氢氧稳定同位素是广泛存在于自然界水体中的环境同位素,其在不同水体中组成特征的差异可以指示水分循环过程及植物用水机制等,从而成为广泛应用于水分循环研究中的重要手段。本文介绍了稳定同位素技术在土壤-植物-大气连续体（SPAC）水分循环中的应用原理及研究进展,并阐述了其在SPAC水分循环应用中存在的问题及发展前景,以期为氢氧稳定同位素技术在SPAC水分循环研究中的深入应用提供参考,为研究水资源、水环境问题,特别是干旱\,半干旱地区的水分利用效率、水分分配机制等关键性问题提供理论依据和技术支持。

The stable hydrogen and oxygen isotopes are kind of environmental isotopes, which widely exist in various kinds of water. Because their relative abundance variation in water can indicate the water circulation and mechanism of water use in plant, isotopic techniques become an increasingly important means to study water cycle. In this paper, the principle of application and the research advances of stable hydrogen and oxygen isotope technique that used in Soil-Plant-Atmosphere Continuum (SPAC) water circulation are reviewed. Meanwhile, the disadvantages and the perspective on its development are put forward in order to provide reference to further application of the stable hydrogen and oxygen isotope technique in SPAC water circulation, and to offer theory bases and technique support to study practical problems of water resource and water environment, especially some crucial ones in arid areas.

降水是流域水循环中重要的输入因子，对其同位素组分的研究有助于确定流域水体间的水力联系，还可反映流域综合自然地理及气象气候信息；结合地表水、土壤水及地下水同位素组分变化，可以确定降水入渗及产汇流过程、地下水补给及更新能力，进而为完整的水循环机理研究提供依据。结合水文气象观测，本文分析了黄土高原典型丘陵沟壑区岔巴沟流域2004年～2005年月降水以及曹坪西沟实验流域次降水环境同位素组分雨量效应、高程效应、季节变化、δD与δ¹⁸O间的关系等，并对不同时空尺度上大气降水线的变化规律进行分析，结果表明该地区不同年份及雨季前后，降水的水汽来源不同且经历蒸发过程差异较大；同时发现大气降水线中斜率与氘盈余之间存在良好的线性关系9.74×S-d=69.3，即虽然不同年份大气降水线存在差异，但两者存在相对稳定的线性关系，该关系可能与水汽来源之外的某种固定的综合自然地理特征有关，也为获得可靠的分析结果提供了参考。

Precipitation is the most important input to water cycle. Study of hydrogen and oxygen isotopes of precipitation can help identify relationships between different waters and reflect integrated geographical and climatic information of the study area, which is the foundation for integrated water cycle research. Combined with isotopic compositions of surface water and groundwater in the study area, systematic analysis for precipitation in different scales can quantify the runoff generating processes, as well as the recharge rate for precipitation reaching water table. By analyzing isotopic compositions of rains between 2004 and 2005 for <i>δD</i>and <i>δ</i>¹⁸<i>O</i>, the study discussed the amount effect, seasonal effect, spatial distribution of δ values not only for monthly precipitation on the upper, middle and lower reaches of the Chabagou Catchment, also for precipitations in Caoping Xigou Experimental Watershed by event scale. In the whole watershed, the isotopic results for monthly precipitation shows obvious spatial and temporal variation, and an altitude effect only prominent from May to August, following which a further decline of δ values for rain in September reflecting that the rains are mainly formed in the process of monsoon vapor withdrawing from the northwest. In the Chabagou Catchment, the notable spatial variation of δ values indicates that spatial variation of δ values should be fully considered when getting a confidential local meteoric water line, which can well reflect the local geographical and climatic characteristics, especially for isotopic ungauged basins with short observing series. Meteoric water lines, i.e. linear relationships between <i>δD</i> and <i>δ</i>¹⁸<i>O</i>, differs from each other both for stations and years, even for different periods of a year, indicating a dissimilar water vapor and variant processes water vapor having experienced before reaching the ground, which can be a good tool for study of water vapor origin if hydrological and climatic observations be involved. And then, relationships between slope (S) and deuterium excess (d) for meteoric water lines at each rain gauge stations or seasons are well linearized. The formula is 9.74×<i>S</i>-<i>d</i>=69.3,namely, though meteoric water line may differ seasonally and annually and relationship between S and d is relatively solid. This formula is also applicable for many other places of China, even for many regions in the world.It gives possible promise for studies from spatial and temporal variation of meteoric line, transportation of water vapor to main geographical and climatic factors affecting the study area, and may make some difference in theoretical and practical system of isotope hydrology. Based on all the analysis above, a further study on relationship between precipitation, surface water, soil water and groundwater will be identified and water cycle mechanism of gully and hilly regions of the Loess Plateau can be studied in detail.

