Temat: suspended sediment - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Evaluating annual and seasonal patterns of suspended sediment loads in a semi-arid watershed, central Algeria
Autorzy:: Rabah, Mosbah
Bouchelkia, Hamid
Belarbi, Fadila
Millares, Agustin
Powiązania:: https://bibliotekanauki.pl/articles/1841958.pdf
Data publikacji:: 2021
Wydawca:: Instytut Technologiczno-Przyrodniczy
Tematy:: erosivity
seasonality
sediment yield
semi-arid environments
suspended sediment dynamics
Opis:: Soil loss is a major problem for watersheds management in semi-arid environments. The objective of the present study is to analyze the annual and seasonal patterns of suspended loads and quantify the specific sediment yields in a semi-arid environment of the Mazafran Watershed in central Algeria. The obtained information of water discharge and suspended sediment load, recorded during 19 years, was confronted with precipitation data in order to establish the relationships between theforcing agents and erosive processes. The specific sediment yield was estimated by assessing rating curve data under two types of identified responses. The obtained results allowedconfirming the seasonality on suspended sediment transport in the studied basin, which accounts for 56% of the total suspended sediment load estimated in winter. The mean annual suspended sediment is estimated at 17.52 Mg∙ha–1·y–1. The results highlighted that the type 2 event dominates the production of sediment in the study area in comparison with type 1 event. The analysis of the variability of rainfall erosivity index showed that there is a strong correlation between the annual precipitation and modified Fournier index (MFI), and a weak correlation with the monthly precipitation concentration index (PCI). Moreover, the spatial distribution of the modified Fournier index at the basin scale showed the highest precipitation aggressiveness in the Southern part of the study region for both type of events, whereas the precipitation aggressiveness low to moderate in the remaining part of the study region.
Źródło:: Journal of Water and Land Development; 2021, 50; 158-172
1429-7426
2083-4535
Pojawia się w:: Journal of Water and Land Development
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: A comparative study of artificial intelligence models for predicting monthly river suspended sediment load
Autorzy:: Rezaei, Khalil
Vadiati, Meysam
Powiązania:: https://bibliotekanauki.pl/articles/292569.pdf
Data publikacji:: 2020
Wydawca:: Instytut Technologiczno-Przyrodniczy
Tematy:: artificial intelligence
data-driven methods
Karaj dam
suspended sediment load
the Karaj River
Opis:: When high precision modelling is required, for example, with the estimation of suspended sediment load (SSL), data-driven models are preferred over physically-based numerical models for their real-time, short-horizon prediction ability. The investigation of SSL, as an important index in engineering practices assessment, like design and operation of the hydraulic structures not only shows the hydrological behaviour of the river, but also illustrates the valuable information about the water quality deterioration, surface-groundwater interaction and land-use changes of the watershed. The following data-driven methods were compared in order to predict SSL at the Seyra gauging station on the Karaj River in Iran: Fuzzy logic (FL), two adaptive neuro-fuzzy inference systems (i.e., ANFIS-GP and ANFIS-FCM models), an artificial neural network (ANN), and least squares support vector machine (LSSVM). Monthly average river flow and SSL data for 50 years were obtained from the Tehran Regional Water Authority (TRWA). The data was first divided into training, validation and test sets and the SSL was then predicted using the ANN, FL, ANFIS, and LSSVM models. The reliability of the applied models was evaluated by the correlation coefficient (R), root mean square error (RMSE), and mean absolute error (MAE). The results showed that the ANFIS models outperformed the ANN, FL, and LSSVM models for predicting SSL using the given input and output data. Overall, the performances of the artificial intelligence models used in the present study were satisfactory in predicting the non-linear behaviour of the SSL.
