干旱区生态环境知识资源中心(Arid): Conservation of oxygen and hydrogen seasonal isotopic signals in meteoric precipitation in groundwater: An experimental tank study of the effects of land cover in a summer monsoon climate

Arid

DOI	10.1016/j.gca.2020.06.032
	Conservation of oxygen and hydrogen seasonal isotopic signals in meteoric precipitation in groundwater: An experimental tank study of the effects of land cover in a summer monsoon climate
	Hu, Yundi; Liu, Zaihua; Ford, Derek; Zhao, Min; Bao, Qian; Zeng, Cheng; Gong, Xiaoyu; Wei, Yu; Cai, Xianli; Chen, Jia
通讯作者	Liu, ZH
来源期刊	GEOCHIMICA ET COSMOCHIMICA ACTA
ISSN	0016-7037
EISSN	1872-9533
出版年	2020
卷号	284 页码:254-272
英文摘要	delta O-18 and delta D values in meteoric groundwaters reflect those in their source precipitation, which normally displays seasonal ranges of several to many permil. Normally there are substantial reductions in the groundwater isotopic ranges due to mixing in any vegetation, soil cover and the aquifer itself, plus the distortions that can be introduced by evaporation. Nevertheless, in carbonate karst regions (and others) many spring waters are found to preserve significant proportions of these seasonal signals. They are of current interest because they may also be detected in calcite speleothems precipitated from groundwater in caves, in calcretes and calcareous nodules in soils, etc. thus permitting detailed paleoclimate reconstructions. This paper presents some baseline data on reduction of isotope seasonal signals in groundwater that are pertinent to such speleothem studies. They are from artificial tank experiments at Shawan Karst Test Site, Guizhou, China. The climate is humid subtropical with mean annual precipitation of 1340 mm, >80% falling between May and October. The concrete tanks measure 20 x 5 m, 3 m deep each, point-drained at one end to simulate a spring. They are filled with 2.5 m of local limestone quarry gravel, creating carbonate aquifers with primary porosities similar to 50%. A first tank is left bare, simulating the rocky desertification found in parts of the region. The other tanks are topped with 0.5 m of local, clay-rich residual soil, one left bare, the other three sown with rainy season corn, permanent grass and permanent shrubs respectively. Measurements cover the three climatic years, November 2015-November 2018. > 90% of the rainfall events were sampled, and the drains every ten days. delta O-18 and dD in the rainfall displayed strong and regular sinusoidal oscillations with the successive seasons. In the bare rock tank these were reduced (damped) by 56 similar to 74% in the different years, with phase (time) lags of 127 similar to 134 days at the drain. In the soil-topped tanks damping ranged from 61% to 93% and the time lags from 164 to 202 days: differences between them are not statistically significant but all do differ significantly from the bare rock. In all cases, the responses of the two isotopes were similar in direction and magnitude. The 0.5 m soil cover had the most important effect. The bare rock aquifer conserved the most information. Losses were similar in the four soil-topped tanks, responding to stronger evaporation and obstruction of flow in the soil. These findings are briefly compared to seasonal isotope variations reported in speleothem drip waters in limestone caves in China and elsewhere in the world. (C) 2020 Elsevier Ltd. All rights reserved.
英文关键词	Groundwater Precipitation Oxygen and hydrogen isotope Land cover Phase lag time Damping effect Isotopic seasonality
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000550182100015
WOS关键词	CAVE DRIP-WATER ; 3 KARST CATCHMENTS ; STABLE-ISOTOPE ; GUIZHOU PROVINCE ; TEST-SITE ; DELTA-O-18 ; SPELEOTHEM ; PALEOCLIMATE ; VARIABILITY ; CARBON
WOS类目	Geochemistry & Geophysics
WOS研究方向	Geochemistry & Geophysics
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/325100
作者单位	[Hu, Yundi; Liu, Zaihua; Zhao, Min; Bao, Qian; Zeng, Cheng; Gong, Xiaoyu; Wei, Yu; Cai, Xianli; Chen, Jia] Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Guizhou, Peoples R China; [Hu, Yundi] Guizhou Normal Univ, Sch Geog & Environm Sci, Guiyang 550025, Guizhou, Peoples R China; [Liu, Zaihua] CAS Ctr Excellence Quaternary Sci & Global Change, Xian 710061, Peoples R China; [Hu, Yundi; Liu, Zaihua; Zhao, Min; Bao, Qian; Zeng, Cheng; Gong, Xiaoyu; Cai, Xianli; Chen, Jia] Chinese Acad Sci, Chinese Ecosyst Res Network, Puding Karst Ecosyst Res Stn, Puding 562100, Guizhou, Peoples R China; [Ford, Derek] McMaster Univ, Sch Geog & Earth Sci, Hamilton, ON L8S 4K1, Canada; [Bao, Qian; Gong, Xiaoyu; Wei, Yu; Cai, Xianli; Chen, Jia] Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Hu, Yundi,Liu, Zaihua,Ford, Derek,et al. Conservation of oxygen and hydrogen seasonal isotopic signals in meteoric precipitation in groundwater: An experimental tank study of the effects of land cover in a summer monsoon climate[J],2020,284:254-272.
APA	Hu, Yundi.,Liu, Zaihua.,Ford, Derek.,Zhao, Min.,Bao, Qian.,...&Chen, Jia.(2020).Conservation of oxygen and hydrogen seasonal isotopic signals in meteoric precipitation in groundwater: An experimental tank study of the effects of land cover in a summer monsoon climate.GEOCHIMICA ET COSMOCHIMICA ACTA,284,254-272.
MLA	Hu, Yundi,et al."Conservation of oxygen and hydrogen seasonal isotopic signals in meteoric precipitation in groundwater: An experimental tank study of the effects of land cover in a summer monsoon climate".GEOCHIMICA ET COSMOCHIMICA ACTA 284(2020):254-272.