Quantitative and qualitative indicators of natural and waste waters in the Dnipro basin

Analysis of the state of water resources in Ukraine provides an opportunity to improve the ecological situation on the basis of hydrographic and water management zoning using the latest methodological approaches and technologies for constructing the water balance of the basin areas. The aim of the research is to establish patterns of change in the quality indicators of the country's water resources in the largest basin of the Dnipro River. The study was carried out on the basis of an assessment of indicators for monitoring changes in the quantitative and qualitative indicators of water resources in the Dnipro basin in 2016-2021.A decrease in the Dnipro runoff was recorded: the average long-term natural runoff at the mouth is 53.3 km3, and the actual runoff is about 11 km3 (20%) less than the natural runoff. A decrease in the quantitative indicators of water intake from the Dnipro basin in 7365 million m3, a decrease in the quantity (up to 547.1 million m3) and a deterioration in the quality of return water and the general state of water resources in the basin from the northwest to the southeast. The measurements’ results of the indicators of the waters’ qualitative state in the reservoirs and the main watercourses of the basin at the locations of the monitoring points indicate that the norms are exceeded by a multiplicity of more than 5 times, including in terms of BOD and COD, which reflect the intensity of pollution of water bodies with easily oxidizing and difficult oxidizing organic compounds. The screening of pollutants revealed the content of pesticides, drugs, antidepressants, heavy metals-carcinogens in the Dnipro water, which makes it possible to investigate the problems with water resources, taking into account the specifics of the river basin. Such an assessment shows that climate change and industrial enterprises, as notable anthropogenic component, are significant factors affecting water resources. This indicates the importance of the direction of the policy of state regulation on water monitoring, the introduction of an irrigation and drainage strategy, the construction of centralized water supply and sanitation systems and strict control over the indicators of wastewater discharge.

Atmospheric methane and nitrous oxide: challenges alongthe path to Net Zero

The causes of methane's renewed rise since 2007, accelerated growth from 2014 and record rise in 2020, concurrent with an isotopic shift to values more depleted in 13 C, remain poorly understood. This rise is the dominant departure from greenhouse gas scenarios that limit global heating to less than 2°C. Thus a comprehensive understanding of methane sources and sinks, their trends and inter-annual variations are becoming more urgent. Efforts to quantify both sources and sinks and understand latitudinal and seasonal variations will improve our understanding of the methane cycle and its anthropogenic component. Nationally declared emissions inventories under the UN Framework Convention on Climate Change (UNFCCC) and promised contributions to emissions reductions under the UNFCCC Paris Agreement need to be verified independently by top-down observation. Furthermore, indirect effects on natural emissions, such as changes in aquatic ecosystems, also need to be quantified. Nitrous oxide is even more poorly understood. Despite this, options for mitigating methane and nitrous oxide emissions are improving rapidly, both in cutting emissions from gas, oil and coal extraction and use, and also from agricultural and waste sources. Reductions in methane and nitrous oxide emission are arguably among the most attractive immediate options for climate action. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 1)'.

Geoarchaeology within the system of archaeological research in the territory of Baikal Siberia

The value of geoarchaeology in archaeological research is discussed with an example of Baikal Siberia. Geoarchaeology is considered as an interface between archaeology and Earth sciences comprising a specific set of approaches, methods, and procedures. Nowadays, geoarchaeology constitutes a full-fledged research branch within the world archaeological practice. However, there are some problems in the determination of the essence and the role of geoarchaeology in archaeological studies, especially in Russia. In particular, the question whether geoarchaeology represents an independent discipline or an interdisciplinary approach has not been resolved yet. Moreover, archaeologists often focus on increasing the number of analytical methods to the detriment of their conceptual basis. In the Russian archaeological practice, the uncertain role of geoarchaeology is manifested by its perception as an auxiliary discipline with limited capabilities for the archaeological interpretations. As a result of many years of research on archaeological sites of Baikal Siberia, we have developed our own concept of geoarchaeology as a source study with a transdisciplinary character. It is based on four principles. Firstly, in our opinion, geoarchaeology constitutes a source study discipline with its own research methods. Geoarchaeological assessment represents one of the most important verification methods aimed at the determination of the degree of correspondence between the results of archaeological and natural science data. Secondly, the main object of research is a geoarchaeological object, which is a composite integral system with a mixture of traces of natural and anthropogenic events encrypted in it. We define the layer with cultural remains, where the natural component predominates, as ‘culture-bearing’. The layer with the predominantly anthropogenic component can be called ‘cultural’. Thirdly, geoarchaeology should be a transdisciplinary branch, the nature of which is determined by the complex origins of the geoarchaeological site. Such an amalgamation allows overcoming disciplinary differences and contradictions which leads to the formation of new knowledge levels. At fourth, geoarchaeological research should be based principally on the methods of actualism and stratigraphy in conjunction with overcoming misidentification of objects and phenomena, as well as on the pedolithological and event-driven approaches.

