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Substances of petroleum origin that reach groundwater limit water use and can have irreversible effects on ecosystems interacting with them. Quantitative changes in groundwater and synergistic effects generated by petroleum products on ecosystems can be objectively quantified based on a scenario for the transport of pollutants concentrations through the aquifer. In this sense, with the help of mathematical models, the research estimates the spatial and temporal dimension of a possible accidental pollution by petro...

Water quality was investigated in Lake Matita, part of the Danube Delta Biosphere Reserve, Romania, to assess the overall status of the freshwater ecosystem, in accordance with the EU Water Framework Directive (WFD ? 2000/60/EC), which addresses all surface waters i.e., rivers, lakes, transitional waters and coastal waters in the EU. From this perspective, a specific physical and chemical analysis of surface water samples was performed, collected in different sectors of the lake, during the summer of June 2020. Se...

This article presents the results of studies of the hydrodynamical and sedimentological conditions of the Sulina Channel, the middle distributary of the Danube within its delta. One field campaign (at low waters) in September 2019 was conducted to analyse the geometry, the sediment composition and hydraulic conditions of the channel. During the field campaign, the measured water mean velocity was from v = 0.01?0.54 m.s-1 for a water discharge (measured upstream, at the bifurcation, knot Ceatal St. George) of 698 m...

In the Danube delta, on the Sulina Channel, the morphology and bedforms characteristics have been investigated. 3D bathymetry, flow velocity, and bed sediments data have been acquired, in order to investigate the dynamic of the bedforms, the distribution of the water, and their influence against the river bed. A single observation (in May 2019) was made regarding the geometry, sediment composition and hydraulic conditions under which the dunes grew and decomposed. The investigation focuses here mostly on the geome...

This article is based on the results of studying the dynamics of long-term fluctuations in the flow of spring floods of the Don and Dnieper river basins in the territory of the Belgorod Region in the period 1968?2018. The object of the study are the maximum water discharges during the spring flood on the Tikhaya Sosna river near the town of Alekseevka (right tributary of the Don river) and Vorskla river near the village of Kozinka (left tributary of the Dnieper river). These rivers were chosen as objects of study ...

The methodology of sustainable forecasting of runoff and diagnosing bifurcations of its formation, being considered in the article, allows solving fundamentally new hydrological problems (including problems of engineering hydrology) related to the possibility of obtaining long-term estimates of the probabilistic characteristics of long-term river runoff under the conditions of evolutionary changes in the runoff formation factors (climate and anthropogenic activity on catchments). Currently, these long-term estimat...

The article considers the solving the problem arising at the mathematical modeling of hydrological processes, namely, the problem of the number of phase variables taken into account in the model. The number of variables in the model can change depending on the climate. The fractal dimension characterizes required number of variables. In the article the results of applying the established regularity of the influence of the long-term norm of surface air temperature on the fractal dimensionality of the annual runoff ...

The purpose of this study was to separate and subsequently investigate the lake governance developments within existing surface water resource governance system in Latvia by looking across all the three country administration levels, namely of the national, regional and municipal levels, in order to determine the actual state and main drawbacks of this step-wise developing lake governance system in Latvian. In this study, lake governance was systemized and characterized, taking note of what particular and eventual...

The paper presents a synthesis of our researches on the main physic - chemical and biological parameters of the Snagov Lake, from Ilfov County, Romania, made since 2013 until 2019. We have developed complex investigations on the most important water quality parameters of the lake, in the purpose of analyze the evolution of the water eutrophication phenomenon in time, in different sampling points, also to establish the optimal methods of control and combat of the studied pollution process. Because the eutrophicatio...

Recently, zeolites have attracted a significant interest due to their potential use in a wide range of applications related to water treatment and environmental remediation. The chemical and thermal treatments are the most used approaches to improve the zeolites properties by enhancement of sorption properties, surface area and porosity. Chemical (2M NaCl), thermal (150 °C for 24 h) and thermo-chemical (2M NaCl, 150 °C for 24 h) activation methods for a natural clinoptilolite based zeolite originated from Romania ...

On the Lower Danube, including the Romanian-Bulgarian common sector (between chainage km 845.5 to km 375), the width of the fairway is generally sufficient to accommodate multiple ships. However, in low water conditions (below 3000 mc/s) the depths are insufficient to ensure the efficient transport of goods. Very often, vessels sailing in the critical navigation areas (bottlenecks) can only be loaded at half of their capacity. This situation can cause significant losses for river transport operators and lead to la...

The article analyses the current state of flood protection of the urban area in the foothill region. Problems of the area were characterized through selected critical points that support the local flood origination. Of course, the flood is a random phenomenon and its behaviour depends on many other factors, such as soil saturation, vegetation cover, river bed channel current state, as well as drainage cuts, soil management, etc. For efficient design of the flood protection measures, it is necessary to have input d...

Objects of geological heritage of international level are located in the Nizhny Novgorod region. This is the Puchezh-Katunki impact crater of an early Jurassic age, the Bathonian-Callovian deposits of the Jurassic system near the settlement of Prosek on the banks of the Volga and karst lakes and caves in the basin of Pyana and Tyosha rivers. A water induced risk assessment was carried out to include it in application for aspiring UNESCO Geoparks network. The assessment includes the risk of landslides, abrasion of ...