Źródło:: Journal of Water and Land Development; 2020, 45; 107-118
1429-7426
2083-4535
Pojawia się w:: Journal of Water and Land Development
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Influence of the manner of water discharge from dam reservoirs on downstream water quality
Autorzy:: Cieśla, Maksymilian
Gruca-Rokosz, Renata
Powiązania:: https://bibliotekanauki.pl/articles/2203542.pdf
Data publikacji:: 2023
Wydawca:: Instytut Technologiczno-Przyrodniczy
Tematy:: dam
environmental pollution
organic matter
retention reservoir
suspended sediment
water quality
water resources
Opis:: The study was carried out in the area of three dam reservoirs: Blizne and Maziarnia (Voivodeship of Podkarpackie) and Nielisz (Voivodeship of Lublin). The main parameter differentiating the reservoirs was the water retention time and the manner of water discharge from the reservoirs. Three test sites were designated in the area of each reservoir: in the river zone of the reservoir, in the central part of the reservoir, and near the reservoir dam. At these sites, the concentrations of suspended sediment in the water and the content of organic matter in it, the concentrations of total phosphorus and total nitrogen, as well as chlorophyll a were monitored. In addition, two control sites were established: on the river upstream of the reservoir and on the river downstream of the dam, respectively. At these points, the concentrations of suspended sediments in the water and their organic matter content were recorded. The obtained results of the study and multivariate analysis of the data showed that morphometric parameters (including water retention time) of reservoirs and the method of water discharge influence water quality in downstream rivers. It was found that by using lower discharge and ensuring a sufficiently long retention time of water in the reservoir, it is possible to effectively limit the negative aspects of hydrotechnical structures’ impact on the natural environment. In practice, the observed relationships may constitute an important and missing link in the aspect of minimising undesirable side effects of this type of hydrotechnical objects.
Źródło:: Journal of Water and Land Development; 2023, 56; 91--101
1429-7426
2083-4535
Pojawia się w:: Journal of Water and Land Development
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Sediment load estimation in the Mellegue catchment, Algeria
Ocena ładunku osadów w zlewni rzeki Mellegue, Algieria
Autorzy:: Selmi, K.
Khanchoul, K.
Powiązania:: https://bibliotekanauki.pl/articles/292644.pdf
Data publikacji:: 2016
Wydawca:: Instytut Technologiczno-Przyrodniczy
Tematy:: erosion
Mellegue watershed
sediment rating curves
sediment transport
suspended sediment concentration
erozja
zlewnia Mellegue
krzywe natężenia przepływu zawiesiny
transport osadów
stężenie zawiesiny
Opis:: Soil erosion by water and the impact of sediment transport on lakes and streams, can seriously degrade soil and create problems for both agricultural land and water quality. The present study has been carried out to assess suspended sediment yield in Mellegue catchment, northeast of Algeria. Regression analysis was used to establish a relationship between the instantaneous water discharge (Q) and the instantaneous suspended sediment concentration (C) based on all recorded data and seasonal ratings for the period 1970–2003. The regression technique used in this paper involved a division of data into discharge – based classes, the mean concentrations and discharges of which are used to develop power regressions, according to single and season ratings, through logtransformation. Sediment loads estimated by stratified rating curves reduced underestimations to a range from 2 to 4%. The mean annual sediment yield during the 34 years of the study period was 589.23 t∙km^–2∙y^–1. Sediment transport is dominated by fall rainstorms accounting for 41% of the annual load. The big supply of sediment during this season confirms the intense geomorphic work by fall storms caused by high intensity rainfall and low vegetation cover.
Erozja wodna gleby i wpływ transportu osadów na rzeki i jeziora może znacząco degradować gleby i stwarzać problemy zarówno na obszarach rolniczych, jak i dla jakości wód. Przedstawione badania prowadzono celem oceny zawiesiny wytworzonej w zlewni rzeki Mellegue w północno-wschodniej Algierii. Analizę regresji użyto do ustalenia zależności pomiędzy chwilowym odpływem wody Q a chwilowym stężeniem zawiesiny C na podstawie wszystkich zebranych danych i przedziałów sezonowych dla lat 1970–2003. Regresje zastosowane w tych badaniach uwzględniały podział danych na klasy bazujący na wielkości odpływu. Średnie stężenia i wielkości odpływu w poszczególnych klasach wykorzystano do skonstruowania funkcji wykładniczej poprzez transformację logarytmiczną. Ładunki osadu ustalone na podstawie stratyfikowanych krzywych natężenia przepływu wykazywały niedoszacowanie w zakresie 2–4%. Średni roczny ładunek wytworzonych osadów dla okresu 34 lat badań wynosił 589.23 t∙km^–2. Transport osadów był spowodowany jesiennymi ulewnymi opadami, które odpowiadały za 41% rocznych ładunków. Duża dostawa osadów w tym okresie potwierdza intensywną aktywność geomorfologiczną jesiennych sztormów wywołaną silnymi opadami i ubogą pokrywą roślinną.
Źródło:: Journal of Water and Land Development; 2016, 31; 129-137
1429-7426
2083-4535
Pojawia się w:: Journal of Water and Land Development
Dostawca treści:: Biblioteka Nauki

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