Journal articles on the topic 'Stable isotopes of water'
To see the other types of publications on this topic, follow the link: Stable isotopes of water.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Stable isotopes of water.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Völpel, Rike, André Paul, Annegret Krandick, Stefan Mulitza, and Michael Schulz. "Stable water isotopes in the MITgcm." Geoscientific Model Development 10, no. 8 (August 25, 2017): 3125–44. http://dx.doi.org/10.5194/gmd-10-3125-2017.
Full textAbstract:
Abstract. We present the first results of the implementation of stable water isotopes in the Massachusetts Institute of Technology general circulation model (MITgcm). The model is forced with the isotopic content of precipitation and water vapor from an atmospheric general circulation model (NCAR IsoCAM), while the fractionation during evaporation is treated explicitly in the MITgcm. Results of the equilibrium simulation under pre-industrial conditions are compared to observational data and measurements of plankton tow records (the oxygen isotopic composition of planktic foraminiferal calcite). The broad patterns and magnitude of the stable water isotopes in annual mean seawater are well captured in the model, both at the sea surface as well as in the deep ocean. However, the surface water in the Arctic Ocean is not depleted enough, due to the absence of highly depleted precipitation and snowfall. A model–data mismatch is also recognizable in the isotopic composition of the seawater–salinity relationship in midlatitudes that is mainly caused by the coarse grid resolution. Deep-ocean characteristics of the vertical water mass distribution in the Atlantic Ocean closely resemble observational data. The reconstructed δ18Oc at the sea surface shows a good agreement with measurements. However, the model–data fit is weaker when individual species are considered and deviations are most likely attributable to the habitat depth of the foraminifera. Overall, the newly developed stable water isotope package opens wide prospects for long-term simulations in a paleoclimatic context.
2
Jensen, Alexandria, William Ford, James Fox, and Admin Husic. "Improving In-Stream Nutrient Routines in Water Quality Models Using Stable Isotope Tracers: A Review and Synthesis." Transactions of the ASABE 61, no. 1 (2018): 139–57. http://dx.doi.org/10.13031/trans.12545.
Full textAbstract:
Abstract. Water quality models serve as an economically feasible alternative to quantify fluxes of nutrient pollution and to simulate effective mitigation strategies; however, their applicability is often questioned due to broad uncertainties in model structure and parameterization, leading to uncertain outputs. We argue that reduction of uncertainty is partially achieved by integrating stable isotope data streams within the water quality model architecture. This article outlines the use of stable isotopes as a response variable within water quality models to improve the model boundary conditions associated with nutrient source provenance, constrain model parameterization, and elucidate shortcomings in the model structure. To assist researchers in future modeling efforts, we provide an overview of stable isotope theory; review isotopic signatures and applications for relevant carbon, nitrogen, and phosphorus pools; identify biotic and abiotic processes that impact isotope transfer between pools; review existing models that have incorporated stable isotope signatures; and highlight recommendations based on synthesis of existing knowledge. Broadly, we find existing applications that use isotopes have high efficacy for reducing water quality model uncertainty. We make recommendations toward the future use of sediment stable isotope signatures, given their integrative capacity and practical analytical process. We also detail a method to incorporate stable isotopes into multi-objective modeling frameworks. Finally, we encourage watershed modelers to work closely with isotope geochemists to ensure proper integration of stable isotopes into in-stream nutrient fate and transport routines in water quality models. Keywords: Isotopes, Nutrients, Uncertainty analysis, Water quality modeling, Watershed.
3
Orlowski, N., P. Kraft, and L. Breuer. "Exploring water cycle dynamics through sampling multitude stable water isotope pools in a small developed landscape of Germany." Hydrology and Earth System Sciences Discussions 12, no. 2 (February 6, 2015): 1809–53. http://dx.doi.org/10.5194/hessd-12-1809-2015.
Full textAbstract:
Abstract. Conducting a dual stable water isotope (δ2H and δ18O) study in the developed landscape of the Schwingbach catchment (Germany) helped to unravel connectivity and disconnectivity between the different water cycle components. The two-year weekly to biweekly measurements of precipitation, stream, and groundwater isotopes revealed that surface and groundwater are decoupled from the annual precipitation cycle but showed bidirectional interactions between each other. Seasonal variations based on temperature effects were observed in the precipitation signal but neither reflected in stream nor in groundwater isotopic signatures. Apparently, snowmelt played a fundamental role for groundwater recharge explaining the observed differences to precipitation δ-values. A spatially distributed snapshot sampling of soil water isotopes in two soil depths at 52 sampling points across different land uses (arable land, forest, and grassland) revealed that top soil isotopic signatures were similar to the precipitation input signal. Preferential water flow paths occurred under forested soils explaining the isotopic similarities between top and subsoil isotopic signatures. Due to human-impacted agricultural land use (tilling and compression) of arable and grassland soils, water delivery to the deeper soil layers was reduced, resulting in significant different isotopic signatures. However, the land use influence smoothed out with depth and soil water approached groundwater δ-values. Seasonally tracing stable water isotopes through soil profiles showed that the influence of new percolating soil water decreased with depth as no remarkable seasonality in soil isotopic signatures was obvious at depth > 0.9 m and constant values were observed through space and time. Little variation in individual isotope time series of stream and groundwater restricted the use of classical isotope hydrology techniques e.g. mean transit time estimation or hydrograph separation. Still, tracing stable water isotopes through the water cycle was valuable for determining interactions between different water cycle components and gaining catchment specific process understanding in a developed, human-impacted landscape.
4
Treydte, Kerstin, Jan Esper, and Holger Gärtner. "Stabile Isotope in der Dendroklimatologie | Stable isotopes and dendroclimatology." Schweizerische Zeitschrift fur Forstwesen 155, no. 6 (June 1, 2004): 222–32. http://dx.doi.org/10.3188/szf.2004.0222.
Full textAbstract:
This paper expounds the basics of isotope fixation in tree rings and relevant field and laboratory procedures. Examples from high mountain regions show both the potential and limits of employing these methods in dendroclimatological studies. Carbon isotopes yield seasonally resolved information on temperature,precipitation and relative humidity, whilst oxygen isotopes provide information on the isotope values of the source water,and thus, on precipitation. Inter-annual and decadal variations, in particular, reflect a strong common climatic signal that extends across a wide range of site ecologies. However, low frequency trends are masked by a non-climatic, human induced long-term trend, especially where carbon isotopes are concerned. At present,detrending methods are of a provisional nature and set a limit to stable isotopes for paleoclimatic questions. Highly resolved plant physiological and biochemical investigations should provide more insight into these unsolved problems.
5
Li, Xiangnan, Baisha Weng, Denghua Yan, Tianling Qin, Kun Wang, Wuxia Bi, Zhilei Yu, and Batsuren Dorjsuren. "Anthropogenic Effects on Hydrogen and Oxygen Isotopes of River Water in Cities." International Journal of Environmental Research and Public Health 16, no. 22 (November 12, 2019): 4429. http://dx.doi.org/10.3390/ijerph16224429.
Full textAbstract:
Stable hydrogen and oxygen isotopes are important indicators for studying water cycles. The isotopes are not only affected by climate, but are also disturbed by human activities. Urban construction has changed the natural attributes and underlying surface characteristics of river basins, thus affecting the isotopic composition of river water. We collected urban river water isotope data from the Global Network for Isotopes in Rivers (GNIR) database and the literature, and collected river water samples from the Naqu basin and Huangshui River basin on the Tibetan Plateau to measure hydrogen and oxygen isotopes. Based on 13 pairs of urban area and non-urban area water samples from these data, the relationship between the isotopic values of river water and the artificial surface area of cities around rivers was analyzed. The results have shown that the hydrogen and oxygen isotope (δD and δ18O) values of river water in urban areas were significantly higher than those in non-urban areas. The isotopic variability of urban and non-urban water was positively correlated with the artificial surface area around the rivers. In addition, based on the analysis of isotope data from 21 rivers, we found that the cumulative effects of cities on hydrogen and oxygen isotopes have led to differences in surface water line equations for cities with different levels of development. The combined effects of climate and human factors were the important reasons for the variation of isotope characteristics in river water in cities. Stable isotopes can not only be used to study the effects of climate on water cycles, but also serve as an important indicator for studying the degree of river development and utilization.
6
Passey, Benjamin H. "Reconstructing Terrestrial Environments Using Stable Isotopes in Fossil Teeth and Paleosol Carbonates." Paleontological Society Papers 18 (November 2012): 167–94. http://dx.doi.org/10.1017/s1089332600002606.
Full textAbstract:
Carbon isotopes in Neogene-age fossil teeth and paleosol carbonates are commonly interpreted in the context of past distributions of C3 and C4 vegetation. These two plant types have very different distributions in relation to climate and ecology, and provide a robust basis for reconstructing terrestrial paleoclimates and paleoenvironments during the Neogene. Carbon isotopes in pre-Neogene fossil teeth are usually interpreted in the context of changes in the δ13C value of atmospheric CO2, and variable climate-dependent carbon-isotope discrimination in C3 plants. Carbon isotopes in pre-Neogene soil carbonates can be used to estimate past levels of atmospheric CO2. Oxygen isotopes in fossil teeth and paleosol carbonates primarily are influenced by the oxygen isotopic compositions of ancient rainfall and surface waters. The oxygen isotopic composition of rainfall is has a complex, but tractable, relationship with climate, and variably relates to temperature, elevation, precipitation amount, and other factors. Mammal species that rely on moisture in dietary plant tissues to satisfy their water requirements (rather than surface drinking water) may have oxygen isotopic compositions that track aridity. Thus, oxygen isotopes of fossil mammals can place broad constraints on paleoaridity. Carbonate clumped isotope thermometry allows for reconstruction of soil temperatures at the time of pedogenic carbonate mineralization. The method is unique because it is the only thermodynamically based isotopic paleothermometer that does not require assumptions about the isotopic composition of the fluid in which the archive mineral formed. Soil temperature reflects a complex interplay of air temperature, solar radiative heating, latent heat effects, soil thermal diffusivity, and seasonal variations of these parameters. Because plants and most animals live in and/or near the soil, soil temperature is an important aspect of terrestrial (paleo)climate.
