Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 3

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
River-lake systems comprise chains of lakes connected by rivers and streams that flow into and out of them. The contact zone between a lake and a river can act as a barrier, where inflowing matter is accumulated and transformed. Magnesium and calcium are natural components of surface water, and their concentrations can be shaped by various factors, mostly the geological structure of a catchment area, soil class and type, plant cover, weather conditions (precipitation- evaporation, seasonal variations), land relief, type and intensity of water supply (surface runoffs and groundwater inflows), etc. The aim of this study was to analyze the influence of a river-lake system on magnesium and calcium concentrations in surface water (inflows, lake, outflow) and their accumulation in bottom deposits. The study was performed between March 2011 and May 2014 in a river-lake system comprising Lake Symsar with inflows, lying in the Olsztyn Lakeland region. The study revealed that calcium and magnesium were retained in the water column and the bottom deposits of the lake at 12.75 t Mg year-1 and 1.97 t Ca year-1. On average, 12.7±1.2 g of calcium and 1.77±0.9 g of magnesium accumulated in 1 kg of bottom deposits in Lake Symsar. The river-lake system, which received pollutants from an agricultural catchment, influenced the Ca2+ and Mg2+ concentrations in the water and the bottom deposits of Lake Symsar. The Tolknicka Struga drainage canal, to which incompletely treated municipal wastewater was discharged, also affected Ca2+ and Mg2+ levels, thus indicating the significant influence of anthropogenic factors.
This study evaluated the influence of the Symsarna River on the spatial distribution of organic matter, Kjeldahl nitrogen (NK) and total phosphorus in the surface layer of bottom sediments. The analyzed site was Symsar Lake in the Olsztyn Lakeland (north-eastern Poland) and the inflows. The results of this study indicate that the lake’s morphology and inflowing streams were largely responsible for the variations in the nutrient content of bottom deposits in the flow-through Symsar Lake. The NK content was significantly correlated with the lake’s depth, whereas TOC levels were determined mainly by the location in the lake. The surface layers of bottom sediments in Lake Symsar were characterized by an average organic matter content of 171.2 g kg-1 and near-neutral pH (6.78-7.77). The average contents of components in the analyzed sediments were determined at 62.01 gTOC kg-1 d.m., 6.08 gNK kg-1d.m. and 2.18 gTP kg-1d.m. Converted to fresh mass, the above contents expressed per square meter of the lake’s sediment reached 3.95 kgTOC m-2 f.m., 0.42 kgNK m-2 f.m. and 0.18 kgTP m-2 f.m. In turn, the average concentrations of components in sediments from the streams, likewise per square meter, equalled 12.4 gTOC m-2 d.m., 0.93 gNK m-2 d.m. and 0.9 gTP m-2 d.m. The highest contents of the analyzed components were observed in bottom sediments near the outflow of a river from the lake and in the lake’s region intersected by the river. The Symsarna River was responsible for the transport of and variability in the deposition of mineral fractions, and for the nutrient accumulation in the surface layer of bottom sediments. A flow-through water body in a river-lake system can contribute to retention in periods when it exerts a negative impact on the trophic status of a lake. From a broader, ecological viewpoint, it can inhibit the transport of pollutants outside the catchment.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.