Diffuse Runoff from Agricultural Lands within a River Basin and Water Protection Measures

This paper is dedicated to the study of the pollutants coming from agricultural lands located within the catchment into the Yakhroma river, a third-order tributary of the Upper Volga. The area of the river catchment is 1437 km2. It is located in the north-eastern part of the Moscow region, which geographically belongs to the Klinsko-Dmitrov ridge (the upper part of the basin) and the Upper Volga Lowland. The slopes and floodplain included in the reclaimed lands (more than 9 th ha) are lined with cities, rural settlements, numerous kitchen gardens, and agricultural lands. Water quality, river profile from the source to the mouth, and sources of pollution within the reclaimed lands of the Yakhroma floodplain were studied from 2004 to the present. A geospatial intelligence system (GIS) was developed for the catchment area. Land areas are allocated according to the conditions of surface runoff formation, taking into account soil types and slopes. The studies of the river water quality, tributaries, and drainage network in the reclaimed lands showed biogenic pollution caused by insufficiently treated wastewater discharged from cities and agricultural land, especially within the reclaimed massif. The calculations of the removal of nitrogen, phosphorus, and potassium from surface and drainage waters revealed that the main role in the pollution of both surface and drainage waters is played by nitrogen and potassium compounds, and to a lesser extent by phosphorus compounds. For nitrogen, removal from surface runoff was 27.36 t/year; for phosphorus it was 6.06 t/year; for potassium it was 242.28 t/year; with drainage runoff, the removal of nitrogen was 98.88 t/year; the removal of phosphorus was 0.38 t/year; the removal of potassium was 37.04 t/year. To reduce the inflow of surface diffuse runoff and to purify collector and drainage waters from nitrogen and phosphorus compounds, including the creation of bioplateaus and biosorption structures, it was proposed to use a set of protective measures, which will significantly reduce the biogenic load on the river flow.

The assessment of microbiological and physicochemical characteristics in drainage waters of the Siriu dam

Based on the balneotherapeutic applications of mineral spring water and particularly sulphurous water, the aim of our research was to study the physicochemical and microbiological parameters of some drainage waters of Siriu dam that showed a strong hydrogen sulphide odour. In addition, due to the corrosive effect of some groups of microorganisms, such as iron-oxidizing bacteria and sulphatereducing bacteria, the present paper also aimed to detect their presence in order to signal the need for some disinfection measures. According to physicochemical analysis, there has been found an external drain that is suitable for use in balneotherapy, presenting a balanced content of mineral elements such as sulphur, calcium, silicon, chlorine and potassium. However, due to the presence of potentially toxic phytoplankton microorganisms such as Microcystis sp. and Phormidium sp. it is necessary to disinfect this water source before using it for any purpose. On the other hand, the identification of both sulphate-reducing bacteria and iron-oxidizing bacteria in the drainage waters of Siriu dam should be considered as an alarm signal as they may lead to bio-corrosion and deterioration of metallic or concrete structures, affecting the integrity of the dam and hydropower constructions.

The role of soils in the regulation of ocean acidification

Soils play an important role in mediating chemical weathering reactions and carbon transfer from the land to the ocean. Proposals to increase the contribution of alkalinity to the oceans through ‘enhanced weathering’ as a means to help prevent climate change are gaining increasing attention. This would augment the existing connection between the biogeochemical function of soils and alkalinity levels in the ocean. The feasibility of enhanced weathering depends on the combined influence of what minerals are added to soils, the formation of secondary minerals in soils and the drainage regime, and the partial pressure of respired CO 2 around the dissolving mineral. Increasing the alkalinity levels in the ocean through enhanced weathering could help to ameliorate the effects of ocean acidification in two ways. First, enhanced weathering would slightly elevate the pH of drainage waters, and the receiving coastal waters. The elevated pH would result in an increase in carbonate mineral saturation states, and a partial reversal in the effects of elevated CO 2 . Second, the increase in alkalinity would help to replenish the ocean's buffering capacity by maintaining the ‘Revelle Factor’, making the oceans more resilient to further CO 2 emissions. However, there is limited research on the downstream and oceanic impacts of enhanced weathering on which to base deployment decisions. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.

HYDROGEOLOGICAL FEATURES OF THE DEVELOPMENT OF THE BOROK QUARRY (NOVOSIBIRSK)

The hydrogeological features of the development of the Borok granite quarry, the oldest in Siberia, are considered in the article. It was found that the hydrogeological conditions of the quarry are quite difficult. Two aquifers: alluvial deposits of the Quaternary age and Paleozoic granites were identified according to the geological structure of the quarry, assessing the main hydrogeochemical indicators of the drainage waters of the quarry. The volume of water inflows for the last 70 years has been analyzed. The role of fissure-vein waters of Paleozoic granites, Quaternary aquifer and atmospheric precipitation during the year is substantiated.