7
Orlowski, Natalie, Philipp Kraft, Jakob Pferdmenges, and Lutz Breuer. "Exploring water cycle dynamics by sampling multiple stable water isotope pools in a developed landscape in Germany." Hydrology and Earth System Sciences 20, no. 9 (September 20, 2016): 3873–94. http://dx.doi.org/10.5194/hess-20-3873-2016.
Full textAbstract:
Abstract. A dual stable water isotope (δ2H and δ18O) study was conducted in the developed (managed) landscape of the Schwingbach catchment (Germany). The 2-year weekly to biweekly measurements of precipitation, stream, and groundwater isotopes revealed that surface and groundwater are isotopically disconnected from the annual precipitation cycle but showed bidirectional interactions between each other. Apparently, snowmelt played a fundamental role for groundwater recharge explaining the observed differences to precipitation δ values. A spatially distributed snapshot sampling of soil water isotopes at two soil depths at 52 sampling points across different land uses (arable land, forest, and grassland) revealed that topsoil isotopic signatures were similar to the precipitation input signal. Preferential water flow paths occurred under forested soils, explaining the isotopic similarities between top- and subsoil isotopic signatures. Due to human-impacted agricultural land use (tilling and compression) of arable and grassland soils, water delivery to the deeper soil layers was reduced, resulting in significant different isotopic signatures. However, the land use influence became less pronounced with depth and soil water approached groundwater δ values. Seasonally tracing stable water isotopes through soil profiles showed that the influence of new percolating soil water decreased with depth as no remarkable seasonality in soil isotopic signatures was obvious at depths > 0.9 m and constant values were observed through space and time. Since classic isotope evaluation methods such as transfer-function-based mean transit time calculations did not provide a good fit between the observed and calculated data, we established a hydrological model to estimate spatially distributed groundwater ages and flow directions within the Vollnkirchener Bach subcatchment. Our model revealed that complex age dynamics exist within the subcatchment and that much of the runoff must has been stored for much longer than event water (average water age is 16 years). Tracing stable water isotopes through the water cycle in combination with our hydrological model was valuable for determining interactions between different water cycle components and unravelling age dynamics within the study area. This knowledge can further improve catchment-specific process understanding of developed, human-impacted landscapes.
8
Wang, Jiaxin, Mingjun Zhang, Athanassios A. Argiriou, Shengjie Wang, Deye Qu, Yu Zhang, and Pengyan Su. "Recharge and Infiltration Mechanisms of Soil Water in the Floodplain Revealed by Water-Stable Isotopes in the Upper Yellow River." Sustainability 13, no. 16 (August 20, 2021): 9369. http://dx.doi.org/10.3390/su13169369.
Full textAbstract:
The stable isotopes (δD and δ18O) in soil water allow tracing of the flow and transportation of water in the soil. However, there are few studies on the use of soil water stable isotopes to explore the soil water in the floodplain, especially in determining the soil water source and infiltration mechanism. The Bayesian mixing model (MixSIAR) was integrated with the line conditioned excess (lc-excess) of stable isotopes (δD and δ18O) in precipitation, soil water (0–150 cm), river water, and groundwater to determinate the source and recharge mechanisms of two different soil profile types in the floodplain of the upper Yellow River in Lanzhou, China. The results showed that soil water below 80 cm was affected by river water recharge, affecting soil water content and stable isotopic composition at S1 sampling points (profile parallel to river water); this effect was not observed at S2 (profile is higher than the river water) sampling points. The isotopic compositions of the soil water sources at the two sampling points (S1: δD = −77.41‰, δ18O = −11.01‰; S2: δD = −74.02‰, δ18O = −10.56‰) were depleted more than those in the long-term amount-weighted precipitation isotopes (δD = −56.30‰, δ18O = −8.17‰). The isotope signatures of soil water sources are similar to the isotope characteristics of some high-intensity precipitation events (≥30 mm/day), indicating that soil water originates from a fraction of the total precipitation. The piston flow (60%) and the preferential flow (40%) coexist, but soil moisture and rainfall intensity will affect the sequence of the two infiltration methods. This study provides insights for understanding the hydrological process of the upper Yellow River and evaluating groundwater quality and protecting the floodplain environment.
9
Reyes-García, Casandra, and José Luis Andrade. "Los isótopos estables del hidrógeno y el oxígeno en los estudios ecofisiológicos de plantas." Botanical Sciences, no. 80 (June 3, 2017): 19. http://dx.doi.org/10.17129/botsci.1742.
Full textAbstract:
Stable isotope studies of elements in biological organisms have become a useful tool to assess the exchange of molecules in the biosphere. Since water is one of the most abundant molecules in such an exchange, studies on stable isotopes of hydrogen and oxygen have become a fundamental component of many plant ecophysiological studies, from the leaf level to the reconstruction of past climates. In this review, we mention the most common methodologies, general notation and the most relevant research on hydrogen and oxygen stable isotopes. Also, we discuss studies on plant water sources, leaf isotopic enrichment due to transpiration, the relationship between environment and oxygen stable isotopes in organic matter, and present studies that propose some plant species as environmental indicators in a globally changing world.
10
Kim, Songyi, Yeongcheol Han, Soon Do Hur, Kei Yoshimura, and Jeonghoon Lee. "Relating Moisture Transport to Stable Water Vapor Isotopic Variations of Ambient Wintertime along the Western Coast of Korea." Atmosphere 10, no. 12 (December 12, 2019): 806. http://dx.doi.org/10.3390/atmos10120806.
Full textAbstract:
Atmospheric water vapor transfers energy, causes meteorological phenomena and can be modified by climate change in the western coast region of Korea. In Korea, previous studies have utilized precipitation isotopic compositions in the water cycle for correlations with climate variables, but there are few studies using water vapor isotopes. In this study, water vapor was directly collected by a cryogenic method, analyzed for its isotopic compositions, and used to trace the origin and history of water vapor in the western coastal region of Korea during the winter of 2015/2016. Our analysis of paired mixing ratios with water vapor isotopes can explain the mechanism of water vapor isotopic fractionation and the extent of the mixing of two different air masses. We confirm the correlation between water vapor isotopes and meteorological parameters such as temperature, relative humidity, and specific humidity. The main water vapor in winter was derived from the continental polar region of northern Asia and showed an enrichment of 10 per mil (δ18O) through the evaporation of the Yellow Sea. Our results demonstrate the utility of using ground-based isotope observations as a complementary resource for constraining isotope-enabled Global Circulation Model in future investigations of atmospheric water cycles. These measurements are expected to support climate studies (speleothem) in the west coast region of Korea.
11
Dietermann, N., and M. Weiler. "Spatial distribution of stable water isotopes in alpine snow cover." Hydrology and Earth System Sciences 17, no. 7 (July 11, 2013): 2657–68. http://dx.doi.org/10.5194/hess-17-2657-2013.
Full textAbstract:
<p><strong>Abstract.</strong> The aim of this study was to analyse and predict the mean stable water isotopic composition of the snow cover at specific geographic locations and altitudes. In addition, the dependence of the isotopic composition of the entire snow cover on altitude was analysed. Snow in four Swiss catchments was sampled at the end of the accumulation period in April 2010 and a second time during snowmelt in May 2010 and analysed for stable isotope composition of <sup>2</sup>H and <sup>18</sup>O. The sampling was conducted at both south-facing and north-facing slopes at elevation differences of 100 m, for a total altitude difference of approximately 1000 m. The observed variability of isotopic composition of the snow cover was analysed with stepwise multiple linear regression models. The analysis indicated that there is only a limited altitude effect on the isotopic composition when considering all samples. This is due to the high variability of the isotopic composition of the precipitation during the winter months and, in particular in the case of south-facing slopes, an enrichment of heavy isotopes due to intermittent melting processes. This enrichment effect could clearly be observed in the samples which were taken later in the year. A small altitudinal gradient of the isotopic composition could only be observed at some north-facing slopes. However, the dependence of snow depth and the day of the year were significant predictor variables in all models. This study indicates the necessity to further study the variability of water isotopes in the snow cover to increase prediction for isotopic composition of snowmelt and hence increase model performance of residence time models for alpine areas in order to better understand the accumulation processes and the sources of water in the snow cover of high mountains.</p>
12
Guo, Rong, Shengjie Wang, Mingjun Zhang, Athanassios A. Argiriou, Xuemei Liu, Bo Su, Xue Qiu, et al. "Stable Hydrogen and Oxygen Isotope Characteristics of Bottled Water in China: A Consideration of Water Source." Water 11, no. 5 (May 22, 2019): 1065. http://dx.doi.org/10.3390/w11051065.
Full textAbstract:
The origin of bottled water can be identified via its stable isotope signature because of the spatial variation of the stable isotope composition of natural waters. In this paper, the spatial pattern of δ2H and δ18O values were analyzed for a total of 242 bottled water samples produced at 137 sites across China that were randomly purchased during 2014–2015. The isotopic ratios of bottled water vary between −166‰ and −19‰ for δ2H, and between −21.6‰ and −2.1‰ for δ18O. Based on multiple regression analyses using meteorological and geographical parameters, an isoscape of Chinese bottled water was created. The results showed that altitude among spatial parameters and precipitation amount and air temperature among meteorological parameters were major natural factors determining the isotopic variation of bottled water. Our findings indicate the potential and the significance of the use of stable isotopes for the source identification of bottled water. An analysis of different origin types (spring, glacier and unmarked) and several different brands of bottled water in the same location reflected different production processes and source signatures.
