青藏高原冻融强度指数

随着大型工程项目在冰缘地区的建设，冻融侵蚀作为第三大岩土体侵蚀类型，日益成为限制工程发展的关键因素，引发广泛关注。冻融侵蚀主要由大气温度频繁正负交替，引起岩土体内的水分相变和不同矿物颗粒产生差异膨胀收缩所致。然而现有的温度参数（如年平均温度、正负积温等）不能充分反映冻融循环对岩石的破坏性影响，往往侧重冻结或融化期间的单一时段内的持续强度与持续时间，而忽略了融化与冻结的交互影响，无法全面反映冻土区冻融循环的复杂性。鉴于以上问题，我们设计了一个新的冻融强度指数（Freeze-thaw intensity，FTI），利用2002-2020年的MODIS地表温度数据（MOD11A2 Collection 6）计算得到正负积温（TDD和FDD），通过综合考虑正负积温来准确量化冻融强度。FTI的设计确保了当DDF和DDT两者同时都较高时，FTI值较大，表明冻融作用较强；而当其中一个值较大，另一个较小时，FTI 值接近0，表明冻融强度较弱。该指数能有效反映温度累积效应对于冻融强度的影响，体现正负积温对于冻融侵蚀的影响程度。冻融强度指数有助于深入理解冰缘环境，为环境监测和工程建设提供可靠的数据支持。

With the construction of large-scale engineering projects in periglacial regions, freeze-thaw erosion, the third most prevalent geotechnical erosion type, has increasingly become a key limiting factor for engineering development and attracted widespread attention. Freeze-thaw erosion is mainly caused by frequent alternation of positive and negative atmospheric temperatures, which triggers water phase changes within geotechnical bodies and differential expansion and contraction of various mineral particles. However, existing temperature parameters (e.g., annual mean temperature, positive and negative accumulated temperatures, etc.) cannot fully reflect the destructive effects of freeze-thaw cycles on rocks. They usually focus on the sustained intensity and duration within a single period during freezing or thawing, while ignoring the interactive effects between melting and freezing, thus failing to comprehensively reflect the complexity of freeze-thaw cycles in frozen soil regions. In view of the above issues, we developed a novel Freeze-thaw Intensity Index (FTI). Using MODIS land surface temperature data (MOD11A2 Collection 6) from 2002 to 2020, we calculated positive and negative accumulated temperatures (TDD and FDD), and accurately quantified freeze-thaw intensity by comprehensively considering these two parameters. The design of FTI ensures that when both DDF and DDT are relatively high, the FTI value will be large, indicating strong freeze-thaw effects; when one of the values is high while the other is low, the FTI value will be close to 0, indicating weak freeze-thaw intensity. This index can effectively reflect the impact of temperature cumulative effects on freeze-thaw intensity, and quantify the degree of influence of positive and negative accumulated temperatures on freeze-thaw erosion. The freeze-thaw intensity index helps to deepen the understanding of periglacial environments, and provides reliable data support for environmental monitoring and engineering construction.

搜集汇总

背景与挑战

背景概述

该数据集提供了青藏高原2000-2024年的冻融强度指数（FTI），时间分辨率为10-100年，空间分辨率为100m-1km，数据大小为9.81 MB，采用开放获取方式共享。FTI通过综合考虑正负积温来量化冻融强度，为冰缘环境研究和工程建设提供重要数据支持。