青藏高原2003—2022年土壤冻融时空变化及驱动因子定量分析  

Quantitative Analysis of Spatial-Temporal Variation and Driving Factors of Soil Freeze-Thaw in the Qinghai-Tibet Plateau from 2003 to 2022

作　　者：张晓龙[1] 赵尚民[1] 李姝贞 ZHANG Xiaolong;ZHAO Shangmin;LI Shuzhen(College of Geological and Surveying Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学地球科学与测绘工程学院,太原030024

出　　处：《地球信息科学学报》2025年第3期716-731,共16页Journal of Geo-information Science

基　　金：国家自然科学基金面上项目(42271432)。

摘　　要：【目的】土壤冻融过程是青藏高原生态系统和气候变化的敏感指示因子,研究其时空变化特征对揭示该地区气候变化及其生态响应具有重要意义。【方法】本文基于2003—2022年的ERA5-LAND地表温度数据,通过Theil-Sen斜率估计法和Mann-Kendall检验法分析了土壤冻结起始时间、冻结结束时间、冻结持续时间和冻结天数在青藏高原的时空变化特征,并结合地理探测器分析冻融参数空间分异的主导因素,最后使用相关性分析法分析冻融参数与主要驱动因子的相关性。【结果】(1)青藏高原土壤冻融过程整体呈现出冻结起始时间由西北向东南推迟的趋势,冻结结束时间、冻结持续时间和冻结天数与此相反,冻结天数显著缩短区域像元面积占比为74.05%;(2)土壤冻融4种参数在不同区域随时间变化显著,多年冻土区冻结起始时间和冻结天数变化速率最快,分别推迟12.7 d和缩短20.4 d;(3)气温是青藏高原区冻结天数空间分异的主导因子,降水和NDVI也有重要作用,任意两种因子交互作用均大于单一因子作用,以气温与其他因子在不同区域的解释力最为显著;(4)在青藏高原区4种参数与气温变化显著相关,与降水和NDVI没有呈现明显相关性;不同海拔下4种参数呈现明显梯度差异,随海拔升高,冻结起始时间提前,结束时间推迟,持续时间和冻结天数延长。【结论】研究结果为进一步理解土壤冻融过程与气候变化的关系提供了数据支撑,并为青藏高原地区的生态环境变化监测及预测提供理论依据。[Objectives]The soil freeze-thaw process is a sensitive indicator of ecosystem and climate change in the Qinghai-Tibet Plateau.Studying its spatial and temporal variation characteristics is crucial for understanding the climate change and its ecological impacts in this region.[Methods]Based on ERA5-LAND surface temperature data from 2003 to 2022,the spatial and temporal variation characteristics of soil freezing start time,freezing end time,freezing duration,and freezing days in the Qinghai-Tibet Plateau were analyzed using the Theil-Sen slope estimation method and the Mann-Kendall test.The dominant factors influencing the spatial differentiation of freeze-thaw parameters were analyzed using the Geodetector method.Finally,correlation analysis was performed to explore the relationships between freeze-thaw parameters and the main driving factors.[Results](1)The soil freeze-thaw process in the Qinghai-Tibet Plateau showed a trend of delayed freezing start times from northwest to southeast.Conversely,freezing end times,durations,and freezing days were significantly shortened,affecting 74.05% of the regional pixel area.(2)The four soil freeze-thaw parameters varied significantly across different regions over time.In permafrost regions,freezing initiation was delayed by 12.7 days,while freezing days were reduced by 20.4 days,showing the fastest changes.(3)Temperature was the dominant factor influencing the spatial differentiation of freezing days in the Qinghai-Tibet Plateau,with precipitation and NDVI also playing significant roles.The interaction of any two factors had a greater explanatory power than a single factor,with temperature’s influence being particularly significant when combined with other factors.(4)Across the Plateau,the four freeze-thaw parameters were significantly correlated with temperature changes but not with precipitation or NDVI.These parameters also showed clear gradient differences with altitudes:as altitude increased,freezing start times occurred earlier,end times were delayed,and freezing d

关 键 词：土壤冻融 时空变化 多年冻土 驱动因子 青藏高原 地理探测器 气温 

分 类 号：G63[文化科学—教育学]