为研究人类活动影响下河流降水径流响应特征,以珠江三角洲典型城镇化流域石马河为研究对象,采集2017年1-12月日降水、河水样品和3场台风期间的时段降水、洪水样品,通过测定其氢氧稳定同位素组成（δD、δ ¹⁸O）,分析流域降水、径流氢氧同位素组成特征,并利用同位素二元混合模型,分割3场台风降水事件中事前水及事件水对流量过程的贡献。结果表明,研究区域大气降水δD、δ ¹⁸O的变化范围分别为-105.10‰~+9.98‰和-14.80‰~-0.55‰,年加权平均值为-57.88‰和-8.61‰,大气降水线为δD = 7.70δ ¹⁸O+8.61（R ²= 0.98）;河水δD、δ ¹⁸O的变化范围分别为-91.23‰~-15.96‰和-12.66‰~-4.01‰,δD-δ ¹⁸O基本落在局地大气降水线上,表明降水是石马河径流的主要来源。3场台风期间,事件水占洪水总径流量的比例分别为59.7%、55.0%和69.4%,均高于事前水占比。洪水涨水初期事前水和事件水同步增长,涨水后期事件水比例逐渐增大,洪峰期间比例大于80%,成为径流主导成分,表明流域城镇化过程中下垫面不透水面积的增加会显著改变水文循环过程。本研究成果可为珠江三角洲城镇化流域水文预报提供理论基础。

In order to study the response characteristics of precipitation-runoff under the influence of human activities, this paper took Shima River, a typical urbanized catchment in the Pearl River Delta as the research area. Daily samples of precipitation and river water were collected from January to December and hourly samples were collected during three typhoon rainstorms in 2017. Based on the stable isotope data (δD, δ ¹⁸O), the characteristics of hydrogen and oxygen isotopes were analyzed. Two-component isotope-based hydrograph separation was used to study the contribution of pre-event water and event water to the runoff process during three typhoon events. The results showed that δD and δ ¹⁸O in precipitation ranged from -105.10‰ to 9.98‰ and -14.80‰ to -0.55‰, respectively, and the annual weighted mean values were -57.88‰ and -8.61‰. The Local Meteoric Water Line was δD=7.70δ ¹⁸O+8.61(R ²=0.98). δD and δ ¹⁸O in river water ranged from -91.23‰ to -15.96‰ and -12.66‰ to -4.01‰, respectively. δD-δ ¹⁸O basically fell on the LMWL indicated that precipitation was the main source of runoff in the Shima River catchment. During the three typhoons, the proportion of event water was 59.7%, 55.0% and 69.4%, respectively, which was higher than that of pre-event water. In the early stage of flood, pre-event water and event water increased synchronously. In the late stage of flood, the proportion of event water increased gradually which was more than 80% during the peak period. This indicated that the increase of impervious areas in the urban regions would significantly alter the hydrological cycle. The results of this study could provide the theoretical foundations for hydrological forecast of urbanized basins in Pearl River Delta.

氢氧稳定同位素作为水的&#x0201c;DNA&#x0201d;,对于研究水分的传输和转化具有重要的意义,而水分耗散是水循环的重要组成部分。简单介绍氢氧稳定同位素在水分耗散研究中应用的主要原理和比较新的一些技术方法,主要对其在森林、草原生态系统和农田生态系统中蒸散发分离,植物水分来源区分、叶片水同位素富集和水分利用效率等方面做较为详细的归纳总结和探讨,最后指出国内此类研究仍然存在的问题和可能的发展方向,以期对未来氢氧稳定同位素技术在水分循环和水分耗散方面的应用研究有借鉴作用。

开展丹江口水库消落带土壤总氮(TN)和总磷(TP)变化特征与通量研究,对明晰消落带污染输出特征、保护水库水质安全有着重要的实践作用。将丹江口水库划分为汉库和丹库两个区域,以不同区域内典型消落带为研究对象,监测分析了2020年9月—2021年9月不同时期不同区域消落带土壤TN和TP的变化特征,并通过收支平衡法构建模型,估算了丹江口水库消落带在不同时期的TN和TP通量。结果表明,2020年9—12月淹水期内,丹江口水库不同区域消落带TN、TP含量变化显著,汉库耕地和园地的TN、TP含量显著上升,其余区域消落带土壤均存在TN、TP流失现象。2021年3—6月落干期内,丹江口水库不同区域消落带TN、TP含量总体上呈现上升积累趋势。2020年9月—2021年9月,丹江口水库不同区域消落带TN、TP含量整体呈下降趋势。丹江口水库消落带在淹水期表现为氮和磷的释放源,TN通量834.66 t,TP通量10 422.12 t;在落干期表现为氮和磷的吸收汇,TN通量-8 623.69 t,TP通量-10 032.94 t。2020年9月—2021年9月,丹江口水库消落带总体上表现为氮和磷的释放源,TN通量20 122.22 t,TP通量1 509.52 t。丹江口水库消落带污染物释放对水库水质安全的风险不容忽视。

