Sedimentation in Lillooet Lake, British Columbia

1975 ◽  
Vol 12 (10) ◽  
pp. 1697-1711 ◽  
Author(s):  
R. Gilbert
Keyword(s):  
British Columbia ◽  
Water Temperature ◽  
Suspended Sediment ◽  
River Basin ◽  
Sedimentary Sequence ◽  
Coarse Sediment ◽  
Sediment Content ◽  
Lake Bottom ◽  
Delta Slope

Sediment from Lillooet River Basin, 3580 sq km of alpine and subalpine landscape, 7% of which is glacier-covered, is deposited in Lillooet Lake. During the summer when the lake is stratified by temperature and suspended sediment content, processes of interflow and underflow distribute sediment throughout the lake and give rise to a distinctive sedimentary sequence of varved silts and clays interspaced irregularly with massive beds of coarser grained sediments up to 120 mm thick. Coarse sediment deposited on the proximal delta slope is redistributed by infrequent slumps; mounds of slumped material cover the foreset slopes to their base at 120 m depth. Thickness of varves is related to the annual inflow to the lake, and continuous records of water temperature near the lake bottom indicate that the numerous laminae within varves are due to intermittent underflow events.

Suspended sediment, turbidity, and stream water temperature in the Sauk River Basin, western Washington, water years 2012-16

2017 ◽  
Author(s):  
Kristin L. Jaeger ◽  
Christopher A. Curran ◽  
Scott W. Anderson ◽  
Scott T. Morris ◽  
Patrick W. Moran ◽  
...  
Keyword(s):  
Water Temperature ◽  
Suspended Sediment ◽  
River Basin ◽  
Stream Water ◽  
Western Washington

scholarly journals Superiority of Hybrid Soft Computing Models in Daily Suspended Sediment Estimation in Highly Dynamic Rivers

2021 ◽  
Vol 13 (2) ◽  
pp. 542
Author(s):  
Tarate Suryakant Bajirao ◽  
Pravendra Kumar ◽  
Manish Kumar ◽  
Ahmed Elbeltagi ◽  
Alban Kuriqi
Keyword(s):  
Time Series ◽  
Wavelet Transform ◽  
Suspended Sediment ◽  
River Basin ◽  
Time Series Data ◽  
Series Data ◽  
Discrete Wavelet ◽  
Original Time Series ◽  
Inference System ◽  
Original Time

Estimating sediment flow rate from a drainage area plays an essential role in better watershed planning and management. In this study, the validity of simple and wavelet-coupled Artificial Intelligence (AI) models was analyzed for daily Suspended Sediment (SSC) estimation of highly dynamic Koyna River basin of India. Simple AI models such as the Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) were developed by supplying the original time series data as an input without pre-processing through a Wavelet (W) transform. The hybrid wavelet-coupled W-ANN and W-ANFIS models were developed by supplying the decomposed time series sub-signals using Discrete Wavelet Transform (DWT). In total, three mother wavelets, namely Haar, Daubechies, and Coiflets were employed to decompose original time series data into different multi-frequency sub-signals at an appropriate decomposition level. Quantitative and qualitative performance evaluation criteria were used to select the best model for daily SSC estimation. The reliability of the developed models was also assessed using uncertainty analysis. Finally, it was revealed that the data pre-processing using wavelet transform improves the model’s predictive efficiency and reliability significantly. In this study, it was observed that the performance of the Coiflet wavelet-coupled ANFIS model is superior to other models and can be applied for daily SSC estimation of the highly dynamic rivers. As per sensitivity analysis, previous one-day SSC (St-1) is the most crucial input variable for daily SSC estimation of the Koyna River basin.

scholarly journals Insights on the Impacts of Hydroclimatic Extremes and Anthropogenic Activities on Sediment Yield of a River Basin

Earth ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 32-50
Author(s):  
Rocky Talchabhadel ◽  
Jeeban Panthi ◽  
Sanjib Sharma ◽  
Ganesh R. Ghimire ◽  
Rupesh Baniya ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
River Basin ◽  
Extreme Precipitation ◽  
Suspended Sediment Concentration ◽  
Anthropogenic Activities ◽  
Sediment Concentration ◽  
Sediment Flux ◽  
Mountain River ◽  
Ecological Processes ◽  
Precipitation Indices

