scholarly journals Characteristics of Stable Isotopes in Precipitation and Their Moisture Sources in the Guanling Region, Guizhou Province

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jialu Wang ◽  
Weijie Li ◽  
Yong Wang ◽  
Jiaojiao Zhang ◽  
Shizhen Xiao
Keyword(s):  
Stable Isotopes ◽  
Meteoric Water ◽  
Guizhou Province ◽  
Monsoon Period ◽  
Water Line ◽  
Meteoric Water Line ◽  
National Centre ◽  
Winter Half ◽  
Summer Half ◽  
Environmental Prediction

Environmental prediction is one of the crucial means for social sustainable development. Based on the continuous sampling of atmospheric precipitation in Guanling County, Guizhou Province, China, from March 2016 to February 2017, and combining the reanalyzed data of the National Centre for Environmental Prediction/National Centre for Atmospheric Research with the Hybrid Single-Particle Lagrangian Integrated Trajectory model, this paper analyzed the variations of δ2H and δ18O in precipitation at the synoptic scale in the Guanling region. The results showed that the variations of δ2H, δ18O, and d-excess values in precipitation exhibited remarkable seasonal variability. The stable isotopic values in precipitation in the winter half-year were higher than those in the summer half-year. The meteoric water line of the winter half-year was close to the annual meteoric water line. The results showed that there was more than one fundamental source of moisture. It was affected by the winter monsoon period, which is longer than the summer monsoon period, so the local evaporation of water vapor participating in the water circulation had a greater impact. With the increase of precipitation, the intercept and slope of the meteoric water line gradually decreased, which indicated that the secondary evaporation was weak under the effect of stable isotope subcloud cluster. The correlations of precipitation δ18O with temperature T and precipitation P vary with time scales. As the time scale decreased, the correlation between δ18O and the temperature and precipitation improved. When P  ≤ 5 mm and 10°C < T ≤ 30°C, the most sensitive changes in stable isotopes were observed. In the study area, the backward trajectory model showed that the moisture in the winter half of the year was mainly from the transportation of the westerlies wind, replenishment, and local reevaporation of near-source ocean water, while the water in the summer half of the year mainly came from the transportation of water from the ocean at low latitudes.

scholarly journals Isotope Evidence of Rainfall and Groundwater for Tracing Recharge Areas in Kaeng Khoi District, Saraburi Province, Thailand

2016 ◽  
pp. 49-58 ◽  
Author(s):  
Wanlapa Wisittammasri ◽  
Srilert Chotpantarat
Keyword(s):  
Stable Isotopes ◽  
Surface Water ◽  
Stable Isotope ◽  
Meteoric Water ◽  
Water Line ◽  
Meteoric Water Line ◽  
Isotope Technique ◽  
Isotope Evidence ◽  
Stable Isotope Technique ◽  
Central Thailand

This study was conducted in the districts of Kaeng Khoi and Muang, located in the center of Saraburiprovince, Central Thailand. The purpose was to use a stable isotope technique to iden-tify recharge areas where rainfall infiltrates. Analysis of stable isotopes in groundwater, surface water and rainwater were conducted in September 2014. Isotope compositions of groundwater were found to have δD values that ranged from -37.55‰ to -48.04‰ while δ18O values ranged from -5.30‰ to -7.34‰. The Local Meteoric Water Line (LMWL) in the study area was indis-tinguishablefrom the Bangkok Local Meteoric Water Line (BKK LMWL), and the stable iso-tope values of rainwater in area were more depleted than BKK LMWL. The isotope compo-sitions of surface water revealed that the effect of evaporation could divide the groundwater into two groups, with the first group locally receiving rainfall and the second group interacting directly with surface water. Therefore, care must be taken to prevent groundwater contamination in the latter group due to polluted surface water caused by human activities.

scholarly journals Hydrochemical and Isotopic Study of Water Resources in Khan Al-Baghdadi Area, Al- Anbar Province / West of Iraq