Study on the variation characteristics and flux of total nitrogen(TN) and total phosphorous (TP) in soil in the water-level-fluctuation zone of Danjiangkou reservoir is of practical significance for clarifying the pollution output characteristics and protecting the water quality of the reservoir. In this paper, Danjiangkou reservoir was divided into Hanku reservoir and Danku reservoir. The variation characteristics of TN and TP in soil in the typical water-level fluctuation zone of Danjiangkou reservoir in different periods from September 2020 to September 2021 were monitored and analyzed. In addition, the TN and TP fluxes were estimated by using the break-even model. Results reveal that during the flooding period from September 2020 to December 2020, the content of TN and TP in different water-level-fluctuating areas of Danjiangkou reservoir changed significantly. To be specific, the content of TN and TP in the farmland and garden fields of Hanku reservoir increased notably, while TN and TP were lost in other areas. During the water-level-falling dry period from March 2021 to June 2021, the content of TN and TP in different water-level-fluctuation zones of Danjiangkou reservoir showed an increasing trend on the whole. From September 2020 to September 2021, the content of TN and TP in different water-level-fluctuation zones of Danjiangkou reservoir displayed a decreasing trend. During flooding period, the water-level-fluctuation zone of Danjiangkou reservoir acted as the release source of nitrogen and phosphorus, with TN flux reaching 834.66 t and TP flux 10 422.12 t. During water-level falling dry period, the water-level-fluctuation zone of Danjiangkou reservoir acted as the sink of nitrogen and phosphorus, with TN flux of -8 623.69 t and TP flux -10 032.94 t. From September 2020 to September 2021, the water-level-fluctuation zone of Danjiangkou reservoir acted as the release source of nitrogen and phosphorus on the whole, with TN flux amounting to 20 122.22 t and TP flux 1 509.52 t. The pollutant release risk of water-level-fluctuation zone of Danjiangkou reservoir should not be ignored as it poses a threat to the water quality of the reservoir.

The relationship between deuterium and oxygen-18 concentrations in natural meteoric waters from many parts of the world has been determined with a mass spectrometer. The isotopic enrichments, relative to ocean water, display a linear correlation over the entire range for waters which have not undergone excessive evaporation.

淮河流域位于我国南北气候过渡带,其复杂多变的降水过程及水汽来源是导致流域洪旱灾害易发、多发的重要因素。以全球降水同位素监测网络(Global Network of Isotope in Precipitation,GNIP)监测的多年降水氢氧稳定同位素数据为基础,探讨了淮河流域大气降水氢氧稳定同位素组成时空变化的驱动因素及其气候指示意义;通过分析氢氧稳定同位素组成(δ¹⁸O、δ²H、氘盈余)、大气降水线特征与流域气温、降水量的响应关系,解析流域不同季节大气降水水汽来源及气团移动路径。结果表明:①淮河流域大气降水氢氧稳定同位素组成能够指示南北气候过渡带特征;②同位素时空变化及异常低的大气降水线斜率、截距与局地降水环境关系不大,主要是由水汽来源差异及降水气团在移动过程中同位素分馏造成的。氘盈余示踪和HYSPLIT模型模拟结果进一步表明流域降水水汽来源及变化受季风活动的控制,冬季风和夏季风的交替进退使得淮河流域的降水氘盈余变化具有明显的“V”型特征。研究成果可为水资源调度管理、极端气候应对决策等提供科学依据。

Located in China's south-north transitional climatic zone, the Huaihe River Basin is prone to flood and drought disasters because of complex and changing precipitation processes and atmospheric moisture sources.Based on the stable hydrogen and oxygen isotopic data from Global Network of Isotopes in Precipitation (GNIP), we investigated into the driving factors of temporal and spatial variations and their climatic implications.By analyzing the isotopic compositions (δ¹⁸O,δ²H, and deuterium surplus) and Local Meteoric Water Line (LMWL) in response to local temperature and precipitation, we expounded the atmospheric moisture sources in different seasons and air-mass moving processes in the basin.Results demonstrated that the isotopic composition of precipitation can be used to indicate south-north transitional climatic features.The spatio-temporal changes of isotopes and abnormally low slope and intercept of LMWL were mainly caused by different moisture sources and isotopic fractionations in the air-mass moving process rather than local precipitation environment.Deuterium tracing and HYSPLIT simulation results further proved that the sources and variations of atmospheric moisture over the Huaihe River Basin were controlled by monsoon activities, and the alternations between winter and summer monsoons led to V-shaped characteristics of deuterium surplus.