Intense Chemical Weathering at Glacial Meltwater-Dominated Hailuogou Basin in the Southeastern Tibetan Plateau

Water

Sha Liu¹  Xiangying Li¹  Zhongbo Yu¹  Qijiang Li²  Qiao Liu³  Yong Zhang⁴  Tianding Han⁵  Zhefan Jing⁵  Yongjian Ding⁵ 

[1] College of Hydrology and Water Resource/State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China;Hydrology and Water Resource Survey Bureau of Qinghai Province, Xining 810001, China;Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China;School of Resource Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;

关键词: meltwater;    chemical weathering;    Hailuogou Glacier;    Tibetan Plateau;   

DOI  :  10.3390/w11061209

来源: DOAJ

【 摘 要 】

Climate warming has caused rapid shrinkage of glaciers in the Tibetan Plateau (TP), but the impact of glacier retreat on the chemical denudation rate remains largely unknown at the temperate glacial basins. The chemical weathering processes were examined at a temperate glacial basin (HLG) in the southeastern TP based on comprehensive data from the supraglacial meltwater, proglacial river water, precipitation and groundwater over two glacier melt seasons in 2008 and 2013. The concentrations of major ions and suspended sediments in river water exhibit a pronounced seasonality and display a close relationship with river discharge, suggesting a strong hydrological control on the chemical and physical weathering processes. Runoff chemistry is dominated by carbonate weathering and sulfide oxidation. HCO₃⁻, Ca²⁺, and/or SO₄²⁻ are the dominant ions in meltwater, river water, precipitation and groundwater. For river water, HCO₃⁻ and Ca²⁺ primarily come from calcite weathering, and SO₄²⁻ is mainly derived from pyrite oxidation. Both solute and sediment fluxes are positively related to river discharge (r = 0.69, p < 0.01 for sediments). The solute flux and yields are 18,095−19,435 t·year⁻¹ and 225−241 t·km⁻²·year⁻¹, and the sediment load and yields are 126,390 t·year⁻¹ and 1570 t·km⁻²·year⁻¹, respectively. The solute yields, cationic denudation rate (CDR; 2850−3108 Σ*meq⁺ m⁻²·year⁻¹) and chemical weathering intensity (CWI; 616−711 Σ*meq⁺ m⁻³·year⁻¹) at HLG are higher than those at most basins irrespective of the lithology, suggesting more intense weathering in the TP in comparison to other glacial basins worldwide.

【 授权许可】

Unknown