水体稳定同位素在青藏高原大气环流研究中的应用

水体稳定同位素作为贯穿水循环的介质,是研究大气环流过程和传输路径的有效手段。介绍了水体稳定同位素技术在青藏高原大气环流研究中的应用,聚焦典型站点降水、河水和冰芯等水体稳定同位素的季节和空间变化特征,揭示了大气环流对地表水稳定同位素高程效应的显著影响,以及大气降水对地表水的主导;引入降水稳定同位素标准判断亚洲夏季风爆发时间;通过冰芯稳定同位素揭示了厄尔尼诺—南方涛动对整个青藏高原水循环的影响及其响应机制的区域差异。在未来的研究中,将加强跟地球系统模型的结合,关注水体稳定同位素在不同时间尺度的控制因子、突变过程以及激发机制,进而量化古气候替代指标中的稳定同位素变化、从较长的时间尺度上重建影响青藏高原的水汽来源的演变历史。同时关注过量氘等具有水汽来源诊断能力的参数,研究其与大尺度环流参数的相关性,从海表温度、蒸发等陆—气相互作用分析并将高原环流过程与全球环流过程紧密结合综合分析。     

北京西山鹫峰地区氢氧稳定同位素特征分析

以北京西山鹫峰低山区为研究对象,通过对降水、土壤水、泉水氢氧同位素的变化特征分析,研究低山区的降水-土壤水-泉水的转化关系。研究结果表明:该地区的雨季降水线与北京地区的地区降水线有明显区别,斜率和截距偏小;随降雨的进行氢氧同位素特征有时程变化和降雨量效应,而降雨的时程变化也对土壤水的同位素特征产生了影响;土壤水分同位素分布特征相对集中,蒸发线方程的斜率和截距相对于当地大气降水线和雨季降水线都偏小,栓皮栎混交林土壤水对于小雨量次降雨事件反应不敏感,而侧柏林的土壤水分运动较栓皮栎混交林快,说明林分类型和土壤特性对不同水体之间的转化有影响;泉水的同位素特征比较稳定,主要分布在地区降水线的右下方与雨季降水线的交点附近;不同水体中降雨的δD、δ18O变化范围较大,土壤水次之,泉水变化最小;而沿着大气降水-土壤水-地下水(泉水)这一水循环路径,水体中的δD、δ18O值总体上呈下降趋势。     

洞庭湖湖区降水-地表水-地下水同位素特征

为探明洞庭湖湖区水体稳定同位素时间和空间上的变化规律,弄清各水体间的相互关系,分别在2012年4月和8月对区域内具有代表性的采样点进行了地表水和地下水的采样。通过对样品进行D、18O同位素分析,结合全球大气降水同位素监测网（GNIP）公布的1988—1992年间长沙降水同位素数据,发现湖区年内受不同盛行风影响,降水及地表水的同位素存在较大的季节性差异,4月份同位素富集,8月份贫化。此外,河水、湖水同位素也呈现明显的空间差异。两个时期地表水的水线斜率均小于当地降水线,地表水在两个时期均存在蒸发作用。虽然地表水和地下水的来源均为大气降水,但与地表水相比,地下水同位素季节变化较小,地下水接受地表水补给是一个较为长期的过程。     

柳江盆地地表水与地下水转化关系的氢氧稳定同位素和水化学证据

地表水与地下水相互作用是水循环研究的重要组成部分,是研究区域水资源量的基础。通过实地水文地质调查和采样,在对水体氢氧稳定同位素和水化学组成测定的基础上,分析了盆地内枯水期河水和地下水的水化学和氢氧同位素组成特征及空间变化规律,旨在揭示河水与地下水的相互转化关系。研究表明:盆地内地下水主要为HCO3-Ca和HCO3-Ca·Mg类型低矿化度水,各区域地下水具有统一联系性,经历了相同或相似的水化学形成作用;河水水化学类型与地下水相同,且水化学成分来源一致。地下水和河水氢氧同位素组成相接近,最终来源主要为大气降水补给。其中河水在径流过程中受蒸发浓缩作用影响,重同位素略富集。受地形地貌、地质及水文地质条件影响,盆地内地下水与河水之间的补给—排泄相互作用关系具有明显的分段性,相互转化频繁。大石河上游区域和东宫河流域总体上表现为河水受两侧地下水补给;大石河下游区域,表现为河水补给两侧地下水。     

