变化环境下青藏高原河流碳循环特征及其对区域碳循环的影响  

Characteristics of riverine carbon cycle in the Qinghai-Xizang Plateau and its impact on regional carbon cycle under changing environment

作　　者：丁佳丽 王根绪 吴碧琼 李宇灏 王莹 王浩宇 宋春林[1] DING Jiali;WANG Genxu;WU Biqiong;LI Yuhao;WANG Ying;WANG Haoyu;SONG Chunlin(State Key Laboratory of Hydraulics and Mountain River Engineering,College of Water Resource and Hydropower,Sichuan University,Chengdu 610065,China;China Yangtze Power Co.,Ltd.,Yichang 443002,Hubei,China)

机构地区：[1]四川大学水利水电学院山区河流保护与治理全国重点实验室,四川成都610065 [2]中国长江电力股份有限公司,湖北宜昌443002

出　　处：《冰川冻土》2025年第2期504-521,共18页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(42471151,423B2102);中国长江电力股份有限公司研发项目“金沙江上游源区河流系统演变及产汇流机理研究”(2423020045)资助。

摘　　要：河流是陆地-海洋之间碳输送的通道和水生生态系统代谢的重要反应器,对陆海水生连续体中碳的迁移转化和流域生态系统碳收支起到重要作用。青藏高原是中低纬度地区最大的高海拔寒区,作为亚洲水塔哺育了多条大江大河,对区域碳循环有重要作用。在气候变化背景下,近年来青藏高原河流碳循环过程受到广泛关注。本研究聚焦青藏高原河流碳循环过程,系统总结近十余年黄河、长江、澜沧江、怒江、雅鲁藏布江等多条源区河流碳循环相关进展发现:(1)青藏高原河流溶解态碳以无机碳为主,溶解有机碳浓度相对较低,未来气候变化导致的冻土融化、风化增强、水文过程改变、侵蚀产沙加剧等因子将进一步增加青藏高原河流横向碳输移通量;(2)当前观测显示青藏高原河流是二氧化碳及甲烷的重要排放源,其过程也受到气候变化影响并有增加趋势;(3)青藏高原河流碳通量对于流域生态系统碳收支有重要影响,较大的河流碳横向及垂直碳通量抵消了部分陆地碳汇,是生态系统碳过程不可忽视的一环。随着青藏高原气候暖湿化,其河流碳循环过程必然发生显著改变,进而影响区域碳汇,但是其影响程度目前还不清楚。未来应进一步利用原位观测、遥感反演、机器学习等手段精准刻画河流碳过程机制,增强对于河流碳循环微观机理的深入认识,并基于相关机理发展适合于青藏高原高寒河流的碳循环模型,加强高原河流碳循环模拟和预测能力。本研究可为深入理解变化环境背景下青藏高原河流在流域碳中和中的作用提供科学依据。River is a channel for carbon transport between land and ocean and an important reactor for the metab⁃olism of aquatic ecosystems.It plays an important role in the migration and transformation of carbon in terrestri⁃al and marine aquatic continuums and the carbon budget of watershed ecosystems.The Qinghai-Xizang Plateau is the largest high-altitude cold region in the mid-latitude region.As an Asian water tower,it has developed many major rivers and plays an important role in the regional carbon cycle.In the context of climate change,the process of riverine carbon cycle in the Qinghai-Xizang Plateau has received extensive attention in recent years.This study focuses on the process of river carbon cycle in the Qinghai-Xizang Plateau,and systematically sum⁃marizes the progress of riverine carbon cycle in many source areas such as the Yellow River,the Yangtze River,the Lancang River,the Nujiang River and the Yarlung Zangbo River in the past decade.It is found that:(1)The dissolved carbon in the rivers of the Qinghai-Xizang Plateau is dominated by inorganic carbon,and the con⁃centration of dissolved organic carbon is relatively low.The factors such as thawing of frozen soil,enhanced weathering,changes in hydrological processes,and increased erosion and sediment production caused by future climate change will further increase the lateral carbon transport flux in the rivers of the Qinghai-Xizang Plateau.(2)Current observations show that rivers on the Qinghai-Xizang Plateau are important sources of carbon dioxide and methane emissions,and their processes are also affected by climate change and have an increasing trend;(3)The river carbon flux in the Qinghai-Xizang Plateau has an important impact on the carbon budget of the basin ecosystem.The large river carbon horizontal and vertical carbon fluxes offset some terrestrial carbon sinks and are an important part of the ecosystem carbon process.With the warm and humid climate of the Qinghai-Xizang Plateau,its river carbon cycle process will inevitably change signifi

关 键 词：河流碳循环 温室气体 碳收支 多年冻土 青藏高原 

分 类 号：X143[环境科学与工程—环境科学] P339[天文地球—水文科学]