The spatiotemporal variations in freeze-thaw erosion in 2003-2020 on the Qinghai-Tibet Plateau

PDF HTML阅读 XML下载 导出引用 引用提醒 2003-2020年青藏高原冻融侵蚀时空变化特征 DOI: 10.5846/stxb202201220211 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 第二次青藏高原综合考察研究项目（2019QZKK0608） The spatiotemporal variations in freeze-thaw erosion 2003-2020 on the Qinghai-Tibet Plateau 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:全球气候变暖导致青藏高原永久冻土逐渐退化，并增加了季节性冻土的面积，但对冻融侵蚀时空变化还缺乏系统的认识。通过权重法对年冻融日循环天数、日冻融相变水量、植被覆盖度、年均降雨量、坡度和坡向6个冻融侵蚀因子进行赋权，分析青藏高原2003-2020年不同强度的冻融侵蚀时空变化和主导驱动因素。结果表明：（1）2003-2020年青藏高原平均冻融侵蚀面积为（161.37±0.42）×104 km2，占青藏高原面积的64.55%，中度及以上侵蚀占冻融侵蚀面积的63.0%，强烈、极强烈和剧烈侵蚀主要分布在雅鲁藏布江流域、昆仑山-祁连山、帕米尔高原地区；（2）2003-2020年青藏高原冻融侵蚀表现为加剧趋势，加剧的区域达到29.79×104 km2，占青藏高原面积的11.6%；2003-2010年中度及以上平均侵蚀面积为（95.71±3.33）×104 km2，2013-2020年为（107.60±3.20）×104 km2，其面积增加了11.89×104 km2，增强的区域主要分布在可可西里山、冈底斯山、藏北高原及三江源地区。（3）日均冻融相变水量变化对侵蚀强度变化的平均贡献率最大，为49.59%，贡献高值区主要位于藏北高原的多年冻土区；年冻融日循环时间变化对侵蚀强度的平均贡献次之，为40.55%。在冻融侵蚀减弱的区域，植被盖度的平均贡献达37.69%。植被覆盖上升减轻了冻融侵蚀，气候变暖加速了冻融侵蚀，但是植被对冻融侵蚀的减轻作用不足以抵消气候变暖背景下相变水量对冻融侵蚀的增强作用。另外，在侵蚀等级增强的区域，最低温的增幅大于最高温的增幅。研究提升了气候、植被变化背景下对青藏高原冻融侵蚀强度时空变化及其驱动机制的认识，为青藏高原冻融侵蚀治理提供了理论依据。 Abstract:On Plateau, global warming has led to gradual melting of permafrost and increased area seasonal permafrost. However, there is still a lack systematic understanding changes erosion. Using weight method, where 6 evaluating factors (annual cycle days, average daily phase change water, vegetation cover, annual precipitation, slope, aspect) were selected, our study determined their driving during Plateau. results showed that:(1) From 2003 2020, Qinghai Tibet was (161.37±0.42)×104 km2, accounting for 64.55% total Moderate above accounted 63.0% Intense, extremely intense, severe mainly distributed Yarlung-Zangbo River basin, Kunlun-Qilian Mountains, Pamirs Plateau; (2) been strengthened, with strengthened 29.79×104 11.6% moderate (95.71±3.33)×104 km2 2003-2010 (107.60±3.20)×104 2013-2020, an increasing 11.89×104 km2. Hoh Xil Mountain, Gangdis Northern Tibetan Sanjiangyuan region. (3) contribution rate everage water variation intensity largest, value 49.59%, high located region northern plateau. daysvariation played less important role than mean affecting intensity, 40.55%. In weakened, coverage 37.69%. increase cover alleviated erosion, while climate accelerated negative effect cannot offset positive context warming. addition, level lowest temperature greater that highest temperature. This improved spatial temporal mechanisms changes, which may provide theoretical basis control