Streamflow and sediment flux variations in a mountain river basin directly affect the downstream biodiversity and ecological processes. Precipitation is expected to be one of the main drivers of these variations in the Himalayas. However, such relations have not been explored for the mountain river basin, Nepal. This paper explores the variation in streamflow and sediment flux from 2006 to 2019 in central Nepal’s Kali Gandaki River basin and correlates them to precipitation indices computed from 77 stations across the basin. Nine precipitation indices and four other ratio-based indices are used for comparison. Percentage contributions of maximum 1-day, consecutive 3-day, 5-day and 7-day precipitation to the annual precipitation provide information on the severity of precipitation extremeness. We found that maximum suspended sediment concentration had a significant positive correlation with the maximum consecutive 3-day precipitation. In contrast, average suspended sediment concentration had significant positive correlations with all ratio-based precipitation indices. The existing sediment erosion trend, driven by the amount, intensity, and frequency of extreme precipitation, demands urgency in sediment source management on the Nepal Himalaya’s mountain slopes. The increment in extreme sediment transports partially resulted from anthropogenic interventions, especially landslides triggered by poorly-constructed roads, and the changing nature of extreme precipitation driven by climate variability.

Fossil Mosses from the Bisaccate Zone of the Mid-Eocene Allenby Formation, British Columbia

1974 ◽  
Vol 11 (3) ◽  
pp. 409-421 ◽  
Author(s):  
Marian Kuc
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Plant Tissues ◽  
Plant Remains ◽  
Lake Bottom ◽  
White Colour

New fossil taxa (Ditrichites fylesi, Muscites maycocki, M. ritchiei, Palaeohypnum jovet-asti and P. steerei); unnamed moss and moss-like fossils, detrital fragments of various plant tissues, and paleobotanical evidence of the bisaccate zone are described from the Middle Eocene Allenby Formation near Princeton, British Columbia. These remains occur in laminated, tuffaceous, silty and pyroclastic shale, deposited under lacustrine conditions.Detailed examination of the various laminae indicates that beds of white colour and composed of coarser silt grains are poor in fossils and could be related to periods of decreasing bioproduction; less silty and darker coloured beds are rich in macro- and microfossils and could be related to periods of extensive bioproduction. The rock features, lamination, and distribution of macrofossils indicate the slow and undisturbed accumulation of plant remains on a lake bottom.

scholarly journals Induced reproduction and reproductive characteristics of Rhinelepis aspera Agassiz, 1829 (osteichthyes: Siluriformes, Loricariidae)

1998 ◽  
Vol 41 (3) ◽  
pp. 309-314 ◽  
Author(s):  
Yoshimi Sato ◽  
Nelsy Fenerich-Verani ◽  
José Roberto Verani ◽  
Hugo Pereira Godinho ◽  
Edson Vieira Sampaio
Keyword(s):  
Body Weight ◽  
Water Temperature ◽  
River Basin ◽  
Fertilization Rate ◽  
Pituitary Extract ◽  
Reproductive Characteristics ◽  
Sao Francisco River ◽  
Absolute Fecundity ◽  
São Francisco River

Rhinelepis aspera is the largest Loricariidae species found in the São Francisco river basin where it is now rarely caught. Brooders kept in tanks were hypophysed with crude carp pituitary extract (CCPE). Approximately 82% of the females responded positive to the treatment. The egg was opaque, demersal, round, yellow and adhesive. Egg stripping was done at 212 hour-degrees (= 8.2 h) after application of the second dose of CCPE (water temperature = 25-26 ºC). Hatching of the larvae occurred at 1022 hour-degrees (= 42.2 h), after fertilization of the eggs (water temperature =24-25 ºC). Fertilization rate of the eggs was 72%. Absolute fecundity (AF), initial fertility (IF) and final fertility (FF) in relation to the females' body weight are expressed, respectively, by the equations: AF = - 33993 + 122308 Wt (r² = 0.88), IF = - 14823 + 58619 Wt (r² = 0.71) and FF = - 6553 + 29741 (r² = 0.61)

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