Natural and anthropogenic impacts on the geochemical composition and metal speciation of fine sediment in a glacier-fed Canadian river basin

2021 ◽  
Author(s):  
M. Stone ◽  
A. L. Collins ◽  
J. P. Laceby
Keyword(s):  
River Basin ◽  
Anthropogenic Impacts ◽  
Metal Speciation ◽  
Fine Sediment ◽  
Geochemical Composition

Chemical Composition and Metal Speciation in Porewaters from the Upper Qu’Appelle River Basin, Saskatchewan

1993 ◽  
Vol 28 (1) ◽  
pp. 83-110 ◽  
Author(s):  
Richard E. Farrell ◽  
Jae E. Yang ◽  
P. Ming Huang ◽  
Wen K. Liaw
Keyword(s):  
Amino Acids ◽  
Trace Metal ◽  
River Basin ◽  
Drainage Basin ◽  
Metal Speciation ◽  
Anthropogenic Activities ◽  
High Concentration ◽  
Metal Concentrations ◽  
Carbonate Equilibria ◽  
The Impact

Abstract Porewater samples from the upper Qu’Appelle River basin in Saskatchewan, Canada, were analyzed to obtain metal, inorganic ligand and amino add profiles. These data were used to compute the aqueous speciation of the metals in each porewater using the computer program GEOCHEM-PC. The porewaters were classified as slightly to moderately saline. Metal concentrations reflected both the geology of the drainage basin and the impact of anthropogenic activities. Whereas K and Na were present almost entirely as the free aquo ions, carbonate equilibria dominated the speciation of Ca. Mg and Mn (the predominant metal ligand species were of the type MCO3 (s). MCO30. and MHCO3+). Trace metal concentrations were generally within the ranges reported for non-polluted freshwater systems. Whereas the speciation of the trace metals Cr(III) and Co(II) was dominated by carbonate equilibria, Hg(II)-, Zn(II)- and Fe(II)-speciation was dominated by hydroxy-metal complexes of the type M(OH)+ and M(OH)2°. The speciation of Fe(III) was dominated by Fe(OH)3 (s). In porewaters with high chloride concentrations (> 2 mM), however, significant amounts of Hg(II) were bound as HgCl20 and HgClOH0. The aqueous speciation of Al was dominated by Al(OH)4− and Al2Si2O4(OH)6 (s). Total concentrations of dissolved free amino acids varied from 15.21 to 25.17 umole L−1. The most important metal scavenging amino acids were histidine (due to high stability constants for the metal-histidine complexes) and tryptophan (due to its relatively high concentration in the porewaters. i.e., 5.96 to 7.73 umole L−1). Secondary concentrations of various trace metal-amino add complexes were computed for all the porewaters, but metal-amino acid complexes dominated the speciation of Cu(II) in all the porewaters and Ni(II) in two of the porewaters.

Influence of land use on fine sediment in salmonid spawning gravels within the Russian River Basin, California

2005 ◽  
Vol 62 (12) ◽  
pp. 2740-2751 ◽  
Author(s):  
Jeff J Opperman ◽  
Kathleen A Lohse ◽  
Colin Brooks ◽  
N Maggi Kelly ◽  
Adina M Merenlender
Keyword(s):  
Land Use ◽  
Land Cover ◽  
River Basin ◽  
Forest Cover ◽  
Multiple Scales ◽  
Explanatory Power ◽  
Fine Sediment ◽  
Road Density ◽  
Watershed Land Use ◽  
Russian River

Relationships between land use or land cover and embeddedness, a measure of fine sediment in spawning gravels, were examined at multiple scales across 54 streams in the Russian River Basin, California. The results suggest that coarse-scale measures of watershed land use can explain a large proportion of the variability in embeddedness and that the explanatory power of this relationship increases with watershed size. Agricultural and urban land uses and road density were positively associated with embeddedness, while the opposite was true for forest cover. The ability of land use and land cover to predict embeddedness varied among five zones of influence, with the greatest explanatory power occurring at the entire-watershed scale. Land use within a more restricted riparian corridor generally did not relate to embeddedness, suggesting that reach-scale riparian protection or restoration will have little influence on levels of fine sediment. The explanatory power of these models was greater when conducted among a subset of the largest watersheds (maximum r2 = 0.73) than among the smallest watersheds (maximum r2 = 0.46).

scholarly journals Transboundary Basins Need More Attention: Anthropogenic Impacts on Land Cover Changes in Aras River Basin, Monitoring and Prediction

