Multi-year, spatially extensive, watershed-scale synoptic stream chemistry and water quality conditions for six permafrost-underlain Arctic watersheds

Repeated sampling of spatially distributed river chemistry can be used to assess the location, scale, and persistence of carbon and nutrient contributions to watershed exports. Here, we provide a comprehensive set of water chemistry measurements and ecohydrological metrics describing the biogeochemical conditions of permafrost-affected Arctic watersheds. These data were collected in watershed-wide synoptic campaigns in six stream networks across northern Alaska. Three watersheds are associated with the Arctic Long-Term Ecological Research site at Toolik Field Station (TFS), which were sampled seasonally each June and August from 2016 to 2018. Three watersheds were associated with the National Park Service (NPS) of Alaska and the U.S. Geological Survey (USGS) and were sampled annually from 2015 to 2019. Extensive water chemistry characterization included carbon species, dissolved nutrients, and major ions. The objective of the sampling designs and data acquisition was to characterize terrestrial–aquatic linkages and processing of material in stream networks. The data allow estimation of novel ecohydrological metrics that describe the dominant location, scale, and overall persistence of ecosystem processes in continuous permafrost. These metrics are (1) subcatchment leverage, (2) variance collapse, and (3) spatial persistence. Raw data are available at the National Park Service Integrated Resource Management Applications portal (O'Donnell et al., 2021, https://doi.org/10.5066/P9SBK2DZ) and within the Environmental Data Initiative (Abbott, 2021, https://doi.org/10.6073/pasta/258a44fb9055163dd4dd4371b9dce945).

Geo-Temporal Signatures of Physicochemical and Heavy Metals Pollution in Groundwater of Khulais Region—Makkah Province, Saudi Arabia

Seawater has intruded into many of Saudi Arabia’s Red Sea coastal aquifers, with varying degrees of extension depending on location, hydrogeology, and population density. This study aimed to evaluate and comprehend the processes that influence the hydrogeochemical characteristics of the coastal aquifer in Saudi Arabia’s Khulais region. Groundwater samples were taken from nineteen locations during the winter and summer of 2021, and data from major ions and trace elements were examined and interpreted using ArcGIS software. The total dissolved solids (TDS) concentrations ranged between 480 and 15,236 mg/L and 887–18,620 mg/L in winter and summer, respectively. Groundwater TDS concentration was observed to be influenced by groundwater flow, lithogenic, anthropogenic, and seawater intrusion in this study (2021) when compared to 2016. The concentration of nitrate (NO3−) and strontium (Sr) in most samples exceeds the drinking guidelines. The occurrence of high concentrations of bromide (Br), Fluoride (F), Iron (Fe) (winter and summer) and Aluminum (Al), Boron (B), Chromium (Cr), Nickel (Ni), lead (Pb), cadmium (Cd), cobalt (Co), copper (Cu) and manganese (Mn) (winter) was also exhibited and observed up to more than drinking and irrigation limits. The central part of the study area was affected by seawater intrusion. The hydraulic conductivity of the topsoil was measured, and it ranged from 0.24 to 29.3 m/day. Based on electrical conductivity (EC) and sodium absorption ratio, most aquifer samples were unsuitable for irrigation (SAR).

Hydrogeochemical and Characteristics of Groundwater in Teluk Nilap Area, Rokan Hilir, Riau

Groundwater plays important role as the main water resource for human needs. The vulnerability of groundwater to contaminants both naturally and by human activities can be not avoided as a trigger for groundwater quality degradation. Hydrogeochemical become important highlights in groundwater studies because groundwater conditions in quality and quantity influenced by the geological formation of rock minerals in aquifer. Naturally, the condition of the research area which consists of peat swamps can also affect the characteristics of groundwater. The aims of this research are to determine groundwater types and groundwater facies in study area with an analytical approach using stiff diagram and piper diagram. The method used was purposive sampling by collecting data from dug wells at the research site. 5 samples from dug wells were used as representatives in the groundwater facies analysis. The groundwater facies analysis was carried out by measuring the concentration of major ions such as Na, K, Ca, Mg, Cl, SO4, and HCO3. The highest groundwater level was in the northern part of study area (7,84 m) while the lowest groundwater level was in the southwest part of study area (2,05 m). The results showed three types of groundwater based on stiff diagram as sodium chloride (NaCl), sodium sulfate (NaSO4) and magnesium sulfate (MgSO4). The lithology conditions that composed the aquifer affected the facies or origin of groundwater. The alluvium layer in the research area which rich in sodium (Na+) minerals with chloride (Cl-) or sulfate (SO42-) anions forms chloride sulfate facies (Cl+SO4) which were located in the middle to the south of the study area and sodium (potassium) chloride (sulfate) facies (Na(K)Cl(SO4)) which were distributed in the northern part of study area.

