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1.
Hydrogen and oxygen isotopes in precipitation have been widely used as effective traces to investigate hydrological processes such as evaporation and atmospheric moisture source. This study analyzed δD and δ~(18)O of precipitation in continuous event-based samples at three stations of Pailugou Catchment from November 2012 to December 2013. The δ~(18)O and δD values ranged from-32.32‰ to +3.23‰ and from-254.46‰ to +12.11‰, respectively. Results show that the δ~(18)O displayed a distinct seasonal variation, with enriched values occurring in summer and relatively depleted values in winter, respectively. There was a statistically significant positive correlation between the δ~(18)O and δD values and local surface air temperature at all the three stations. The nearest Global Network of Isotopes in Precipitation(GNIP) station(Zhangye), compared to the Meteoric Water Lines for this study, showed the obvious local evaporation effects with lower intercept and slope. Additionally, d-excess(δD- 8δ~(18)O) parameter in precipitation exhibited an anti-phase seasonal variability with the δ~(18)O. The 96-h back trajectories for each precipitation event using Hybrid Single Particle Lagrangian Integrated Trajectory(HYSPLIT) model indicated a dominant effect of westerly air masses in summer and the integrated influence of westerly and polar air masses in winter.  相似文献   

2.
戴里铅锌矿集区位于印度尼西亚苏门答腊岛西北部,是一个主要产于页岩、具有巨型规模的Sedex型铅锌矿。通过系统的流体包裹体测试及H、O、S、Pb等同位素分析,以对其成因进行约束。分析结果表明:①戴里铅锌矿流体包裹体均一温度范围为189~315℃,峰值为220~240℃;②δDV-SMOW值范围为-68.7‰~-76.4‰,平均为-72.9‰,δ18OV-SMOW值范围为+5.9‰~+19.5‰,平均为+16.6‰;③黄铁矿δ34SCDT值为正值,集中分布在+25.49‰~+26.36‰之间;④铅同位素显示较高的μ值(9.92~10.17,平均值为10.04)和ω值(38.06~40.51,平均值为39.26)。该矿床成矿流体温度为中温(220~240℃),成矿流体可能以岩浆水为主,有少量浅源水的加入,硫、铅均为单一来源,其中硫主要来自海水,铅来源于上地壳。   相似文献   

3.
To evaluate isotopic tracers at natural abundances by providing basic isotope data of the hydrological investigations and assessing the impacts of different factors on the water cycle, a total of 197 water samples were collected from the Laohugou Glacial catchment in the Shule River basin northwestern China during the 2013 ablation seasons and analyzed their H- and O-isotope composition. The results showed that the isotopic composition of precipitation in the Qilianshan Station in the Laohugou Glacial catchment was remarkable variability. Correspondingly, a higher slope of δ~(18)O-δD diagram, with an average of 8.74, is obtained based on the precipitation samples collected on the Glacier No.12, mainly attributed to the lower temperature on the glacier surface. Because of percolation and elution, the isotopic composition at the bottom of the firn is nearly steady. The δ~(18)O /altitude gradients for precipitation and melt water were -0.37‰/100 m and -0.34‰/100 m, respectively. Exposed to the air and influenced by strong ablation and evaporation, the isotopic values and the δ~(18)O vs δD diagram of the glacial surface ice show no altitudinal effect, indicating that glacier ice has the similar origins with the firn. The variation of isotopic composition in the melt water, varying from -10.7‰ to -16.9‰(δ~(18)O) and from -61.1‰ to -122.1‰(δD) indicates the recharging of snowmelt and glacial ice melt water produced at different altitudes. With a mean value of -13.3‰ for δ~(18)O and -89.7‰ for δD, the isotopic composition of the stream water is much closer to the melt water, indicating that stream water is mainly recharged by the ablation water. Our results of the stable isotopic compositions in natural water in the Laohugou Glacial catchment indicate the fractionations and the smoothing fluctuations of the stable isotopes during evaporation, infiltration and mixture.  相似文献   

