气候变化下的黄河源区化学风化

Chemical weathering to climatic variations in the Yellow River source region

高海拔流域是全球气候变暖背景下地球系统演变的重要前哨。该研究基于青藏高原黄河源区唐乃亥水文站2002—2019年间的径流量序列与水化学数据重建了该时期的化学风化过程,探讨了气候变化下青藏高原黄河源区化学风化特征。2002—2019年,黄河源区温度明显上升,降水量和径流量出现增长;年度化学风化速率在30.9~78 t·km^(-2)之间,平均值为53.2 t·km^(-2),是全球平均化学风化速率的2倍以上。黄河源区年度化学风化速率随流域温度的上升呈现增加的趋势,平均每年增加1.13 t·km^(-2)。在全球气候变暖背景下,青藏高原高海拔流域在陆地与海洋之间的物质交换和平衡大气CO_(2)浓度中均发挥着重要作用。

High-elevation catchments are critical indicators of the earth's response to global warming.This study collected water chemistry data for runoff in the Yellow River source region from 2002 to 2019 to reconstruct the chemical weathering processes.From 2002 to 2019,the temperature in this region increased significantly along with the precipitation and runoff.The annual chemical weathering rates in this region ranged from 30.9 to 78 t·km^(-2),with an average of 53.2 t·km^(-2),which is more than twice the average chemical weathering rate of all global rivers.The annual chemical weathering processes in this region increased with increasing temperature at a rate of 1.13 t·km^(-2)/a.In the context of global warming,the Tibetan high-elevation catchments play important roles in the material exchanges between the land and the oceans and contribute to the stabilization of atmospheric CO2.