开滦范各庄矿地下水氢氧同位素和水化学研究及其实际应用

通过范各庄老矿区地下水的氢氧同位素和δ¹⁸O值与Ca²⁺的活度积关系的研究,以及Na⁺、Ca²⁺和Mg²⁺浓度与其离子势关系的研究,可以判识各层地下水及其混合作用、地下水的补给和水力联系。     

产出水识别及受污染地下水水化学和氢氧稳定同位素特征

识别地下水污染来源、认识受该类污染源污染的地下水化学特征是地下水污染防治工作的重中之重。产出水作为石油、天然气工业的废水,具有组分复杂、危害性大的特点。针对受产出水污染的地下水研究较少,受污染地下水的特征以及识别该污染源的方法尚不明确的问题,笔者以延安某地下水污染场地为研究区,利用水文地球化学和氢氧稳定同位素的方法探讨受产出水污染的地下水的水化学和同位素特征,并通过对比地下水和油层水的钠氯系数、氯镁系数、脱硫系数和碳酸盐平衡系数对产出水进行识别。研究结果表明,该区域受产出水污染的地下水表现为高TDS和贫化的氢氧稳定同位素特征;其水化学类型以Cl−Na型、Cl−Mg·Ca·Na型为主,且随着受产出水影响程度降低,地下水由Cl−Na型转化为Cl−Mg·Ca·Na型,再到HCO3·SO4−Na·Ca·Mg型;离子比例关系较正常地下水混乱,无线性规律;受产出水污染的地下水的钠氯系数、氯镁系数、脱硫系数和碳酸盐平衡系数大小均在长6油层水的范围内,表明判断油气成藏条件的相关参数可以用来识别产出水污染。该研究探讨了受产出水污染的地下水的水化学特征和氢氧稳定同位素特征,提出对比地下水和油层水的相关参数来识别产出水污染的方法,对产出水污染场地的识别、认识、调查、监测、和修复具有重要意义。     

蒲阳河流域地下水水化学及同位素特征

保定西部山前地区位于太行山及华北平原交界带,为缓解极端气候灾害对生产生活的影响,维持地下水资源的可持续开发利用,开展相关的地下水水化学及同位素特征研究。研究区地下水化学类型以HCO3—Ca·Mg、HCO3·SO4—Ca·Mg及SO4·HCO3—Ca·Mg为主,区内地下水主要来源于大气降水,流域内地表水补给地下水;地下水中化学成分为Ca2＋、Mg2＋、HCO-3、SO2-4,主要来源于岩石风化作用,同时受到人类活动的影响,地下水中硝酸盐含量明显升高;由于受到褶皱构造的控制,流域的上游及平原区均出现年龄大于60年的地下水,多数岩溶水年龄较复杂,从现代水到大于60年的水均有分布。研究成果为流域内水资源的合理开发利用提供建议,区内岩溶地下水的开发将在一定程度上缓解极端天气的影响。     

三江平原地表水与地下水氢氧同位素和水化学特征

地表水与地下水的相互作用是水循环研究中的重要组成部分,是水资源管理、规划和优化配置的基础。通过野外考察取样和室内测试分析,应用同位素和水化学方法分析了三江平原地表水与地下水的相互作用关系。结果表明:兴凯湖水氢氧同位素最富集,乌苏镇井水同位素最贫化。松花江、黑龙江和乌苏里江沿河流流向,δD都呈现贫化的趋势;δ18O在松花江和黑龙江沿河流流向有富集的趋势,而沿乌苏里江则呈现贫化趋势。在松花江和黑龙江汇合处,黑龙江江水同位素贫化,电导率低。深井的氢氧同位素比浅井贫化,电导率较小。三江平原当地大气降水线(LMWL)为δD=7.4δ18O-3.1。三江平原水化学主要是Ca·Mg-HCO3型,在人类活动较大的地方,水化学类型发生了改变。利用氢氧同位素和水化学分析表明降水是地表水和地下水的补给源,地表水与地下水水力联系较强。地表水与地下水应作为统一体进行水资源管理。     