黑河流域不同水体中δ18O的变化

水资源短缺和合理利用是干旱半干旱区黑河流域面临的一个严峻问题,解决问题的关键是要深入了解水循环机理,而分析不同水体中环境同位素变化特征是应用同位素示踪技术研究水循环机理所必须的前提。根据测得的黑河流域降水、河水和地下水中δ18O,分析了取样期间不同水样δ18O的变化,揭示了降水中δ18O存在显著的温度效应、季节效应、高程效应以及与降水量的正相关关系;河水中δ18O的时空变化特征,即出山口地区河水中δ18O统计值低于山区和盆地,山区河水中δ18O的时间分布与大气降水一致,出山口河水中δ18O时间分布与大气降水相反,河水中δ18O沿黑河流程存在显著递增趋势;地下水中δ18O在张掖变化幅度较大,在临泽较均一且9月份普遍高于6月份,而在高台则分为显著的2组,较高的一组9月份普遍低于6月份。研究了不同因素对水循环过程中δ18O变化的影响及相互作用,为同位素技术在黑河流域水循环研究中的应用提供科学依据。     

新疆阿勒泰地区地表水体氢氧同位素组成及空间分布特征

氢氧同位素可以识别水体来源,示踪水循环,自20世纪50年代以来已被广泛应用于水文地球化学领域。已有学者开展了新疆大气降水及部分河流湖泊的稳定同位素研究,而关于阿勒泰地区大气降水之外的地表水体稳定同位素研究尚需加强。本文采用液体水激光同位素分析法开展了新疆阿勒泰地区地表河水、湖泊、山泉水、雪水、锂矿坑裂隙水五类水体的氢氧同位素组成研究。结果表明:阿勒泰地区各种类型水体氢氧同位素组成差异明显,地表河流的δ~(18)O及δD值变化范围分别为-15.4‰～-11.5‰及-114‰～-100‰,氘过量参数(d值)变化范围为-12.4‰～12.4‰;乌伦古湖湖水的δ~(18)O及δD值均远高于地表河流,平均值分别为-5.95‰及-78.5‰,氘过量参数远低于地表河流,均值为-30.9‰。地表河流与全球及乌鲁木齐大气降水线相比差异很大,河水除了大气降水外还受到冰川融水的补给,且在水循环过程中经历了蒸发分馏作用,地表河流之间的氢氧同位素组成差异主要受水体补给来源及蒸发程度强弱的控制。由于氢氧同位素温度效应、纬度效应等的存在,阿勒泰地区水体δD及δ~(18)O与水温(T)、总溶解性固体(TDS)及主要离子Na~+、K~+、Ca~(2+)、Cl~-、SO■摩尔浓度呈显著正相关关系,而与采样点纬度及溶解氧含量(DO)呈显著负相关关系(P0.05,n=32)。本研究获得的氢氧同位素组成特征为阿勒泰地区各类型水体稳定同位素研究提供了基础数据。     

乌鲁木齐河流域不同水体中的氧稳定同位素

采用乌鲁木齐河流域历年采集的降水、表层粒雪、冰川融水和河川径流等水样资料,分析了取样期间不同水样中氧稳定同位素的变化,揭示了降水中氧稳定同位素变化存在着明显的温度效应,而温度效应又与海拔高度有关;表层粒雪和冰川融水中氧稳定同位素则无明显的高度效应;冰川融水中的氧稳定同位素比率小于河川径流中的氧稳定同位素比率。评估了不同影响因子对水循环过程中稳定同位素变化的影响及相互作用,为稳定同位素技术在水循环研究中的应用提供了实例。     

渭北东部奥陶系岩溶地下水环境同位素特征分析

本文通过对渭北东部岩溶地下水环境同位素组成特征的研究,分析了大气降水、地表水、地下水三者之间的转化关系,并对研究区岩溶地下水的形成进行了初步探讨,认为大气降水是研究区岩溶地下水的补给源,地表水与地下水之间存在水力联系,地表水对地下水的补给占补给水源的74.3%.西部岩溶裸露区为岩溶水的直接补给区,其周边浅埋区为岩溶水的间接补给区,东南部的岩溶中-深埋区为岩溶水的径流排泄区.     

