Application of multivariate statistical procedures on major ions and trace elements in a multilayered coastal aquifer: the case of the south Rhodope coastal aquifer

Galazoulas, Evangelos C.; Petalas, C.

doi:10.1007/s12665-014-3315-5

Cited by 11 publications

(2 citation statements)

References 46 publications

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“…Numerous wells are drilled in the area, penetrating either the shallow semi-confined aquifer or the main confined aquifer or both, thus allowing groundwater transfer through well screens and mixing of different quality water masses. In the recent years, due to the rapid saltwater intrusion progress and the depletion of freshwater resources (Petalas and Lambrakis, 2006;Petalas et al, 2009;Galazoulas and Petalas, 2014), various wells have been drilled at greater depths, penetrating the deep aquifer system located underneath the main confined aquifer.…”

Section: Geological and Hydrogeological Settingmentioning

confidence: 99%

Large Scale Electrical Resistivity Tomography Survey Correlated to Hydrogeological Data for Mapping Groundwater Salinization: A Case Study from a Multilayered Coastal Aquifer in Rhodope, Northeastern Greece

et al. 2015

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A large scale two dimensional electrical resistivity survey was carried out to investigate groundwater salinization phenomena of a multilayered coastal aquifer in south Rhodope area, northeastern Greece. The electrical resistivity tomography (ERT) profiles, calibrated with lithological, physicochemical and geophysical log data, were used to demarcate the geometry of the aquifer system and characterize the extent of the interface between saline and freshwater in a coastal groundwater system, which has been subject to overexploitation for the last 35 years. In total, 12 deep high resolution ERT profile lines, covering a distance of approximately 15 km were carried out at key locations across the downgraded part of the aquifer system. The resistivity sections were calibrated using a reference dataset of 45 information wells incorporating 28 lithological logs, 31 groundwater quality samples from a variety of screen placements and five gamma ray logs. Results revealed the presence of four major resistivity zones ranging in values between 0.1 and 150 Ωm at various depths and locations. A very low resistivity zone (0.1-5 Ωm) correlated with saline water saturated layers, a medium resistivity zone (5-15 Ωm) attributed to clays and silts, and two high resistivity zones generally representing freshwater saturated sediments of coarse grain size (15-40 Ωm) or alterations of thin marl and fine sand layers (40-150 Ωm). It is demonstrated that extensive use of high resolution deep geoelectrical sections, calibrated with a large number of hydrogeological data can successfully delineate aquifer geometry dimensions, identify hydraulic boundaries and clarify ambiguous field measurements, thus allowing the development of a thorough hydrogeological conceptual model.

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Section: Geological and Hydrogeological Settingmentioning

confidence: 99%

Large Scale Electrical Resistivity Tomography Survey Correlated to Hydrogeological Data for Mapping Groundwater Salinization: A Case Study from a Multilayered Coastal Aquifer in Rhodope, Northeastern Greece

et al. 2015

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“…In that way, data structure hidden from direct observation can be recognized and explained as natural processes in the system. Such analysis is often used in hydrogeological and environmental studies for estimating the source of pollution and for various similar purposes [33][34][35][36][37]. For this purpose, software STATISTICA 7.0 was used.…”

Section: Methodsmentioning

confidence: 99%

Groundwater Quality on the Adriatic Karst Island of Mljet (Croatia) and Its Implications on Water Supply

2019

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Water supply of the islands is a global challenge, especially in the countries which have highly indented coastlines with numerous islands. The island of Mljet in Croatia was investigated due to its unique source of water supply: desalination of water from brackish lakes—blatinas—fed by groundwater and connected to the sea by karst conduits. Water sampling and chemical analyses were performed during hydrological minimum and maximum with regard to groundwater levels in 2005/2006 and minimum in 2016. A total of 13 samples were analysed within the study: 10 samples were taken from blatinas, 1 from pit well, and 2 from borehole wells. All waters sampled from the lakes are of Na-Cl type. The seawater percentage in the lakes used to extract feed water for desalination plants, calculated by conservative mixing approach, is relatively low (0.7-9.8%) and varies in correlation with hydrological seasons. Low proportion of seawater is an essential factor of cost minimisation in desalination by the installed reverse osmosis (RO) plants. Daily monitoring of total dissolved solids in the feed water was introduced in May 2016, and its results were analysed in the context of precipitation—a sole source of island aquifer recharge. Maximum concentrations were observed during September and interpreted to be caused by a combination of natural and anthropogenic pressure during the summer tourist season. Minimum concentrations were expected after the rainy season in the cold part of the year but were observed in June instead. Due to a short observation period and untypical distribution of precipitation in the same time interval, the data can only be considered indicative. An unusual pattern of sulphate anion concentrations, which cannot be attributed solely to fresh- and seawater mixing, was observed in one of the blatinas, but its origin could not be determined based on available data. Taking into account all the presented data on groundwater quality, climate change predictions, the connection of water supply system to the mainland and problems with the effluent treatment, it is clear that the main future challenge will be the creation of an island-wide sustainable water management plan followed by continuous monitoring and research.

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Hydrochemistry and coal mining activity induced karst water quality degradation in the Niangziguan karst water system, China

Zhang

Gao

2015

Environ Sci Pollut Res

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Hydrogeochemical analysis, statistical analysis, and geochemical modeling were employed to evaluate the impacts of coal mining activities on karst water chemistry in Niangziguan spring catchment, one of the largest karst springs in Northern China. Significant water quality deterioration was observed along the flow path, evidenced from the increasing sulfate, nitrate, and TDS content in karst water. Karst water samples are Ca-Mg-HCO3 type in the recharge areas, Ca-Mg-HCO3-SO4 type in the coal mining areas, and Ca-Mg-SO4-HCO3/HCO3-SO4 type in the rural areas and discharge areas. A four-factor principal component analysis (PCA) model is conducted which explains over 82.9% of the total variation. Factor 1, which explained the largest portion (45.33%) of the total variance, reveals that coal mining activities and natural water-rock interaction as the primary factors controlling karst water quality. Anthropogenic effects were recognized as the secondary factor with high positive loadings for NO3 (-) and Cl(-) in the model. The other two factors are co-precipitation removal of trace elements and silicate mineral dissolution, which explained 20.96% of the total variance. A two-end mixing modeling was proposed to estimate the percentage of coal wastewater giving on karst water chemistry, based on the groundwater sulfate chemistry constrains rather than sulfur isotopes. Uncertainty of sulfur isotope sources led to an overestimation of coal mining water contribution. According to the results of the modeling, the contribution of coal mining waste on karst water chemistry was quantified to be from 27.05 to 1.11% which is ca. three times lower than the values suggested using a sulfur isotope method.

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Application of multivariate statistical procedures on major ions and trace elements in a multilayered coastal aquifer: the case of the south Rhodope coastal aquifer

Cited by 11 publications

References 46 publications

Large Scale Electrical Resistivity Tomography Survey Correlated to Hydrogeological Data for Mapping Groundwater Salinization: A Case Study from a Multilayered Coastal Aquifer in Rhodope, Northeastern Greece

Large Scale Electrical Resistivity Tomography Survey Correlated to Hydrogeological Data for Mapping Groundwater Salinization: A Case Study from a Multilayered Coastal Aquifer in Rhodope, Northeastern Greece

Groundwater Quality on the Adriatic Karst Island of Mljet (Croatia) and Its Implications on Water Supply

Hydrochemistry and coal mining activity induced karst water quality degradation in the Niangziguan karst water system, China

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