2021 ◽  
pp. 204-217
Author(s):  
Sarmad Jamal Hussien ◽  
Firas Mudhafar Abdulhussein
Keyword(s):  
Stable Isotopes ◽  
Surface Water ◽  
Water Resources ◽  
Meteoric Water ◽  
Hard Water ◽  
Euphrates River ◽  
Water Line ◽  
Meteoric Water Line ◽  
Groundwater Samples ◽  
Surface And Groundwater

This hydrochemical study of the surface and groundwater in Khan AL-Baghdadi  area, western Iraq,  included the interpretation of physical, chemical, and biological properties. Water samples were collected from wells (14 samples) and surface water of Euphrates River (6 samples) for the dry and wet periods of October 2018 and April 2019, respectively. The stable isotopes analysis was performed for the dry period only. The surface water samples were characterized by slightly alkaline, fresh, excessively mineralized, Ca-chloride type, and hard to very hard water class. While the groundwater samples were characterized by slightly alkaline, brackish, excessively mineralized, Ca-chloride and Na-Chloride type, and hard to very hard water class. The stable isotopic analysis was used in studying the interaction between water resources of Euphrates River and groundwater. Stable isotopes (δD and δ18O) were used to study the hydrological aspects of water resources in the study area. The results showed that surface and groundwater samples have similar source with a correlation relationship between them, in addition to the clear effect of river recharge on groundwater. The variation in δ2H and δ18O signature of groundwater in the study area is caused mainly by variation in isotopic composition of recharge water zone and mixing water. Using the δ 2H and δ 18O diagram, all surface and groundwater samples were plotted below the global meteoric water line (GMWL) and Local Meteoric Water line (LMWL), indicating the influences of the evaporation processes and seasonal variation.

Temporal variations of stable isotopes in precipitation from Yungui Plateau: Insights from moisture source and rainout effect

2021 ◽  
Keyword(s):  
Meteoric Water ◽  
East Asian Monsoon ◽  
Precipitation Amount ◽  
Correlation Coefficients ◽  
Temporal Variations ◽  
Monsoon Period ◽  
Factors Affecting ◽  
Water Line ◽  
Moisture Source ◽  
Meteoric Water Line

Abstract Long-term continuous monitoring of precipitation isotopes has great potential to advance our understanding of hydrometeorological processes that determine stable isotope variability in the monsoon regions. This study presents 4–year daily precipitation isotopes from Yungui Plateau in southwestern China that is influenced by Indian summer monsoon and East Asian monsoon. The local meteoric water line (LMWL, δ2H=8.12 δ18O+11.2) was firstly established at the Tengchong (TC) site, which was close to the global meteoric water line (GMWL, δ2H=8 δ18O+10) indicating little secondary sub–cloud evaporation in the falling rain. Precipitation δ18O values exhibited significant inverse relationships with precipitation amount (r = −0.42), air temperature (r = −0.43), and relative humidity (r = −0.41) with lower correlation coefficients throughout the entire period, which indicated that precipitation isotopic variability in TC could not be well explained by the local meteorological factors but influenced by other combined factors of regional precipitation amount and upstream rainout. Precipitation δ18O values showed a clear V–shaped trend throughout the observation period, characterized by higher δ18O values during the pre–monsoon period whereas lower values during the post–monsoon period. This seasonal variation of precipitation δ18O values was associated with the seasonal movement of the Intertropical convergence zone and seasonal changes in moisture transport. Combined with backward trajectory analysis, precipitation δ18O values were estimated by a Rayleigh distillation model showing that upstream rainout processes from Bay of Bengal (BoB) towards land (Myanmar), and recycling moisture over land were key factors affecting the isotopic compositions of the TC precipitation. These findings could enhance our understanding of atmospheric dynamics and moisture source in the monsoon regions and will potentially facilitate the interpretation of numerous isotopic proxy records from this region.

scholarly journals Contrasting Water Use Strategies of Tamarix ramosissima in Different Habitats in the Northwest of Loess Plateau, China

