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Liu, F., Wang, S., Wang, L., Shi, L., Song, X., Yeh, T. - C. J., et al. (2019). Coupling hydrochemistry and stable isotopes to identify the major factors affecting groundwater geochemical evolution in the Heilongdong Spring Basin, North China. Journal of Geochemical Exploration, 205.
Abstract: Understanding the interference of natural processes and anthropogenic activities in geochemical evolution of groundwater is vital for groundwater sustainable management in water-stressed regions. This study is devoted to the identification of the main factors controlling the evolution of groundwater chemistry by the combined use of hydrogeochemical indicators along with isotope tracers in the Heilongdong Spring Basin, North China. Thirty-nine groundwater samples and twelve surface water samples were collected, and major ions and stable isotopes were measured during the two campaigns (December 2017 and August 2018). The isotope approach indicates that the groundwater is recharged by precipitation infiltration after evaporation, and interacts with surface water along preferential flow paths in fault zones and karst conduits. Currently, the main chemical facies of groundwater evolve from Ca-HCO3 and Ca-Mg-HCO3 types with low TDS, through Ca-Mg-HCO3-SO4 and Ca-HCO3-SO4 types with moderate TDS, to Ca-SO4, Ca-SO4-Cl and CaCl types with high TDS. Apart from natural processes (involving dissolution/precipitation of minerals, cation exchange, and evaporation) regulating the groundwater quality, the stagnant zones also play a crucial role in the formation of severe localized nitrate contamination. The deterioration in groundwater quality can be attributed to anthropogenic factors (including the change in groundwater exploitation, the leaching of solid waste, and the overuse of agricultural fertilizers). The high loads of agricultural fertilizers in irrigation return flows are likely to be the main contributor of the dissolved nitrate in groundwater. The findings of this work not only have important implications for groundwater sustainable utilization, but also could serve as a template for other rapidly industrialized and water-stressed regions.
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Kumar, A. R., & Riyazuddin, P. (2011). Speciation of selenium in groundwater: Seasonal variations and redox transformations. Journal of hazardous materials, 192(1), 263–269.
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Jalali*, M., Karami, S., & Marj, A. F. (2019). On the problem of the spatial distribution delineation of the groundwater quality indicators via multivariate statistical and geostatistical approaches. Environ. Monit. Assess., 191(S2), 323.
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Di Lorenzo, T., & Galassi, D. M. P. (2013). Agricultural impact on Mediterranean alluvial aquifers: do groundwater communities respond? Fundamental and Applied Limnology/Archiv für Hydrobiologie, 182(4), 271–282.
Abstract: In Mediterranean countries agricultural development heavily depends on groundwater availability due
to arid and semi-arid climate and poor surface-water resources. Agriculture represents one of the most relevant
pressures which generate impacts in alluvial aquifers by means of fertilizers and pesticides usage and groundwater
overexploitation. Until now, very few studies have addressed the ecological response of groundwater fauna to
groundwater contamination and overexploitation due to agricultural practices. We investigated a Mediterranean
alluvial aquifer heavily affected by nitrates contamination and groundwater abstraction stress due to crop irrigation. The aim of this study was to evaluate the sensitivity of groundwater communities to (a) groundwater nitrate
contamination, (b) groundwater abstraction due to irrigation practices, and (c) saltwater intrusion. The present
work suggests that nitrate concentration lower than 150 mg l
–1 is not an immediate threat to groundwater biodiversity in alluvial aquifers. This conclusion must be carefully considered in the light of the total lack of knowledge
of the effects of long-term nitrate pollution on the groundwater biota. Moreover, local extinctions of less tolerant
species, prior to monitoring, cannot be ruled out. Conversely, species abundances in ground water are affected by
groundwater withdrawal, but species richness may be less sensitive. This result is attributable to the disappearance
of saturated microhabitats and to the depletion of fine unconsolidated sediments, reducing the surface available
to bacterial biofilm, which represent the trophic resource for several groundwater invertebrates and where the
main aquifer self-purification processes, such as denitrification, take place. Saltwater intrusion seems not to affect
groundwater species at the values measured in this coastal aquifer.
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Sivakumar*, B., Harter, T., & Zhang, H. (2005). A fractal investigation of solute travel time in a heterogeneous aquifer: transition probability/Markov chain representation. Ecol. Modell., 182, 355–370.
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