13
Hu, Hai Ying. "Application of Isotopic Technology in Aqueous Environment." Advanced Materials Research 356-360 (October 2011): 2325–28. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.2325.
Full textAbstract:
The aqueous environment quality plays an important role in controlling the circulation track of ecological environment. Environmental isotopes widely exist in various kinds of water and can be extensively applied in water environment. Isotopes as natural tracers can be used to trace the transportation process of water in hydrologic cycle and the variations of isotopic value can also provide the information about the transference of contamination. The dynamical process of the movement and mix of waters can be studied by applying the composition characteristics of stable isotopes contained in natural waters, thus the main processes of water resources formation and aqueous environment evolution as well as their driving forces mechanism can be revealed. In this paper, the development history of the application of stable isotopes in the water circulation is reviewed, the application theory and analytical method of the environmental stable isotopes, and the new progress of the applied study on water resources formation and aqueous environment evolution are mainly discussed.
14
Herbstritt, Barbara, Benjamin Gralher, and Markus Weiler. "Continuous, near-real-time observations of water stable isotope ratios during rainfall and throughfall events." Hydrology and Earth System Sciences 23, no. 7 (July 17, 2019): 3007–19. http://dx.doi.org/10.5194/hess-23-3007-2019.
Full textAbstract:
Abstract. The water isotopic composition of throughfall is affected by complex diffusive exchange with ambient water vapour, evaporative enrichment of heavy isotopes, and mixing processes in the tree canopy. All interception processes occur simultaneously in space and time, generating a complex pattern of throughfall depth and water isotopic composition. This pattern ultimately cascades through the entire hydrologic system and is therefore crucial for isotope studies in catchment hydrology, where recharge areas are often forested, while reference meteorological stations are generally in the open. For the quasi real-time observation of the water isotopic composition (δ18O and δ2H) of both gross precipitation and throughfall, we developed an approach combining a membrane contactor (Membrana) with a laser-based Cavity Ring-Down Spectrometer (CRDS, Picarro), obtaining isotope readings every 2 s. A setup with two CRDS instruments in parallel analysing gross precipitation and throughfall simultaneously was used for the continuous observation of the temporal effect of interception processes on the stable isotopes of water. All devices were kept small to minimize dead volume with time lags of only 4 min for water from the rainfall collectors to the isotope analysers to increase the temporal resolution of isotope observations. Complementarily, meteorological variables were recorded at high temporal resolution at the same location. The achieved evolution from discrete liquid or event-based bulk samples to continuous measurements allows for direct comparison of water stable isotope data with common meteorological measurements. Future improvements of the spatial representativeness will make our approach an even more powerful tool towards detailed insight into the dynamic processes contributing to interception during rainfall events.
15
Gao, Jing, V. Masson-Delmotte, T. Yao, L. Tian, C. Risi, and G. Hoffmann. "Precipitation Water Stable Isotopes in the South Tibetan Plateau: Observations and Modeling*." Journal of Climate 24, no. 13 (July 1, 2011): 3161–78. http://dx.doi.org/10.1175/2010jcli3736.1.
Full textAbstract:
Abstract Measurements of precipitation isotopic composition have been conducted on a daily basis for 1 yr at Bomi, in the southeast Tibetan Plateau, an area affected by the interaction of the southwest monsoon, the westerlies, and Tibetan high pressure systems, as well as at Lhasa, situated west of Bomi. The measured isotope signals are analyzed both on an event basis and on a seasonal scale using available meteorological information and airmass trajectories. The processes driving daily and seasonal isotopic variability are investigated using multidecadal climate simulations forced by twentieth-century boundary conditions and conducted with two different isotopic atmospheric general circulation models [the isotopic version of the Laboratoire de Météorologie Dynamique GCM (LMDZiso) and the ECHAM4iso model]. Both models use specific nudging techniques to mimic observed atmospheric circulation fields. The models simulate a wet and cold bias on the Tibetan Plateau together with a dry bias in its southern part. A zoomed LMDZ simulation conducted with ~50-km local spatial resolution dramatically improves the simulation of isotopic compositions of precipitation on the Tibetan Plateau. Simulated water isotope fields are compared with new data and with previous observations, and regional differences in moisture origins are analyzed using back-trajectories. Here, the focus is on relationships between the water isotopes and climate variables on an event and seasonal scale and in terms of spatial and altitudinal isotopic gradients. Enhancing the spatial resolution is crucial for improving the simulation of the precipitation isotopic composition.
16
Du, Mingxia, Mingjun Zhang, Shengjie Wang, Fenli Chen, Peipei Zhao, Su’e Zhou, and Yaning Zhang. "Stable Isotope Ratios in Tap Water of a Riverside City in a Semi-Arid Climate: An Application to Water Source Determination." Water 11, no. 7 (July 12, 2019): 1441. http://dx.doi.org/10.3390/w11071441.
Full textAbstract:
Stable isotopes (e.g., δ2H and δ18O) in tap water are important tools to understand the local climate or environment background, water sources and the state of regional water supply. Based on 242 tap water samples, 35 precipitation samples and 24 surface water samples gathered in the urban area of Lanzhou, the basic spatiotemporal characteristics of isotopes in tap water, their connection with isotopes in other water bodies and change during the process from raw water to tap water are discussed in detail, combining the information of local tap water supply and water source. It can provide reliable help for understanding the isotope characteristics of local tap water, regional water supply management and determination of tap water source of in a small area. Except for the establishment of a new data set of isotopes in tap water with complete time series and uniform spatial distribution of sampling sites, other results show that: (1) The Local Tap Water Line (LTWL) of Lanzhou is δ2H = (6.03 ± 0.57) δ18O + (−8.63 ± 5.44) (r2 = 0.41, p < 0.01). (2) For seasonal variations, δ2H and δ18O in tap water both are higher in autumn and lower in spring. The diurnal and daily variations of isotopes in tap water are not large. As for spatial variations, the monthly mean values of δ2H and δ18O in tap water at each sampling site show little difference. The isotopes in tap water collected from one single sampling site can be considered as a representative for isotopes in tap water in the area with a single tap water source. (3) Isotopes in tap water show weak connection with precipitation isotopes, but exhibit good connection (consistent seasonal variation, similar numerical range, small numerical difference and high correlation) with isotopes in surface water, which is the direct water source. Isotopes in water change little from raw water to tap water. Isotopic composition of tap water in Lanzhou can be used as a representative of isotopes in surface water.
17
Sturm, C., Q. Zhang, and D. Noone. "An introduction to stable water isotopes in climate models: benefits of forward proxy modelling for paleoclimatology." Climate of the Past Discussions 5, no. 3 (June 30, 2009): 1697–729. http://dx.doi.org/10.5194/cpd-5-1697-2009.
Full textAbstract:
Abstract. Stable water isotopes have been measured in a wide range of climate archives, with the purpose of reconstructing regional climate variations. Yet the common assumption that the isotopic signal is a direct indicator of temperature proves to be misleading under certain circumstances, since its relationship with temperature also depends on e.g. atmospheric circulation and precipitation seasonality. The present article introduces the principles, benefits and caveats of using climate models with embedded water isotopes as a support for the interpretation of isotopic climate archives. A short overview of the limitations of empirical calibrations of isotopic proxy records is presented, with emphasis on the physical processes that infirm its underlying hypotheses. The simulation of climate and its associated isotopic signal, despite difficulties related to downscaling and intrinsic atmospheric variability, can provide a "transfer function" between the isotopic signal and the considered climate variable. The multi-proxy data can then be combined with model output to produce a physically consistent climate reconstruction and its confidence interval. A sensitivity study with the isotope-enabled global circulation model CAM3iso under idealised present-day, pre-industrial and mid-Holocene is presented to illustrate the impact of a changing climate on the isotope-temperature relationship.
18
Hita, Luis González, Miguel Angel Mejía-González, Blanca Carteño Martinez, Juan Carlos Aparicio-González, and Dustin Mañón Flores. "Isotopic composition of rainfall in Baja California Sur, México." International Journal of Hydrology 5, no. 3 (June 1, 2021): 93–100. http://dx.doi.org/10.15406/ijh.2021.05.00271.
Full textAbstract:
The study of the connection between precipitation and groundwater recharge/discharge using stable isotopes has been limited in México. One of the main limitations is the lack of local stable isotopes monitoring for rainfall. Indeed, only two stations of the Global Network of Isotopes in Precipitation operated in Mexico from 1962 to 1988. This study reports temporal characterization of stable isotopes in meteoric waters in the northwest of Mexico that has been lacking up to the present. Stable isotope analyses of the rain collected in the city of Loreto, state of Baja California Sur, from 2018 to 2021 were conducted using laser water isotope analyzers Picarro L2110-i and Los Gatos Research LWIA-45EP. A least squares regression of the isotope data was used to obtain the local meteoric water line: δ2H =8 δ18O + 9.4 (r2=0.98). The average value of winter rain is δ18O=-2.46 ‰ and δ2H=-10.2 ‰, monsoon rain δ18O=-4.93 ‰ y δ2H=-30.3 ‰, atmospheric river rain δ18O=-5.35 ‰ and δ2H=-33.3 ‰ and tropical cyclones rain δ18O= -10.7 ‰ y δ2H=-76.3. Isotope data indicated that tropical cyclones are the main source of recharge for the coastal aquifers of Baja California, Sur.