4.
Stable isotope values of oxygen(~(18)O) and hydrogen(~(2)H) of surface waters were used to study the origin and environmental significances in the Issyk-Kul basin of Kyrgyzstan in Central Asia, which is the most important intermountain basin in the modern Tien Shan orogen. This study is the first analysis of hydrochemical spatial differentiation in the stable isotopes of surface waters in this watershed.75 samples were collected from rivers, springs, lakes,rain and snow during the rainy season in July and August of 2016. Stable isotopes of ~(18)O and ~(2)H were studied for all samples, and cation ratios(Sr/Ca and Mg/Ca) were also determined for lake water samples.Stable isotope values from precipitation scattered around the Local Meteoric Water Line(determined from Urumqi Station of the global network of isotopes in precipitation(GNIP)), together with values of the Deuterium excess parameter(d) from 15.3‰ to30.5‰, with an average of 19.8‰, indicating that the moisture sources are primarily from regions with low relative humidity. The δ~(18)O and δ~(2)H values were significantly different between the river and lake samples, indicating that regional evaporation caused the isotopic enrichment of lake water. Geospatial autocorrelation, measured by Moran's I coefficient,indicated weak spatial autocorrelation within stable isotopes of oxygen and hydrogen in the surface waters of the studied area, which is primarily an effect of climate during the water chemistry evolution. The cation ratios Sr/Ca and Mg/Ca in lake water samples were not correlated with the concentration of total dissolved solids, but did show correlation with stable isotopic values, which is significant for paleoenvironmental reconstruction.  相似文献   

5.
1 Introduction18Oinmarineenvironmentplaysanimportantroleinoceanographicalstudy .Asastableisotopeofoxygen ,18OtogetherwithhydrogenatomsconstituteswatermoleculeH218OandmoveswithalargeamountofH2 Omoleculesinseawater.Sothatδ18Obecomesanidealtracerforthemovemento…  相似文献   

6.
Under the increasing pressure of water shortage and steppe degradation,information on the hydrological cycle in steppe region in Inner Mongolia,China is urgently needed.An intensive investigation of the temporal variations ofδD andδ1 8O in precipitation was conducted in 2007-2008 in the Xilin River Basin,Inner Mongolia in the northern China.TheδD andδ1 8O values for 54 precipitation samples range from+1.1‰to-34.7‰and-3.0‰to -269‰,respectively.This wide range indicates that stable isotopes in precipitation are primarily controlled by different condensation mechanisms as a function of air temperature and varying sources of vapor.The relationship between δD andδ1 8 O defined a well constrained line given by δD =7.89 δ18O+9.5,which is nearly identical to the Meteoric Water Line in the northern China.The temperature effect is clearly displayed in this area.The results of backward tra- jectory of each precipitation day show that the vapor of the precipitation in cold season(October to March)mainly originates from the west while the moisture source is more complicated in warm season(April to September).A light precipitation amount effect existes at the precipitation event scale in this area.The vapor source of precipitation with higher d-excesses are mainly from the west wind or neighboring inland area and precipitation with lower d-excesses from a monsoon source from the southeastern China.  相似文献   

7.
水文地球化学是识别地下水流系统的重要方法,然而区域尺度上多级嵌套地下水流系统的复杂性使地下水化学组成的分析和解释难度增加。以鄂尔多斯北部盆地湖泊集中区典型的胡同察汗淖地下水流系统为例,基于丰水期和枯水期3个期次不同深度地下水样品的物理化学数据,应用时空聚类与主成分分析方法,揭示地下水化学组成的空间分布特征、变化规律及其作用机制,分析水化学时空聚类结果对多级嵌套地下水流系统划分的可行性。该聚类结果将地下水样品分为3类,其中C1为以Na-HCO3型为主的深层地下水,具有偏负的氢氧同位素组成(δD < -70‰,δ18O < -9‰)和极低浓度的NO3-;C2为Ca-HCO3为主的浅层地下水,具有偏正的氢氧同位素组成(δD > -70‰,δ18O > -9‰)和高浓度的NO3-;而C3呈无优势阳离子、δD和δ18O变化范围大且显著线性相关等深、浅地下水混合特征。呈南北条带分布在苏贝淖-胡同察汗淖排泄区的C2和部分C3水化学组成有一定的季节变化。研究验证了研究区受地形和湖泊排泄控制的浅层局部和深层区域地下水流系统的空间分布,识别了苏贝淖-胡同察汗淖排泄区受浅循环和深循环共同影响的强烈作用带,证明了水化学时空聚类方法识别多级嵌套地下水流系统的可行性。   相似文献   

