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

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 1,2,4; Liu, Zaihua 1,3,4; Ford, Derek 5; Zhao, Min 1,4; Bao, Qian 1,4,6; Zeng, Cheng 1,4; Gong, Xiaoyu 1,4,6; Wei, Yu 1,6; Cai, Xianli 1,4,6; Chen, Jia 1,4,6
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2020-09-01
卷号	284 页码:254-272
关键词	Groundwater Precipitation Oxygen and hydrogen isotope Land cover Phase lag time Damping effect Isotopic seasonality
ISSN号	0016-7037
DOI	10.1016/j.gca.2020.06.032
通讯作者	Liu, Zaihua(liuzaihua@vip.gyig.ac.cn) ; Ford, Derek(dford@mcmaster.ca)
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.
资助项目	Strategic Priority Research Program of Chinese Academy of Sciences[XDB 40020000] ; National Natural Science Foundation of China[U1612441] ; National Natural Science Foundation of China[41921004] ; National Natural Science Foundation of China[41673136] ; Guizhou Science and Technology Supporting Plan[2020-4Y013]
WOS关键词	CAVE DRIP-WATER ; 3 KARST CATCHMENTS ; STABLE-ISOTOPE ; GUIZHOU PROVINCE ; TEST-SITE ; DELTA-O-18 ; SPELEOTHEM ; PALEOCLIMATE ; VARIABILITY ; CARBON
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000550182100015
资助机构	Strategic Priority Research Program of Chinese Academy of Sciences ; National Natural Science Foundation of China ; Guizhou Science and Technology Supporting Plan
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/158320]
专题	中国科学院地理科学与资源研究所
通讯作者	Liu, Zaihua; Ford, Derek
作者单位	1.Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Guizhou, Peoples R China 2.Guizhou Normal Univ, Sch Geog & Environm Sci, Guiyang 550025, Guizhou, Peoples R China 3.CAS Ctr Excellence Quaternary Sci & Global Change, Xian 710061, Peoples R China 4.Chinese Acad Sci, Chinese Ecosyst Res Network, Puding Karst Ecosyst Res Stn, Puding 562100, Guizhou, Peoples R China 5.McMaster Univ, Sch Geog & Earth Sci, Hamilton, ON L8S 4K1, Canada 6.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]. GEOCHIMICA ET COSMOCHIMICA ACTA,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.