scholarly journals Untangling hydrological pathways and nitrate sources by chemical appraisal in a stream network of a reservoir catchment

2012 ◽  
Vol 16 (3) ◽  
pp. 787-799 ◽  
Author(s):  
M. A. Yevenes ◽  
C. M. Mannaerts
Keyword(s):  
Pore Water ◽  
Stream Water ◽  
Shallow Groundwater ◽  
Water Source ◽  
Water Sources ◽  
Sediment Pore Water ◽  
Nitrate Sources ◽  
Alluvial Sediment ◽  
Source Contributions ◽  
End Members

Abstract. The knowledge of water source contributions to streamflow is important for understanding chemical contamination origins and the status of biogeochemical cycling in stream networks of catchments. In this study, we evaluated whether a limited number of spatially distributed geochemical tracer data sampled during different hydrological seasons were sufficient to quantify water flow pathways and nitrate sources in a catchment. Six geochemical water constituents (δ2H, δ18O, Cl−, SO2−4, Na+, NO−3 and K+) of precipitation, stream water, alluvial sediment pore water and shallow groundwater of a 352 km2 agricultural catchment in the Alentejo region of Portugal were analysed. Exploratory data analysis and end-member mixing analysis (EMMA) were performed to estimate the water source mixing proportions. Residual analysis of principal components was used to identify the appropriate geochemical tracers and the number of end-members (water sources and flow paths), and their proportional contributions to streamflow were quantified. Spearman's rank correlation analysis was further used to identify nitrate origins in the streamflow. Results showed that, when using data from both wet and dry seasons, streamflow chemistry was strongly influenced by shallow groundwater. When only wet season data were modelled, streamflow chemistry was controlled and generated by three end-members: shallow groundwater, alluvial sediment pore water and precipitation. Isotope signatures of stream water were located mostly below the local meteoric water line (LMWL) and plotted along a local evaporation line (LEL), reflecting the permanence in the streamflow of shallow groundwater subjected to prior evaporation. Interpretation of isotope signatures during summer showed an isotopic enrichment in both streamflow and shallow groundwater. Measured and historical stream nitrate concentrations appeared to be strongly related to shallow groundwater. In addition, two hydrochemical data outliers for almost every solute from two sample points were identified by the analysis and could be related to local waste water outfalls. The results of this study have improved our understanding of water source contributions to streamflow in the catchment, and also yielded indications of nitrate consumption related to biogeochemical processes in the streamflow network. Moreover, we could conclude that the relatively limited geochemical spatial sample database used in this study was an adequate input for the end-member mixing analysis and diagnostic tools to quantify water sources and nitrate origins in the streamflow of the catchment.

scholarly journals Water Taxation and Subsidy Analysis Based on Consumer Water Use Behavior and Water Sources Inside the Kathmandu Valley

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1802 ◽  
Author(s):  
Rajit Ojha ◽  
Bhesh Thapa ◽  
Sadhana Shrestha ◽  
Junko Shindo ◽  
Hiroshi Ishidaira ◽  
...  
Keyword(s):  
Water Use ◽  
Rainwater Harvesting ◽  
Groundwater Resources ◽  
Shallow Groundwater ◽  
Water Source ◽  
Water Sources ◽  
Water Price ◽  
Kathmandu Valley ◽  
Total Expenditure ◽  
Groundwater Exploitation

Groundwater is a major alternative water source used to cover the deficit of water supplied by Kathmandu Upatyaka Khanepani Limited (KUKL), the authority responsible for water supply inside Kathmandu Valley. The groundwater price relative to that of KUKL affects priority of usage, and hence, groundwater resources sustainability. Therefore, taxation or subsidies on water sources become necessary based on their implication on environment. In this study, we evaluate volumetric water price, including initial investment, operation and maintenance (O&M) cost for different water sources, and compare it with the water price of KUKL, Kathmandu. The results show that shallow groundwater is cheaper than KUKL’s water. For groundwater sustainability, taxation on shallow groundwater seems necessary. For the recent water use of 97 LPCD (liters per capita per day) the taxation requirement is Nepalese Rupee (NRs.) 320/month (0.35% of total expenditure) if the initial investment for well construction and O&M cost are considered, and NRs. 626 (0.7% of total expenditure) if only O&M cost is considered. On the other hand, rainwater harvesting and recharging, the measures to cope with groundwater exploitation, might need 40% to 50% subsidy for their initial investment.