19
Jung, Hyejung, Dong-Chan Koh, Yun Kim, Sung-Wook Jeen, and Jeonghoon Lee. "Stable Isotopes of Water and Nitrate for the Identification of Groundwater Flowpaths: A Review." Water 12, no. 1 (January 1, 2020): 138. http://dx.doi.org/10.3390/w12010138.
Full textAbstract:
Nitrate contamination in stream water and groundwater is a serious environmental problem that arises in areas of high agricultural activities or high population density. It is therefore important to identify the source and flowpath of nitrate in water bodies. In recent decades, the dual isotope analysis (δ15N and δ18O) of nitrate has been widely applied to track contamination sources by taking advantage of the difference in nitrogen and oxygen isotope ratios for different sources. However, transformation processes of nitrogen compounds can change the isotopic composition of nitrate due to the various redox processes in the environment, which often makes it difficult to identify contaminant sources. To compensate for this, the stable water isotope of the H2O itself can be used to interpret the complex hydrological and hydrochemical processes for the movement of nitrate contaminants. Therefore, the present study aims at understanding the fundamental background of stable water and nitrate isotope analysis, including isotope fractionation, analytical methods such as nitrate concentration from samples, instrumentation, and the typical ranges of δ15N and δ18O from various nitrate sources. In addition, we discuss hydrograph separation using the oxygen and hydrogen isotopes of water in combination with the nitrogen and oxygen isotopes of nitrate to understand the relative contributions of precipitation and groundwater to stream water. This study will assist in understanding the groundwater flowpaths as well as tracking the sources of nitrate contamination using the stable isotope analysis in combination with nitrate and water.
20
Vreča, Polona, and Zoltán Kern. "Use of Water Isotopes in Hydrological Processes." Water 12, no. 8 (August 7, 2020): 2227. http://dx.doi.org/10.3390/w12082227.
Full textAbstract:
Stable (16O, 17O, 18O, 1H, 2H) and radioactive (3H) isotopes in water are powerful tools in the tracking of the path of water molecules in the whole water cycle. In the last decade, a considerable number of studies have been published on the use of water isotopes, and the number continues to grow due to the development of new measurement techniques (i.e., laser absorption spectroscopy) that allow measurements of stable isotope ratios at ever-higher resolutions. Therefore, this Special Issue (SI) has been compiled to address current state-of-the-art water isotope methods, applications, and hydrological process interpretations and to contribute to the rapidly growing repository of isotope data important for future water resource management. We are pleased to present here a compilation of 14 papers reporting the use of water isotopes in the study of hydrological processes worldwide, including studies on the local and regional scales related either to precipitation dynamics or to different applications of water isotopes in combination with other hydrochemical parameters in investigations of surface water, snowmelt, soil water, groundwater, and xylem water to identify the hydrological and geochemical processes.
21
Benbow, Timothy J., Alan R. Hayman, Robert Van Hale, and Russell Frew. "Preparation of aqueous fatty acids for hydrogen and carbon stable isotope analysis by solid phase extraction." Marine and Freshwater Research 64, no. 4 (2013): 294. http://dx.doi.org/10.1071/mf12192.
Full textAbstract:
Stable isotope analyses of fatty acids in environmental waters provides important information as to their source(s). Analysis is often confounded due to low concentrations of fatty acids and/or a complex sample matrix requiring separation of the target analyte. The purpose of this study was to validate a method to extract fatty acids from natural waters using solid phase extraction (SPE) before compound specific isotope analysis (CSIA). Three SPE cartridges and multiple eluting solvents were tested to determine the efficiency, isotopic fractionation, and reproducibility of each extraction technique. Our results indicated that surface-modified styrene divinylbenzene cartridges, when eluted with methanol, caused negligible fractionation of the hydrogen isotopes and minimal fractionation of the carbon isotopes, but that isotopic fractionation occurred when compounds were only partially eluted from SPE cartridges. Compounds were also extracted from landfill leachate using both SPE and liquid–liquid extraction (LLE). The hydrogen isotope composition (δ2H) of compounds extracted from water using either method were within experimental precision and the carbon isotope composition (δ13C) of all but one fatty acid were within experimental precision. Therefore, these experiments prove the aforementioned SPE methods to be a convenient and precise method to extract fatty acids from natural waters before CSIA.
22
Alderton, David H. M. "Oxygen isotope fractionation between cassiterite and water." Mineralogical Magazine 53, no. 371 (June 1989): 373–76. http://dx.doi.org/10.1180/minmag.1989.053.371.13.
Full textAbstract:
Analysis of stable isotopes in coexisting minerals has found wide application in the study of hydrothermal mineral deposits, particularly for elucidating the temperature and source of the fluid phase involved in mineralisation. For these purposes the temperature dependence of isotopic fractionation in several mineral-water systems has already been established (e.g. Friedman and O'Neil, 1977; O'Neil, 1986). Unfortunately, the oxygen isotope fractionation between cassiterite (SnO2) and water has not been adequately characterized, and this has hindered a full utilization of oxygen isotope data derived from studies of tin deposits (e.g. Harzer, 1970; Patterson et al., 1981; Kelly and Rye, 1979). Because of this situation, an attempt is made here to derive a relationship between temperature and the fractionation of oxygen isotopes (Δ) between quartz and cassiterite, based on the fractionations observed in naturally-occurring assemblages and independent temperature estimates.
23
Babre, Alise, Andis Kalvāns, Aija Dēliņa, Konrāds Popovs, and Jānis Bikše. "Investigation of surface water – groundwater interactions in the Salaca headwaters using water stable isotopes." Folia Geographica 15 (2016): 6–9. http://dx.doi.org/10.22364/fg.15.1.
Full text
24
Hamzić Gregorčič, Staša, Doris Potočnik, Federica Camin, and Nives Ogrinc. "Milk Authentication: Stable Isotope Composition of Hydrogen and Oxygen in Milks and Their Constituents." Molecules 25, no. 17 (September 2, 2020): 4000. http://dx.doi.org/10.3390/molecules25174000.
Full textAbstract:
This paper summarises the isotopic characteristics, i.e., oxygen and hydrogen isotopes, of Slovenian milk and its major constituents: water, casein, and lactose. In parallel, the stable oxygen isotope ratios of cow, sheep, and goat’s milk were compared. Oxygen stable isotope ratios in milk water show seasonal variability and are also 18O enriched in relation to animal drinking water. The δ18Owater values were higher in sheep and goat’s milk when compared to cow milk, reflecting the isotopic composition of drinking water source and the effect of differences in the animal’s thermoregulatory physiologies. The relationship between δ18Omilk and δ18Olactose is an indication that even at lower amounts (>7%) of added water to milk can be determined. This procedure once validated on an international scale could become a reference method for the determination of milk adulteration with water.
25
Knapp, Julia L. A., Colin Neal, Alessandro Schlumpf, Margaret Neal, and James W. Kirchner. "New water fractions and transit time distributions at Plynlimon, Wales, estimated from stable water isotopes in precipitation and streamflow." Hydrology and Earth System Sciences 23, no. 10 (October 28, 2019): 4367–88. http://dx.doi.org/10.5194/hess-23-4367-2019.
Full textAbstract:
Abstract. Long-term, high-frequency time series of passive tracers in precipitation and streamflow are essential for quantifying catchment transport and storage processes, but few such data sets are publicly available. Here we describe, present, and make available to the public two extensive data sets of stable water isotopes in streamflow and precipitation at the Plynlimon experimental catchments in central Wales. Stable isotope data are available at 7-hourly intervals for 17 months, and at weekly intervals for 4.25 years. Precipitation isotope values were highly variable in both data sets, and the high temporal resolution of the 7-hourly streamwater samples revealed rich isotopic dynamics that were not captured by the weekly sampling. We used ensemble hydrograph separation to calculate new water fractions and transit time distributions from both data sets. Transit time distributions estimated by ensemble hydrograph separation were broadly consistent with those estimated by spectral fitting methods, suggesting that they can reliably quantify the contributions of recent precipitation to streamflow. We found that on average, roughly 3 % of streamwater was made up of precipitation that fell within the previous 7 h, and 13 %–15 % of streamwater was made up of precipitation that fell within the previous week. The contributions of recent precipitation to streamflow were highest during large events, as illustrated by comparing new water fractions for different discharges and precipitation rates. This dependence of new water fractions on water fluxes was also reflected in their seasonal variations, with lower new water fractions and more damped catchment transit time distributions in spring and summer compared to fall and winter. We also compared new water fractions obtained from stable water isotopes against those obtained from concentrations of chloride, a solute frequently used as a passive tracer of catchment transport processes. After filtering the chloride data for dry deposition effects, we found broadly similar new water fractions using chloride and stable water isotopes, indicating that these different tracers may yield similar inferences about catchment storage and transport, if potentially confounding factors are eliminated. These stable isotope time series comprise some of the longest and most detailed publicly available catchment isotope data sets. They complement extensive solute data sets that are already publicly available for Plynlimon, enabling a wide range of future analyses of catchment behavior.
26
Clay, A., C. Bradley, A. J. Gerrard, and M. J. Leng. "Using stable isotopes of water to infer wetland hydrological dynamics." Hydrology and Earth System Sciences 8, no. 6 (December 31, 2004): 1164–73. http://dx.doi.org/10.5194/hess-8-1164-2004.
