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    Assessment of hydrogeochemistry and environmental isotopes of surface and groundwaters in the Kiitahya Plain, Turkey
    (Pergamon-Elsevier Science Ltd, 2017) Berhe, Berihu Abadi; Dokuz, Ugur Erdem; Celik, Mehmet
    The aim of the present work is to determine the geochemical processes that control the nature of the groundwater and assess the quality of water for drinking and public health purposes. Surface and groundwater samples of Kutahya plain were analyzed for their physio-chemical and environmental isotope properties. The relative concentrations of the water ions were found to occur in the order of Ca2+>Mg2+>(K+ + Na+) and HCO3->SO42->CI-. Piper diagram shows that Ca-Mg/Mg-Ca-HCO3 was the dominant water types. Waters in the area were super -saturated with respect to carbonates. However, they were under -saturated with respect to sulphate minerals. The groundwaters had a mean isotopic composition of -67.32 delta H-2 and- 9.72 delta O-18 and were comparatively lower than surface waters -64.64 delta H-2 and 9.25 delta O-18. Tritium activities in groundwater from the wells ranged from 1.00 to 8.38 TU with a mean value of 4.37 TU. The impact of agricultural practices and poor sanitation conditions is indicated by the positive correlation between K+ - NO3-, K+- NO2- and HCO3- - Cl- ions as well as Na+ and Mg2+ ions with Salon. The groundwater quality of Kutahya plain is influenced by various natural and anthropogenic factors. (C) 2017 Elsevier Ltd. All rights reserved.
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    EVALUATION OF THE TRANSPORT OF HIGH NITRATE CONCENTRATIONS AND CHEMICAL COMPOSITION OF GROUNDWATER IN A SEMIARID-CALCAREOUS AREA IN SOUTHEASTERN ANATOLIA
    (Parlar Scientific Publications (P S P), 2018) Avci, Halim; Dokuz, Ugur Erdem; Avci, Ahmet Selcuk
    Groundwater is a major source of water for domestic, industrial and agricultural uses in many parts of the world, where arid environments are common. Groundwater was collected from 120 wells in a semi-arid and calcareous area, area of Gaziantep, Southeastern Anatolia to determine hydrochemical characteristics, mechanisms for nitrate transport, the concentration of major ions. Relationships between ion concentrations (as meq/L) were analyzed through linear modeling and calculation of coefficients of determination (R-2). The relationships between NO3 and alkaline earth metal ions (M2+) (excess [Ca2+Mg2+] over [HCO3-]) were investigated. There is a strong linear relationship (R-2>0.90) between molar concentrations of the excess M2+ and NO3- ions. Nitrogen compounds originating primarily from microbially-driven processes such as nitrification are expected to react with carbonate minerals (e.g., CaCO3) and may migrate to groundwater as in the following reaction; 2NO(3)((aq))(-) + CaCO3(s) -> Ca(NO3)(2(aq)) + CO3(aq)2-
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    Fluid pathways identified beneath Narli Lake (Central Anatolia) show the geothermal potential of former volcanoes
    (Nature Portfolio, 2021) Brehme, Maren; Giese, Ronny; Dokuz, Ugur Erdem; Bulut, Fatih
    We investigated the volcanic Narli Lake in Central Anatolia combining high-resolution bathymetry and geochemical measurements. In this study, we present it as proof of a new concept to verify fluid pathways beneath lakes integrating the structure of the geothermal reservoir into the surrounding tectonic frame. We recognized dextral faults fracturing inherited volcanic formations and thus generating highly permeable zones beneath the lake. At intersection points of faults, reservoir fluids discharge from deep holes as imaged by the high-resolution bathymetry at the bottom of the Narli Lake. Onshore, the tectonic setting also generates both extensional and compressional structures. Extensional structures result in extensive fluid discharge through hot springs while compressional structures do not discharge any fluid. The water of the lake as well as in the hot springs is highly saline and has relatively high concentrations of Cl, HCO3, SO4, Na, Ca, Mg, and Si. In several hot springs, we observed mixtures of high-saline fluids having a deep origin and low-saline shallow groundwater. We observed discharge into the lake by gas bubbles, which contain probably CO2 or H2S. Mineral precipitation indicates a carbonatic source at the lake bottom and along the shoreline. Extensive travertine precipitation also occurs near hot springs along the nearby extensional zone of Ihlara Valley. In summary, the composition of fluids and minerals is controlled by water-rock interaction through the volcanic and carbonatic rocks beneath this volcanic lake.