scholarly journals Potential effects of cryogenic extraction biases on inferences drawn from xylem water deuterium isotope ratios: case studies using stable isotopes to infer plant water sources

2021 ◽  
Author(s):  
Scott T. Allen ◽  
James W. Kirchner
Keyword(s):  
Water Source ◽  
Water Sources ◽  
Plant Water ◽  
Dual Isotope ◽  
Cryogenic Vacuum ◽  
Potential Impact ◽  
End Members ◽  
Plant Water Source ◽  
Plant Water Sources ◽  
The Impact

Abstract. Recent studies have demonstrated that plant and soilwater extraction techniques can introduce biases and uncertainties in stable isotope analyses. Here we show how recently documented δ2H biases resulting from cryogenic vacuum distillation of water from xylem tissues may have influenced the conclusions of five previous studies, including ours, that have used δ2H to infer plant water sources. Cryogenic extraction biases that reduce xylem water δ2H will also introduce an artifactual evaporation signal in dual-isotope (δ2H vs. δ18O) analyses. Calculations that estimate the composition of the source precipitation of xylem waters by compensating for their apparent evaporation will amplify the bias in δ2H, and also introduce new biases in the δ18O of the inferred pre-evaporation source precipitation. Cryogenic extraction biases may substantially alter plant water source attributions if the spread in δ2H among the potential end members is relatively narrow. By contrast, if the spread in δ2H among the potential end members is relatively wide, the impact of cryogenic extraction biases will be less pronounced, and thus suggestions that these biases universally invalidate inferences drawn from plant water δ2H are unwarranted. Nonetheless, until reliable correction factors for cryogenic extraction biases become available, their potential impact should be considered in studies using xylem water isotopes.

Sediment–pore water partition of PAH source contributions to the Yellow River using two receptor models

2012 ◽  
Vol 12 (7) ◽  
pp. 1154-1163 ◽  
Author(s):  
Guo-Liang Shi ◽  
Ying-Ze Tian ◽  
Chang-Sheng Guo ◽  
Yin-Chang Feng ◽  
Jian Xu ◽  
...  
Keyword(s):  
Pore Water ◽  
Yellow River ◽  
The Yellow River ◽  
Sediment Pore Water ◽  
Receptor Models ◽  
Source Contributions

Brief history and ways of further development of the department of hydraulic engineering and hydraulics FSBI «VNIIGiM named after A.N. Kostyakov»

2020 ◽  
pp. 18-23
Author(s):  
Alexey Shcherbakov ◽  
Valentin Zhezmer
Keyword(s):  
Land Reclamation ◽  
Water Source ◽  
Water Sources ◽  
Hydraulic Engineering ◽  
Negative Effects ◽  
Extensive Experience ◽  
Safety Level ◽  
Theoretical Substantiation ◽  
Wide Range ◽  
Construction Operation

Department of hydraulic engineering and hydraulics FGBNU «VNIIGiM them. A.N. Kostyakova «has a long history. For many years, the department’s staff has been such scientists and water engineers with extensive experience as M.A. Volynov, V.S. Verbitsky, S.S. Medvedev, N.V. Lebedev, B.C. Panfilov, T.G. Voynich-Syanozhentsky, V.A. Golubkova, G.V. Lyapin and others. The department solved a wide range of tasks, the main areas of research were the following: – theoretical and applied hydrodynamics and hydraulics, with reference to the open channel flows that affect the state and level of safety of the hydraulic structures; – integrated use and protection of water bodies – water sources and water sources of water resources used in land reclamation; – development of measures and technical solutions for the protection of objects from the negative effects of water; – theoretical substantiation of works to improve the safety level of the GTS (declaration); – development and implementation of digitalization methods for solving design, construction, operation and control of landreclamation facilities. Currently, promising areas of research is the development of a decision-making algorithm in the designation of measures to rationalize the provision of resources to water amelioration. The algorithm is developed on the basis of a detailed study, systematization and processing of data both on safety and on the efficiency of systems and structures, ensuring the delivery of irrigation water of the required quality and in sufficient quantity from a water source to the field.