河南嵩县北部基岩山区地下水水化学特征和环境同位素特征分析

嵩县北部基岩山区位于熊耳山脉东段南部,地下水与地表水分布不均,为研究基岩山区地下水特征和补径排关系,指导缺水山区地下水找水工作,通过现场调查、地下水采样,测定不同水体中的水化学成分及环境同位素,分析其变化特征,判明地下水的补给来源及各含水层的相互联系。水化学和环境同位素研究结果表明,大气降水是研究区地下水的主要补给来源,人工开采是其主要的排泄方式;研究区基岩地下水化学特征较复杂,松散岩类孔隙水、浅(深)层半固结层裂隙孔隙水地下水以Ca~(2+)和HCO_3~–为主,属HCO_3-Ca型水;松散岩类孔隙水、浅层半固结层裂隙孔隙水含水层之间的水力联系较为密切,基岩裂隙水通过发育的导水构造断裂与现代水连接,均具有较好的开发利用价值,而深层半固结层裂隙孔隙水参与水循环的能力较弱,开采应持慎重态度。该研究成果为缺水山区地下水的合理开采利用提供了科学依据和数据支持。     

基于氢氧同位素和水化学的废弃煤矿充水水源识别

峰峰矿区地处太行山东麓边缘,属华北地层区,矿区含水层可分为四大含水岩系,其中第四系孔隙含水层地下水和二叠系砂岩含水层地下水主要接受降水补给,石炭系薄层灰岩含水层地下水除接受沟谷河段渗漏补给外,在局部接受下伏奥陶系灰岩地下水的补给,奥陶系灰岩含水层地下水主要接受鼓山、九山及西北部灰岩裸露区降水补给。峰峰矿区有生产矿井13对,废弃矿井4对,本次研究对象为废弃的一矿和二矿。本文运用水化学成分和氢氧稳定同位素作为水循环过程的示踪剂,研究了峰峰矿区不同含水层地下水的水文地球化学特征,并在此基础上识别了废弃矿井主要充水来源。通过现场调查,系统采集了该区废弃矿井水、奥灰水、薄层灰岩水、砂岩水和松散岩类孔隙水水样,并采用离子色谱法、滴定法和高分辨率激光光谱法在实验室完成了水化学成分（K+、Na+、Ca2+、Mg2+、Cl-、SO42-、HCO3-和Sr2+）和氢氧稳定同位素组分（D和 18O）测定。水化学分析结果显示,废弃矿井水、奥灰水的水化学类型主要为HCO3-SO4-Ca-Mg,属于低矿化度水;不同水体Sr2+含量存在一定的差异,废弃矿井水和奥灰水Sr2+平均值分别为0.67mg/L 和0.69mg/L,且二者Sr2+/Ca2+和Sr2+/Mg2+比值比较接近,可能说明二者存在密切的水力联系;不同水体水化学成分主要受到溶滤作用的影响。氢氧稳定同位素研究表明,砂岩水和孔隙水δD和 δ18O相对富集,废弃矿井水和奥灰水δD和 δ18O值比较接近。结合矿区奥灰含水层富水性强并与煤系地层存在密切水力联系的水文地质条件,说明奥灰水为废弃矿井水的主要充水水源。     

南伊沟水体水化学及氢氧同位素特征分析

南伊沟是林芝地区重要水源涵养区,研究南伊沟水体水化学和氢氧同位素特征,揭示"三水转化"规律,对提高林芝地区水体水文地球化学研究程度,支撑当地林水关系研究,服务高原地区水生态保护具有重要意义。运用水化学和氢氧同位素分析方法,分析了地区水化学特征、水岩作用情况和水循环特征。结果表明: 南伊沟水体为极低矿化度淡水,地表水水化学类型为HCO3-Ca・Mg型和SO4・HCO3-Ca・Mg型,地下水水化学类型为HCO3-Ca・Na型; 地表水和地下水的水化学离子成分主要受岩石风化控制,离子来源主要受碳酸盐岩溶解和硅酸盐岩风化影响,地表水中Na+、K+、Cl-主要来源于盐岩溶解,同时还受降雨影响,地表水和地下水中Ca2+、Mg2+主要来源于碳酸盐岩矿物溶解; 地下水和地表水水岩作用较弱,对比上游雅鲁藏布江和拉萨河地表水,大部分δ18O、δD值具有明显的高度效应和大陆效应; 南伊沟枯水年内强烈的不平衡蒸发作用是导致地区大气降雨线斜率和截距偏小的主要原因之一。     

