Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2026/r/gumushane/13832
  Multi-scale greening dynamics in Türkiye’s Ecoregions (2001–2024): the effects of elevation and land cover on NDVI change tendencies

  Işık, Fatih; Eraslan, Selim

  Understanding vegetation dynamics in terrestrial ecosystems is critical under the pressures of global climate change and anthropogenic activities. This study analyzes vegetation dynamics from 2001 to 2024 in Türkiye’s 13 biodiverse terrestrial ecoregions using a multi-scale approach, focusing not only on the main drivers, but also on the interactive and context-specific role of these factors. Using the Google Earth Engine (GEE) platform and MODIS Normalized Difference Vegetation Index (NDVI) data, integrated through a structured multi-scale framework, we applied statistical methods including the Mann–Kendall test, Kruskal–Wallis test, and LOESS curves optimized with leave-one-out cross-validation (LOOCV) to objectively model non-linear dynamics. The results revealed statistically significant positive NDVI change tendencies in all 13 terrestrial ecoregions (Mann–Kendall test, p < 0.05). Forest-dominated ecoregions exhibited the strongest greening, with Sen’s slope values reaching +0.0032 NDVI year⁻1 in the Euxine–Colchic Broadleaf Forests, whereas steppe ecosystems showed more moderate increases (e.g., Central Anatolian Steppe: + 0.0019 NDVI year⁻1). Across elevation gradients, the most consistent and strongest greening occurred at mid-elevations (500–1500 m; τ ≈ 0.40–0.65), while change tendencies weakened and became more heterogeneous at higher elevations. Land-cover-based analysis further showed that natural vegetation types exhibited the strongest nationwide tendencies (“Trees”: τ = 0.71; “Shrubland”: τ = 0.66), whereas anthropogenically influenced classes displayed weaker or regionally variable responses. Beyond documenting general greening patterns, the original contribution of this study lies in introducing a structured multi-scale framework that integrates long-term MODIS NDVI time series (2001–2024) with ecoregion, elevation, and land cover contexts. This approach enables the objective identification of ecosystem-specific and scale-dependent vegetation dynamics that cannot be captured by conventional single-scale or linear trend-based analyses commonly applied in previous studies in Türkiye.

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• MakaleYalnız künye2025/r/gumushane/12406
  First evaluation and ecological risk of potentially toxic elements in the formations of Akçakale cave (Gümüşhane-NE-Türkiye)

  Saydam Eker, Çiğdem; Külekçi, Gökhan; Uçak, Gül

  In this study, the potential toxic element levels (PTEs) and adverse health effects of Akçakale cave formations were evaluated using geochemical parameters such as enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), ecological risk factor (Eri), potential ecological risk index (PERI), and non-carcinogenic hazard index (HI). Water does not pose a pollution risk, as the concentrations of potentially toxic elements in all samples are within the permissible limits for drinking water. According to the calculated geochemical parameters, all the samples were polluted with As, Co, Ni, Cu, V, and Pb. Ni, As, Cu, and Pb show very high ecological risk (PER > 320) in all samples, except Cu and Pb in T2T. The PERI values of the PTEs were more than 600 in all samples, indicating a very high potential ecological risk. The HI > 1 values for Co and As in all samples for both adults and children suggested potential non-carcinogenic health risks from exposure to these elements in the cave environment. The PTEs in the Akçakale cave formation were most likely linked to lithogenic, geogenic (Pb–Zn-Cu mineralization), and anthropogenic (agricultural activities) processes, per the findings of the data analysis using multivariate statistics (PCA and PCC). These data obtained are the first findings regarding the potential toxic element content of Akçakale cave.

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• MakaleYalnız künye2021/r/gumushane/14699
  Preparation of melon peel biochar/CoFe2O4 as a new adsorbent for the separation and preconcentration of Cu(II), Cd(II), and Pb(II) ions by solid-phase extraction in water and vegetable samples

