近日，北京大学李东锋团队报道了泛北极地区河流沉积物浓度和通量的增加。相关论文发表在2026年4月13日出版的《自然—地球科学》杂志上。

北极河流输送着水、沉积物和碳，在海岸稳定性和生物地球化学循环中发挥着核心作用。尽管近几十年来注入北冰洋的淡水量有所增加，但有限的观测数据阻碍了对长期、河段尺度沉积物动力学的系统性评估。

研究组开发了一个针对泛北极区域的、基于卫星和机器学习的框架，用于重建4,331条河段长达四十年的悬沙浓度动态变化。该分析显示，在流经连续永久冻土带的河段中（2,158条中的858条），40%的河段悬沙浓度显著增加，其主要驱动因素是径流量增加、热融喀斯特扰动加剧以及野火频发。泛北极陆地到海洋的沉积物通量平均为每年315 ± 33兆吨，其中每年198 ± 35兆吨（63%）来自六大主要河流（叶尼塞河、勒拿河、鄂毕河、科雷马河、育空河和马更些河），每年117 ± 13兆吨（37%）来自先前被忽视的263条中小型沿海河流。

总的陆海沉积物通量从20世纪80年代的每年约299 ± 28兆吨增加到了2010年代的每年344 ± 29兆吨，增幅约为15%。这些结果为泛北极河流沉积物动力学提供了基线数据，并强调了中小型沿海河流对北极景观和碳循环变化虽重要但一直被低估的贡献。

附：英文原文

Title: Increasing river sediment concentration and flux across the pan-Arctic

Author: Tian, Shang, Li, Dongfeng, Zhang, Ting, McClelland, James W., Overeem, Irina, Lane, Stuart N., Spencer, Robert G. M., Wohl, Ellen, Sha, Anmeng, Zhao, Yi, Miao, Chiyuan, Ning, Munan, Yuan, Li, Ni, Jinren

Issue&Volume: 2026-04-13

Abstract: Arctic rivers transport water, sediment and carbon, playing a central role in coastal stability and biogeochemical cycling. Although freshwater discharge to the Arctic Ocean has increased in recent decades, limited observations have hindered system-wide assessment of long-term, reach-level sediment dynamics. Here we develop a pan-Arctic-specific, satellite- and machine learning-based framework to reconstruct four decades of suspended sediment concentration dynamics for 4,331 river reaches. Our analysis reveals a significant increase in suspended sediment concentration in 40% of river reaches (858 out of 2,158) draining continuous permafrost zone, primarily driven by increasing discharge, intensified thermokarst disturbances and fires. The pan-Arctic land–ocean sediment flux averages 315±33 Mt yr1, with 198±35 Mt yr1 (63%) from the six major rivers (Yenisey, Lena, Ob’, Kolyma, Yukon and Mackenzie) and 117±13 Mt yr1 (37%) from 263 previously overlooked small- and medium-sized coastal rivers. The total land–ocean sediment flux has increased by ~15%, from ~299±28 Mt yr1 in the 1980s to 344±29 Mt yr1 in the 2010s. These results provide a baseline for pan-Arctic river sediment dynamics and underscore the essential yet underappreciated contribution of small- and medium-sized coastal rivers to Arctic landscape and carbon cycle changes.

DOI: 10.1038/s41561-026-01960-z

Source: https://www.nature.com/articles/s41561-026-01960-z