Contrasting land-uses in two small river basins impact the colored dissolved organic matter concentration and carbonate system along a river-coastal ocean continuum

Dissolved organic matter concentration changes in river waters of Latvia Amounts of natural organic matter in surface waters reflect the character and intensity of biological processes in water bodies, human impact and depend on the physico-geographical environment and land-use in the catchments. Thus, analysis of the concentrations and loadings of organic substances to adjacent water bodies can be used to indicate environmental change and human impacts. This study revealed significant increasing trends of total organic carbon (TOC) and water colour in most of the studied Latvian rivers during the last decade. However, over longer time periods, there have been pronounced oscillations of TOC concentrations, stressing the importance of long-term changes of river discharge. On a yearly basis, there was a positive correlation between parameters of organic matter concentration and discharge in all selected rivers. The impact of discharge on concentrations of organic matter can be masked by other factors, such as changes in precipitation, biological processes, soil types and land-use.

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Hydrophysical research in the Kruglaya Bay (Sevastopol)

Ekologicheskaya bezopasnost pribrezhnoy i shel fovoy zon morya ◽

10.22449/2413-5577-2021-3-107-122 ◽

2021 ◽

Author(s):

A. A. Latushkin ◽

A. I. Chepyzhenko ◽

A. V. Prazukin ◽

A. A. Chepyzhenko ◽

Yu. K. Firsov ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Suspended Matter ◽

Water Layer ◽

Water Area ◽

Matter Content ◽

Total Suspended Matter ◽

Dynamic Activity ◽

Organic Matter Concentration ◽

Matter Concentration

On the basis of two hydrophysical surveys (August 28 and November 14, 2019), the spatial distribution was investigated of temperature, salinity, total suspended matter, dissolved organic matter features, and total suspended matter dynamic activity in the waters of the Kruglaya Bay. The horizontal and vertical distributions of these characteristics were considered. The hydrophysical parameters were measured from a small vessel at anchored stations using Kondor Sounding Complex. The analysis of obtained distributions showed that less saline and more turbid waters were observed in the apex of the bay. The highest content of suspended particles and dissolved organic matter were detected in this water area. An almost uniform stratification of hydrological parameters and total suspended matter concentration were observed in the vertical distribution over the entire water area of the bay. In the vertical dissolved organic matter distribution, an increase under the water surface layer of ~ 1–5 m was observed both in August and in November. This layer was more pronounced in November. The total suspended matter content in the surface water layer in August 2019 was on average twice as high as in November of the same year, and the dissolved organic matter concentration was lower.

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