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2791
Author(s):  
Pengyan Su ◽  
Mingjun Zhang ◽  
Deye Qu ◽  
Jiaxin Wang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Loess Plateau ◽  
Meteoric Water ◽  
Water Source ◽  
Water Sources ◽  
Tamarix Ramosissima ◽  
Water Line ◽  
Meteoric Water Line ◽  
Utilization Ratio

As a species for ecological restoration in northern China, Tamarix ramosissima plays an important role in river protection, flood control, regional climate regulation, and landscape construction with vegetation. Two sampling sites were selected in the hillside and floodplain habitats along the Lanzhou City, and the xylems of T. ramosissima and potential water sources were collected, respectively. The Bayesian mixture model (MixSIAR) and soil water excess (SW-excess) were applied to analyze the relationship on different water pools and the utilization ratios of T. ramosissima to potential water sources in two habitats. The results showed that the slope and intercept of local meteoric water line (LMWL) in two habitats were smaller compared with the global meteoric water line (GMWL), which indicated the existence of drier climate and strong evaporation in the study area, especially in the hillside habitat. Except for the three months in hillside, the SW-excess of T. ramosissima were negative, which indicated that xylems of T. ramosissima are more depleted in δ2H than the soil water line. In growing seasons, the main water source in hillside habitat was deep soil water (80~150 cm) and the utilization ratio was 63 ± 17% for T. ramosissima, while the main water source in floodplain habitat was shallow soil water (0~30 cm), with a utilization ratio of 42.6 ± 19.2%, and the water sources were different in diverse months. T. ramosissima has a certain adaptation mechanism and water-use strategies in two habitats, and also an altered water uptake pattern in acquiring the more stable water. This study will provide a theoretical basis for plant water management in ecological environment protection in the Loess Plateau.

scholarly journals Global perspective of local meteoric water lines based on daily and monthly data: a consideration of climate types

2021 ◽  
Author(s):  
Yang Song ◽  
Shengjie Wang ◽  
Athanassios Argiriou ◽  
Mingjun Zhang ◽  
Yudong Shi
Keyword(s):  
Least Squares ◽  
Meteoric Water ◽  
Major Axis ◽  
Ordinary Least Squares ◽  
Weighted Regression ◽  
Precipitation Data ◽  
Monthly Data ◽  
Water Line ◽  
Meteoric Water Line ◽  
Event Based

The stable hydrogen and oxygen isotopes as well as their correlation in precipitation have been widely investigated for the understanding of various hydrological processes. Monthly precipitation data were usually recommended in order to establish a linear relationship between the stable hydrogen and oxygen isotope ratios (also known as local meteoric water lines or LMWL for a specific location); however, the LMWL based on daily (or event-based) precipitation data is usually different from that using monthly data. Based on 83 sampling stations across the world from 2000 to 2017, local meteoric water lines were calculated using daily (or event-based) precipitation data (n=9354) and corresponding monthly data (n=1895), respectively; multiple regression methods were used, including ordinary least squares, reduced major axis and major axis regressions as well as their precipitation-weighted counterparts. The global meteoric water line from daily data is δ2H = (7.72 ± 0.02) δ18O + (6.84 ± 0.15) (n=9354, r2=0.96) and from monthly data is δ2H = (7.81 ± 0.04) δ18O+(7.61 ± 0.32) (n=1895, r2=0.96). The stations used in this study were grouped into five climate types, according to the Köppen Climate classification. The precipitation-weighted regression may increase the long-term receptiveness of LMWL using daily-based (or event-based) samples, not only for arid regions, but also for cold regions. When only relatively short-term isotopic records in event-based precipitation samples are available, which is usual in modern hydrological studies, the weighted regression (especially precipitation weighted ordinary least squares regression, PWLSR) is helpful to create a respective local meteoric water line.

scholarly journals Tracing groundwater salinization processes in coastal aquifers: a hydrogeochemical and isotopic approach in the Na-Cl brackish waters of northwestern Sardinia, Italy

