Tracing the Spatial Distribution of Whole-Lake Exchange of Groundwater and Lake Water in Low-Hydraulic Gradient Systems Using δ18O and Electrical Conductivity and Uncertain End-Member Mixing Analysis

δ18O and electrical conductivity (EC) were used successfully to trace the spatial distribution of whole-lake groundwater-lake exchange for a small (four ha) groundwater-fed lake situated in a low relief and low hydraulic gradient area. The method relies on quick sampling of shallow groundwater, direct analysis of EC in the field, and relatively in-expensive analysis of δ18O in the laboratory. Ternary uncertain end-member mixing analysis (precipitation, groundwater, and lake water) quantified the composition of water discharging to and recharging from the lake. The tracer distribution and mixing analysis were in agreement with the interpreted groundwater flow near the lake. The use of only one tracer (either δ18O or EC) gave the same results for the recharge segments, but the discharge segments changed the origin of the water from being groundwater to precipitation controlled. The two tracers complemented each other, especially with different signals in precipitation and groundwater. The uncertain end-members were assessed based on local (groundwater and lake water) and off-site (precipitation) data. The off-site data were found to be useful if it contained representative information on local-site seasonality (uncertainty, variance). Final end-member concentrations could explain the transience of the hydrology at the site (i.e., flooding of the area adjacent to the lake during periods with high precipitation, and variability of the δ18O signal in precipitation). This methodology potentially represents a new option to study groundwater-lake systems. The tracer information collected over only two days is useful by itself for developing the next steps like the quantification of fluxes based on other standard methods (Darcy approach, seepage meters, or temperature). The tracer information can provide quantitative estimation of inputs and outputs by using the mixing analysis.

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An Investigation of the Quantity, Quality and Sources of Groundwater Seepage into the St. Clair River near Sarnia, Ontario, Canada

Water Quality Research Journal ◽

10.2166/wqrj.1986.031 ◽

1986 ◽

Vol 21 (3) ◽

pp. 351-367 ◽

Cited By ~ 5

Author(s):

Michael Sklash ◽

Sharon Mason ◽

Suzanne Scott ◽

Chris Pugsley

Keyword(s):

Electrical Conductivity ◽

River Water ◽

Organic Contaminants ◽

Shallow Groundwater ◽

Seepage Rate ◽

Groundwater Seepage ◽

Seepage Meters ◽

Groundwater Samples ◽

Hydraulic Gradients ◽

Unidentified Source

Abstract We used seepage meters and minipiezometers to survey a 100 m by 7 km band of streambed of the St. Clair River near Sarnia, Ontario, Canada, to determine the quantity, quality, and sources of groundwater seepage into the river. The average observed seepage rate, 1.4 x 10−8 m3/s/m2, suggests higher than expected hydraulic conductivities and/or hydraulic gradients in the streambed. We found detectable levels of some organic contaminants in streambed groundwater samples from 1.0 and 1.5 m depths, however , concentrations did not exceed drinking water guidelines. Our isotopic and electrical conductivity data indicate that: (l) the streambed groundwater is not just river water, (2) groundwater from the “freshwater aquifer” at the base of the overburden Is not a significant component of the streambed groundwater, (3) some of the streambed groundwater is partially derived from a shallow groundwater flow system, and (4) an unidentified source of water with low tritium, river water-like δ18O, and very high electrical conductivity, contributes to the streambed groundwater.

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Spatial and Temporal Variability of Soil Salinity in the Yangtze River Estuary Using Electromagnetic Induction

Remote Sensing ◽

10.3390/rs13101875 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1875

Author(s):

Wenping Xie ◽

Jingsong Yang ◽

Rongjiang Yao ◽

Xiangping Wang

Keyword(s):

