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Wyświetlanie 1-3 z 3
Tytuł:
A pedological study attempting to combine soil taxonomy and WRB classification systems
Autorzy:
Zayed, Adel M.A.
Abdel Ghaffar, Mamdouh K.
Ali, Faiza S.
Ewida, Esmail H.
Powiązania:
https://bibliotekanauki.pl/articles/27312660.pdf
Data publikacji:
2023
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
North-East Nile Delta
pedological study
physiographic units
soil classification
Opis:
The study area is located in the North-Eastern part of the Nile Delta, northern of Ismailia canal and western Suez Canal. It comprises an area of about 3,058.8 km 2 (728,285.38 feddans). This work aims to identify the main physiographic units and its features, as well as emphasise the importance of combining soil taxonomy (2014) and WRB classification (2022) systems. Two main physiographic units were distinguished in the study area according to the previous studies, interpretation of satellite image and digital elevation model (DEM) as well as field observations; the first consists of fluvio-marine flats and the second river terraces which include the fluvial and deltaic origin. According to field morphological descriptions as well as chemical and physical analyses, representative profiles are classified by using both Soil Taxonomy and WRB systems. The current study is the third manuscript to emphasise the importance of using both systems together in order to obtain maximum possible characteristics of the earth. Below are examples that illustrate this importance. Soils of profile No. 4 which represent the fluvio-marine soils are classified according to soil taxonomy as follows: Typical Haplosalids, fine silty, mixed, thermic. While these soils are classified according to WRB as follows: Fluvic Sodic Solonchaks (Siltic/Loamy/Clayic, Chloridic, Evapocrustic, Ochric, Hypersalic). Soils of gypsiferous which represent soils of profile No. 6 are classified according to Soil Taxonomy as: Gypsic Aquisalids, loamy over sandy, mixed, thermic, whereas the application of the WRB system reveals the following: Fluvic Calcic Gypsic Sodic Gleyic Solonchaks (Loamic, Chloridic, Hypersalic).
Źródło:
Journal of Water and Land Development; 2023, 57; 197--203
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling the hydrodynamic interactions between the river morphology and navigation channel operations
Autorzy:
Badawy, Neveen Abdel-Mageed
El-Hazek, Alaa N.
Elsersawy, Hossam Mohamed
Mohammed, Ebtesam Rezk
Powiązania:
https://bibliotekanauki.pl/articles/2048502.pdf
Data publikacji:
2021
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
adaptive hydraulics (ADH) model
draw down
navigation channel
the Nile River
restricted waterway
return flow
shear stress
Opis:
The Nile River is the main route for inland navigation in Egypt. The vessels navigating through inland waterways generate complex physical forces that need to be studied extensively. Quantifying the effects of vessels sailing along a waterway is a complex problem because the river flow is unsteady and the river bathymetry is irregular. This paper aims to investigate the hydrodynamic effects resulting from the movement of vessels such as return currents around the vessel, the draw down of the water surface, under keel clearance, and the shear stress induced by vessels operating in the Nile River. Modeling such effects has been performed by applied the two-dimensional ADH (adaptive hydraulics) model to a river reach for different navigation channel operation scenarios. The obtained results show that the draw down heights, the water fluctuation, and the shear stress magnitude are larger when the river cross sectionals are narrow and the shallow water depths. These river sections are considered more disposed to bed erosion and it is morphologically unsafe. The section having the narrowest width and the lowest depth was associated with the largest drawdown percentages of 98.3% and 87.3% in one-way and two-way scenarios. While the section having the widest width and the largest depth was associated with the least drawdown percentages of 48.5% and 51.9% in one-way and two-way scenarios. The section having the narrowest width and the lowest depth was associated with the largest fluctuations of 22.0 cm and 41.9 cm in one-way and two-way scenarios. While the section having the widest width and the largest depth was associated with the least fluctuations of 0.6 cm and 1.8 cm in one-way and two-way scenarios. The section having the narrowest width and the lowest depth was the worst section for under keel clearance of 5.0 cm and 33.3 cm in one-way and two-way scenarios. While the section having the widest width and the largest depth was the best section, where its clearance values were 183.2 cm and 155.0 cm in one-way and two-way scenarios. It is concluded that a numerical model is a valuable tool for predicting and quantifying the hydrodynamic effects of vessels moving through a two-dimensional flow field and can be used to evaluate different scenarios that are difficult to measure in the field or a physical model. Also, it provides visualization products that help us understand the complicated forces produced by vessels moving in a navigation channel.