8.
Changes in sea surface temperature(SST), seawater oxygen isotope(δ 18 O sw), and local salinity proxy(δ 18 O sw-ss) in the past 155 ka were studied using a sediment core(MD06-3052) from the northern edge of the western Pacifi c Warm Pool(WPWP), within the fl ow path of the bifurcation of the North Equatorial Current. Our records reveal a lead-lag relationship between paired Mg/Ca-SST and δ 18 O during Termination II and the last interglacial period. Similarity in SST between our site and the Antarctic temperature proxy and in CO 2 profi le showed a close connection between the WPWP and the Antarctic. Values of δ 18 O sw exhibited very similar variations to those of mean ocean δ 18 O sw, owing to the past sea-level changes on glacial-interglacial timescale. Calculated values of δ 18 O sw-ss refl ect a more saline condition during high local summer insolation(SI) periods. Such correspondence between δ 18 O sw-ss and local SI in the WPWP may refl ect complex interaction between ENSO and monsoon, which was stimulated by changes in solar irradiance and their infl uence on the local hydrologic cycle. This then caused a striking reorganization of atmospheric circulation over the WPWP.  相似文献   

9.
Based on the isotope analysis result of water samples in the 18 sections of the Yellow River, the variation of δ18Oand δD have been analyzed. From near the source to the entrance to the sea, the Yellow River has a general trend that the ratios of the stable isotope increase progressively; The main factors affecting the isotopes in the river water are mixing of external water bodies, evaporation and others; In the river segment between Lanzhou and Baotou and in lower reaches, the extent of the evaporation effect on the isotope fractionation from the river water surface is limited but the evaporation from the irrigated river water and the return flow is one of the main factors affecting the isotopes in river water.  相似文献   

10.
Trophic interaction among various biomass groups in a swimming crab Portunus trituberculatus polyculture pond was investigated using carbon and nitrogen stable isotope analysis. The polycultured animal species also included white shrimp Litopenaeus vannamei, short-necked clam Ruditapes philippinarum, and redlip mullet Liza haematochila. The mean δ13C value for all the biomass groups in polyculture ecosystem ranged from ?25.61‰ to ?16.60‰, and the mean δ15N value ranged from 6.80‰ to 13.09‰. Significant difference in the δ13C value was found between particulate organic matter (POM) and sediment organic matter (SOM) (P < 0.05), indicating that these two organic matter pools have different material sources. Assuming that a 13C-enrichment factor of 1.00‰ and a 15N-enrichment factor of 2.70‰ existed between consumer and prey, diets of the four cultured animals were estimated using a stable isotope mixing model. The estimated model results indicated that P. trituberculatus mainly feed on Aloidis laevis; L. vannamei mainly feed on shrimp feed; while A. laevis, R. philippinarum and L. haematochelia mainly feed on POM. Shrimp feed was also an important food source of R. philippinarum and L. haematochelia. The diets of P. trituberculatus, L. vannamei, R. philippinarum, and L. haematochila showed complementary effects in this polyculture ecosystem. Our finding indicated that the polyculture of these four organisms with suitable farming density could make an effective use of most of the food sources, which can make a highly efficient polyculture ecosystem.  相似文献   

11.
As apex predators, sharks are of ecological and conservation importance in marine ecosystems. In this study, trophic positions of sharks were estimated using stable isotope ratios of carbon and nitrogen for five representative species caught by the Chinese longline fleet in the mid-east Pacific, i.e., the blue shark(Prionace glauca), the bigeye thresher shark(Alopias superciliosus), the silky shark(Carcharhinus falciformis), the scalloped hammerhead(Sphyrna lewini), and the oceanic whitetip shark(Carcharhinus longimanus). Of these species, oceanic whitetip shark has the lowest trophic level and mean δ15N value(3.9 and 14.93‰± 0.84‰), whereas bigeye thresher shark has the highest level/values(4.5 and 17.02‰± 1.21‰, respectively). The bigeye thresher shark has significantly higher δ15N value than other shark species, indicating its higher trophic position. The blue shark and oceanic whitetip shark has significantly higher δ13C values than bigeye thresher shark, silky shark and scalloped hammerhead, possibly due to different diets and/or living habitats. The stable isotope data and stomach content data are highly consistent, suggesting that stable isotope analysis supplements traditional feeding ecology study of sharks, and thus contributes to understanding their trophic linkage.  相似文献   