Hydrochemical Characterization of Nabeghlavi Underground Mineral Waters

Georgia is rich in groundwater deposits, which renew over time and are characterized by the best indicators of water quality and a stable regime. Groundwater is one of the main natural productive forces of Georgia, which plays an important role in the economic development and export industry. During 2015–2020, chemical composition of the Nabeghlavi mineral waters has been studied by the means of the modern unified methods. Almost all data from previous chemical analyzes have also been retrieved and systematized/collated. Using mathematical statistical analysis, the maximum, minimum, and mean arithmetic values of the major and specific components of water and the empirical deviation from the arithmetic mean have been calculated. Though comparison of the recent and historic data on chemical composition, based on the results of statistical analysis of the major ions, the natural fluctuation limits of the waters and stability of waters from all exploitation drill holes have been shown. According to the chemical composition and total mineralization there are three groups of waters in fresh and low mineralized category. It is shown that chemical composition of water from all exploitation drill holes meets requirements for the natural mineral water category, both the normative document of Georgia and directive of the European Commission.

Using stable isotopes and major ions to identify recharge characteristics of the Alpine groundwater-flow dominated Triglavska Bistrica River

Triglavska Bistrica is a typical Alpine river in the north-western part of Slovenia. Its recharge area includes some of the highest peaks in the Julian Alps. The hydrogeological conditions and flow of the river depend largely on groundwater exchange between the karstified aquifer in the carbonate rocks and the intergranular aquifer in the glaciofluvial deposits. The average volume of the river flow is up to several m3/s. In this study, water samples from different locations along the river were analysed for stable isotope ratios of oxygen and hydrogen, major ions, and concentration of tritium activity. The correlation of major ions suggests that the recharge area consists of both limestone and dolomite rocks. The δ18O and δ2H values decrease downstream, implying that the average recharge elevation increases. At the downstream sampling site V-5, located approx. 300 m upstream from the confluence of the Sava Dolinka River, the calculated mean recharge altitude is estimated to be 1,996 m.

Modelling competition between the siderophore ferrioxamine B and humic like binding sites in seawater v1

Here we archive a protocol that can be used to determine competition between a siderophore (ferrioxamine B) and humic like binding sites that are present in marine DOM. We use the NICA-Donnan model to describe binding by humic like binding sites in DOM. Constants for Fe binding to marine DOM are taken from Zhu et al., (2021). Thermodynamic constants describing binding between major ions, iron and ferrioxamine B are taken from Schijf and Burns, (2016). References Schijf, J., Burns, S.M., 2016. Determination of the Side-Reaction Coefficient of Desferrioxamine B in Trace-Metal-Free Seawater. Front. Mar. Sci. 3, 117. https://doi.org/10.3389/fmars.2016.00117 Zhu, K., Birchill, A.J., Milne, A., Ussher, S.J., Humphreys, M.P., Carr, N., Mahaffey, C., Lohan, M.C., Achterberg, E.P., Gledhill, M., 2021a. Equilbrium calculations of iron speciation and apparent iron solubility in the Celtic Sea at ambient pH using the NICA-Donnan model. Mar. Chem

Hydrochemistry of the Lhasa River, Tibetan Plateau: Spatiotemporal Variations of Major Ions Compositions and Controlling Factors Using Multivariate Statistical Approaches

Spatiotemporal variations of the hydrochemical major ions compositions and their controlling factors are essential features of a river basin. However, similar studies in the southern Tibetan Plateau are relatively limited. This study focuses on the chemical compositions of the dissolved loads in the Lhasa River (LR) in the southern Tibetan Plateau. Two sampling campaigns were conducted during the rainy and dry seasons across the LR basin to systematically investigate the spatiotemporal variations of water chemistry and sources of the dissolved loads. The results show that the river water possesses slight alkalinity with an average pH of 8.05 ± 0.04. Total dissolved solids (TDS) and oxidation-reduction potential (ORP) range widely from 39.8 mg/L to 582.6 mg/L with an average value of 165.6 ± 7.7 mg/L and from −9.4 mV to 295 mV with a mean value of 153.7 ± 6.9 mV, respectively. The major cations follow the decreasing order of Ca2+, Mg2+, Na+, and K+ while HCO3−, SO42−, Cl−, and NO3− for anions. Ca2+ and Mg2+ account for 87.8% of the total cations, while HCO3− and SO42− accounts for 93.9% of the total anions. All the major ions show higher concentrations in the dry season. NO3−, HCO3−, and Mg2+ show significant spatial variations due to the influence of basin lithology and anthropogenic activity. Multi-variables statistical analysis reveals that the mechanisms controlling the LR hydrochemistry are mainly carbonate weathering followed by silicate weathering. Geothermal springs and anthropogenic activities also play crucial roles in altering river water ions composition in the middle stream and downstream. The relatively high NO3− value (3 ± 0.2 mg/L) suggests water quality will be under the threat of pollution with the increase of anthropogenic activities.