Electrical Conductivity ◽

Spatial Distribution ◽

Soil Salinity ◽

Yangtze River ◽

Laboratory Data ◽

River Estuary ◽

Yangtze River Estuary ◽

Soil Electrical Conductivity ◽

The Yangtze River ◽

The Yangtze River Estuary

Soil salt-water dynamics in the Yangtze River Estuary (YRE) is complex and soil salinity is an obstacle to regional agricultural production and the ecological environment in the YRE. Runoff into the sea is reduced during the impoundment period as the result of the water-storing process of the Three Gorges Reservoir (TGR) in the upper reaches of the Yangtze River, which causes serious seawater intrusion. Soil salinity is a problem due to shallow and saline groundwater under serious seawater intrusion in the YRE. In this research, we focused on the temporal variation and spatial distribution characteristics of soil salinity in the YRE using geostatistics combined with proximally sensed information obtained by an electromagnetic induction (EM) survey method in typical years under the impoundment of the TGR. The EM survey with proximal sensing method was applied to perform soil salinity survey in field in the Yangtze River Estuary, allowing quick determination and quantitative assessment of spatial and temporal variation of soil salinity from 2006 to 2017. We developed regional soil salinity survey and mapping by coupling limited laboratory data with proximal sensed data obtained from EM. We interpreted the soil electrical conductivity by constructing a linear model between the apparent electrical conductivity data measured by an EM 38 device and the soil electrical conductivity (EC) of soil samples measured in laboratory. Then, soil electrical conductivity was converted to soil salt content (soil salinity g kg−1) through established linear regression model based on the laboratory data of soil salinity and soil EC. Semivariograms of regional soil salinity in the survey years were fitted and ordinary kriging interpolation was applied in interpolation and mapping of regional soil salinity. The cross-validation results showed that the prediction results were acceptable. The soil salinity distribution under different survey years was presented and the area of salt affected soil was calculated using geostatistics method. The results of spatial distribution of soil salinity showed that soil salinity near the riverbanks and coastlines was higher than that of inland. The spatial distribution of groundwater depth and salinity revealed that shallow groundwater and high groundwater salinity influenced the spatial distribution characteristics of soil salinity. Under long-term impoundment of the Three Gorges Reservoir, the variation of soil salinity in different hydrological years was analyzed. Results showed that the area affected by soil salinity gradually increased in different hydrological year types under the impoundment of the TGR.

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Spatial Distribution of Surface Soil Acidity, Electrical Conductivity, Soil Organic Carbon Content and Exchangeable Potassium, Calcium and Magnesium in Some Cropped Acid Soils of India

Land Degradation and Development ◽

10.1002/ldr.2306 ◽

2014 ◽

Vol 26 (1) ◽

pp. 71-79 ◽

Cited By ~ 99

Author(s):

Sanjib Kumar Behera ◽

Arvind Kumar Shukla

Keyword(s):

Electrical Conductivity ◽

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Acidity ◽

Surface Soil ◽

Acid Soils ◽

Organic Carbon Content ◽

Exchangeable Potassium ◽

Calcium And Magnesium

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Spatial distribution and hydrochemistry of springs and seepage springs in the Lubuska Upland of western Poland

Hydrology Research ◽

10.2166/nh.2013.249 ◽

2013 ◽

Vol 45 (3) ◽

pp. 379-390 ◽

Cited By ~ 6

Author(s):

Anna Maria Szczucińska

Keyword(s):

Electrical Conductivity ◽

Spatial Distribution ◽

Trace Metals ◽

Calcium Ions ◽

Major Part ◽

Major Ions ◽

Water Type ◽

Average Temperature ◽

Last Glaciation ◽

River Valleys

The major part of the Polish Plain (central Europe) was shaped during the last glaciation and so far has been considered to be poor in groundwater outflows. The present study aimed to map the groundwater outflows and to analyse their water properties in the Lubuska Upland, western Polish Plain. The mapping of the groundwater outflows was supplemented by hydrochemical analyses (major ions and trace metals) of selected outflows. Altogether, approximately 600 groundwater outflows were recorded, of which 45% were springs. The outflow water discharges ranged from 0.001 to 45 L s−1. Most of them were located at the bottom of the slopes of river valleys. The water was neutral (pH 6.9 to 8.11), with electrical conductivity from 261 to 652 μS cm−1 and average temperature ~10 °C. The most common water type was dominated by bicarbonate, sulphates and calcium ions. The waters often exceeded the quality limits for total Fe and Mn2+. This study revealed that groundwater outflows are a common feature of the areas shaped by former glaciations and are most likely supplied by shallow aquifers.