12.
In order to investigate the transformation among the precipitation,groundwater,and surface water in the Sanjiang Plain,Northeast China,precipitation and groundwater samples which were collected at the meteorological station of the Sanjiang Mire Wetland Experimental Station,Chinese Academy of Sciences and the surface water which collected from the Wolulan River were used to identify the transformation of three types of water.The isotope composition of different kinds of water sources were analyzed via stable isotope(deuterium and oxygen-18) investigation of natural water.The results show a clear seasonal difference in the stable isotopes in precipitation.During the cold half-year,the mean stable isotope in precipitation in the Sanjiang Plain reaches its minimum with the minimum temperature.The δ18O and δD values are high in the rainy season.In the Wolulan River,the evaporation is the highest in August and September.The volume of evaporation and the replenishment to the river is mostly same.The groundwater is recharged more by the direct infiltration of precipitation than by the river flow.The results of this study indicate that the water bodies in the Sanjiang Plain have close hydrologic relationships,and that the transformation among each water system frequently occurs.  相似文献   

13.
高氯酸盐同位素测试技术能够为环境介质中高氯酸盐污染物来源的判识、降解途径与修复效果的监测与评价提供重要的分析工具。在国内建立高氯酸盐稳定氯、氧同位素测试技术,采用真空热解方法组建同位素真空制样系统,并结合GasBenIIIRMS联用技术实现在线高精度测试。实验结果表明,真空制样系统稳定性高,最佳热解反应温度为650℃,样品量约10μmol ClO-4。δ18O、Δ17O和δ37Cl的方法分析精度分别为0.3‰,0.04‰和0.1‰,达到国际水平,为我国高氯酸盐环境污染的防治研究提供了先进的方法与手段。   相似文献   

14.
Ice and snow chemistry of alpine glaciers is crucial for the research of regional atmospheric environment change. Fresh snow samples were weekly collected from Urumqi Glacier No.1 in the Tianshan Mountains, Xin- jiang, China, and the chemical characteristics and seasonal variations of major ions, mineral dust, δ18O and trace metals were measured. Results show that the concentrations of major ions in the snow are Ca2+ SO42- NH4+ NO3- Cl- Na+ Mg2+ K+, in which Ca2+ is the dominant cation, and SO42-is the dominant anion. All major ions have close positive correlations with each other except NO3-. δ18O shows positive correlation with air temperature change during the study period. Mineral dust particle and major ionic concentrations in fresh snow have obvious seasonal change, with high concentration in spring but low concentration in summer and autumn, which indicates that the chemical mass input from Asian dust activity to snow is very significant. Temporal changes of trace metals in fresh snow, e.g., Cd, Pb, Zn, Al, Fe, have shown that human-induced pollution of central Asian region also has large contribution to the snow chemistry on alpine glaciers of the Tianshan Mountains.  相似文献   

15.
ISOTOPICEVIDENCEFORHOLOCENECLIMATICCHANGESINBOSTENLAKE,SOUTHERNXINJIANG,CHINAZhongWei(钟巍)XiongHeigang(熊黑钢)DepartmentofGeograp...  相似文献   

16.
To better understand the process of precipitation and water cycle, the composition of stable isotope in precipitation and its influences by different vapor sources in the eastern of Qilian Mountains were conducted from June 2013 to May 2014. The total of 100 precipitation samples were collected in Wushaoling national meteorological station located in the eastern of Qilian Mountains. The analysis indicates that the slope of Local Meteoric Water Line is lower than that of Global Meteoric Water Line. The average values of δ18 O and δD in precipitation are higher in summer but lower in winter. Except for negative correlation with relative humidity, the stable isotope values in precipitation are positive correlations with temperature, precipitation and water vapor pressure. Influenced by water vapor source, the values of d-excess are lower for the Westerly wind and the South Asia Monsoon onJuly and the Westerly wind and the East Asia Monsoon on August, but they are higher for the Westerly wind on other months, that they are also influenced by the weather conditions in rainfall process. The variation of stable isotope in precipitation exhibited significant temperature effect, and there is also some precipitation amount effect in spring and summer.  相似文献   

