阿勒泰地区风吹雪空间分布特征及机制分析

Spatial Distribution Characteristics and Mechanisms of Blowing Snow in the Altay Region

摘要: 阿勒泰地区风吹雪灾害具有典型性，是特定地理环境下雪源条件与风动力条件耦合作用的结果。充沛的固态降水奠定了坚实的物质基础，而复杂地形调制下的强风场则提供了持续的动力来源，二者共同控制了该灾害的时空分布与强度。此类天气现象不仅对交通运行安全带来直接危害，亦对公众生命与财产构成持续性威胁。本文基于2019~2024年冬季阿勒泰地区地面自动站的逐日气象观测数据，通过趋势分析、空间插值及相关分析等研究方法，系统研究了风吹雪事件的时空分布格局及变化特征，并初步探讨了风速与积雪深度的耦合机制。研究结果表明：阿勒泰地区风吹雪日数呈现显著的“西高东低”空间分异，西部吉木乃县、哈巴河县等地为高发区；风吹雪事件以低风险等级为主(占比>80%)，但中、高风险事件在吉木乃县表现出高度集聚性。机理分析揭示，风速与积雪深度存在非线性响应关系：在13.9~20.8 m/s风速区间形成“最优堆积窗口”，积雪深度达到峰值；当风速超过20.8 m/s临界阈值后，动力机制由堆积转为吹蚀主导，导致积雪深度显著下降。

Abstract: The predominance of blowing snow disasters in the Altay region stems from the coupling of snow supply and wind dynamics under specific geographical conditions: abundant solid precipitation provides the material foundation, while strong wind fields modulated by complex topography form the persistent dynamic source. Together, these factors govern the spatiotemporal distribution and intensity of such disasters. This weather phenomenon not only poses immediate threats to transportation safety but also endangers public lives and property with lasting consequences. Using daily meteorological data from automatic stations (2019~2024 winters), this study analyzes the spatiotemporal patterns of blowing snow via trend analysis, spatial interpolation, and correlation methods, and preliminarily explores the coupling mechanism between wind speed and snow depth. Results show a “high-west, low-east” spatial divide in blowing snow frequency, with Jeminay and Habahe counties in the western Altay region identified as high-risk zones. Most events were low-risk (>80%), though medium- and high-risk events clustered notably in Jeminay. Mechanistically, wind speed and snow depth exhibit a nonlinear relationship: an “optimal accumulation window” occurs at 13.9~20.8 m/s, maximizing snow depth. Beyond 20.8 m/s, erosion dominates, reducing accumulation.