Unraveling Misunderstandings about Desertification: The Paradoxical Case of the Tabernas-Sorbas Basin in Southeast Spain

From its origins, the concept of desertification has been controversial. The prevailing confusion between two desertification visions, one that considers it as the expansion of deserts and another that emphasizes its anthropogenic component, has been transferred to society. Here we illustrate misunderstandings about desertification using a very illustrative case from the Tabernas-Sorbas Basin (Almeria, Spain), where striking badlands that are often used as an image of desertification coexist with an intensive olive agriculture that is irreversibly deteriorating the only oasis in continental Europe (Los Molinos spring). The olive tree is a traditional Mediterranean dryland crop and until the 1950s only about 200 ha were irrigated in this area. However, the profitability of the crop has caused irrigation to expand to 4400 ha in the last two decades. The process of intensification has been reinforced giving way to super-intensive irrigation, which involves going from 210 to 1550 trees/ha, which in a few years already occupies more than 1500 ha. The effects on the water balance of the aquifer feeding these crops have been severe, and the flow of the Los Molinos spring has gone from more than 40 L/s for the period 1970–2000 to the current 7.28 L/s. Unraveling the mechanisms of land degradation and its main drivers are the first step to propose management actions to achieve a more sustainable use of resources and to combat desertification.

Urban CO2 Budget: Spatial and Seasonal Variability of CO2 Emissions in Krakow, Poland

Krakow, with an area of 327 km2 and over 750,000 inhabitants, is one of the largest cities in Poland. Within the administrative city borders several anthropogenic CO2 source types are located, including car traffic, household coal and natural gas burning, and industrial emissions. Additionally, the biosphere produces its own, seasonally variable, input to the local atmospheric carbon budget. In order to quantify each of CO2 budget contributions to the local atmosphere, a number of analytical and numerical techniques have been implemented. The seasonal variability of CO2 emission from soils around the city has been directly measured using the chamber method; CO2 net flux from an area containing several source types has been measured with a relaxed eddy accumulation—a variation of the eddy covariance method. Global emissions inventory, as well as local statistical data have been utilized to assess anthropogenic component of the budget. As other cities where CO2 budget was quantified, Krakow proved to be a net source of this greenhouse gas, and the calculated annual mean net flux of CO2 to the atmosphere equal 6.1 kg C m−2 is consistent with previous estimations.

Modern changes of nutrients’ removal into the southern forest zone rivers of Volga basin

The article analyzes on the example of the Linda river basin, the tributary of the Cheboksary reservoir, contribution of the main elements of its vertical hydrological structure (precipitation, surface and underground runoff, verhovodka runoff) in the formation of nutrients removal from rivers catchments in the southern forest zone of the Russian plain. The removal of nutrients from the Linda river catchment area with various elements of water flow for the year, its high-water and low-water periods was calculated. It is shown that due to the increased role of the changed hydro-climatic conditions, especially due to the increased flow of infiltration origin (underground and verhovodka runoff), the nutrients removal has increased in recent years. Anthropogenic component of nutrient leaching into the Cheboksary reservoir from Linda river catchment was identified. It is reduced in recent decades by the background dispersion in the catchment, diffuse nutrients leaching to surface and underground flow of natural origin.

