Seasonal Variations of Chemical Weathering and CO2 Consumption Processes in the Headwater (Datong River Basin) of the Yellow River Draining the Tibetan Plateau

The Yellow River basin covers contrasting tectonics, climate, and vegetation settings. To explore the seasonal chemical weathering differences from upstream to downstream of basin, we collected weekly river waters Datong draining Tibetan Plateau in 2017. Our results show remarkably variations major ions. A forward model was employed quantify contribution silicate, carbonate, sulfide oxidation/evaporite atmospheric input cations, which yielded contributions 9.21 ± 1.57%, 46.07 1.4%, 21.46 1.03%, 23.26 1.72%, respectively, indicating a dominated carbonate chemistry. significant correlation between rate runoff suggests critical control on catchment. comprehensive comparison upper middle-lower reaches shows declined silicate CO 2 consumption (ØCO 2sil ) downstream. In contrast, physical erosion an increased trend, with most prominent increase midstream Loess Plateau. further 4.5 times higher ØCO but 9.5 lower rate. conclusion, propose that runoff, rather than erosion, plays central role provides insight for in-depth understanding surficial global carbon cycle.