黄土丘陵区降水-土壤水-地下水转化实验研究

通过对黄土丘陵区燕沟流域2005~2007年雨季的多次降水、0~400 cm土层土壤水、沟道地表水、地下水(泉水、井水)水样中D和18O采样分析,研究了该区降水、土壤水、地表水、地下水的转化关系.结果认为:燕沟流域的降水线与中国、世界的降水线有明显区别,斜率和截距偏小;降水、地表水、土壤水、地下水逐渐富集δD和δ18O,且δ18O富集速度高于δD,由D和18O的蒸发分馏差异所致,可利用各类水体的δD和δ18O变化情况甄别水体之间的水量转化;土壤水δD和δ18O剖面在200 cm深度处出现低值区,应是降水补给到达该深度且土壤蒸发影响逐渐衰减共同作用的结果,其在200 cm以下逐渐升高则因为降水补给影响逐渐降低、土壤水本底同位素影响增强所致.由于380~400 cm深层土壤水的δD和δ18O对降水事件的响应存在,因此认为降水-地下水的转化存在,降水补给泉水的滞后期小于35 d.而对井水的补给滞后时间以及土壤水对地下水的补给量还需进一步研究.     

郑州市矿泉水环境同们位素特征

通过对郑州市地下水,地表水,降水等水体环境同位素的分析,着重阐述了郑州市矿泉水中同位素氘,氧－１８,氘的组成特征及其分布规律,并对同位素结果及矿泉水成因问题进行了初步解释。     

锡林河流域地表水和浅层地下水的稳定同位素研究

2006年4—9月,在从锡林河源头沿河流进行地表水和地下水同位素样品采集和分析的基础上,利用全球降水同位素监测网(GNIP)包头站的大气降水稳定同位素资料,结合锡林河流域的气象和水文资料,对锡林河流域大气降水、地表水和地下水稳定同位素进行了研究.结果表明:地下水中δ18O和δD值分别集中在-11.7‰～-14.9‰和-80‰～-89.5‰范围内,δ18O沿地下水流向有增加的趋势,大部分地下水中δ18O的季节波动性不大;河流干流δ18O和δD的年算术平均值从源区的-12.8‰和-94.5‰到入锡林河水库处的-10.0‰和-79.3‰,差值分别约为3‰和15‰.河水中的δ18O值沿流程增加而增大的现象可归结为受含有较高δ18O值的地下水补给作用和河水的蒸发作用的共同影响,其中对δ18O蒸发富集的研究显示,蒸发引起δ18O富集值为1‰.通过地下水线(GWL)和地表水线(SWL)及区域大气降水线(LMWL)的对比分析发现,在径流季节,降水对地表水的贡献小,地下水是地表水主要的补给源,地表径流基本是地下水的排泄.     

Quantifying groundwater recharge and discharge for the middle reach of Heihe River of China using isotope mass balance method

Quantifying the inflow and outflow of groundwater is essential to understand the interaction between surface water and groundwater. It is difficult to determine these elements in relation to groundwater recharge and discharge to the river, because they cannot be directly measured through site specific study. The methods of isotope mass balance combining with water budget were used to quantify the groundwater recharge from and discharge to the Heihe River, northwest China. The mean isotope ratios of monthly monitoring data for one hydrological year were selected to be the isotope rations of end members in isotope mass balance. The results from the isotope mass balance analysis, incorporating with the 35-year hydrological data, suggest that about 0.464×10~9 m~3/a of runoff flowing out Qilian Mountains is contributed to groundwater recharge(about 28% inflow of the Heihe River), while about 1.163×10~9 m~3/a of runoff is discharged from groundwater in the middle reach of the river, which accounts for about 46% of river runoff in the basin. The analysis offers a unique, broad scale studies and provides valuable insight into surface water-groundwater interaction in arid area.     

