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1.
Zihan Zhang Liangju Zhao Ninglian Wang Hang Liu Cong Xie Xiying Dong Xingru Li 《水文研究》2024,38(1):e15067
Stable isotopic compositions of precipitation (δ18Op, δ2Hp and d-excessp) and atmospheric vapour (δ18Ov, δ2Hv and d-excessv) with high spatial–temporal resolution are crucial in revealing hydrologic cycle. Based on the variation characteristics of δ18Op/δ18Ov, δ2Hp/δ2Hv and d-excessp/d-excessv in the headwaters of the Shule River (HSR) on hourly and daily scales from June to September 2018, this study analysed the relationships between δ18Op/δ2Hp and δ18Ov/δ2Hv combined with the equilibrium fractionation model, as well as δ18Op/δ18Ov and meteorological factors. The slopes of local meteoric water line (LMWL) and the δ2Hv-δ18Ov fitting equation were similar (7.96 and 7.94) with both intercepts exceeding 10, reflecting the great contribution of recycling moisture. The values of δ18Ov/δ2Hv were lower than δ18Op/δ2Hp but with consistent variation patterns throughout the period. The equilibrium simulation results suggested that precipitation and atmospheric vapour almost approached isotopic equilibrium state, especially during monsoon intrusion period. Affected by monsoon intrusion, the slopes and intercepts of the LMWLs and the δ2Hv-δ18Ov fitting equations were smaller than those during non-monsoon period and d-excess and δ18O were negatively correlated. Relative humidity had significant negative correlations with δ18Op and δ18Ov in the whole period, however, the positive correlations between δ18Op/δ18Ov and temperature were observed during non-monsoon and monsoon intrusion period, respectively. Our results demonstrated that precipitation and atmospheric vapour isotopic compositions exhibited consistency under the influence of diverse moisture sources, while more complex relationships were found between δ18Op/δ18Ov and meteorological factors. This research provided evidence for using the isotopic compositions of atmospheric vapour to indicate moisture sources, and can improve understanding of the water cycle and eco-hydrological process from the perspective of the interaction between water and gas phases of the inland river basin in northwest China. 相似文献
2.
Modern hot spring geochemistry at the Tanlu fault and Jiaoliao block in eastern China 总被引:1,自引:0,他引:1
Zhiguan Shangguan Jikui Du Wei Zang Jihua Wang Lingchang Kong Songsheng Gao 《中国科学D辑(英文版)》1998,41(1):87-94
The δD, δ18O values of the hot springs are always more negative than those of the local cold springs. The main cause for the ocrurrence
is physically isotope fractionation during the deep circulating process of the groundwater. The relational expression between
the δD, δ18O values and the maximum circulating depths of the groundwaters is given. The gases escaped from the geothermal fluid are
mostly crust-derived gases in the studied area. The compressive structure of the Tanlu fault could extend to the deep crust,
and basically stop the ascent of deep-seated gases towards the surface.
Project supported by the National Natural Science Foundation of China (Grant No. 49373165) 相似文献
3.
Continuous real‐time analysis of the isotopic composition of precipitation during tropical rain events: Insights into tropical convection
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Shaoneng He Nathalie F. Goodkin Dominik Jackisch Maria Rosabelle Ong Dhrubajyoti Samanta 《水文研究》2018,32(11):1531-1545
To investigate stable isotopic variability of precipitation in Singapore, we continuously analysed the δ‐value of individual rain events from November 2014 to August 2017 using an online system composed of a diffusion sampler coupled to Cavity Ring‐Down Spectrometer. Over this period, the average value (δ18OAvg), the lowest value (δ18OLow), and the initial value (δ18OInit) varied significantly, ranging from ?0.45 to ?15.54‰, ?0.9 to ?17.65‰, and 0 to ?13.13‰, respectively. All 3 values share similar variability, and events with low δ18OLow and δ18OAvg values have low δ18OInit value. Individual events have limited intraevent variability in δ‐value (Δδ) with the majority having a Δδ below 4‰. Correlation of δ18OLow and δ18OAvg with δ18OInit is much higher than that with Δδ, suggesting that convective activities prior to events have more control over δ‐value than on‐site convective activities. The d‐excess of events also varies considerably in response to the seasonal variation in moisture sources. A 2‐month running mean analysis of δ18O reveals clear seasonal and interannual variability. Seasonal variability is associated with the meridional movement of the Intertropical Convergence Zone and evolution of the Asian monsoon. El Niño–Southern Oscillation is a likely driver of interannual variability. During 2015–2016, the strongest El Niño year in recorded history, the majority of events have a δ18O value higher than the weighted average δ18O of daily precipitation. δ18O shows a positive correlation with outgoing longwave radiation in the western Pacific and the Asian monsoon region, and also with Oceanic Niño Index. During El Niño, the convection centre shifts eastward to the central/eastern Pacific, weakening convective activities in Southeast Asia. Our study shows that precipitation δ‐value contains information about El Niño–Southern Oscillation and the Intertropical Convergence Zone, which has a significant implication for the interpretation of water isotope data and understanding of hydrological processes in tropical regions. 相似文献
4.
