三江源地区季节冻土时空格局及影响因子

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 三江源地区季节冻土时空格局及影响因子 DOI: 10.5846/stxb202108172267 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 三江源国家公园联合专项（LHZX-2020-07）；第二次青藏高原科考项目（2019QZKK0105） Spatio-temporal pattern and influencing factors of seasonal frozen soil in the Three Rivers Source Region Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:根据三江源地区21个气象台站的最大冻土深度、气温、降水观测数据和欧洲中心再分析资料，利用旋转经验正交分解等方法对1981-1010年三江源地区季节最大冻土深度（MFSD）的时空分布特征进行了分析，并探讨了季节冻土与气候因子之间的关系，结果表明：（1）40年来三江源地区平均MFSD为136.66cm，空间分布呈现出以玛多站最大中心值（218.85cm），向四周递减的分布特征。（2）40年平均变率空间分布和旋转正交经验分解第一模态时间系数均表现出三江源地区MFSD呈现明显下降趋势，季节冻土层明显减薄，平均MFSD递减率为0.51cm/a。（3）表征热力状况的气候因子中，湿润指数、气温和降水是影响三江源地区季节冻土较为重要的气候因子。（4）三江源地区季节冻土的关键区在东北部，MFSD典型高值年有1983年等4个年份；典型低值年有1988年等7个年份。通过对500hPa位势高度场典型高值年、低值年合成分析，季节冻土典型高（低）值年，北半球500hPa位势高度场负（正）异常；同时，南亚高压负（正）异常，其范围偏小（大），强度偏弱（强），温度场中心温度更低（高），对应三江源地区应季节冻土更厚（薄）；研究结果可为三江源地区开展冻土保育、退化湿地修复、退化草地近自然恢复等生态环境保护治理技术研发和示范提供气象支撑，为揭示土壤-大气互相影响的机制，应对气候变化，建设三江源国家公园提供理论依据。 Abstract:In this paper, the observation data of maximum frozen soil depth, air temperature and precipitation of 21 meteorological stations in the Three Rivers Source Region and the reanalysis data of European Center (EC) were used. The temporal and spatial distribution characteristics of seasonal maximum permafrost depth (MFSD) in Three Rivers Source Region were analyzed by means of rotating empirical orthogonal function (REOF), and the relationship between seasonal permafrost and climatic factors was also discussed. The results showed:(1) the spatial distribution of average MFSD in the Three Rivers Source Region in recent 40 years showed that Maduo station was the maximum, decreasing in all directions, the maximum value in the center was 218.85 cm, and the average MFSD in the whole region was 136.66 cm. (2) The spatial distribution of average variability in 40 years and the first mode time coefficient of REOF showed that MFSD in the Three Rivers Source Region presented an obvious downward trend in recent 40 years, the frozen soil layer was obviously thinner, and the average MFSD decline rate in the whole region was 0.51 cm/a. (3) Among the themal climatic factors, the humidity index, air temperature and precipitation were the more important climatic factors affecting the seasonal frozen soil in the Three Rivers Source Region. (4) The key area of seasonal frozen soil in the Three Rivers Source Region was in the northeast, including 7 meteorological stations. The typical high value years of MFSD were 1983, etc. and the typical low years were 1988, etc. Through the composite analysis of 500 hPa potential height field typical high value years and typical low value years, in the typical high (low) value years of seasonal frozen soil, 500 hPa potential height field showed the negative anomaly, the range of South Asia high was smaller (larger), the strength was weaker (stronger), the temperature at the center of the temperature field is lower (higher), and the seasonal frozen soil was thicker (thinner). The research results can provide meteorological support for the research, development and demonstration of eco-environmental protection technologies such as permafrost conservation, degraded wetland restoration, degraded grassland near-natural restoration, reveal the mechanism of soil-atmosphere interaction in the Three Rivers Source Region, deal with climate change, and provide a theoretical basis for the construction of Sanjiangyuan National Park. 参考文献 相似文献 引证文献