2013 ◽  
Vol 17 (7) ◽  
pp. 2917-2928 ◽  
Author(s):  
G. Mongelli ◽  
S. Monni ◽  
G. Oggiano ◽  
M. Paternoster ◽  
R. Sinisi
Keyword(s):  
Coastal Aquifers ◽  
Meteoric Water ◽  
Major Ions ◽  
Mediterranean Islands ◽  
Rock Interaction ◽  
Water Line ◽  
Brackish Waters ◽  
Meteoric Water Line ◽  
The Mediterranean ◽  
Water Rock Interaction

Abstract. Throughout the Mediterranean, salinization threatens water quality, especially in coastal areas. This salinization is the result of concomitant processes related to both seawater intrusion and water–rock interaction, which in some cases are virtually indistinguishable. In the Nurra region of northwestern Sardinia, recent salinization related to marine water intrusion has been caused by aquifer exploitation. However, the geology of this region records a long history from the Palaeozoic to the Quaternary, and is structurally complex and comprises a wide variety of lithologies, including Triassic evaporites. Determining the origin of the saline component of the Jurassic and Triassic aquifers in the Nurra region may provide a useful and more general model for salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activity and recent climatic change, the Nurra has become vulnerable to desertification and, in common with other Mediterranean islands, surface water resources periodically suffer from severe shortages. With this in mind, we report new data regarding brackish and surface waters (outcrop and lake samples) of the Na-Cl type from the Nurra region, including major ions and selected trace elements (B, Br, I, and Sr), in addition to isotopic data including δ18O, δD in water, and δ34S and δ18O in dissolved SO4. To identify the origin of the salinity more precisely, we also analysed the mineralogical and isotopic composition of Triassic evaporites. The brackish waters have Cl contents of up to 2025 mg L−1 , and the ratios between dissolved ions and Cl, with the exception of the Br / Cl ratio, are not those expected on the basis of simple mixing between rainwater and seawater. The δ18O and δD data indicate that most of the waters fall between the regional meteoric water line and the global meteoric water line, supporting the conclusion that they are meteoric in origin. A significant consequence of the meteoric origin of the Na-Cl-type water studied here is that the Br / Cl ratio, extensively used to assess the origin of salinity in fresh water, should be used with care in carbonate aquifers that are near the coast. Overall, δ34S and δ18O levels in dissolved SO4 suggest that water–rock interaction is responsible for the Na-Cl brackish composition of the water hosted by the Jurassic and Triassic aquifers of the Nurra, and this is consistent with the geology and lithological features of the study area. Evaporite dissolution may also explain the high Cl content, as halite was detected within the gypsum deposits. Finally, these Na-Cl brackish waters are undersaturated with respect to the more soluble salts, implying that in a climate evolving toward semi-arid conditions, the salinization process could intensify dramatically in the near future.

scholarly journals Isotopes of oxygen-18 and deuterium in precipitation in Slovakia / Izotopy kyslíka-18 A deutéria v zrážkach na Slovensku

2012 ◽  
Vol 60 (4) ◽  
pp. 265-276 ◽  
Author(s):  
Ladislav Holko ◽  
Michal Dóša ◽  
Juraj Michalko ◽  
Martin Šanda
Keyword(s):  
Isotopic Composition ◽  
Air Temperature ◽  
Meteoric Water ◽  
Precipitation Amount ◽  
Data Series ◽  
Water Line ◽  
Temperature And Precipitation ◽  
Meteoric Water Line ◽  
The Mean ◽  
Available Information