Spatial,seasonal, and source variability in the stable oxygen and hydrogen isotopic composition of tap waters throughout the USA
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To assess spatial, seasonal, and source variability in stable isotopic composition of human drinking waters throughout the entire USA, we have constructed a database of δ18O and δ2H of US tap waters. An additional purpose was to create a publicly available dataset useful for evaluating the forensic applicability of these isotopes for human tissue source geolocation. Samples were obtained at 349 sites, from diverse population centres, grouped by surface hydrologic units for regional comparisons. Samples were taken concurrently during two contrasting seasons, summer and winter. Source supply (surface, groundwater, mixed, and cistern) and system (public and private) types were noted. The isotopic composition of tap waters exhibits large spatial and regional variation within each season as well as significant at‐site differences between seasons at many locations, consistent with patterns found in environmental (river and precipitation) waters deriving from hydrologic processes influenced by geographic factors. However, anthropogenic factors, such as the population of a tap's surrounding community and local availability from diverse sources, also influence the isotopic composition of tap waters. Even within a locale as small as a single metropolitan area, tap waters with greatly differing isotopic compositions can be found, so that tap water within a region may not exhibit the spatial or temporal coherence predicted for environmental water. Such heterogeneities can be confounding factors when attempting forensic inference of source water location, and they underscore the necessity of measurements, not just predictions, with which to characterize the isotopic composition of regional tap waters. Published 2013. This article is a U.S. Government work and is in the public domain in the USA. 相似文献
5.
6.
利用薄膜扩散平衡技术分析沉积物间隙水溶解态反应性磷 总被引:5,自引:0,他引:5
沉积物间隙水溶解态反应性磷(SRP)是反映沉积物磷地球化学特征的敏感指标,对其高分辨率获取一直是难点.基于薄膜扩散平衡(DET)原理,以琼脂糖为原料制备薄膜,通过平衡、切片、提取、测定等步骤,获得溶解态反应性磷的含量信息.实验确定薄膜在磷溶液中的平衡时间为24h,通过0.25mol/L硝酸提取16h可将薄膜萃取的磷提取完全.利用DET技术对不同沉积物间隙水SRP进行了分析,与实际浓度的差异在±5%以内;对沉积物剖面的分析结果与Rhizon、微型Peeper等采样技术基本一致,垂直分辨率可达到3mm左右.利用DET技术对太湖草型和藻型湖区沉积物间隙水SRP进行丁分析,发现草型湖区间隙水剖面SRP呈峰形分布,且横向空间分异明显;藻型湖区间隙水SRP随沉积深度的增加呈升高趋势,扩散梯度随水温升高而增强. 相似文献
7.