  Ozdes, Duygu; Duran, Celal

  The present research describes the successful preparation of melon peel biochar modified with CoFe2O4 (MPBC/CoFe2O4) followed by its usage as a new sorbent to separate, preconcentrate, and determine the toxic heavy metal ions by magnetic solid-phase extraction. The metal ion desorption was performed by 0.1 M HCl solution with a volume of 5.0 mL. Flame atomic absorption spectrometry (FAAS) was utilized for detection of the analyte levels. SEM–EDX, TEM, XRD, and FTIR techniques were carried out to illuminate the structure of MPBC/CoFe2O4. The fundamental variables affecting the adsorption and elution efficiencies of the analyte ions including solution pH, MPBC/CoFe2O4 amount, type and concentration of eluent, adsorption and desorption equilibrium time, and sample volume were optimized. The detection limits were calculated as 0.41, 1.82, and 3.16 µg L−1 for Cu2+, Cd2+, and Pb2+ ions, respectively, with the relative standard deviation of lower than 4.2%. There were no substantial interference effects on the analyte ion recovery due to the presence of foreign ions at high levels. Five minutes of contact time was adequate to attain the adsorption equilibrium. The adsorption capacity of MPBC/CoFe2O4 was obtained as 106.4, 65.4, and 188.7 mg g−1 for Cu2+, Cd2+, and Pb2+ ions, respectively, by utilizing Langmuir isotherm model. The pseudo-second order model is favorable to identify the adsorption kinetics. The method was validated by spike/recovery test, and then, it was successfully implemented to determine the aforementioned analyte levels in sea and stream water, pepper, black cabbage, eggplant, and tomato samples.

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• MakaleYalnız künye2020/r/gumushane/14833
  Investigation of the relationship between rare earth elements, trace elements, and major oxides in soil geochemistry

  Vural, Alaaddin

  Investigation on the behavior of elements in the soil is important both in exploration and environmental geochemistry studies. Rare earth elements (REEs) are the most useful among all trace elements. REE studies have shown that they have important applications in igneous, sedimentary, and metamorphic petrology. This work aims to investigate the relationship of these elements with one another and the behavior of the major oxides and trace elements with REEs. Soil samples were obtained from the alteration site possibly related to mineralization and were analyzed for major oxides, trace elements, and REEs. The relationships between the major oxide–trace element/heavy metal and REE were investigated by statistical methods, such as descriptive statistics, correlation coefficient, and principle component analysis. According to the correlation coefficient matrix, light REEs (LREEs) showed weak to moderate negative correlation with MgO and MnO and moderately positive correlation with SiO2 and K2O. No association was detected between the heavy REEs (HREEs) and the main oxides, but a strong positive correlation with LREEs was observed. For the trace elements, LREE showed a weak positive correlation with Ba and Sn and moderate to strong positive correlation with As, Hf, Nb, Rb, Ta, Th, U, W, and Zr. They also displayed weak to moderate correlation with Sc, Co, Zn, Ni, and V. HREE showed weak to moderate positive correlation with Ni, Cs, Ga, Hf, Th, Zr, As, and LREE. Although REEs exhibited no direct correlation with Au and Ag, they showed a good correlation with some trace elements that are related to hydrothermally altered products. This study showed that REEs can also be used in exploration and environmental geochemistry studies by exploiting the relationship between REEs and other trace/heavy metal elements.

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• MakaleYalnız künye2020/r/gumushane/14633
  Validating InSAR-SBAS results by means of different GNSS analysis techniques in medium- and high-grade deformation areas

  Yalvac, Sefa

  This study aimed to validate the interferometric synthetic aperture radar (InSAR) method by using relative and absolute Global Navigation Satellite System (GNSS) techniques. In this context, two land subsidence areas, one high (Mexico City) and one medium (Aguascalientes), were monitored between 2014 and 2018 by using Sentinel 1A satellite data. The monitoring was carried out with the Small Baseline Subset (SBAS) technique using 46 images for Mexico City and 18 images for Aguascalientes. Concordantly, the GNSS Continuously Operating Reference Station (CORS) data in the regions were analyzed with relative and Precise Point Positioning (PPP) GNSS analysis techniques. The time series obtained from three different analyses were compared and the results were evaluated in light of statistical criteria. According to the results, it is determined that the InSAR-SBAS technique can vary up to ± 20 mm from the displacement values obtained from GNSS due to various noise sources. Such deviations were limited to a few samples, and in general the differentiations were reasonable in the range of 7–8 mm. The difference between the deformation velocity estimation results obtained from the three different methods varied between 3 and 10 mm/year. In this context, these findings suggest that the InSAR-SBAS technique is an effective method for monitoring land deformation with the accuracy of sub-centimeter decided. In addition, PPP which has become an increasingly popular technique showed fast and reliable results in the range of 5–10 mm for InSAR verification. Moreover, with this study, most current results for Mexico City, which is the world’s fastest subsiding metropole, were achieved. In the central region of the city, the detected 300 mm/year of subsidence rate was updated as 370 mm/year. In addition, Aguascalientes was monitored by using the Sentinel 1A satellite mission for the first time in this study. The 60 mm/year subsidence rate obtained for Aguascalientes in previous studies was updated and it was estimated that there are zones where this rate reaches up to − 115 mm/year levels. In this regard, it was concluded that the deformation rate has increased for both regions since the previous monitoring studies.