The article synthesizes available information on isotopic composition of precipitation in Slovakia (the Western Carpathians). Monthly δ18O data from eleven stations and period 1988-1997 were used to investigate correlations among the stations, altitude, air temperature and precipitation amount effects. The mean annual altitude and air temperature gradients of δ18O in precipitation were 0.21‰/100 m and 0.36‰/1°C, respectively. Maps of spatial distribution of mean annual δ18O in precipitation based on both gradients were constructed. The two maps do not significantly differ for the majority of Slovakia. δ2H data were available for only three stations. Local meteoric water line derived for the station with the longest data series (δ2H = = 7.86δ18O + 6.99) was close to the Global Meteoric Water line. Its parameters in periods 1991-1993 and 1991-2008 did not change. The study indicates that a more detailed monitoring of isotopic composition of precipitation in mountains should be carried out in the future. The highest station exhibited very small seasonal variability of δ18O in precipitation compared to other Slovak stations. The second highest mountain station had significantly higher deuterium excess than the neighboring stations located in the valley. In some analyses the data from the nearest stations situated abroad (Vienna, Krakow) were used.

Interactions between 2H and 18O natural abundance variations and DLW measurements of energy expenditure

1996 ◽  
Vol 271 (2) ◽  
pp. E302-E308 ◽  
Author(s):  
P. Ritz ◽  
T. J. Cole ◽  
P. S. Davies ◽  
G. R. Goldberg ◽  
W. A. Coward
Keyword(s):  
Energy Expenditure ◽  
Dose Level ◽  
Meteoric Water ◽  
Natural Abundance ◽  
Doubly Labeled Water ◽  
Water Line ◽  
Optimal Ratio ◽  
Meteoric Water Line ◽  
Within Subjects

Appropriate corrections for 2H and 18O natural abundance are necessary in energy expenditure measurements with the doubly labeled water (DLW) method. The contribution of natural abundance variations to errors in the method is generally ignored if an appropriate dose level is given. Calculation of the appropriate dose level assumes that 2H and 18O natural abundance values are covariant and have a fixed slope. This study has investigated the between- and within-subject natural abundance variations, the latter over periods of time similar to those used in DLW experiment. Although 2H and 18O natural abundance values are covariant between subjects, the slope of their relationship is different from that of the Meteoric Water Line. Within subjects there is no such demonstrable covariance. It is concluded that: 1) the determinants of 2H and 18O natural abundance are different within and between subjects; 2) the concept of an optimal ratio of doses is not valid, and a safer strategy is probably to use a ratio > 10; 3) natural abundance variations may contribute significantly to the magnitude of error in the DLW measurements of energy expenditure.

scholarly journals Contribution of glacial melt to river runoff as determined by stable isotopes at the source region of the Yangtze River, China

2015 ◽  
Vol 47 (2) ◽  
pp. 442-453 ◽  
Author(s):  
Zhaofei Liu ◽  
Zhijun Yao ◽  
Rui Wang
Keyword(s):  
Yangtze River ◽  
Meteoric Water ◽  
Stream Water ◽  
Source Region ◽  
Upstream Region ◽  
The Yangtze River ◽  
Hydrograph Separation ◽  
Water Line ◽  
Total Runoff ◽  
Meteoric Water Line

The primary objective of this study was to quantify the contribution of glacial melt to total runoff in the Gaerqu River catchment, which is located in the source region of the Yangtze River, China. The isotope hydrograph separation method was used to separate glacier melt runoff from total runoff in the catchment. The degree-day method was used to investigate temporal variations in glacial melt runoff. The results showed that the contribution of glacial melt runoff to total runoff was 15.0%. The uncertainty of the separation was ± 3.7% at the confidence level of 95%. Glacial melt runoff was mainly generated in June, July, and August. The runoff coefficient was 0.23 for the catchment. Precipitation-induced runoff constituted 19.9% of the total precipitation, meaning that precipitation loss was &gt;80% across the study period (a hydrological year). The Local Meteoric Water Line (LMWL) of the catchment was fitted as δ2H = 7.75 δ18O + 5.93. This line has a smaller slope and intercept than the Global Meteoric Water Line. The regression-lines for the δ18O and δ2H values of stream water indicated that evaporation was greater over the entire catchment than it was for the upstream region alone.

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