气候变化领域集成服务门户(CCPortal): Small-catchment perspective on chemical weathering and its controlling factors in the Nam Co basin, central Tibetan Plateau

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DOI	10.1016/j.jhydrol.2021.126315
	Small-catchment perspective on chemical weathering and its controlling factors in the Nam Co basin, central Tibetan Plateau
	Yu, Zhengliang; Wu, Guangjian; Li, Fei; Huang, Ju; Xiao, Xiong; Liu, Keshao
通讯作者	Wu, GJ (通讯作者)
发表日期	2021
ISSN	0022-1694
EISSN	1879-2707
卷号	598
英文摘要	Very little data is available on chemical weathering and its controlling factors in small catchments of the central Tibetan Plateau (TP) despite being the main part of the plateau. Hydrochemistry of river water in 24 small catchments in the Nam Co basin draining different strata and recharge forms was investigated monthly during the 2018 monsoon season. The results show that carbonate dissolution is the most important geochemical process controlling the evolution of hydrochemistry of most river water in the Nam Co basin (the average contribution to riverine solutes reaches 46%) even though its contribution shows significant spatial distribution: low values occur in some granite regions (e.g. 27% in H10) but is high in catchments where carbonate rocks are prevalent (e.g. 68% in H23). The contribution of silicate weathering is low, with an average of 11% in catchments located on the east and south banks draining sandstone/mudstone, while this value increases to 32% in catchments on the south bank which pass through granite, and on the west bank. The contribution of sulfide oxidation in most rivers on the south bank is unexpectedly high (40%) but is much lower in other rivers (13%). This spatial difference is attributed to the influence of topography, particularly slope. The carbonate weathering rate (CWR) in small catchments of the Nam Co basin shows spatial heterogeneity and is significantly and positively correlated with the lithologic coefficient which proposed to indicate the degree of rock weatherability and negatively correlated with mean slope and mean altitude. The spatial distribution of the silicate weathering rate (SWR) is not as significant as the CWR and is mainly governed by runoff depth. Chemical weathering rates in the glacierised catchments are 1.3 times higher than those in the non-glacierised regions which share similar lithology. Thus, glaciation enhances chemical weathering in the study area. The area-weighted average value of CWR and SWR in the study area is 23.2 t/km(2)/y and 5.2 t/km(2)/y, respectively. Chemical weathering rates in the Nam Co basin, central TP are relatively low when compared with those in catchments located on the edge of the TP, indicating the carbon sequestration effect caused by this supergene geological process in this area may be insignificant.
关键词	MAJOR ION CHEMISTRY RIVER SYSTEM ATMOSPHERIC CO2 HIGH HIMALAYAS YELLOW-RIVER CONSUMPTION CARBONATE RATES GLACIER EROSION
英文关键词	Small catchments; Nam Co basin; Central Tibetan Plateau; Chemical weathering; Controlling factors
语种	英语
WOS研究方向	Engineering ; Geology ; Water Resources
WOS类目	Engineering, Civil ; Geosciences, Multidisciplinary ; Water Resources
WOS记录号	WOS:000661813200116
来源期刊	JOURNAL OF HYDROLOGY
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/260185
推荐引用方式 GB/T 7714	Yu, Zhengliang,Wu, Guangjian,Li, Fei,et al. Small-catchment perspective on chemical weathering and its controlling factors in the Nam Co basin, central Tibetan Plateau[J]. 中国科学院青藏高原研究所,2021,598.
APA	Yu, Zhengliang,Wu, Guangjian,Li, Fei,Huang, Ju,Xiao, Xiong,&Liu, Keshao.(2021).Small-catchment perspective on chemical weathering and its controlling factors in the Nam Co basin, central Tibetan Plateau.JOURNAL OF HYDROLOGY,598.
MLA	Yu, Zhengliang,et al."Small-catchment perspective on chemical weathering and its controlling factors in the Nam Co basin, central Tibetan Plateau".JOURNAL OF HYDROLOGY 598(2021).