2020 ◽  
Vol 12 (20) ◽  
pp. 3329
Author(s):  
Sajad Khoshnoodmotlagh ◽  
Jochem Verrelst ◽  
Alireza Daneshi ◽  
Mohsen Mirzaei ◽  
Hossein Azadi ◽  
...  
Keyword(s):  
Land Cover ◽  
River Basin ◽  
Urban Areas ◽  
Anthropogenic Impacts ◽  
Anthropogenic Activities ◽  
Kappa Index ◽  
The Caspian Sea ◽  
The Past ◽  
Agricultural Areas ◽  
Aras River

Changes in land cover (LC) can alter the basin hydrology by affecting the evaporation, infiltration, and surface and subsurface flow processes, and ultimately affect river water quantity and quality. This study aimed to monitor and predict the LC composition of a major, transboundary basin contributing to the Caspian Sea, the Aras River Basin (ARB). To this end, four LC maps of ARB corresponding to the years 1984, 2000, 2010, and 2017 were generated using Landsat satellite imagery from Armenia and the Nakhchivan Autonomous Republic. The LC gains and losses, net changes, exchanges, and the spatial trend of changes over 33 years (1984–2017) were investigated. The most important drivers of these changes and the most accurate LC transformation scenarios were identified, and a land change modeler (LCM) was applied to predict the LC change for the years 2027 and 2037. Validation results showed that LCM, with a Kappa index higher than 81%, is appropriate for predicting LC changes in the study area. The LC changes observed in the past indicate significant anthropogenic impacts on the basin, mainly by constructing new reservoir dams and expanding agriculture and urban areas, which are the major water-consuming sectors. Results show that over the past 33 years, agricultural areas have grown by more than 57% from 1984 to 2017 in the study area. Results also indicate that the given similar anthropogenic activities will keep on continuing in the ARB, and agricultural areas will increase by 2% from 2017 to 2027, and by another 1% from 2027 to 2037. Results of this study can support transboundary decision-making processes to analyze potential adverse impacts following past policies with neighboring countries that share the same water resources.

Anthropogenic impacts influence the functional traits of Chironomidae (Diptera) assemblages in a neotropical savanna river basin

2021 ◽  
Author(s):  
Isabela Martins ◽  
Diego M. P. Castro ◽  
Diego R. Macedo ◽  
Robert M. Hughes ◽  
Marcos Callisto
Keyword(s):  
River Basin ◽  
Functional Traits ◽  
Anthropogenic Impacts ◽  
Neotropical Savanna

scholarly journals Environmental/hydrological problems of the Mekong River Delta

2019 ◽  
Author(s):  
Keyword(s):  
River Basin ◽  
Crop Production ◽  
Anthropogenic Impacts ◽  
World Ocean ◽  
River Delta ◽  
Mekong River ◽  
Water Runoff ◽  
Hydroelectric Power ◽  
Mekong River Delta ◽  
Power Stations

The article shows how anthropogenic impacts on the hydrological regime in the upper part of the river basin together with climatic changes lead to an ecological catastrophe in the delta of the river. We have considered the Mekong River basin, which is located on the territory of six countries, where more than 30 hydroelectric power stations are already operating in the upper part of the basin, and another 10 are under construction. The number of hydroelectric power stations in the basin is planned to be increased to 170. The Mekong River Delta, completely located on the territory of Vietnam, is experiencing huge multifaceted problems. The delta has been growing towards the sea for many centuries, but in recent decades it has been receding, primarily due to a sharp decrease in the inflow of sediment in the delta, which is detained by numerous dams upstream. Uncontrolled until recently the extraction of sand and gravel mixtures from the riverbed also has an impact. On the other hand, the construction of hydraulic structures is not only a very important factor in the economic development of the basin countries, but also an important tool in combating the growing contrast of the climate, when floods are becoming more powerful, and the decline of the runoff in the dry period is becoming lower. Reduction of low-water runoff is exacerbated by the pumping out of groundwater for the needs of water supply. Reduction of the solid flow and low-water flow against the background of the growth of the world ocean level caused by climate change leads to a significant penetration of sea salt waters along the canal and channel systems into the delta. This has an extremely adverse effect on crop production and fish farming. At the same time, the Mekong Delta is the most important agricultural sector in Vietnam, accounting for more than 50% of total rice production and 60% of fish production. An article is devoted to the investigation of these problems and the identification of ways to solve them.

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