Jeerapong Laonamsai Kimpei Ichiyanagi Kiattipong Kamdee Aksara Putthividhya Masahiro Tanoue 《水文研究》2021,35(1):e13995
Spatial and temporal variations of the isotopic composition of precipitation over Thailand were investigated. The local meteoric water line for Thailand deviates slightly from the global meteoric water line, with lower slopes (7.62 ± 0.07, 7.59 ± 0.08) and intercepts (6.42 ± 0.39, 6.22 ± 0.42) using ordinary and precipitation weighted methods. Differences in spatial and temporal δ18O distributions between the tropical monsoon and tropical savanna climate zones were found due to differing moisture source contributions and seasonal precipitation patterns. The temporal data reveals that the northeast monsoon rains originate from isotopically-enriched local moisture with isotope values of −9.36 to −0.09‰ (mean − 3.73 ± 0.42‰), whereas the southwest monsoon clouds had a more significant rainout effect from Rayleigh distillation, with isotope values of −9.56 to −1.78‰ (mean − 5.40 ± 0.38‰). The precipitation amount at each site was negatively correlated with δ18O (−0.24 to −3.20‰ per 100 mm, R2 = 0.1–0.9). Furthermore, δ18O was negatively correlated with geography (latitude, altitude) for the southwest monsoon periods, as expected based on other observed correlations. However, an inverse correlation was seen in the northeast monsoon due to differing moisture transportation as part of the continental effect. The correlation coefficient (R) was higher in the southwest monsoon (−0.84 for latitude effect, −0.64 for altitude effect) than the northeast monsoon (0.67 for latitude effect, 0.35 for altitude effect). The spatial pattern of isotopic composition reflects the southwest monsoon more clearly than the northeast monsoon, but the two monsoons also have a cancelling impact on orographic patterns. An agreement of the δ18O and deuterium excess (d-excess) was a negative correlation and found to reflect precipitation sources and re-evaporation processes. The d-excess was slightly higher for the northeast monsoon, bringing moisture from the Pacific Ocean and travelling across the continent before reaching the observed stations. By contrast, the d-excess was relatively lower for the Indian Ocean's moisture in the southwest monsoon. 相似文献
8.
电磁扰动是近年来日益被关注的地震监测手段。分析了郑州晶微公司的电磁扰动监测仪在安徽、河南、山东和四川的9个电磁波台站的数据,结果表明,地震前确实存在各种形式、不同频段的电磁波辐射,其异常信息的研究对地震预测,特别是短临预测有一定的意义。 相似文献
9.
浅水湖泊生态系统的多稳态理论及其应用 总被引:37,自引:11,他引:37
在“八五”期间太湖研究工作的基础上,发展和充实了浅水湖泊多稳态理论,简要介绍了多稳态概念模型,并将这一理论和模型贯穿于太湖富营养化防治研究中;总结了太湖各湖区的状态演化过程,提出保护东太湖生态环境和治理五里湖的策略及技术路线,并付诸于实验;证明了利多稳态理论和多稳态模型指导湖泊富营养化防治的可行性。 相似文献
10.
Characteristics of an early Holocene climate and environment from lake sediments in Ebinur region, NW China 总被引:8,自引:0,他引:8
WU Jinglu SHEN Ji WANG Sumin JIN Zhangdong & YANG Xiangdong Nanjing Institute of Geography & Limnology Chinese Academy of Sciences Nanjing China 《中国科学D辑(英文版)》2005,48(2):258-265
The characteristics of climatic environment in the early Holocene epoch were studied through analyzing environmental proxies from the sediments in the Ebinur Lake——a closed one in the arid region. The pollen assemblage and other geochemical indices showed that, the temperature was somewhat low in the period (8.0-11.5 cal kaBP) as a whole, but in the early period (11.5-10.6 cal kaBP) the temperature was higher, in company with more precipitation. In the conversion period from the early Holocene epoch to the middle Holocene epoch (8.9-8.0 cal kaBP) the climate fluctuated remarkably. Particularly the three layers of peat sediment revealed the strong instability of climate in the early Holocene epoch in the Ebinur region. All information on the development of peat and the experimental data of pollen and stable isotopes implied that, the climatic condition at 8.2, 8.6 and 10.5 cal kaBP was characterized by noticeable cold and humidness, and could be regarded as three cold and humid events in the early Holoc 相似文献
11.
采用数据挖掘技术中的聚类分析,综合考虑地震区域、震级、深度等因素,对海南及邻近地区地震数据进行聚类,通过聚类结果,分析各类特征,可发现该区域呈现较为规律的地震分布格局,在一定程度上为探讨该区域地震趋势、中长期地震预测等提供应用前景. 相似文献
12.
Observation and experimental analysis of soluble salt deposit along four profiles across the strata deposited in Nihewan paleolake
basin enabled us to recognize the nature and evolution stages of the Nihewan paleolake and its significance in stratigraphical
division and pa-leo-environmental reconstruction. The Nihewan paleolake was at least a weak-saline to semi-saline lake and
represents an intracontinental lake in the semi-arid region. The lower member of sedimentary strata in the paleolake contains
gypsum layer and gypsum lamellae. Soluble salt is mainly composed of SO
4
2-
and Ca2+ ions, representing a trend of the paleolake evolving into a stage of sulfate lake. The upper member of the strata has predominantly
Cl-, K+, and Na+ ions in soluble salt, indicating a starting development of the paleolake to chlorite lake, but no salt rock was deposited,
indicating a drying trend of the area. 相似文献
13.