Pollution threatens water quality in the Central Marshes of Southern Iraq

Water pollution is an issue that can be exacerbated by drought as increased concentrations of unwanted substances are a consequence of lower water levels. Polluted water that flows into natural marshlands leads to the deposition of pollutants in the interior of the marsh. Here we present evidence that the interior of the Central Marsh (CM) in southern Iraq suffers from higher levels of pollution than areas closer to the source of water entering the marsh (the Euphrates River). A 1.7m embankment that halts the flow of the Euphrates is only infrequently breached and so the CM is effectively the terminal destination of the waters (and their associated pollutants and agricultural waste) flowing from the West of Iraq. A range of water quality metrics were measured where the Euphrates enters the CM and at increasing distances into the interior of the CM. The following measures were taken: NO2, NO3, PO4 , Salinity, Major ions, and Heavy Metals (Cu, Ni, Pb, Cd, Zn). The area of study was divided into four horizontal zones (the river and three zones inside the marsh) and eight field surveys were carried out from November 2013 to June 2014 to collect water samples by using a transect line methodology. Salinity and major ions (Na, K, Cl, Ca, and Mg) were significantly higher inside the marsh compared with levels in the river water immediately before it entered the CM. These findings indicate the increased risk of these pollutants to humans and wildlife living in and using the CM. This issue requires urgent attention, especially to the status of the CM as a World Heritage site (for the ecosystem services provided to local people) as an Important Biodiversity Area. The reported declines in water quantity in the Euphrates over recent decades will likely further exacerbate the problems we report.

Hydrochemical and Hydroacoustic Investigation of the Yugama Acid Crater Lake, Kusatsu-Shirane, Japan

The gases dissolved in the waters of volcanic lakes can present a serious hazard if the physical-chemical conditions change due to variations in the supply of magmatic gases. The monitoring of gases such as CO2 and He help us understand the degassing process and their connection with magmatic/hydrothermal system. One of the most acidic volcanic lakes on the planet is the Yugama, on Kusatsu Shirane volcano (Japan). We report the results of an interdisciplinary study carried out in August 2013 at Yugama consisting of the first estimation of rate of diffuse CO2 emission, the chemical and isotopic analysis of water and dissolved gases in samples from vertical lake profiles, and an echo-sounding survey. The lake water has an average temperature of 24-25°C, pH 1.01, concentrations of SO42- between 1,227 and 1,654 mgL−1 and Cl− between 1,506 and 2,562 mgL−1, with gas bubbling at several locations and floating sulfur globules with sulfide inclusions. A total of 66 CO2 efflux measurements were taken at the lake surface by means of the floating accumulation chamber method to estimate the diffuse CO2 output from the studied area. CO2 efflux values ranged from 82 up to 25,800 g m−2 d−1. Estimation of the diffuse CO2 emission at Yaguma Crater Lake was 30 ± 12 t d−1. Normalized CO2 emission rate (assuming an area of 0.066 km2) was 454 t km−2 d−1, a value within the range of acid volcanic lakes. Vertical profiles of major ions and dissolved gases showed variations with increases in ion content and dissolved CO2 and He with depth. Acoustic imaging shows the presence of intense bubbling and provides important information on the bathymetry of the lake. The 50–200 kHz echograms exhibit frequent vertical plumes of rising gas bubbles. Within the crater-lake, three circular submarine vents have been identified showing flares due to a significant activity of sublacustrine emissions. This work shows the first data of diffuse CO2 degassing, dissolved gases in water and echosounding (ES) from Yugama Crater Lake. Periodic hydrogeochemical and hydroacoustic surveys at Yugama Crater Lakemay thus help to document changes in the state of activity of this high-risk volcanic area.