scholarly journals Spatio-temporal Variation in Nutrient Profiles and Exchange Fluxes at the Sediment-Water Interface in Yuqiao Reservoir, China

2019 ◽  
Vol 16 (17) ◽  
pp. 3071 ◽  
Author(s):  
Wen ◽  
Wu ◽  
Yang ◽  
Jiang ◽  
Zhong
Keyword(s):  
Pore Water ◽  
Water Source ◽  
Water Soluble ◽  
Drinking Water Source ◽  
Eutrophic Lakes ◽  
Overlying Water ◽  
Total N ◽  
Yuqiao Reservoir ◽  
Nutrient Profiles ◽  
Main Component

Nutrients released from sediments have a significant influence on the water quality in eutrophic lakes and reservoirs. To clarify the internal nutrient load and provide reference for eutrophication control in Yuqiao Reservoir, a drinking water source reservoir in China, pore water profiles and sediment core incubation experiments were conducted. The nutrients in the water (soluble reactive P (SRP), nitrate-N (NO3−-N), nitrite-N (NO2−-N), and ammonium-N (NH4+-N)) and in the sediments (total N (TN), total P (TP) and total organic carbon (TOC)) were quantified. The results show that NH4+-N was the main component of inorganic N in the pore water. NH4+-N and SRP were higher in the pore water than in the overlying water, and the concentration gradient indicated a diffusion potential from the sediment to the overlying water. The NH4+-N, NO3−-N, and SRP fluxes showed significant differences amongst the seasons. The NH4+-N and SRP fluxes were significantly higher in the summer than in other seasons, while NO3−-N was higher in the autumn. The sediment generally acted as a source of NH4+-N and SRP and as a sink for NO3−-N and NO2−-N. The sediments release 1133.15 and 92.46 tons of N and P, respectively, to the overlying water each year.

scholarly journals Phosphorous Supply to a Eutrophic Artificial Lake: Sedimentary versus Groundwater Sources

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 563
Author(s):  
Wiebe Förster ◽  
Jan C. Scholten ◽  
Michael Schubert ◽  
Kay Knoeller ◽  
Nikolaus Classen ◽  
...  
Keyword(s):  
Water Quality ◽  
Stable Isotope ◽  
Pore Water ◽  
Lake Water ◽  
Sediment Cores ◽  
Eutrophic Lake ◽  
Stable Water Isotopes ◽  
Artificial Lake ◽  
Sediment Pore Water ◽  
Mass Balance Models

The eutrophic Lake Eichbaumsee, a ~1 km long and 280 m wide (maximum water depth 16 m) dredging lake southeast of Hamburg (Germany), has been treated for water quality improvements using various techniques (i.e., aeration plants, removal of dissolved phosphorous by aluminum phosphorous precipitation, and by Bentophos® (Phoslock Environmental Technologies, Sydney, Australia), adsorption) during the past ~15 years. Despite these treatments, no long-term improvement of the water quality has been observed and the lake water phosphorous content has continued to increase by e.g., ~670 kg phosphorous between autumn 2014 and autumn 2019. As no creeks or rivers drain into the lake and hydrological groundwater models do not suggest any major groundwater discharge into the lake, sources of phosphorous (and other nutrients) are unknown. We investigated the phosphorous fluxes from sediment pore water and from groundwater in the water body of the lake. Sediment pore water was extracted from sediment cores recovered by divers in August 2018 and February 2019. Diffusive phosphorous fluxes from pore water were calculated based on phosphorus gradients. Stable water isotopes (δ2H, δ18O) were measured in the lake water, in interstitial waters in the banks surrounding the lake, in the Elbe River, and in three groundwater wells close to the lake. Stable isotope (δ2H, δ18O) water mass balance models were used to compute water inflow/outflow to/from the lake. Our results revealed pore-water borne phosphorous fluxes between 0.2 mg/m2/d and 1.9 mg/m2/d. Assuming that the measured phosphorous fluxes are temporarily and spatially representative for the whole lake, about 11 kg/a to 110 kg/a of phosphorous is released from sediments. This amount is lower than the observed lake water phosphorous increase of ~344 kg between April 2018 and November 2018. Water stable isotope (δ2H, δ18O) compositions indicate a water exchange between an aquifer and the lake water. Based on stable isotope mass balances we estimated an inflow of phosphorous from the aquifer to the lake of between ~150 kg/a and ~390 kg/a. This result suggests that groundwater-borne phosphorous is a significant phosphorous source for the Eichbaumsee and highlights the importance of groundwater for lake water phosphorous balances.

