China will likely exhibit greater variability. Overall, this study highlights the spatiotemporal differentiation of extreme precipitation evolution in China’s mountainous areas, offering scientific evidence to support regional disaster risk prevention and control.

     

/

返回文章
返回