纵向岭谷区气象水文干旱变化及其传播特性

Variation and propagation characteristics of meteorological and hydrological droughts in Longitudinal Range-Gorge Region

摘要

【目的】全球气候变化和人类活动深刻改变了干旱动态,特别是在生态敏感区域。分析纵向岭谷区高黎贡山南段两侧气象干旱(MD)和水文干旱(HD)的传播特征与机制,为制定有效的水资源管理和灾害预防提供科学依据。【方法】以高黎贡山南段两侧显著的水文气象分异特性,基于1981—2020年代表流域的月降水和径流数据,采用标准化降水指数(SPI)和标准化径流指数(SRI)评估MD和HD的强度与频率,利用Mann-Kendall趋势检验分析干旱指数变化趋势,通过游程理论评估MD向HD的传播滞后时间,并结合贝叶斯序数概率回归模型量化累积降水亏缺(SPIm)与HD严重度之间的关系。【结果】显示:过去40年纵向岭谷区气象干旱的强度显著增加,相较于水文干旱事件,气象干旱事件的发生频率更高(MD约为2.2~2.5次/年;HD约为1.1~1.5次/年);水文干旱则持续时间更长(2.18~3.04个月)且更严重(1.18~1.76)。MD向HD的传播相对迅速,平均滞后期在0.5~0.7个月,但恢复过程的滞后较长(1.2~2.2个月)。贝叶斯序数概率回归分析进一步揭示SPIm与HD严重度呈负相关,且在极端MD条件下,这种关系的不确定性增加。【结论】高强度HD可能会对该地区的农业和其他社会经济活动造成限制,气象干旱的快速响应与水文干旱的缓慢恢复表明该区域水资源可持续利用面临挑战。这些发现有助于深化对山地生态系统中干旱传播的理解,并为应对气候变化的水资源管理策略调整提供科学依据。

Abstract

[Objective] Global climate change and human activities have profoundly altered drought dynamics, particularly in ecologically sensitive regions. This study analyzes the propagation characteristics and mechanisms of meteorological drought(MD) and hydrological drought(HD) on both sides of the southern Gaoligong Mountains within the Longitudinal Range-Gorge Region( LRGR), aiming to provide scientific foundation for effective water resource management and disaster prevention. [Methods] Based on the significant hydrometeorological differentiation between both sides of the southern Gaoligong Mountains,and using monthly precipitation and runoff data between 1981 and 2020 from representative river basins, the intensity and frequency of MD and HD were evaluated using the standardized precipitation index(SPI) and standardized runoff index(SRI).Variation trends of drought indices were analyzed through Mann-Kendall trend tests. Run theory was employed to evaluate the propagation time lag from MD to HD, followed by a Bayesian ordinal probit regression model to quantify the relationship between cumulative precipitation deficits(SPIm) and HD severity. [Results] The result showed that over the past four decades, MD intensity in the LRGR had increased significantly. The frequency of MD events( approximately 2. 2 to 2. 5 events/year) was notably higher than that of HD events(approximately 1. 1 to 1. 5 events/year). HD events demonstrated longer duration(2. 18 to 3. 04 months) and greater severity(1. 18 to 1. 76). The propagation from MD to HD was relatively rapid, with an average time lag of 0. 5 to 0. 7 months, while the recovery process showed longer lags(1. 2 to 2. 2 months). The Bayesian analysis revealed a negative correlation between SPIm and HD severity, with increased uncertainty in this relationship under extreme MD conditions. [Conclusion] High-intensity HD may constrain agricultural and socio-economic activities in the region. The rapid response to MD and the prolonged HD recovery highlight emerging challenges for sustainable water resource utilization in this area. These findings enhance the understanding of drought propagation processes in mountainous ecosystems and provide scientific support for adapting water resource management strategies to climate change.

关键词

气候变化 / 气象干旱 / 水文干旱 / 干旱传播 / 纵向岭谷区 / 影响因素

Key words

climatic change / meteorological drought / hydrological drought / drought propagation / Longitudinal Range-Gorge Region / influencing factors

基金资助

怒江下游山地农业生态系统云南省野外科学观测研究站项目(202305AM340031)

国家自然科学基金项目(32160078)

国家重点研发计划项目(2022YFF13024)