基于水化学和氢氧同位素的峡口隧道涌水来源识别

峡口隧道是一条位于岩溶山区的深埋特长型隧道,遭遇了历时近两年来源不明的复杂涌水过程。为查明隧道的涌水来源和充水途径,通过解读隧道区的水文地质条件,分析对比不同涌水点的水化学及氢氧同位素组成差异,查明了隧道右洞北侧涌水主要来源于二叠—三叠系岩溶含水层,其他均来自于侏罗系裂隙含水层,二叠系灰岩与泥盆系石英砂岩接触部位发育的岩溶裂隙带为主要的充水途径。     

格尔木河流域平原区地下水同位素及水化学特征

通过对格尔木河流域天然水中H、O同位素的系统分析,根据地球水化学组分循环演化规律所对应流域不同类型水体的同位素组成的研究,结果表明流域地下水化学组分随流程增加溶滤作用增强,地下水中HCO3-逐渐减少,Cl-则增加。运用δD、δ18O和3H值建立了流域大气降水线方程,确定了山区河水非当年降水补给,河水以地下水补给为主、其次是冰雪融水和大气降水补给。山区降水δD、δ18O均值低于平原区,表明平原区降水受蒸发作用影响水中富重同位素。平原区地下水中的δD、δ18O值与河水基本一致,说明平原区地下水主要受河水出山后入渗补给。承压自流水δD和δ18O值与潜水基本一致,根据地下水的3H值确定早于潜水年龄,且随埋深增加δD、δ18O值减少的趋势,其年龄亦由新变老。     

八岭山古墓群保护区地下水水化学特征及其对古墓的影响

湖北荆州八岭山地下埋藏有特大型、大型及中型古墓560余座,具有极大的历史文化价值,然而长期以来对影响古墓保存条件的地下水水文地球化学特征缺乏深入认识,因此,开展该保护区地下水水位动态监测与分析十分必要。基于水文地质调查、地下水水化学、同位素分析和地球化学模拟,识别了八岭山古墓群保护区地下水水文地球化学特征,揭示了地下环境中主要的水文地球化学过程。结果表明：研究区地下水主要来源于大气降雨,雨水经包气带入渗向下依次补给潜水、潜水-承压水、承压水,潜水-承压水经历了一定程度的蒸发过程;地下水pH值范围为6.50～8.06,总体上为微酸性到弱碱性的水环境条件;水化学类型以Ca-HCO₃型为主,溶解性总固体(total dissolved solids, TDS)含量范围为149.30～608.56 mg/L,离子组分主要来源于水-岩相互作用;硅酸盐岩的风化溶解以及方解石、白云石的溶解-沉淀平衡和离子交换是八岭山古墓群保护区地下水水化学的主要控制过程;垂向渗滤是八岭山古墓群保护区地下水运移和影响古墓葬埋藏条件的一个重要形式,强烈的水-岩相互作用形成的水环境条件可能对古墓葬埋...     

诺木洪冲洪积扇地下水氢氧同位素特征及更新能力研究

诺木洪地区是柴达木盆地中发育较为典型的冲洪积扇,研究其地下水同位素特征及更新能力对于整个盆地地下水资源研究具有重要意义。分析了诺木洪地区地下水中的2H、3H、18O同位素特征,利用3H数据建立相应的数学物理模型,计算出冲洪积扇不同位置地下水的更新速率,并以此为依据定性划分了当地的地下水流动系统。山区至冲洪积扇中部地下水更新速率达5%/a~10%/a,更新能力较强。冲洪积扇前缘地下水更新速率为0.08%/a~1.4%/a,而在溢出带以下至盆地中心地下水更新速率小于0.07%/a,更新能力极弱。     

氢氧同位素在地下水流系统的重分布：从高程效应到深度效应

大气降水的氢氧同位素含量具有高程效应,降水入渗后参与地下水循环,其高程效应如何受地下水流系统的影响转化为地下水氢氧同位素的深度效应？现有研究对于这个问题缺少定量认识。文章构建单向倾斜盆地和双峰波状盆地的稳态地下水循环理论模型,采用MODFLOW模拟剖面二维地下水流场、采用MT3DMS模拟重同位素分子的对流-弥散过程,得到地下水D和¹⁸O含量的空间分布,探讨了氢氧同位素高程效应在地下水流系统转化为深度效应的机理。结果表明：在单斜盆地,补给区大气降水D和¹⁸O含量的高程效应转化为排泄区地下水δD和δ¹⁸O值随埋深增大而指数型衰减的深度效应;在双峰波状盆地,当含水层渗透性相对入渗强度较大时(K₀/w=1 000),仅发育一个区域地下水流系统,在区域地下水的排泄区δD和δ¹⁸O随埋深增大呈现S形曲线分布;当含水层渗透性相对入渗强度较小时(K0/w=250),双峰波状盆地发育多个局部地下水流系统,区域地下水的排泄区δD和δ¹⁸O随埋深增大呈现S形曲线,而局部地下水排...     