scholarly journals Omnipresent distribution of herbicides and their transformation products in all water body types of an agricultural landscape in the North German Lowland

2021 ◽  
Author(s):  
Uta Ulrich ◽  
Matthias Pfannerstill ◽  
Guido Ostendorp ◽  
Nicola Fohrer
Keyword(s):  
Drinking Water ◽  
Oxalic Acid ◽  
Water Body ◽  
Sulfonic Acid ◽  
Stream Water ◽  
Parent Compound ◽  
Shallow Groundwater ◽  
Transformation Products ◽  
Small Scale ◽  
Rainfall Events

AbstractThe research of the environmental fate of pesticides has demonstrated that applied compounds are altered in their molecular structure over time and are distributed within the environment. To assess the risk for contamination by transformation products (TP) of the herbicides flufenacet and metazachlor, the following four water body types were sampled in a small-scale catchment of 50 km2 in 2015/2016: tile drainage water, stream water, shallow groundwater, and drinking water of private wells. The TP were omnipresent in every type of water body, more frequently and in concentrations up to 10 times higher than their parent compounds. Especially metazachlor sulfonic acid, metazachlor oxalic acid, and flufenacet oxalic acid were detected in almost every drainage and stream sample. The transformation process leads to more mobile and more persistent molecules resulting in higher detection frequencies and concentrations, which can even occur a year or more after the application of the parent compound. The vulnerability of shallow groundwater and private drinking water wells to leaching compounds is proved by numerous positives of metazachlor-TP with maximum concentrations of 0.7 μg L−1 (drinking water) and 20 μg L−1 (shallow groundwater) of metazachlor sulfonic acid. Rainfall events during the application period cause high discharge of the parent compound and lower release of TP. Later rainfall events lead to high displacement of TP. For an integrated risk assessment of water bodies, the environmental behavior of pesticide-TP has to be included into regular state-of-the-art water quality monitoring.

scholarly journals Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 202
Author(s):  
Meilian Chen ◽  
Ji-Hoon Kim ◽  
Sungwook Hong ◽  
Yun Kyung Lee ◽  
Moo Hee Kang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Phytoplankton Bloom ◽  
Ocean Surface ◽  
The Arctic ◽  
Sediment Pore Water ◽  
Ice Edge ◽  
Accumulation Trend ◽  
Arctic Fjords

Fjords in the high Arctic, as aquatic critical zones at the interface of land-ocean continuum, are undergoing rapid changes due to glacier retreat and climate warming. Yet, little is known about the biogeochemical processes in the Arctic fjords. We measured the nutrients and the optical properties of dissolved organic matter (DOM) in both seawater and sediment pore water, along with the remote sensing data of the ocean surface, from three West Svalbard fjords. A cross-fjord comparison of fluorescence fingerprints together with downcore trends of salinity, Cl−, and PO43− revealed higher impact of terrestrial inputs (fluorescence index: ~1.2–1.5 in seawaters) and glaciofluvial runoffs (salinity: ~31.4 ± 2.4 psu in pore waters) to the southern fjord of Hornsund as compared to the northern fjords of Isfjorden and Van Mijenfjorden, tallying with heavier annual runoff to the southern fjord of Hornsund. Extremely high levels of protein-like fluorescence (up to ~4.5 RU) were observed at the partially sea ice-covered fjords in summer, in line with near-ubiquity ice-edge blooms observed in the Arctic. The results reflect an ongoing or post-phytoplankton bloom, which is also supported by the higher levels of chlorophyll a fluorescence at the ocean surface, the very high apparent oxygen utilization through the water column, and the nutrient drawdown at the ocean surface. Meanwhile, a characteristic elongated fluorescence fingerprint was observed in the fjords, presumably produced by ice-edge blooms in the Arctic ecosystems. Furthermore, alkalinity and the humic-like peaks showed a general downcore accumulation trend, which implies the production of humic-like DOM via a biological pathway also in the glaciomarine sediments from the Arctic fjords.

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