在某污染的工业废物填埋场环境水文 地质评价中的同位素水文学研究

本文论述了某污染的工业废物填埋场场址的地质、水文地质条件,应用水化学方法、环境同位素技术(地下水中氚及氢、氧稳定同位素)和同位素单孔示踪技术等同位素水文学领域中的新方法对区内地下水的活动条件以及填埋场场址区分布的第四系孔隙潜水和第三纪红层孔隙-裂隙水的成因进行了分析,测量并确定了填埋场下部地下水的流速及流向。研究结果表明场区地下水的运动与地表水无直接水力联系。污染的工业废物填埋后不会通过地下水的迁移造成对地表水的污染,进而证实填埋场的地质、水文地质条件对处置污染的工业废物是安全可靠的。     

黑河流域地下水与地表水转化研究进展

地处我国干旱内陆区的黑河流域,其地表水与地下水在不同的地貌单元发生着大数量的、有规律的、重复的转化过程,极大地提高了水资源的利用率。早在20世纪80年代,甘肃省地矿局等单位率先开展了有关黑河流域地表水与地下水转化过程研究的国家"七五"、"八五"科技攻关项目,取得了丰富的勘查研究成果,促进了这一地区有限水资源的合理开发利用。进入21世纪以来,随着勘查研究理论的丰富和环境同位素技术的广泛应用,黑河流域地表水与地下水资源及其循环转化引起了学术界的广泛关注,并相继完成并发表了一批具有较高水平和学术价值的科研成果,进一步提高了干旱区水资源的开发与保护。但仍存在着水资源转化关系和转化规律还缺乏流域系统研究、中下游盆地深层地下水的补给来源尚不能确定等方面的不足,不利于协调社会经济发展与生态环境保护之间的用水矛盾。     

联合稳定同位素与水化学方法确定地下水污染源

地下水污染是废水参与地球水循环的结果,稳定同位素在全球水循环中的应用原理同样适用于研究地下水的地表污染源.通过与水化学方法结合,确定地下水的地表污染来源,计算了污水的混入比例,为今后地下水污染的治理提供了可靠的依据.     

淮河下游地区地表水与地下水同位素特征分析

为探明淮河下游地区地表水与地下水稳定同位素的组成特征,于2020年11月对该区域进行代表性采样,共采集地表水样13个,地下水样82个.结合全球大气降水同位素监测网(GNIP)公布的南京降水同位素数据,根据最小二乘法得出当地大气降水线(LMWL)方程为:δD=8.49δ18O+17.71,其斜率和截距高于全球大气降水线(...     

Analysis of the exchange of groundwater and river water by using Radon-222 in the middle Heihe Basin of northwestern China

In arid regions of western China, water resources come from mountain watersheds and disappear in the desert plain. The exchange of surface water and groundwater takes place two or three times in a basin. It is essential to analyze the interaction of groundwater with surface water to use water resources effectively and predict the change in the water environment. The conventional method of analysis, however, measures only the flow of a stream and cannot determine groundwater seepage accurately. As the concentration of Radon-222 (²²²Rn) in groundwater is much higher than in surface water, the use of ²²²Rn was examined as an indicator for the analysis of the interaction between surface water and groundwater. Measurement of the ²²²Rn concentration in surface water was conducted to detect groundwater seepage into a stream in the middle Heihe Basin of northwestern China. Furthermore, the simultaneous groundwater flow into and out of a stream from the aquifers was quantified by solving the ²²²Rn mass balance equation, in which the losses of gas exchange and radioactive decay of ²²²Rn are considered. Meanwhile, river runoff was gauged to determine the exchange rates between surface water and groundwater. The result shows that ²²²Rn isotope can be used as a good environmental tracer with high sensitivity for the interaction between surface water and groundwater, especially in the fractured aquifer system, karst aquifer system and discharge basins.     