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• MakaleYalnız künye2015/r/gumushane/15352
  Biogeochemical characteristics of Rosa canina grown in hydrothermally contaminated soils of the Gümüşhane Province, Northeast Turkey

  Vural, Alaaddin

  Kırkpavli alteration area (Gümüşhane, Northeast Turkey) is contaminated by heavy metals such as Cd, Pb, As, Cu and Zn. The quantity of accumulation of heavy metal trace elements and macroelements in 32 leaves of Rosa canina of the Kırkpavli alteration area has been studied within the scope of geochemical studies. Element contents of samples were assessed using various parameters including descriptive statistics, factor analysis, correlation coefficients and bioaccumulation factor. Concentrations were detected in the acceptable range for Mo, Cu, Pb, Ni, As, Cd, Sb, P, Ti, Na, Se and Sn. Concentrations of Co, Mn, Ba and Hg were detected close to the acceptable values, whereas Zn, Fe, Sr, V, Ca, Cr, Mg, B, Al, K, W, Sc, Cs and Rb concentrations were detected above the acceptable values. Principal component analysis was used to identify the elements that have a close relationship with each other and/or similar origins. It has been concluded that Zn, Cu, As and Mo content of the plant were related to hydrothermal alteration process and they behaved together, whereas Mn and Fe were especially products of weathering conditions, also behaved together. In terms of macroelements, Ca, Mg and Na had similar behaviour, while P and K had the same correlation.

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• MakaleYalnız künye2013/r/gumushane/15620
  Biosorption properties of Morus alba L. for Cd (II) ions removal from aqueous solutions

  Serencam, Huseyin; Ozdes, Duygu; Duran, Celal; Tufekci, Mehmet

  The abundantly available industrial waste product Morus alba L. pomace (MAP) is one of the cost-effective biosorbent for removal of metal ions from aqueous solutions. Hence, in the present study, we aimed to test the ability of MAP to remove Cd(II) ions through batch biosorption process. Firstly, MAP was characterized using several techniques, and then the influence of various experimental parameters such as initial pH of the aqueous solution, initial Cd(II) concentration, contact time, MAP concentration, and temperature were evaluated upon the biosorption process. It was found that the maximum uptake of Cd(II) ions occurred at initial pH 6.0 and optimum contact time was observed as 60 min. Cd(II) ions adsorption on MAP analyzed by the Langmuir and Freundlich isotherm models and the maximum monolayer biosorption capacity of MAP was found to be 21.69 mg g-1 by using the Langmuir isotherm model. The pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models were employed to describe the biosorption kinetics. In order to investigate the thermodynamic properties of the biosorption process, the changes in the Gibbs free energy (â̂†G), enthalpy (â̂†H), and entropy (â̂†S) were also evaluated and it has been concluded that the process was feasible, spontaneous, and endothermic in the temperature range of 5-40 C.

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• MakaleYalnız künye2013/r/gumushane/13140
  Determination of Pb(II), Zn(II), Cd(II), and Co(II) ions by flame atomic absorption spectrometry in food and water samples after preconcentration by coprecipitation with Mo(VI)-diethyldithiocarbamate

  Tufekci, Mehmet; Bulut, Volkan Numan; Elvan, Hamide; Ozdes, Duygu; Soylak, Mustafa; Duran, Celal

  A new, simple, and rapid separation and preconcentration procedure, for determination of Pb(II), Cd(II), Zn(II), and Co(II) ions in environmental real samples, has been developed. The method is based on the combination of coprecipitation of analyte ions by the aid of the Mo(VI)-diethyldithiocarbamate- (Mo(VI)-DDTC) precipitate and flame atomic absorption spectrometric determinations. The effects of experimental conditions like pH of the aqueous solution, amounts of DDTC and Mo(VI), standing time, centrifugation rate and time, sample volume, etc. and also the influences of some foreign ions were investigated in detail on the quantitative recoveries of the analyte ions. The preconcentration factors were found to be 150 for Pb(II), Zn(II) and Co(II), and 200 for Cd(II) ions. The detection limits were in the range of 0.1-2.2 μg L-1 while the relative standard deviations were found to be lower than 5 % for the studied analyte ions. The accuracy of the method was checked by spiked/recovery tests and the analysis of certified reference material (CRM TMDW-500 Drinking Water). The procedure was successfully applied to seawater and stream water as liquid samples and baby food and dried eggplant as solid samples in order to determine the levels of Pb(II), Cd(II), Zn(II), and Co(II) ions.

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