Full textAbstract:
Abstract. This paper considers the potential of oxygen and hydrogen isotope ratios to identify spatial and temporal changes in the water source of a lowland headwater wetland situated adjacent to the River Tern in Shropshire, UK. Stable isotope composition (d18O) of end-members varied between –7.5 and –8.0‰ for groundwater, –7.3 and –8.5‰ for river-water and –4.5 and –8.0‰ for precipitation. Water samples were extracted from six nests each comprising three porous cup samplers at depths of 0.2 m, 0.5 m and 1.0 m between June 2000 and October 2001, and their isotope compositions determined. Groundwater appears to be the main source of water to the wetland, but stable isotope ratios enable seasonal variations in the contribution of precipitation to be determined, and indicate the extent of precipitation storage within the wetland. Keywords: oxygen and hydrogen isotopes, water source, hydrodynamics, lowland wetland
27
Volkmann, T. H. M., and M. Weiler. "Continual in-situ monitoring of pore water stable isotopes in the subsurface." Hydrology and Earth System Sciences Discussions 10, no. 11 (November 5, 2013): 13293–331. http://dx.doi.org/10.5194/hessd-10-13293-2013.
Full textAbstract:
Abstract. The stable isotope signature of pore water provides an integral fingerprint of water origin, flow path, transport processes, and residence times and can thus serve as a powerful tracer of hydrological processes in the unsaturated and saturated zone. However, the full potential of stable isotopes to quantitatively characterize subsurface water dynamics is yet unfolded due to the difficulty in obtaining extensive detailed and continual measurements of spatiotemporally variable pore water signatures. With the development of field-deployable laser-based isotope analyzers, such measurements are now becoming feasible. This study presents the development and application of a functional, automatable, and cost-efficient system for non-destructive continual in-situ monitoring of pore water stable isotope signatures with high resolution. The monitoring system uses automatic-controllable valve arrays to continuously extract diluted soil air water vapor via a branching network of multiple small microporous probes into a commercial isotope analyzer. Soil temperature observations are used to convert obtained vapor phase into liquid phase water isotope signatures, but these can also be obtained based on vapor concentration measurements. In-situ sampling was conducted at six depths for each of three plots planted with varying vegetation on an experimental site in SW Germany. Two different methods based on advective and diffusive soil water vapor probing were employed suitable under unsaturated and all (including saturated) moisture conditions, respectively. The advective sampling method was applied using multiple permanently installed probes (continual mode) and using a single probe subsequently inserted to sample the various locations (push-in mode), while the diffusive sampling method was applied in push-in mode only. Using a specific identical treatment onsite calibration approach along with basic corrections for instrument bias and temperature dependent free water-vapor isotopic equilibrium fractionation, the monitoring system facilitated inference of normalized liquid pore water isotopic composition with sufficiently high accuracy and precision at sampling intervals of less than four minutes and resolved the isotopic variability along natural depth profiles. Comparison indicated that the presented in-situ approaches may be used interchangeably with each other and with concurrent laboratory-based direct equilibration measurements of destructively collected samples, such that the choice of method will depend upon the task and anticipated conditions of sampling. The introduced sampling techniques provide powerful tools towards a detailed quantitative understanding of dynamic and heterogeneous shallow subsurface and vadose zone processes.
28
Nan, Yi, Fuqiang Tian, Hongchang Hu, Lixin Wang, and Sihan Zhao. "Stable Isotope Composition of River Waters across the World." Water 11, no. 9 (August 23, 2019): 1760. http://dx.doi.org/10.3390/w11091760.
Full textAbstract:
Stable isotopes of O and H in water are meaningful indicators of hydrological and ecological patterns and processes. The Global Network of Isotopes in Precipitation (GNIP) and the Global Network of Isotopes in Rivers (GNIR) are the two most important global databases of isotopes in precipitation and rivers. While the data of GNIP is almost globally distributed, GNIR has an incomplete spatial coverage, which hinders the utilization of river isotopes to study global hydrological cycle. To fill this knowledge gap, this study supplements GNIR and provides a river isotope database with global-coverage by the meta-analysis method, i.e., collecting 17015 additional data points from 215 published articles. Based on the newly compiled database, we find that (1) the relationship between δ18O and δ2H in river waters exhibits an asymmetric imbricate feature, and bifurcation can be observed in Africa and North America, indicating the effect of evaporation on isotopes; (2) multiple regression analysis with geographical factors indicates that spatial patterns of river isotopes are quite different across regions; (3) multiple regression with geographical and meteorological factors can well predict the river isotopes, which provides regional regression models with r2 of 0.50 to 0.89, and the best predictors in different regions are different. This work presents a global map of river isotopes and establishes a benchmark for further research on isotopes in rivers.
29
Kakareka, S. V., T. I. Kukharchyk, A. A. Ekaykin, and Yu G. Giginyak. "Stable isotopes in the snow of the coastal areas of Antarctica." Doklady of the National Academy of Sciences of Belarus 65, no. 4 (September 2, 2021): 495–502. http://dx.doi.org/10.29235/1561-8323-2021-65-4-495-502.
Full textAbstract:
The first results of study of stable isotopes of oxygen (δ18O) and hydrogen (δD) in the snow samples taken on the islands of Marguerite Bay (Antarctic Peninsula), in the Vecherny Oasis (Enderby Land), and Larsemann Hills (Princess Elizabeth Land) by the participants of the 12th Belarusian Antarctic Expedition (January–March 2020) are presented. The concentration of water isotopes: deuterium (D) and oxygen-18 (18O) in the samples was determined using a laser isotope composition analyzer Picarro L2130. A total of 32 snow samples were analyzed. The statistical parameters of the isotopic composition of snow were estimated, and the main differences in the content of δ18O and δD between the study areas were shown. A decrease in the content of heavy oxygen and hydrogen isotopes in the newly fallen snow to the old snow of the surface horizons is shown. The maximum values of δ18O and δD are typical for the Maritime Antarctica, decreasing towards the coastal zone and further – towards its continental part. The possible factors affecting the isotope content are described. It is shown that the monitoring of the isotope composition can be an integral part of the monitoring of climatic changes within the area of operation of the Belarusian Antarctic Expedition. The study of the isotopic composition of surface snow is important for the reconstruction of the paleoclimate of the marginal zone of the Antarctic ice sheet based on the ice cores study.
30
McNicol, Gavin, Zhongjie Yu, Z. Carter Berry, Nathan Emery, Fiona M. Soper, and Wendy H. Yang. "Tracing plant–environment interactions from organismal to planetary scales using stable isotopes: a mini review." Emerging Topics in Life Sciences 5, no. 2 (February 26, 2021): 301–16. http://dx.doi.org/10.1042/etls20200277.
Full textAbstract:
Natural isotope variation forms a mosaic of isotopically distinct pools across the biosphere and flows between pools integrate plant ecology with global biogeochemical cycling. Carbon, nitrogen, and water isotopic ratios (among others) can be measured in plant tissues, at root and foliar interfaces, and in adjacent atmospheric, water, and soil environments. Natural abundance isotopes provide ecological insight to complement and enhance biogeochemical research, such as understanding the physiological conditions during photosynthetic assimilation (e.g. water stress) or the contribution of unusual plant water or nutrient sources (e.g. fog, foliar deposition). While foundational concepts and methods have endured through four decades of research, technological improvements that enable measurement at fine spatiotemporal scales, of multiple isotopes, and of isotopomers, are advancing the field of stable isotope ecology. For example, isotope studies now benefit from the maturation of field-portable infrared spectroscopy, which allows the exploration of plant–environment sensitivity at physiological timescales. Isotope ecology is also benefiting from, and contributing to, new understanding of the plant–soil–atmosphere system, such as improving the representation of soil carbon pools and turnover in land surface models. At larger Earth-system scales, a maturing global coverage of isotope data and new data from site networks offer exciting synthesis opportunities to merge the insights of single-or multi-isotope analysis with ecosystem and remote sensing data in a data-driven modeling framework, to create geospatial isotope products essential for studies of global environmental change.
31
ROSADO, BRUNO H. P., EDUARDO A. DE MATTOS, and LEONEL DA S. L. STERNBERG. "Are leaf physiological traits related to leaf water isotopic enrichment in restinga woody species?" Anais da Academia Brasileira de Ciências 85, no. 3 (September 2013): 1035–46. http://dx.doi.org/10.1590/s0001-37652013005000051.
Full textAbstract:
During plant-transpiration, water molecules having the lighter stable isotopes of oxygen and hydrogen evaporate and diffuse at a faster rate through the stomata than molecules having the heavier isotopes, which cause isotopic enrichment of leaf water. Although previous models have assumed that leaf water is well-mixed and isotopically uniform, non-uniform stomatal closure, promoting different enrichments between cells, and different pools of water within leaves, due to morpho-physiological traits, might lead to inaccuracies in isotopic models predicting leaf water enrichment. We evaluate the role of leaf morpho-physiological traits on leaf water isotopic enrichment in woody species occurring in a coastal vegetation of Brazil known as restinga. Hydrogen and oxygen stable isotope values of soil, plant stem and leaf water and leaf traits were measured in six species from restinga vegetation during a drought and a wet period. Leaf water isotopic enrichment relative to stem water was more homogeneous among species during the drought in contrast to the wet period suggesting convergent responses to deal to temporal heterogeneity in water availability. Average leaf water isotopic enrichment relative to stem water during the drought period was highly correlated with relative apoplastic water content. We discuss this observation in the context of current models of leaf water isotopic enrichment as a function of the Péclet effect. We suggest that future studies should include relative apoplastic water content in isotopic models.
32
Swart, Peter K., and Jim J. Leder. "The utility of stable isotopic signatures in coral skeletons." Paleontological Society Papers 1 (October 1996): 249–91. http://dx.doi.org/10.1017/s1089332600000127.
