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Wyszukujesz frazę "Wkra River" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
The evaluation of hydrodynamic balance at the Wkra River estuary
Autorzy:
Siwicki, P.
Urbański, L.
Hejduk, L.
Gładecki, J.
Powiązania:
https://bibliotekanauki.pl/articles/108490.pdf
Data publikacji:
2016
Wydawca:
Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Tematy:
river bed stability
armoring
bed load
Wkra River
Opis:
The river bed stability analysis at the Wkra estuary reach is presented in this paper. When a flood appears, channel and river bed erosion can reach a significant size. During such a situation, flow and water velocity exceed critical values for particular bed sediment grain sizes. This causes the breakage of bed armouring, and then bed mass motion begins. For the estimation of the sandy Wkra River bed the criteria of average velocity and bed armouring were applied with the use of ARMOUR software. The two Wkra River cross-sections at km 1+000 and km 3+200 distance were analysed. The calculation of the characteristics of bed sediment velocities was performed on the basis of, among other factors, probable river flow data, longitudinal slope, and grain size distribution of the bed. The results of the calculations were compared with average velocities in the analysed cross-sections. The results indicate the there is a threat to the stability of the Wkra River bed, especially during long-lasting high water stages. The prognosis of river bed stability loss performed by use of ARMOUR software shows that the bed armour breakage will take place in both considered cross-sections at relatively low water stages (about 40 cm), and mass motion of bed sediments in cross-section P-2 will occur at a flow of slightly lower than Q50% ,and in cross-section P-1 at flows greater then Q0,3%.
Źródło:
Meteorology Hydrology and Water Management. Research and Operational Applications; 2016, 4, 2; 29-34
2299-3835
2353-5652
Pojawia się w:
Meteorology Hydrology and Water Management. Research and Operational Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Pleistocene and Holocene environmental evolution of the Wkra River Valley near Bielawy Gołuskie (central Poland) recorded in palaeo-oxbow lake deposits
Autorzy:
Niska, M.
Jonczak, J.
Gadziszewska, J.
Powiązania:
https://bibliotekanauki.pl/articles/2060392.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
oxbow lake
Wkra River
Polska
Multi-proxy analysis
Early Holocene
Opis:
This study aimed to reconstruct environmental changes in the Wkra River Valley near Bielawy Gołuskie (central Poland) based on geochemical, palynological and subfossil Cladocera analysis of deposits filling a palaeo-oxbow lake. Two sediment boreholes collected from the palaeochannel bend (BG-1) and neck (BG-2) include full sequences of organic deposits lying on clastic deposits. The lower part of the BG-1 borehole contains gyttja that accumulated during the Younger Dryas and the Preboreal, which is covered by reed peat of Preboreal and Boreal age. On top of this is alder peat that accumulated during the Atlantic. The ages of the gyttja and peat were confirmed by both radiocarbon dating and palynological analysis. The peats are characterized by a significant content of organic matter, which is relatively stable over time. This indicates a low intensity of mechanical denudation in the catchment, which is supported by low concentrations of aluminum and potassium. Calcium values greatly exceed these elements, suggesting that the lake was mainly fed by groundwater. Variation in trophic conditions over time is indicated by a vertical variability in the content of nitrogen, as well as by the Cladocera population. The strong decomposition of peat in the top layer of the mire, and increased concentrations of phosphorus and heavy metals, testify to increasing human activity during the most recent time periods.
Źródło:
Geological Quarterly; 2017, 61, 2; 305--318
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Krzyżacki przekop w rejonie rzek Wel i Wkra pod Lidzbarkiem. Konfrontacja dawnej i nowej historiografii z badaniami terenowymi
Teutonic ditch in the area of the Wel and Wkra rivers near Lidzbark. Confrontation of old and new historiography with field research
Autorzy:
Główczyński, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/27316308.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Wel river
Wkra river
border of Masovia
Teutonic Knights
hydraulic engineering
Welski Landscape Park
Wel
Wkra
granica Mazowsza
Krzyżacy
prace hydrotechniczne
Welski Park Krajobrazowy
Opis:
Every so often we witness a return of a hitherto unresolved topic about the hydraulic engineering works conducted by the Teutonic Knights in the vicinity of Lidzbark. There are several opinions concerning the location of and reasons for their endeavor. There is original documentation in Latin from the mid-14th century with a reference to the approximate location of the works. Subsequent information on this subject appeared at the end of the 19th century. On the basis of contemporary geological studies, the author tries to refute the thesis that the Teutonic Knights dug a trench from Cibórz to Lidzbark, thus connecting two rivers called Wel and Wkra. The presumed 14th-century construction is a watercourse from the Wel River in Bełk (below Cibórz) to Turza Mała and the Płośniczanka River. The Wel river was called Vcra (1260); Wykara (1303), Welle (1600), or Wkra (1945), while on the Henneberger map from 1600, the Płośniczanka river was called Wellefl uss, and the changes in its course are most visible in the vicinity of the Koty village. Presumably there was a translation error: the Teutonic Knights made a ditch in the vicinity of Cibórz and released water to Lidzbark, which was interpreted as: ‘The Teutonic Knights made a ditch from Cibórz to Lidzbark’. Contemporary geological studies and maps exclude the possibility of connecting the Wel and Wkra rivers in the Middle Ages, while in the Holocene, there was a natural connection, the trace of which is the old riverbed called Martwica. The article describes the present physical state of the area in the Lubawa region.
Źródło:
Kwartalnik Historii Nauki i Techniki; 2022, 67, 3; 25--42
0023-589X
2657-4020
Pojawia się w:
Kwartalnik Historii Nauki i Techniki
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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