Źródło:
Journal of Water and Land Development; 2021, 51; 1-10
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Drought sensitivity characteristics and relationships between drought indices over Upper Blue Nile basin
Charakterystyka wrażliwości na suszę i zależności między jej wskaźnikami dla regionu górnego Nilu Błękitnego
Autorzy:
Kebede, Abebe
Raju, Jaya Prakash
Korecha, Diriba
Takele, Samuel
Nigussie, Melessew
Powiązania:
https://bibliotekanauki.pl/articles/292513.pdf
Data publikacji:
2019
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
drought
drought indices relationships
soil moisture index SMI
standardized reconnaissance drought index (RDIst)
standardized precipitation index SPI
surface runoff index (SRI)
standaryzowany wskaźnik odpływu (SRI)
susza
wskaźnik standaryzowanego opadu SPI
wskaźnik uwilgotnienia gleby SMI
zależność między wskaźnikami suszy
Opis:
Drought is an extreme event that causes great economic and environmental damage. The main objective of this study is to evaluate sensitivity, characterization and propagation of drought in the Upper Blue Nile. Drought indices: standardized precipitation index (SPI) and the recently developed standardized reconnaissance drought index (RDIst) are applied for five weather stations from 1980 to 2015 to evaluate RDIst applicability in the Upper Blue Nile. From our analysis both SPI and RDIst applied for 3-, 6-, 12 month of time scales follow the same trend, but in some time steps the RDIst varies with smaller amplitude than SPI. The severity and longer duration of drought compared with others periods of meteorological drought is found in the years 1984, 2002, 2009, 2015 including five weather stations and entire Upper Blue Nile. For drought relationships the correlation analysis is made across the time scales to evaluate the relationship between meteorological drought (SPI), soil moisture drought (SMI), and hydrological drought (SRI). We found that the correlation between three indices (SPI, SMI and SRI) at different time scales the 24-month time scale is dominant and are given by 0.82, 0.63 and 0.56.
Susza jest ekstremalnym zjawiskiem, które powoduje ogromne straty ekonomiczne i szkody środowiskowe. Celem badań było określenie wrażliwości na suszę, charakterystyk i propagacji suszy w regionie górnego Nilu Błękitnego. Dwa wskaźniki suszy – wskaźnik standaryzowanego opadu (SPI) i niedawno opracowany wskaźnik RDIst (ang. standardized reconnaissance drought index) zastosowano do danych z pięciu stacji meteorologicznych z lat 1980 do 2015, aby ocenić przydatność tego drugiego do oceny sytuacji w regionie. Z analiz przeprowadzonych przez autorów niniejszej publikacji wynika, że oba wskaźniki wykazywały podobny trend zmian w przedziałach czasowych 3-, 6- i 12-miesięcznych, ale w pewnych okresach wskaźnik RDIst cechowała mniejsza amplituda zmian niż wskaźnik SPI. W odniesieniu do pięciu stacji meteorologicznych i całego obszaru górnego biegu Nilu Błękitnego najbardziej surowe i długotrwałe susze stwierdzono w latach 1984, 2002, 2009 i 2015 w porównaniu z innymi latami badań. Wykonano także analizę korelacji między wskaźnikami suszy meteorologicznej SPI, suszy glebowej SMI i suszy hydrologicznej SRI. Najsilniejszą korelację między tymi wskaźnikami stwierdzono dla 24-miesięcznych przedziałów czasowych, a odpowiednie współczynniki korelacji wynosiły 0,82, 0,63 i 0,56.
Źródło:
Journal of Water and Land Development; 2019, 43; 64-75
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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