Full textAbstract:
There is a fundamental ecologic differentiation between zooxanthellate and non-zooxanthellate corals. This paper reviews factors which govern the stable carbon and oxygen isotopic composition of these groups of corals. Although the stable carbon and oxygen isotope compositions of coral skeletons are strongly influenced by environmental and physiological factors, the precise mechanisms remain a matter of debate. In particular the oxygen isotopic composition is known to be governed by the temperature and the oxygen isotopic composition of the water and perhaps also by kinetic factors. In contrast the carbon isotopic composition is controlled by a combination of photosynthesis, respiration, autotrophy, heterotrophy, and the isotopic composition of dissolved inorganic carbon. Using a combination of carbon and oxygen isotopes it is possible to distinguish zooxanthellate from non-zooxanthellate corals.
33
Volkmann, T. H. M., and M. Weiler. "Continual in situ monitoring of pore water stable isotopes in the subsurface." Hydrology and Earth System Sciences 18, no. 5 (May 20, 2014): 1819–33. http://dx.doi.org/10.5194/hess-18-1819-2014.
Full textAbstract:
Abstract. Stable isotope signatures provide an integral fingerprint of origin, flow paths, transport processes, and residence times of water in the environment. However, the full potential of stable isotopes to quantitatively characterize subsurface water dynamics is yet unfolded due to the difficulty in obtaining extensive, detailed, and repeated measurements of pore water in the unsaturated and saturated zone. This paper presents a functional and cost-efficient system for non-destructive continual in situ monitoring of pore water stable isotope signatures with high resolution. Automatic controllable valve arrays are used to continuously extract diluted water vapor in soil air via a branching network of small microporous probes into a commercial laser-based isotope analyzer. Normalized liquid-phase isotope signatures are then obtained based on a specific on-site calibration approach along with basic corrections for instrument bias and temperature dependent isotopic fractionation. The system was applied to sample depth profiles on three experimental plots with varied vegetation cover in southwest Germany. Two methods (i.e., based on advective versus diffusive vapor extraction) and two modes of sampling (i.e., using multiple permanently installed probes versus a single repeatedly inserted probe) were tested and compared. The results show that the isotope distribution along natural profiles could be resolved with sufficiently high accuracy and precision at sampling intervals of less than four minutes. The presented in situ approaches may thereby be used interchangeably with each other and with concurrent laboratory-based direct equilibration measurements of destructively collected samples. It is thus found that the introduced sampling techniques provide powerful tools towards a detailed quantitative understanding of dynamic and heterogeneous shallow subsurface and vadose zone processes.
34
Mazariegos, Junior G., Jennifer C. Walker, Xiaomei Xu, and Claudia I. Czimczik. "Tracing Artificially Recharged Groundwater using Water and Carbon Isotopes." Radiocarbon 59, no. 2 (August 11, 2016): 407–21. http://dx.doi.org/10.1017/rdc.2016.51.
Full textAbstract:
AbstractWe conducted an isotopic analysis of groundwater in Orange County, California, USA, around the Talbert Seawater Injection Barrier to determine if recycled water, used to artificially recharge local aquifers, carries a unique isotopic signature that can be used as a tracer. From September 2014 to April 2015, we collected groundwater from six privately owned wells within the coastal groundwater basin, along with various surface waters. All water samples were analyzed for their stable isotopic composition (δ18O, δD), the δ13C and 14C signature of the dissolved inorganic carbon (DIC) pool, DIC concentration, pH, and salinity. The DIC of groundwater mixing with recycled water is enriched in 14C above natural background levels, with varying signal strength through time, depleted in δ13C, and low in DIC concentration. Water isotopes further suggest that recycled water is a mixture of Colorado River water and regional groundwater. In contrast, groundwater found further away from the injection barrier has carbon and water isotope composition consistent with regional groundwater and Santa Ana River water. Our findings imply that recycled water injected through the Talbert Barrier is isotopically unique, and that 14C enrichment may be used as an intrinsic tracer of artificial recharge within the basin.
35
Benettin, Paolo, Till H. M. Volkmann, Jana von Freyberg, Jay Frentress, Daniele Penna, Todd E. Dawson, and James W. Kirchner. "Effects of climatic seasonality on the isotopic composition of evaporating soil waters." Hydrology and Earth System Sciences 22, no. 5 (May 15, 2018): 2881–90. http://dx.doi.org/10.5194/hess-22-2881-2018.
Full textAbstract:
Abstract. Stable water isotopes are widely used in ecohydrology to trace the transport, storage, and mixing of water on its journey through landscapes and ecosystems. Evaporation leaves a characteristic signature on the isotopic composition of the water that is left behind, such that in dual-isotope space, evaporated waters plot below the local meteoric water line (LMWL) that characterizes precipitation. Soil and xylem water samples can often plot below the LMWL as well, suggesting that they have also been influenced by evaporation. These soil and xylem water samples frequently plot along linear trends in dual-isotope space. These trend lines are often termed “evaporation lines” and their intersection with the LMWL is often interpreted as the isotopic composition of the precipitation source water. Here we use numerical experiments based on established isotope fractionation theory to show that these trend lines are often by-products of the seasonality in evaporative fractionation and in the isotopic composition of precipitation. Thus, they are often not true evaporation lines, and, if interpreted as such, can yield highly biased estimates of the isotopic composition of the source water.
36
Busari, M. A., F. K. Salako, C. Tuniz, G. M. Zuppi, B. Stenni, M. T. Adetunji, and T. A. Arowolo. "Estimation of soil water evaporative loss after tillage operation using the stable isotope technique." International Agrophysics 27, no. 3 (September 1, 2013): 257–64. http://dx.doi.org/10.2478/v10247-012-0093-8.
Full textAbstract:
Abstract Application of stable isotopes in soil studies has improved quantitative evaluation of evaporation and other hydrological processes in soil. This study was carried out to determine the effect of tillage on evaporative loss of water from the soil. Zero tillage and conventional tillage were compared. Suction tubes were installed for soil water collection at the depths 0.15, 0.50, and 1.0 m by pumping soil water with a peristaltic pump. Soil water evaporation was estimated using stable isotopes of water. The mean isotopic composition of the soil water at 0.15 m soil depth were -1.15‰ (δ18O) and -0.75‰ (δD) and were highly enriched compared with the isotopic compositions of the site precipitation. Soil water stable isotopes (δ18O and δD) were more enriched near the surface under zero tillage while they were less negative down the profile under zero tillage. This suggests an occurrence of more evaporation and infiltration under conventional then zero tillage, respectively, because evaporative fractionation contributes to escape of lighter isotopes from liquid into the vapour phase leading to enrichment in heavy isotopes in the liquid phase. The annual evaporation estimated using the vapour diffusion equation ranges from 46-70 and 54-84 mm year-1 under zero and conventional tillage, respectively, indicating more evaporation under conventional tillage compared with zero tillage. Therefore, to reduce soil water loss, adoption of conservation tillage practices such as zero tillage is encouraged.
37
Smith, Abigail M., and Marcus M. Key. "Controls, variation, and a record of climate change in detailed stable isotope record in a single bryozoan skeleton." Quaternary Research 61, no. 2 (March 2004): 123–33. http://dx.doi.org/10.1016/j.yqres.2003.11.001.
Full textAbstract:
The long-lived (about 20 yr) bryozoan Adeonellopsis sp. from Doubtful Sound, New Zealand, precipitates aragonite in isotopic equilibrium with seawater, exerting no metabolic or kinetic effects. Oxygen isotope ratios (δ18O) in 61 subsamples (along three branches of a single unaltered colony) range from −0.09 to +0.68‰ PDB (mean = +0.36‰ PDB). Carbon isotope ratios (δ13C) range from +0.84 to +2.18‰ PDB (mean = +1.69‰ PDB). Typical of cool-water carbonates, δ18O-derived water temperatures range from 14.2 to 17.5 °C. Adeonellopsis has a minimum temperature growth threshold of 14 °C, recording only a partial record of environmental variation. By correlating seawater temperatures derived from δ18O with the Southern Oscillation Index, however, we were able to detect major events such as the 1983 El Niño. Interannual climatic variation can be recorded in skeletal carbonate isotopes. The range of within-colony isotopic variability found in this study (0.77‰ in δ18O and 1.34 in δ13C) means that among-colony variation must be treated cautiously. Temperate bryozoan isotopes have been tested in less than 2% of described extant species — this highly variable phylum is not yet fully understood.
38
Abiye, Tamiru A., Molla B. Demlie, and Haile Mengistu. "An Overview of Aquifer Physiognomies and the δ18O and δ2H Distribution in the South African Groundwaters." Hydrology 8, no. 2 (April 19, 2021): 68. http://dx.doi.org/10.3390/hydrology8020068.
Full textAbstract:
A comprehensive assessment of the stable isotope distribution in the groundwater systems of South Africa was conducted in relation to the diversity in the aquifer lithology and corresponding hydraulic characteristics. The stable isotopes of oxygen (18O) and hydrogen (2H) in groundwater show distinct spatial variation owing to the recharge source and possibly mixing effect in the aquifers with the existing water, where aquifers are characterized by diverse hydraulic conductivity and transmissivity values. When the shallow aquifer that receives direct recharge from rainfall shows a similar isotopic signature, it implies less mixing effect, while in the case of deep groundwater interaction between recharging water and the resident water intensifies, which could change the isotope signature. As aquifer depth increases the effect of mixing tends to be minimal. In most cases, the isotopic composition of recharging water shows depletion in the interior areas and western arid zones which is attributed to the depleted isotopic composition of the moisture source. The variations in the stable isotope composition of groundwater in the region are primarily controlled by the isotope composition of the rainfall, which shows variable isotope composition as it was observed from the local meteoric water lines, in addition to the evaporation, recharge and mixing effects.