湖泊表层沉积物可溶性有机氮含量及分布特性 总被引:7,自引:1,他引:7
选择鄱阳湖、洞庭湖等6个湖泊的15个表层沉积物样品,用1mol/L KCl溶液提取沉积物中的可溶性有机氮(SON),并研究了SON的含量、分布状况及特性.结果表明,所研究的沉积物SON含量变异较大,在17.18-292.31mg/kg之间波动,平均为134.45 mg/kg,占可溶性总氮(TSN)的51.86%,沉积物总氮的7.14%.污染程度重的沉积物中SON含量均较污染程度轻的高,且SON含量与TN、TSN含量呈正相关,即与沉积物氮污染程度呈正相关,分布状况则与湖泊污染程度、人类活动干扰强度等紧密相关,所研究表层湖泊沉积物巾游离氨基酸(FAA)含量处于4.69-42.04mg/kg间,平均为23.27mg/kg,占SON的18.80%,TN的1.24%,FAA与SON含量呈显著正相关,在沉积物中的平均含骨及在SON中的比例均较土壤中高,说明湖泊沉积物SON有较大的易分解组分,SON与沉积物可溶忭无机氮、有机质、CEC等显著相关,因此,SON是湖泊沉积物氮的重要组成部分,对湖泊富营养化具有重要的影响,特别是对污染严重的沉积物而言,更应重视其SON在湖泊氮循环及富营养化中的作用. 相似文献
14.
ZHANG Yuquan XIE Yingwen LI Xianhua QIU Huaning LIANG Huaying LI Jianping ZHAO Zhenhua DENG Wanming CHUNG Sunlin 《中国科学D辑(英文版)》2001,44(1)
The Cenozoic magmatic rocks of shoshonitic series in the easternQinghai-Tibet Plateau include potassic alkaline plutonic rocks, volcanic rocks, lamprophyres and acidic porphyries. Analytical results show that these different lithological rocks are extremely similar in Sr, Nd and Pb isotopic compositions with the range of 0.705 187-0.707 254 for 87Sr/86Sr, 0.512 305-0.512 630 for 143Nd/144Nd, 18.53-18.97 for 206Pb/204Pb, 15.51-15.72 for 207Pb/204Pb and 38.38-39.24 for 208Pb/204Pb. They are isotopically similar to the EMII end-member. This indicates that mantle metasomatism must have taken place in their source region. The formation of these particular rocks is related to crustal thinning and mantle upwelling in a large-scale strike-slip and pull-apart fault zone at about 40 Ma in northern and eastern Qinghai-Tibet Plateau. 相似文献
15.
广州花园酒店原结构及改造后结构均不满足我国现行规范的抗震构造要求。本文依据基于性能的抗震设计思想,提出结构宏观上的层间位移角目标和微观上的结构构件变形及损伤目标,采用PKPM系列2005年版SATWE和ETABS 9.0中文版进行结构弹性分析,采用PKPM系列EPDA和美国Buffalo大学的IDARC 2D 6.0进行弹塑性静力推覆分析和弹塑性动力时程分析,并采用TNO公司的DIANA8.0进行单榀剪力墙的极限承载力分析,研究结构是否满足设定的整体及结构构件性能目标要求,确保改造后的结构达到"小震不坏、中震可修、大震不倒"的要求。 相似文献
16.
The 982 Ma Re-Os age of copper-nickel sulfide ores in the Baotan area, Guangxi and its geological significance 总被引:1,自引:0,他引:1
Re-Os dating on copper-nickel sulfide ores from the Baotan area, Guangxi, yielded an ore-forming age of 982 ± 21 Ma (2σ),
which demonstrates that copper-nickel sulfide deposits and their related mafic-ultramafic rocks occurred in the same period
of time with the ophiolites in northeastern Jiangxi. Both of them are the products of collision-convergence between the Cathaysian
plate and Yangtze plate and the subsequent extensional environment. Calculation of the γOs of the 982 Ma copper-nickel sulfide ores and its correlation with Re/Os indicate that injection-type massive ores display
lower γOs values (-15.6 to -8.2) and lower Re/Os ratios (0.32 to 0.43), while basal liquation-type ores have γOs-27.9 to -7.3 and Re/Os=5.36 to 11.24. This suggests that these copper-nickel sulfide ores and their related mafic-ultramafic
rocks were derived from a Re-depleted mantle source and that contamination with some crustal material occurred during their
intrusion. 相似文献
17.