Quantifying fluvial carbon losses from lowland peatland ecosystems across a drainage-impact spectrum

<p>The export of Dissolved Organic Carbon (DOC) and evasion of carbon dioxide (CO<sub>2</sub>) from inland waters is increasingly being recognized as a key part of the terrestrial carbon (C) cycle, with recent global estimates suggesting that the magnitude of the aquatic CO<sub>2</sub> conduit is equivalent to global Net Ecosystem Productivity (2.0 Gt C yr-1; Tranvik et al., 2009). However, a major weakness in the carbon balance estimation of terrestrial ecosystems, such as peatlands, is the poor quantification of DOC and CO<sub>2</sub> evasion fluxes associated with drainage waters. This has implications for conservation, land-use management and climate change mitigation. Whilst intact peatland systems typically sequester carbon, drainage reverts peatlands to being C sources due, primarily, to the degradation of organic peat soil. This study examines the export of C in fluvial pathways from relatively intact catchments to those that are heavily drained, and also from peatland sites undergoing restoration works. This research is being carried out parallel other linked studies that are quantifying the carbon gaseous emissions from directly from the different bogs in order to determine the comparative net carbon budgets.</p><p>This study will focus on three raised bog sites in the midlands of Ireland: one in near natural condition (Clara bog), one significantly drained and degraded due to peat extraction (Garryduff) and one undergoing rehabilitation following many years of peat extraction (Cavemount). Flumes and sondes, with fluorescent dissolved organic matter (fDOM), temperature/conductivity and turbidity sensors, have been installed on the sites. The fDOM measurements will be correlated to grab samples taken every two weeks to give half hour proxy measurements for DOC.</p><p>Preliminary results suggest that DOC flux from the heavily drained and mined peatland site is some 295 times higher than that from the catchment with minimal interference. In addition to this, drainage waters are super-saturated in CO<sub>2</sub> and rapidly evades back to the atmosphere resulting in an additional C loss. Thus, C losses in the drainage systems of peatland catchment areas are significantly under-reported and a significant source of C in countries with significant peat land cover such as Ireland. This research is thereby addressing the magnitude of C losses in fluvial pathways, the associated effects on ecosystem biodiversity and the effectiveness of restoration activities on mitigating against net C loss in degraded systems.</p>

Living Particulate Fluxes in Throughfall and Stemflow During a Pollen Event

Pollen shedding can produce rapid, abundant exchanges of nutrient-rich biomass 9 from plant canopies to the surface. When pollen deposits onto understory plants, it can be 10 washed off during storms via throughfall (a drip flux) and stemflow (a flux down plant stems). 11 Pollen deposition may also alter the organismal community on plant surfaces, changing other 12 biological particulates transported by throughfall and stemflow. We report concentrations and 13 fluxes of pollen and other biological particulates (flagellate cells, nematodes, rotifers, mites and 14 hexapodans) in throughfall and stemflow from an understory forb, Eupatorium capillifolium 15 (Lam. dogfennel), during a Pinus palustris (Mill. longleaf pine) pollen shedding event, then 16 compare these results to observations collected when pollen was absent. Pollen flux was 95.6 x 17 106 grains ha-1 season-1 from dogfennel canopies (63% and 37% transported by throughfall and 18 stemflow, respectively), representing 0.1-3.2 g ha-1. Median concentrations in flagellates, 19 nematodes and rotifers for throughfall and stemflow were higher during pollen shedding; 20 however, mites and hexapodan concentrations were similar regardless of pollen presence. This 21 is the first report of flagellate and hexapodan concentrations in canopy drainage waters. 22 Flagellate concentrations were higher than for other organisms—being similar to those 23 reported for streams, 105-107 cells L-1—and hexapodan fluxes were ~50 individuals m-2 per 1 cm 24 of rainfall. These results indicate that throughfall and stemflow can (i) transport ecologically 25 relevant amounts of pollen and organisms from the phyllosphere to the surface, and (ii) that 26 the composition and flux of biological particulates can change markedly during pollen shedding.

Irrigation of the cultivated area with groundwater from vertical drainage wells

In recent years, there has been a shortage of water resources in the basins of the Amu Darya and Syrdarya rivers, which is the result of the development of new lands for irrigation and the inappropriate use of water and land resources. A side effect of irrigation and land reclamation is the increasing flow of collector-drainage waters every year, which leads to a deterioration in the land reclamation state and pollution of water resources, which can lead to the ecological disaster of land and water resources. Currently, in the Republic of Uzbekistan, from the total volume of water resources of the Amu Darya and Syrdarya rivers, up to 68% is used for irrigation. Of this volume on the Republic territory, about 12% of collector-drainage waters of deteriorated quality are formed. With a shortage of water resources, they are used for irrigation. But irrigation with saline waters can lead to a deterioration in the land reclamation state. In this regard, new irrigation technologies are proposed, which can save both irrigation water and it is advisable to use underground pumped water for irrigation. Field experiments were carried out in the farm "Khozhilkhon-hozhi" in the farm named after A. Niyazov, Kuva district, Fergana region. A feature of the soil conditions in this farm is the small thickness of the covered fine earth, underlain by highly permeable gravel, strong and increased water permeability, with a deep groundwater level (GWL> 3 m). Large water losses are observed during irrigation. The calculation task was to determine how many hectares of land can be irrigated from one vertical drainage well, taking into account the irrigation time, inter-irrigation period, etc. The water-salt balance of the reclaimed lands for 2017-2019 was compiled. The water-salt balance showed that water supply and filtration from canals and atmospheric precipitation play the main role in the inlet part. In the consumable part, the main place is occupied by evapotranspiration and drainage flow. In general, a negative balance is formed on the territory annually by the type of a small salt carryover within 2.85 t / ha. On the territory of the farm and the experimental plot, cotton of the S-6524 variety was sown, the flow rate of the well is 30 l / s, the furrow consumption is 0.5 l / s. The composition of hypothetical salts in the pumped-out waters is calculated After the first irrigation of our field, the pumped-out water is diverted to the neighboring fields, while the first inter-irrigation period is 20 days. In the interval of these 20 days until the second irrigation of the cotton of the original field, it is possible to irrigate the same fields 5 hectares 8 times, in total 40 hectares of land. The experiments showed that irrigation with pumped water from vertical drainage wells did not have a negative impact on the yield of cotton. And the use of the recommended irrigation technology will reduce the shortage of irrigation water and improve the ecological situation of water resources.