39
Barbieri, Maurizio. "Isotopes in Hydrology and Hydrogeology." Water 11, no. 2 (February 7, 2019): 291. http://dx.doi.org/10.3390/w11020291.
Full textAbstract:
The structure, status, and processes of the groundwater system, which can only be acquired through scientific research efforts, are critical aspects of water resource management. Isotope hydrology and hydrogeology is a genuinely interdisciplinary science. It developed from the application of methods evolved in physics (analytical techniques) to problems of Earth and the environmental sciences since around the 1950s. In this regard, starting from hydrogeochemical data, stable and radioactive isotope data provide essential tools in support of water resource management. The inventory of stable isotopes, which has significant implications for water resources management, has grown in recent years. Methodologies based on the use of isotopes in a full spectrum of hydrological problems encountered in water resource assessment, development, and management activities are already scientifically established and are an integral part of many water resource investigations and environmental studies. The driving force behind this Special Issue was the need to point the hydrological and water resource management societies in the direction of up-to-date research and best practices.
40
Sprenger, Matthias, Pilar Llorens, Carles Cayuela, Francesc Gallart, and Jérôme Latron. "Mechanisms of consistently disjunct soil water pools over (pore) space and time." Hydrology and Earth System Sciences 23, no. 6 (June 28, 2019): 2751–62. http://dx.doi.org/10.5194/hess-23-2751-2019.
Full textAbstract:
Abstract. The storage and release of water in soils is critical for sustaining plant transpiration and groundwater recharge. However, how much subsurface mixing of water occurs, and how much of the water is available for plants or otherwise percolates to streams and the groundwater is not yet understood. Based on stable isotope (2H and 18O) data, some studies have found that water infiltrating into soils can bypass older pore water. However, the mechanisms leading to the separation of water routed to the streams and water held tightly in smaller pores are still unclear. Here, we address the current limitations of the understanding of subsurface mixing and their consequences regarding the application of stable isotopes in ecohydrological studies. We present an extensive data set, for which we sampled the isotopic composition of mobile and bulk soil water in parallel with groundwater at a fortnightly temporal resolution and stream water and rainfall at a much higher resolution in a Mediterranean long-term research catchment, in Vallcebre, Spain. The data reveal that the mobile and tightly bound water of a silty loam soil in a Scots pine forest do not mix well; however, they constitute two disjunct subsurface water pools with little exchange, despite intense rainfall events leading to high soil wetness. We show that the isotopic compartmentalization results from the rewetting of small soil pores by isotopically depleted winter/spring rain. Thus, stable isotopes, and, in turn, water residence times, do not only vary across soil depth, but also across soil pores. Our findings have important implications for stable isotope applications in ecohydrological studies assessing the water uptake by plants or the process realism of hydrological models, as the observed processes are currently rarely implemented in the simulation of water partitioning into evapotranspiration and recharge in the critical zone.
41
Cervi, Dadomo, and Martinelli. "The Analysis of Short-Term Dataset of Water Stable Isotopes Provides Information on Hydrological Processes Occurring in Large Catchments from the Northern Italian Apennines." Water 11, no. 7 (June 30, 2019): 1360. http://dx.doi.org/10.3390/w11071360.
Full textAbstract:
This study discusses a dataset of water stable isotopes from precipitation (4 rain gauges) and surficial water (9 rivers) from the northern Italian Apennines, an area in which clay-rich bedrocks widely outcrop and the runoff response to precipitation events is very rapid. The dataset has been compiled starting from existing data that had previously been published in the literature and consists of monthly values of stable isotopes oxygen-18 (18O) and deuterium (2H) lasting over the period from January 2003 to December 2006 (precipitation) and from January 2006 to December 2007 (surficial water). For this period, mean residence times estimated by means of a sine-wave fitting technique make evident the significant differences over time spent by water molecules within the 9 catchments. Moreover, isotopic compositions of rivers deviated from those of precipitations revealing the influence of some catchment characteristics in differentiating the isotopic composition in rivers. Further correlations between mean residence times of river water and selected catchment characteristics reveal the role of orography and bedrocks in delaying the water molecules during their flow-paths. In addition, time series and cross–correlation analyses indicate a certain control by the main watershed divide on the isotopic composition of river waters, which is reflected in a progressive isotopic variation with longitude. The study shows that, despite using a short-time dataset (2-years for surficial water) of sparse stable isotopes can provide remarkable indications for depicting hydrological processes in large catchments made up of clay-rich bedrocks.
42
Pfahl, S., H. Wernli, and K. Yoshimura. "The isotopic composition of precipitation from a winter storm – a case study with the limited-area model COSMO<sub>iso</sub>." Atmospheric Chemistry and Physics Discussions 11, no. 9 (September 22, 2011): 26521–70. http://dx.doi.org/10.5194/acpd-11-26521-2011.
Full textAbstract:
Abstract. Stable water isotopes are valuable tracers of the atmospheric water cycle, and potentially provide useful information also on weather-related processes. In order to further explore this potential, the water isotopes H218O and HDO are incorporated into the limited-area model COSMO. In a first case study, the new COSMOiso model is used for simulating a winter storm event in January 1986 over the eastern United States associated with intense frontal precipitation. The modelled isotope ratios in precipitation and water vapour are compared to spatially distributed δ18O observations. COSMOiso very accurately reproduces the statistical distribution of δ18O in precipitation, and also the synoptic-scale spatial pattern and temporal evolution agree well with the measurements. Perpendicular to the front that triggers most of the rainfall during the event, the model simulates a gradient in the isotopic composition of the precipitation, with high δ18O values in the warm air and lower values in the cold sector behind the front. This spatial pattern is created through an interplay of large scale air mass advection, removal of heavy isotopes by precipitation at the front and microphysical interactions between rain drops and water vapour beneath the cloud base. This investigation illustrates the usefulness of high resolution, event-based model simulations for understanding the complex processes that cause synoptic-scale variability of the isotopic composition of atmospheric waters. In future research, this will be particularly beneficial in combination with laser spectrometric isotope observations with high temporal resolution.
43
Pfahl, S., H. Wernli, and K. Yoshimura. "The isotopic composition of precipitation from a winter storm – a case study with the limited-area model COSMO<sub>iso</sub>." Atmospheric Chemistry and Physics 12, no. 3 (February 14, 2012): 1629–48. http://dx.doi.org/10.5194/acp-12-1629-2012.
Full textAbstract:
Abstract. Stable water isotopes are valuable tracers of the atmospheric water cycle, and potentially provide useful information also on weather-related processes. In order to further explore this potential, the water isotopes H218O and HDO are incorporated into the limited-area model COSMO. In a first case study, the new COSMOiso model is used for simulating a winter storm event in January 1986 over the eastern United States associated with intense frontal precipitation. The modelled isotope ratios in precipitation and water vapour are compared to spatially distributed δ18O observations. COSMOiso very accurately reproduces the statistical distribution of δ18O in precipitation, and also the synoptic-scale spatial pattern and temporal evolution agree well with the measurements. Perpendicular to the front that triggers most of the rainfall during the event, the model simulates a gradient in the isotopic composition of the precipitation, with high δ18O values in the warm air and lower values in the cold sector behind the front. This spatial pattern is created through an interplay of large scale air mass advection, removal of heavy isotopes by precipitation at the front and microphysical interactions between rain drops and water vapour beneath the cloud base. This investigation illustrates the usefulness of high resolution, event-based model simulations for understanding the complex processes that cause synoptic-scale variability of the isotopic composition of atmospheric waters. In future research, this will be particularly beneficial in combination with laser spectrometric isotope observations with high temporal resolution.
44
Lisowska-Gaczorek, Aleksandra, Beata Cienkosz-Stepańczak, and Krzysztof Szostek. "Oxygen stable isotopes variation in water precipitation in Poland – anthropological applications." Anthropological Review 80, no. 1 (March 1, 2017): 57–70. http://dx.doi.org/10.1515/anre-2017-0005.
Full textAbstract:
Abstract The main objective of oxygen isotope analysis is to determine the probable place of origin of an individual or the reconstruction of migration paths. The research are methodologically based on referencing oxygen isotope ratios of apatite phosphates (δ18Op) to the range of environmental background δ18O, most frequently determined on the basis of precipitation. The present work is a response to the need for providing background for oxygen isotope studies on skeletons excavated in Poland. Currently there no monitoring of the isotope composition of precipitation water in Poland is conducted. For this reason, based on the data generated in the Online Isotopes In Precipitation Calculator (OIPC), a database was developed, containing δ18O levels in precipitation for locations in which exploration work was carried out in the archaeological fields from Poland. In total, 279 locations were analysed. The result of the data analysis was a complete isotope composition map for Poland with four zones distinguished by δ18Ow values. The observable differences in oxygen isotope composition of precipitation in Poland are sufficient to trace migrations of individuals and populations, although accurate only at the level of macroregions.
45
Andhihutomo, Rismah Taufik, Satrio Satrio, Rasi Prasetio, and Agus Budhie Wijatna. "Studi Interaksi Air Tanah Dangkal dan Air Sungai di Sepanjang Daerah Aliran Kali Garang Semarang Menggunakan Isotop Stabil δ18O dan δ2H." EKSPLORIUM 38, no. 1 (June 21, 2017): 43. http://dx.doi.org/10.17146/eksplorium.2017.38.1.3247.