Variation of 14C in Japanese Tree Rings Related to the Fukushima Nuclear Accident

ABSTRACTRadiocarbon (14C) analysis was performed on Japanese cedar (Cryptomeria japonica) tree rings from Koriyama, Fukushima prefecture. Our primary aim was to detect any 14C release from the Fukushima Dai-ichi nuclear power plant accident on 11 March 2011. We also completed and assessed the 14C level in Japanese tree rings for the period of 1990–2014 because of the lack of environmental 14C results in the Japanese island that time. For this reason, we used a trajectory model to investigate the air mass forward and backward trajectories at the area of the power plant and sampling site. The modeling data show that the air masses mainly moved to the Pacific Ocean, both during March 2011 and during the growing season (March–September). During the period 1990–2014 there was no significant 14C excess in any of the samples, but there was a detectable Suess effect in almost every tree ring sample. The average fossil contribution was 0.83 ± 0.01% and the calculated anthropogenic component ratio, the 14C excess varied between +0.5 and –1.6%. The Δ14C value decreased from 150.0‰ to 9.5‰ from 1990–2014, which follows the decline of the 14C bomb peak, in addition to any detectable Suess effect.

ANTHROPOGENIC COMPONENT OF ATMOSPHERIC AEROSOL SUBSTANCE OF ZAPORIZHZHIA CITY

The article is devoted to the study of the influence of technogenic processes on the environment, in particular the determination of the contribution of a substance formed in the course of economic activity to the total composition of the solid component of atmospheric aerosol. The actual material was obtained on the basis of the system monitoring of surface air flows within such a powerful industrial center as Zaporizhzhia city. Samples of suspended atmospheric matter accumulated on the filter textile were taken monthly for two years. Parallel continuous observations of hydrometeorological factors (speed, direction, duration of winds, rainfall) provided an integrated approach to the development and synthesis of research results. Field observations and laboratory studies determined a number of patterns in the distribution of the sedimentation substance in the air and the interrelations of the anthropogenic and natural constituents of the substance. The publication describes the features of the chemical composition and morphology of detrital particles, the entry of which into the air caused by technogenic processes, as well as the condensation component of the aeolian suspension, the origin of which is associated with high-temperature processes. The changes in the ratio of the natural / anthropogenic components in the material composition of the aerosol under the influence of external factors (natural and anthropogenic) were investigated. These changes also affect the redistribution of quantitative ratios between the condensed and dispersed components of the aeolian suspension. At the same time, the detrital component can reach the aleuritic dimension, the iron content exceeds 90 %, and the proportion of impurities of a number of ferrous and heavy metals, in particular titanium, manganese, nickel, copper, lead, zinc can reach 40% or more. Heavy metals are also found in the form of separate detrital and condensation formations, where their content varies in the range of 50 – 70 %. Analysis of the condensation component in the aerosol samples for the period of the research allowed us to give a general characteristic of it and to carry out a preliminary classification by chemical composition. The possibility of determining the focus of atmospheric pollution in terms of the shape, chemical composition and size of aerosols, seasonal factors and characteristics of atmospheric flows were also outlined.

Current CaCO3 dissolution at the seafloor caused by anthropogenic CO2

Oceanic uptake of anthropogenic CO2 leads to decreased pH, carbonate ion concentration, and saturation state with respect to CaCO3 minerals, causing increased dissolution of these minerals at the deep seafloor. This additional dissolution will figure prominently in the neutralization of man-made CO2. However, there has been no concerted assessment of the current extent of anthropogenic CaCO3 dissolution at the deep seafloor. Here, recent databases of bottom-water chemistry, benthic currents, and CaCO3 content of deep-sea sediments are combined with a rate model to derive the global distribution of benthic calcite dissolution rates and obtain primary confirmation of an anthropogenic component. By comparing preindustrial with present-day rates, we determine that significant anthropogenic dissolution now occurs in the western North Atlantic, amounting to 40–100% of the total seafloor dissolution at its most intense locations. At these locations, the calcite compensation depth has risen ∼300 m. Increased benthic dissolution was also revealed at various hot spots in the southern extent of the Atlantic, Indian, and Pacific Oceans. Our findings place constraints on future predictions of ocean acidification, are consequential to the fate of benthic calcifiers, and indicate that a by-product of human activities is currently altering the geological record of the deep sea.