Variations of stable isotopic compositions in precipitation on the Tibetan Plateau and its adjacent regions 总被引:15,自引:3,他引:15
There is no temperature effect in the southern Tibetan Plateau and South Asia to the south of the Tanggula Mountains. Amount
effect has been observed at a few sampling stations accounting for about a half of the statistical stations. There is notable
temperature effect in the middle and northern Tibetan Plateau and its adjacent Central Asia to the north of the Tanggula Mountains.
Because vapor directly originates from low-latitude oceans, the relative heavy δ18O with small variation characterizes the rainfall in South Asia. A sharp depletion of the stable isotopic compositions in
precipitation takes place from Kyangjin on the southern slope of the Himalayas to the Tanggula Mountains in the middle plateau.
From the Tanggula Mountains to the northern Tibetan Plateau, the δ18O in precipitation increases with increasing latitude. 相似文献
18.
YANG Zhi ZOU CaiNeng HE Sheng LI QiYan HE ZhiLiang WU HengZhi CAO Feng MENG XianLong WANG FuRong & XIAO Qilin State Key Laboratory of EOR Research Institute of Petroleum Exploration & Development PetroChina Beijing China Key Laboratory of Tectonics Petroleum Resources of Ministry of Education China University of Geosciences Wuhan State Key Laboratory of EOR Petrochina Research Institu... 《中国科学:地球科学(英文版)》2010,(4)
Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements in the carbonate cemented zones indicate that:(1) carbonate cements are composed dominantly of ferrocalcite,ferroan dolomite,and ankerite;(2) carbonate cements are formed under a high temperature circumstance in the subsurface,and organic fluid migration has an important effect on the formatio... 相似文献
19.
Water samples from the Yamuna and its tributaries, one of the major river systems draining the Himalaya, have been analysed for their stable oxygen and hydrogen isotopes during three seasons (summer, monsoon and post‐monsoon). The data show clear seasonal and altitudinal variations; waters from higher altitudes and those collected during monsoon season are characterized by relatively depleted isotopic composition. Regression analysis of δD–δ18O data of samples collected during summer and monsoon seasons shows that the slope of the best‐fit lines are nearly identical to those of precipitation at New Delhi for the same period. The similarity in their slopes suggests that the isotopic composition of precipitation contributing water to these rivers are reasonably well preserved in both monsoon and non‐monsoon seasons, however, during the non‐monsoon period both rainfall and river waters carry signatures of evaporation. The ‘deuterium excess’ in river waters during the three seasons though overlap with each other, the values during October are higher. This can be understood in terms of recycled moisture contributions to precipitation. The ‘altitude effect’ for δ18O in these waters is determined to be 0·11‰ per 100 m, a factor of about two less than that reported for the Ganga source waters from similar altitudinal range. The variability in altitude effects in rivers draining the Himalaya seems to be controlled by the ‘amount effect’ associated with the monsoon. The significant spatial variability in altitude effect in these river basins, which are a few hundred kilometers apart, suggests that reconstruction of palaeoelevation in the Himalaya, based on δ18O‐altitude gradients, would depend critically on its proper assessment in the region. This study has established a relationship between total cation abundance and δ18O in waters of the Yamuna mainstream; total cations (corrected for cyclic components) double for a 1·4 km decrease in altitude as the Yamuna flows downstream. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
20.
Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications 总被引:15,自引:0,他引:15
Many researchers have focused on the tectonic evolution of North Qilian Mountains (NQM) since the 1970s[1―7]. However, the tectonic affinity of the an- cient oceanic mantle in early Paleozoic remains in de-bate. Three general explanations for it have been pro- posed. The first one suggests that the ancient ocean was a part of Proto-Tethys, and the tectonic evolution of NQM should be regarded as a portion of the562 Science in China: Series D Earth Sciences Tethyan tectonic domain[1]. … 相似文献