Full textAbstract:
ABSTRAKPenelitian mengenai interaksi airtanah dangkal dengan air sungai Kali Garang di Semarang, Jawa Tengah, menggunakan parameter isotop 18O dan 2H telah dilakukan. Sebanyak 16 sampel air tanah dangkal dan 3 sampel air sungai diambil untuk analisis kandungan isotop stabil d18O dan d2H menggunakan alat Liquid Water Isotope Analyzer LGR DLT-100. Hasil analisis memperlihatkan adanya dua asal daerah masukan air: daerah pertama memiliki kandungan isotop d18O antara -9,41 ‰ hingga-8,5 ‰ dan d2H antara -58,2 ‰ hingga -51,6 ‰; daerah kedua memiliki kandungan isotop d18O dan d2H masing-masing -7,15 ‰ dan -41,55 ‰. Dengan demikian, hasil tersebut mengindikasikan bahwa sampel-sampel air pertama berasal dari elevasi yang relatif lebih tinggi jika dibandingkan dengan asal sampel air kedua, namun keduanya tidak mengalami interaksi dengan air sungai. Sedangkan sampel air tanah lainnya menunjukkan bahwa satu sampel (R4) memiliki interelasi berupa pencampuran dengan air sungai dan dua sampel lainnya (L1 dan R1) mengalami pencampuran dengan air asin atau air laut. ABSTRACTA study related to shallow groundwater interaction with Kali Garang River water in Semarang, Central Java using stable isotopes of 18O and 2H has been conducted. As much as 16 groundwater and 3 river water samples were taken for stable isotopes d18O and d2H analysis using Liquid water isotope analyzer LGR DLT-100. The results of analysis shows that there are two area of water recharge origin: the first area contains d18O isotope ranging between -9.41 ‰ to -8.5 ‰ and d2H between -58.2 ‰ to -51.6 ‰; the second area contains isotopes of d18O and d2H -7.15 and -41.55 ‰, respectively. Thus, these results indicate that the first water samples originate from a higher elevation than the origin of the second water sample, but both of them have no interrelation with river water. Whereas, other groundwater samples show that the sample (R4) has interrelation (i.e. mixing) with the river water and two other samples (L1 and R1) have interrelation with salty water or seawater.
46
Ford, William, Mark R. Williams, Megan B. Young, Kevin W. King, and Eric Fischer. "Assessing Intra-Event Phosphorus Dynamics in Drainage Water Using Phosphate Stable Oxygen Isotopes." Transactions of the ASABE 61, no. 4 (2018): 1379–92. http://dx.doi.org/10.13031/trans.12804.
Full textAbstract:
Abstract. Quantifying fluxes and pathways of dissolved reactive phosphorus (DRP) in tile-drained landscapes has been hampered by a lack of measurements that are sensitive to P fate and transport processes. One potential tool to help understand these dynamics is the oxygen isotope signature of phosphate (d18OPO4); however, its potential benefits and limitations are not well understood for intra-event dynamics at the field scale. The objectives of this study were to quantify intra-event variability of d18OPO4 signatures in tile drainage water and assess the efficacy of d18OPO4 to elucidate mechanisms and flow pathways controlling DRP transport to tile drains. We collected water samples during a summer storm event from a subsurface (tile)-drained field located in west-central Ohio and analyzed for d18OPO4 of DRP. Supplementary water quality measurements, hydrologic modeling, and soil temperature data were used to help understand intra-event d18OPO4 dynamics. Results of the soil extraction analysis from our study site highlight that the soil water-extractable P (WEP) pool was not in equilibrium with long-term, temperature-dependent water isotope values. This result suggests that P-rich soils may, at least partially, retain their original source signature, which has significant implications for identifying hotspots of P delivery in watershed-scale applications. Results of the storm event analysis highlight that equilibration of leached DRP in soil water creates a gradient between isotopic compositions of pre-event shallow subsurface sources, pre-event deep subsurface sources, and the WEP tied up in surface soils. The current study represents the first intra-event analysis of d18OPO4 and highlights the potential for phosphate oxygen isotopes as a novel tool to improve understanding of P fate and transport in artificially drained agroecosystems. Keywords: Agriculture, Edge-of-field, Macropores, Phosphate oxygen isotopes, Tile-drainage.
47
Hussain, Shakir, Song Xianfang, Iqtidar Hussain, Liu Jianrong, Han Dong Mei, Yang Li Hu, and Wei Huang. "Controlling Factors of the Stable Isotope Composition in the Precipitation of Islamabad, Pakistan." Advances in Meteorology 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/817513.
Full textAbstract:
Significant temporal variations inδ18O and deuterium isotopes were found in the rainfall water of Islamabad, Pakistan, over a 15-year period (1992–2006). The data were obtained from the International Atomic Energy Agency/Global Network of Isotopes in Precipitation (IAEA/GNIP) database, and statistical correlations were investigated. In particular, this study provides the first detailed analysis of GNIP data for Islamabad. Both dry (1999-2000) and wet years (1994, 1997, and 2000) were chosen to investigate the correlations between precipitation amount, vapor flux, and temperature. We observed obvious differences between the dry and wet years and among seasons as well. Long-term features in the isotope composition agreed with the global meteorological water line, whereas short-term values followed rainfall amounts; that is, a total of 72% of the precipitation’s isotopic signature was dependent on the rainfall amount, and temperature controlled 73% of the isotopic features during October to May. The lowerd-excess values were attributed to conditions during the spring season and a secondary evaporation boost during dry years; precipitation originating from the Mediterranean Sea showed highd-excess values. Overall, the results of this study contribute to the understanding of precipitation variations and their association with water vapor transport over Islamabad, Pakistan.
48
Halder, J., S. Terzer, L. I. Wassenaar, L. J. Araguás-Araguás, and P. K. Aggarwal. "The Global Network of Isotopes in Rivers (GNIR): integration of water isotopes in watershed observation and riverine research." Hydrology and Earth System Sciences 19, no. 8 (August 5, 2015): 3419–31. http://dx.doi.org/10.5194/hess-19-3419-2015.
Full textAbstract:
Abstract. We introduce a new online global database of riverine water stable isotopes (Global Network of Isotopes in Rivers, GNIR) and evaluate its longer-term data holdings. Overall, 218 GNIR river stations were clustered into three different groups based on the seasonal variation in their isotopic composition, which was closely coupled to precipitation and snowmelt water runoff regimes. Sinusoidal fit functions revealed phases within each grouping and deviations from the sinusoidal functions revealed important river alterations or hydrological processes in these watersheds. The seasonal isotopic amplitude of δ18O in rivers averaged 2.5 ‰, and did not increase as a function of latitude, like it does for global precipitation. Low seasonal isotopic amplitudes in rivers suggest the prevalence of mixing and storage such as occurs via lakes, reservoirs, and groundwater. The application of a catchment-constrained regionalized cluster-based water isotope prediction model (CC-RCWIP) allowed for direct comparison between the expected isotopic compositions for the upstream catchment precipitation with the measured isotopic composition of river discharge at observation stations. The catchment-constrained model revealed a strong global isotopic correlation between average rainfall and river discharge (R2 = 0.88) and the study demonstrated that the seasonal isotopic composition and variation of river water can be predicted. Deviations in data from model-predicted values suggest there are important natural or anthropogenic catchment processes like evaporation, damming, and water storage in the upstream catchment.
49
Halder, J., S. Terzer, L. I. Wassenaar, L. J. Araguás-Araguás, and P. K. Aggarwal. "The Global Network of Isotopes in Rivers (GNIR): integration of water isotopes in watershed observation and riverine research." Hydrology and Earth System Sciences Discussions 12, no. 4 (April 22, 2015): 4047–79. http://dx.doi.org/10.5194/hessd-12-4047-2015.
Full textAbstract:
Abstract. We introduce a new online global database of riverine water stable isotopes (Global Network of Isotopes in Rivers) and evaluate its longer-term data holdings. Overall, 218 GNIR river stations were clustered into 3 different groups based on the seasonal variation in their isotopic composition, which was closely coupled to precipitation and snow-melt water run-off regimes. Sinusoidal fit functions revealed periodic phases within each grouping and deviations from the sinusoidal functions revealed important river alterations or hydrological processes in these watersheds. The seasonal isotopic amplitude of δ18O in rivers averaged 2.5 ‰, and did not increase as a function of latitude, as it does for global precipitation. Low seasonal isotopic amplitudes in rivers suggest the prevalence of mixing and storage such as occurs via lakes, reservoirs, and groundwater. The application of a catchment-constrained regionalized cluster-based water isotope prediction model (CC-RCWIP) allowed direct comparison between the expected isotopic composition for the upstream catchment precipitation with the measured isotopic composition of river discharge at observation stations. The catchment-constrained model revealed a strong global isotopic correlation between average rainfall and river discharge (R2 = 0.88) and the study demonstrated that the seasonal isotopic composition and variation of river water can be predicted. Deviations in data from model predicted values suggest there are important natural or anthropogenic catchment processes, like evaporation, damming, and water storage in the upstream catchment.
50
Wang, Yong Sen, Zheng He Xu, and Si Fang Dong. "An Oxygen Isotope Study of Seasonal Trends in Jinxiuchuan River of Jinan South Mountain." Applied Mechanics and Materials 522-524 (February 2014): 954–57. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.954.
Full textAbstract:
The stable isotope composition of river water contains some information of water cycle and climatic factors, such as precipitation, evaporation and temperature. Oxygen isotopes in river water were monitored at one site in Jinxiuchuang basin of Jinan southern mountain.δ18O values of river water show a variation from-7.82 on July 6 to-9.98 on June 6. The result reveals that the river water was mainly supplied by the precipitation. The isotopic variations at Jinxiuchuan river have strong precipitation patterns owning to different rainfall in summer.