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1

Short-term dynamics of river water turbidity

Chalov S. R., Tsyplenkov A. S.

Geography and Tourism

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2018

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Vol. 6, No. 1

7--14

EN

An overview of the recently collected datasets of highly discrete water turbidity measurements has allowed for the first hydrological and geographical analysis of short-term fluctuations in water turbidity and the composition of suspended sediments. The novel methodology has been developed to estimate a value of TI, which is the ratio of the difference between the maximum and minimum turbidity for a short period of time (ΔTi) (1 hour with the measurement frequency of 20 minutes) and the total turbidity difference for the water regime phase under study (ΔTHE). Higher TI values correspond to a greater contribution of diurnal (20-minute) turbidity fluctuations to the seasonal variability of sediment yield. Rivers have been grouped according to the value of water turbidity fluctuations within one hour (20-minute): glacier-fed rivers (the Tarfala, the Dzhankuat) (TI amounts to 0.17-0.22); volcanic rivers (0.22–0.25) and lowland rivers (the Selenga, the Western Dvina) (0.09).

2

Dynamics of the daily course of water temperature in Polish lakes

Skowron R., Piasecki A.

Journal of Water and Land Development

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2016

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no. 31

149--156

EN

The study focuses on short-term changes in surface water temperature in Polish lakes, and is based upon the experimental measurements of water temperature conducted every 60 minutes during the years 1971–2015. 19 lakes were selected on the grounds of their morphometric properties. The examinations were carried out in the system of expeditionary measurements (up to 8 days) and stationary measurements (over 2 months), and included temperature of surface water and its vertical distribution. The analysis of the results showed that temperature differences of water (daily amplitudes) were observed in both time and spatial distribution. The biggest differences in water temperature occurred during spring warming, and often reached 4–5°C, while rarely exceed 2°C in the remaining periods of the yearly cycle. The mean day value occurs twice; in the morning between 8:00 (7:00 GMT) and 11:00 (10:00 GMT), and in the evening at 20:00 (19:00 GMT) and 22:00 (21:00 GMT). Daily changes in the vertical distribution of water temperature are clearly visible down to the depth of 2.5–3.5 m, whereas are just perceptible to the depth of 5.5–7.0 m.

PL

Praca dotyczy krótkotrwałych zmian temperatury wody powierzchniowej w jeziorach w Polsce. Została ona opracowana na podstawie eksperymentalnych pomiarów temperatury wody prowadzonych co 60 minut w latach 1971–2015 w 19 jeziorach wytypowanych na podstawie cech morfometrycznych. Badania prowadzono w systemie pomiarów ekspedycyjnych (do 8 dni) i stacjonarnych (ponad 2 miesiące) i obejmowały temperaturę powierzchniową wody oraz jej pionowy rozkład. Na podstawie analizy wyników stwierdzono różnice temperatury wody (amplitudy dobowe) zarówno w rozkładzie czasowym, jak i przestrzennym. Największe różnice temperatury wody występowały w okresie wiosennego nagrzewania i często osiągały 4–5°C, natomiast w pozostałych okresach cyklu rocznego rzadko przekraczały 2°C. Na podstawie cogodzinnych pomiarów temperatury wody można stwierdzić, że temperatura przed południem między godziną 8:00 a 11:00 (7:00 a 10:00 GMT) oraz późnym wieczorem w godzinach 20:00–22:00 (19:00–21:00 GMT) była najbardziej zbliżona do średniej dobowej. Zmiany dobowe w rozkładzie pionowym temperatury wody wyraźnie zaznaczają się do głębokości 2,5–3,5 m, natomiast dostrzegane są do głębokości 5,5–7,0 m.

3

Short-term changes in specific conductivity in Polish coastal lakes (Baltic Sea basin)

Cieśliński R.

Oceanologia

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2013

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No. 55 (3)

639--661

EN

The paper discusses hourly changes in specific conductivity in two lakes and compares them to changes over longer time intervals. The short time intervals between measurements are designed to help assess the course of seawater intrusions. Two lakes on the Polish coast were selected for research purposes - Lakes Gardno and Łebsko. Specific conductivity was measured using an automatic YSI Sontek 6920V2 probe. It was shown that Lake /Lebsko has a permanently elevated specific conductivity, whereas Lake Gardno experiences episodes of fluvial influence. The specific conductivity was shown to change constantly in both lakes, as evidenced by multi-day, daily and hourly data.