Fractionation of oxygen and hydrogen isotopes in evaporating water

Variations in oxygen and hydrogen isotope ratios of water and ice are powerful tools in hydrology and ice core studies. These variations are controlled by both equilibrium and kinetic isotope effects during evaporation and precipitation, and for quantitative interpretation it is necessary to understand how these processes affect the isotopic composition of water and ice. Whereas the equilibrium isotope effects are reasonably well understood, there is controversy on the magnitude of the kinetic isotope effects of both oxygen and hydrogen and the ratio between them. In order to resolve this disagreement, we performed evaporation experiments into air, argon and helium over the temperature range from 10 to 70 °C. From these measurements we derived the isotope effects for vapor diffusion in gas phase (ε_{diff(HD¹⁶O)} for D/H and ε_{diff(H2¹⁸O)} for ¹⁸O/¹⁶O). For air, the ratio ε_{diff(HD¹⁶O)}/ε_{diff(H2¹⁸O)} at 20 °C is 0.84, in very good agreement with Merlivat (1978) (0.88), but in considerable inconsistency with Cappa et al. (2003) (0.52). Our results support Merlivat’s conclusion that measured ε_{diff(HD¹⁶O)}/ε_{diff(H2¹⁸O)} ratios are significantly different than ratios calculated from simplified kinetic theory of gas diffusion. On the other hand, our experiments with helium and argon suggest that this discrepancy is not due to isotope effects of molecular collision diameters. We also found, for the first time, that the ε_{diff(HD¹⁶O)}/ε_{diff(H2¹⁸O)} ratio tends to increase with cooling. This new finding may have important implications to interpretations of deuterium excess (d-excess = δD − 8δ¹⁸O) in ice core records, because as we show, the effect of temperature on d-excess is of similar magnitude to glacial interglacial variations in the cores.     

Research on hydrogen and oxygen isotopes of paleoclimate reconstruction in Nuomuhong

As a typical alluvial-proluvial fan area in the Qaidam Basin, Nuomuhong is important to the research on paleoclimate reconstruction in proluvial fan areas and basin climate change and ecological protection. This paper analyzes features of ~2H, ~3H, ~(18) O and ~(14) C isotopes in Nuomuhong and reconstructs paleoclimate in this area. According to the results: since 28 ka B.P., the ground average temperature decreases and then increases in the Qaidam watershed, reaching the lowest in 17.7 ka B.P. before increasing gradually. In the past 30 000 years, average temperature has changed ranged from 1 ℃ to 5 ℃ in this area; the lowest temperature was different from today's temperature only by 3 ℃. This shows that climate conditions and natural environment in this area have been relatively stable in the past 30 000 years.     

A study on groundwater recharge in the Anyanghe River alluvial fan,North China Plain,based on hydrochemistry,stable isotopes and tritium

Studies on groundwater recharge are essential for sustainable exploitation of groundwater resources, especially in areas of extensive groundwater exploitation such as the Anyanghe River alluvial fan (ARAF) in the North China Plain (NCP). However, the recharge sources and processes and the contribution of each recharge flow component remain unclear. This study used hydrochemistry, stable isotopes, and tritium to investigate sources and underlying processes of groundwater recharge, along with the steady flow Mixing Cell Model (MCMsf) to quantify the proportion of each source flow for the shallow confined groundwater system in the medial fan. The results showed that groundwater mainly originates from precipitation occurring on the eastern Taihang Mountain area with average elevation estimated at 700–1,000 m above sea level during the East Asia summer monsoon period since 1952. Recharge mechanisms are: (1) river water seepage for the unconfined aquifers of the proximal and medial fan; (2) lateral flow for the confined aquifers of the medial and distal fan; and (3) precipitation infiltration for the phreatic water system. The MCMsf simulation showed that the shallow confined groundwater system in the central zone of the medial fan mainly recharged by the lateral flow from the proximal fan, a constant and considerable recharge flow from the southwestern and southern hills, and river water seepage in the medial fan; the lateral recharge flow from the Zhanghe alluvial aquifer was insignificant by comparison. The results of this study can act as a valuable reference for sustainable groundwater management in the ARAF.