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Micro-spectroscopy of HKUST-1 metal–organic framework crystals loaded with tetracyanoquinodimethane: effects of water on host–guest chemistry and electrical conductivity

Physical Chemistry Chemical Physics ◽

10.1039/c9cp05082e ◽

2019 ◽

Vol 21 (46) ◽

pp. 25678-25689 ◽

Cited By ~ 3

Author(s):

Miguel Rivera-Torrente ◽

Matthias Filez ◽

Christian Schneider ◽

Ewout C. van der Feltz ◽

Konrad Wolkersdörfer ◽

...

Keyword(s):

Electrical Conductivity ◽

Spatial Distribution ◽

Water Vapor ◽

Metal Organic Framework ◽

Next Generation ◽

Metal Organic ◽

Spectroscopy Studies ◽

Organic Framework ◽

Guest Chemistry

Guest@MOF materials have potential in next-generation materials for electroconductive devices. Micro-spectroscopy studies of TCNQ@HKUST-1 electroconductive composites revealed the effects of spatial distribution and water vapor on this material.

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Spatial distribution and origin of shallow groundwater iodide in a rapidly urbanized delta: A case study of the Pearl River Delta

Journal of Hydrology ◽

10.1016/j.jhydrol.2020.124860 ◽

2020 ◽

Vol 585 ◽

pp. 124860 ◽

Cited By ~ 2

Author(s):

Guanxing Huang ◽

Chunyan Liu ◽

Liangping Li ◽

Fenge Zhang ◽

Zongyu Chen

Keyword(s):

Spatial Distribution ◽

Pearl River Delta ◽

Shallow Groundwater ◽

River Delta ◽

Pearl River ◽

The Pearl River Delta ◽

The Pearl River

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Characteristics of Hydrogeochemistry and Groundwater Quality in a Riverbank Filtration Site, Northeastern China

10.5194/egusphere-egu2020-4690 ◽

2020 ◽

Author(s):

Yanguo Teng ◽

Yuanzheng Zhai ◽

Haiyang Chen ◽

Ruihui Chen

Keyword(s):

Spatial Distribution ◽

Groundwater Quality ◽

Land Surface ◽

Evaluation Method ◽

Major Ions ◽

Comprehensive Evaluation ◽

Shallow Groundwater ◽

Distribution Patterns ◽

Total Hardness ◽

Spatial Distribution Patterns

Studies on hydrogeochemical characteristics and an assessment of the groundwater quality for drinking purposes were conducted in and around the riverside source field of Wuchang, Northeast China. Twenty-seven and twenty-three shallow groundwater samples were collected for measuring on-site parameters and major components in the years 2000 and 2014, respectively. In 2014, the average concentrations of major ions of shallow groundwater were found to be in the following order: Ca2+> Na+> Mg2+> K+ for cations and HCO3-> SO42-> Cl-> NO3- for anions. The spatial distribution patterns of K+ and NO3- had no obvious regularity, whereas Cl- and Na+ showed similar spatial distribution patterns. Ca-HCO3 and mixed type water were the dominant hydrochemical types. The analysis of the SI values for minerals and the Gibbs plot illustrated that the concentrations of major components were mainly controlled by rock weathering, such as the dissolution of calcite, dolomite, halite, gypsum and aragonite, followed by ion exchange. Indicators, such as Total hardness (TH), Total Dissolved Solids (TDS), Cl-, SO42- and NO3-, were selected to assess the groundwater quality using a comprehensive evaluation method of dividing the groundwater quality into five classes: excellent, good, fair, poor and very poor water. The results showed that 7.4% and 34.8% of the total groundwater sample in 2000 and 2014, respectively, were unsuitable for drinking use, indicating that the shallow groundwater quality has gradually worsened in the past few decades. The concentration of NO3- was a major factor that influenced the observed groundwater quality changes.Acknowledgments This study was supported by the NSFC (No.41877355), Beijing Advanced Innovation Program for Land Surface Science, and the&#160;111 Project of China (B18006).

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