Long-term meteorological data and isotopic composition in precipitation, surface water and groundwater revealed hydrologic sensitivity to climate change in East Ukraine.

Our study focused on the incorporation of stable isotope ratios in water in climatic and hydrological observations to understand local hydroclimatic processes and determine basic hydrological sensitivity to climate change in East Ukraine. Long-term meteorological data from two stations at Kharkiv and Izyum showed that air temperature was significantly increased only for the cold period (November-April), while precipitation amount increased during all seasons. Applying two-component mixing model with stable isotope ratios in water, we determined that surface water in both regions was dominantly recharged by the cold precipitation. The highest share of cold precipitation contribution (∼79 %) was found in the river with the shortest water transit time. The isotopic signature of groundwater also indicated that water resources were mainly recharged during the cold period. Our findings reveal that basic hydrological sensitivity of the transboundary (Ukraine/Russian Federation) Seversky Donets River basin relates to hydroclimate changes mainly observed in November-April. We suggest that climate changes can influence surface water and groundwater but also the overall regional water availability that is highly dependent on the cold precipitation in these regions.

Defining a stable water isotope framework for isotope hydrology application in a large trans-boundary watershed (Russian Federation/Ukraine).

Stable isotopes of hydrogen (2H) and oxygen (18O) of the water molecule were used to assess the relationship between precipitation, surface water and groundwater in a large Russia/Ukraine trans-boundary river basin. Precipitation was sampled from November 2013 to February 2015, and surface water and groundwater were sampled during high and low flow in 2014. A local meteoric water line was defined for the Ukrainian part of the basin. The isotopic seasonality in precipitation was evident with depletion in heavy isotopes in November-March and an enrichment in April-October, indicating continental and temperature effects. Surface water was enriched in stable water isotopes from upstream to downstream sites due to progressive evaporation. Stable water isotopes in groundwater indicated that recharge occurs mainly during winter and spring. A one-year data set is probably not sufficient to report the seasonality of groundwater recharge, but this survey can be used to identify the stable water isotopes framework in a weakly gauged basin for further hydrological and geochemical studies.

Trace metals in wine and vineyard environment in southern Ukraine.

The study was focused on measuring the concentration levels of trace metals in the environment, vines and wine within the wine-growing region of Ukraine and comparing the findings to the data from well known wine-growing areas. Analysis was carried out of Cr, Cu, Ni, Pb and Zn in irrigation water, grape juice and wine, Cu, Pb and Zn in soil (pseudo-total and acid-soluble fractions) and Vitis vinifera L. in leaves and grapes. The accumulation levels of Cu and Zn from soil to leaves were significantly higher than from soil to grapes. Pb had lower potential to accumulate in aerial parts than Cu and Zn. Higher contents of Cu and Zn were observed in Muscat white grape juice compared to Chardonnay. The concentration levels of Zn and Cu were higher in wine than in juice. Trace metals were regulated by the soil composition and biological specificity of cultivars. The data obtained from the study area did not exceed the international limits.