     

Using hydrochemistry and environmental isotopes in the assessment of groundwater quality in the Euphrates alluvial aquifer,Syria

Hydrochemical and environmental isotope methods were used to characterize the groundwater quality in ten wells belonging to the Euphrates alluvial aquifer in Syria, with the aim to assess the origin and dynamic of groundwater salinization in this system. The Euphrates River (ER) water along its entire course in Syria is rather fresh (TDS < 0.5 g/L), and thus, it is suitable for drinking and irrigation purposes. Groundwater salinity progressively increases from north to south, changing from almost freshwater (TDS < 0.6 g/L), with a Ca–Mg and HCO₃ type near the Syrian–Turkish border to brackish water (1 < TDS < 3 g/L), with a Ca–Mg or Na–Ca–Mg and SO₄–HCO₃ type in the vicinity of Al-Raqqa, and hence it can safely be used for irrigation. Downstream Deir-Ezzor the groundwater quality becomes fairly saline to very saline (3 < TDS < 29 g/L), with a Na–Cl type, and therefore it has an absolute hazard (SAR > 5) for irrigation uses. This pattern of chemical evolution, which is also clearly reflected in the variations of groundwater ionic ratios, completely agrees with the thermodynamic simulation results obtained by an experimental evaporation essay of a water sample taken from the ER near Deir-Ezzor. Stable isotopes permit the distinction between three main evaporation processes: under high, intermediate and low humidity conditions. Radioisotopes (³H and ¹⁴C) indicate the recent age and renewability of groundwater in this aquifer and confirm that its origin is entirely belonged to the ER water, either by direct bilateral interconnection or by vertical infiltration of the irrigation water totally taken from the ER. Relationships between major ions and δ¹⁸O values of the groundwater allow to differentiate between two main enrichment processes: either evaporation only or evaporation plus dissolution, that can explain altogether the development of groundwater salinity in such a dry area.     

涞源北盆地地下水氢氧同位素特征及北海泉形成模式

拒马源泉群作为拒马河的源头,受到了较多专家和学者的关注。但这些研究多集中在地下水的水化学、水位动态、泉流量等特征上,对地下水氢氧同位素特征的分析几乎没有,且对北海泉的成因解释多为粗略的定性概述。为了说明涞源北盆地地下水的氢氧同位素特征,详细揭示北海泉的形成模式,首次系统地采集了不同含水岩组的地下水样品,测定了水样的氢氧同位素组分。结果表明:样品点δD和δ18O值均落在区域大气降水线上或附近,大气降水是研究区地下水的主要补给来源;白云岩、灰岩含水岩组高程效应较明显,径流途径长,松散含水层径流途径短,受蒸发作用较强;白云岩、灰岩含水岩组和松散含水层氘盈余d值分别为6.0‰～11.6‰、4.2‰～11.2‰、3.8‰～8.0‰,较大气降水大部分偏小,表明岩溶水和松散孔隙水经历了不同的流动过程;白云岩、灰岩含水岩组从补给区向排泄区各自流动过程中,在小西庄、香炉屯村附近断裂带发生沟通混合,然后在向盆地中心径流过程中受断层阻水上升,上升过程中又接受了松散孔隙水的补给,最后在松散岩层中出露成泉,形成北海泉。在孔隙水混入前,两者的平均补给比例大约为48.4%～57.6%和42.4%～51.6%。     

Characterizing groundwater recharge using oxygen and hydrogen isotopes: a case study in a temperate forested region,South Korea

In the cool temperate region of South Korea, oxygen and hydrogen isotopes of groundwater, lake water, and precipitation were studied to determine the season of groundwater recharge. All the groundwater samples, irrespective of season, on δ¹⁸O–δ²H scale plotted along the summer precipitation, suggesting summer precipitation largely modulates recharge. The deuterium excess values of groundwater (d-excess) show clear seasonal difference, higher in winter (> 18‰) and lower in summer (< 10‰). And its resemblance to the summer precipitation d-excess value further suggests dominant role of summer precipitation in groundwater recharge. Based on the mass balance equation, with end-member d-excess values of seasonal precipitation and groundwater as input variables, groundwater is composed of 66% summer and 34% winter precipitation. Despite the study area being heavily forested, summer rainfall contribution higher than winter suggests that evapotranspiration effect is minimal in the region; may be due to thin sand–gravel-based porous soil overlying highly weathered granitic rock system.