17.
识别地下水溶解性硫酸盐来源及其生物地球化学循环过程是保障饮用水安全和水生态安全的重要前提, 对于地下水资源的管理和保护具有重要的意义。在广泛查阅文献的基础上, 总结了不同地下水硫酸盐来源δ34SSO4δ18OSO4值域范围; 综述了地下水硫酸盐溯源及硫生物地球化学循环过程解析的研究进展, 指出了存在问题和发展趋势。地下水硫酸盐来源识别方法经历了水化学方法→单同位素→双同位素→多同位素和多示踪剂定性识别→定量评估的发展历程; 因特定地域来源的硫、氧同位素差异和生物地球化学转化过程等因素的影响, 地下水硫酸盐溯源尚存在较大的不确定性。建议在地下水流系统框架上结合土地利用分布, 布置采样点采集污染源和地下水样品, 测定水化学和硫酸盐的硫氧同位素值及其他辅助性示踪剂同位素值或浓度, 利用多学科、多方法充分融合研究区水文地球化学、渗流场、土地利用等信息, 解析地下水硫酸盐的来源及其贡献, 以支撑地下水资源保护和污染防治的科学实施。   相似文献   

18.
利用稳定同位素碳比率δ13C作为天然示踪物,对高位养殖池生态系统中人工饲料和天然饵料提供的能源物质对养殖凡纳滨对虾生长的贡献比率进行研究。结果表明:虾体的δ13C值受食物δ13C值的影响,由于其摄食饵料的δ13C值逐渐减小,虾体的δ13C值也逐渐降低,逐渐接近于最后人工饲料的δ13C值,试验虾体的δ13C值由养殖开始时的-19.52‰±0.09‰变为实验结束时的-21.74‰±0.17‰;对虾的食性在10d左右时发生转变,34d左右时人工饲料和浮游动物对虾体的能量贡献基本相同,养殖结束时对虾生长能量的97.29%±0.98%来源于人工饲料。  相似文献   

19.
Based on stable isotope analysis, we characterized the dietary regime of the Manila clam Ruditapes philippinarum inhabiting intertidal areas along the Liaodong Peninsula, Northern China. Samples, including particulate organic matter (POM; n =30), benthic microalgae (BMI; n =30) and R. philippinarum (n =60), were collected from six sampling sites displaying the same ecological conditions. Of the two primary food sources, POM was more depleted in δ 13C (?20.61‰ to ?22.89‰) than BMI was (?13.90‰ to ?16.66‰). With respect to 15N, BMI was more enriched (2.90‰ to 4.07‰) than POM was (4.13‰ to 5.12‰). The δ 13C values of R. philippinarum ranged from ?18.78‰ to ?19.35‰ and the δ 15N values from 7.96‰ to 8.63‰, which were intermediate between the POM and BMI values. In a two-source isotope mixing model, we estimated the relative contributions of POM and BMI to the diet of R. philippinarum to be 74.2% and 25.8%, respectively. We conclude that R. philippinarum feeds mainly on POM, and BMI is also an important supplemental food source in intertidal areas.  相似文献   

20.
云南禄劝乌东德水电站是我国第三座超千万千瓦级水电站,其建设所采用的混凝土人工骨料来源于坝址下游施期料场的中元古代落雪组灰岩。在骨料勘察和实际开采过程中,发现灰岩与白云岩在同一层位产出,其岩性变化界线切割岩层面,该类现象为工程地质研究中所罕见,引起了高度关注。以施期料场灰岩-白云岩过渡带和骨料开采残留的一处白云岩凸起岩块为重点研究对象,开展了野外地质调查、室内岩相学、微区矿物形貌和成分、碳氧同位素以及流体包裹体分析,深入探讨了研究区碳酸盐岩成岩演化和岩相转变过程与机理,提出了新的白云岩化成因模式。结果表明:①矿物形貌和空间分布特征指示与灰岩过渡的白云岩为早期灰岩经过后期白云岩化形成;②白云岩中发育的斑马纹构造、鞍状白云石及其伴生的硫化物和碳质物等,指示其经历了热液白云岩化过程。鞍状白云石中流体包裹体的均一温度(183~215℃)显著高于围岩方解石中流体包裹体均一温度(102~152℃);③白云岩普遍具有较轻的O同位素值(δ18O=-13.3‰~-7.8‰),而其中鞍状白云石的δ18O最低(-13.3‰),表明它们可能为热液流体直接沉淀的产物,而其他白云岩由于受热液流体影响程度较低而具有较低的包裹体均一温度和较高的δ18O值;④乌东德地区近直立的岩层产状和断裂可能为热液流体运移提供了通道,而其上覆的近水平震旦系灯影组厚层白云岩则起到了封堵作用,使热液流体在不整合面之下与灰岩发生长时间反应;热液流体的运移方向决定了最终的热液白云岩的分布。   相似文献   

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