Assessment of interconnection between surface water and groundwater in Sawa Lake area,southern Iraq,using stable isotope technique

Interaction between surface water represented by the Euphrates River, natural springs, and Sawa Lake with groundwater (11 wells) in southern Iraq was investigated in this study. Water samples were collected for hydrochemistry and stable isotope (²H and ¹⁸O) analysis. Sampling of water from determined stations (10 stations along the Euphrates, 3 springs, and Sawa Lake) were carried out during two stages; the first was in October 2013(dry season) and the second one was in March 2014 (wet season). The aim of the research is to assess the interaction of groundwater–surface water, which includes Al-Atshan River (branch of the Euphrates River), Sawa Lake, and the groundwater in the study area by using hydrochemistry and stable isotope techniques. The results indicate that surface waters have a different type of water from that of groundwater. In δ ²H and δ ¹⁸O diagrams, all groundwater, springs, and Sawa Lake waters are plotted below the Global Meteoric Water Line (GMWL) and the local meteoric water line (LMWL) indicating the influence of evaporation processes and seasonal variation. The LMWL deviates by a d-excess about +13.71 toward the East Mediterranean meteoric water line (EMWL) indicating that the origin of the vapor source is the Mediterranean Sea. The river water has different isotopic compositions from that of groundwater, springs, and Sawa Lake. The final conclusion is that there is no clear influence of the groundwater on the river water while there is an intermixing between the groundwater in the different locations in the study area.     

Characterizing the interaction of groundwater and surface water in the karst aquifer of Fangshan,Beijing (China)

Correct understanding of groundwater/surface-water (GW–SW) interaction in karst systems is of greatest importance for managing the water resources. A typical karst region, Fangshan in northern China, was selected as a case study. Groundwater levels and hydrochemistry analyses, together with isotope data based on hydrogeological field investigations, were used to assess the GW–SW interaction. Chemistry data reveal that water type and the concentration of cations in the groundwater are consistent with those of the surface water. Stable isotope ratios of all samples are close to the local meteoric water line, and the ³H concentrations of surface water and groundwater samples are close to that of rainfall, so isotopes also confirm that karst groundwater is recharged by rainfall. Cross-correlation analysis reveals that rainfall leads to a rise in groundwater level with a lag time of 2 months and groundwater exploitation leads to a fall within 1 month. Spectral analysis also reveals that groundwater level, groundwater exploitation and rainfall have significantly similar response periods, indicating their possible inter-relationship. Furthermore, a multiple nonlinear regression model indicates that groundwater level can be negatively correlated with groundwater exploitation, and positively correlated with rainfall. The overall results revealed that groundwater level has a close correlation with groundwater exploitation and rainfall, and they are indicative of a close hydraulic connection and interaction between surface water and groundwater in this karst system.     

Trace elements and environmental isotopes as tracers of surface water–groundwater interaction: a case study at Xin’an karst water system,Shanxi Province,Northern China

In this case study, silica concentration, oxygen and strontium isotopes of water samples were used to study surface water–groundwater interaction at the Xin’an karst water system. The silica concentration in rain water is commonly less than 1 mg/l. In the areas around the south tributary of the Zhuozhang River, silica concentrations in the groundwater in Quaternary aquifers range between 4.04 and 7.66 mg/l while that of the surface water varies from 1.49 to 6.9 mg/l. Silica concentrations of most surface water samples increase with TDS, indicating the effect of groundwater recharge on river water chemistry. On the contour map of silica concentration of groundwater in Quaternary aquifers, samples located close to surface water often have lower silica concentrations as a result of surface water recharge. Both overland flow and surface water have impact on karst water according to our hydrogeochemical study of stable oxygen isotope, Sr isotope and strontium contents. Calculation results of three end member mixing model show that the contribution of karst water, surface water and overland flow water is 45, 28 and 27%, respectively.