scholarly journals Near-Bed Monitoring of Suspended Sediment during a Major Flood Event Highlights Deficiencies in Existing Event-Loading Estimates

Water ◽  
2018 ◽  
Vol 10 (2) ◽  
pp. 34 ◽  
Author(s):  
Alistair Grinham ◽  
Nathaniel Deering ◽  
Paul Fisher ◽  
Badin Gibbes ◽  
Remo Cossu ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Flood Event ◽  
Loading Estimates

scholarly journals Physical and chemical characterization of a spring flood event, Bench Glacier, Alaska, U.S.A.: evidence for water storage

1999 ◽  
Vol 45 (150) ◽  
pp. 177-189 ◽  
Author(s):  
Suzanne Prestrud Anderson ◽  
Katherine M.H. Fernald ◽  
Robert S. Anderson ◽  
Neil F. Humphrey
Keyword(s):  
Suspended Sediment ◽  
Water Discharge ◽  
Drainage System ◽  
Chemical Characterization ◽  
Flood Event ◽  
Spring Flood ◽  
Outlet Stream ◽  
Speed Up ◽  
Physical And Chemical

AbstractPrevious studies of alpine glaciers have demonstrated that as water discharge increases through the summer, the predominant mode of subglacial drainage shifts from a distributed system to a more efficient conduit drainage system. We observed an early-melt-season speed-up and flood event lasting roughly 2 days in a small, uncomplicated Alaskan glacier that appears to have resulted from a sudden shift of the subglacial system in response to a significant accumulation of meltwater within the glacier. Calculated melt-water inputs exceeded discharge before the event; the implied change in storage over this 10 day period was equivalent to roughly 0.13 m averaged over the entire glacier bed. The pattern of discharge and suspended-sediment variations and the appearance of large ice chunks in the stream suggest that the speed-up occurred during a period of establishment of new subglacial conduits. A culminating flood and associated suspended-sediment pulse appear to have marked the final establishment of the new section of subglacial conduit. The flood ended the episode of high sliding velocity, but released water with high solute concentrations that reflect relatively long contact time with sediments. Discharge of stored water, inferred from high solute concentrations and lack of diurnal variation in discharge, continued for at least 3 days. While events such as this must recur through the melt season as the conduit system extends up-glacier and the locus of meltwater inputs shifts, their manifestations in the outlet stream will likely be more subdued later in the season.

scholarly journals Physical and chemical characterization of a spring flood event, Bench Glacier, Alaska, U.S.A.: evidence for water storage

1999 ◽  
Vol 45 (150) ◽  
pp. 177-189 ◽  
Author(s):  
Suzanne Prestrud Anderson ◽  
Katherine M.H. Fernald ◽  
Robert S. Anderson ◽  
Neil F. Humphrey
Keyword(s):  
Suspended Sediment ◽  
Water Discharge ◽  
Drainage System ◽  
Chemical Characterization ◽  
Flood Event ◽  
Spring Flood ◽  
Outlet Stream ◽  
Speed Up ◽  
Physical And Chemical

AbstractPrevious studies of alpine glaciers have demonstrated that as water discharge increases through the summer, the predominant mode of subglacial drainage shifts from a distributed system to a more efficient conduit drainage system. We observed an early-melt-season speed-up and flood event lasting roughly 2 days in a small, uncomplicated Alaskan glacier that appears to have resulted from a sudden shift of the subglacial system in response to a significant accumulation of meltwater within the glacier. Calculated melt-water inputs exceeded discharge before the event; the implied change in storage over this 10 day period was equivalent to roughly 0.13 m averaged over the entire glacier bed. The pattern of discharge and suspended-sediment variations and the appearance of large ice chunks in the stream suggest that the speed-up occurred during a period of establishment of new subglacial conduits. A culminating flood and associated suspended-sediment pulse appear to have marked the final establishment of the new section of subglacial conduit. The flood ended the episode of high sliding velocity, but released water with high solute concentrations that reflect relatively long contact time with sediments. Discharge of stored water, inferred from high solute concentrations and lack of diurnal variation in discharge, continued for at least 3 days. While events such as this must recur through the melt season as the conduit system extends up-glacier and the locus of meltwater inputs shifts, their manifestations in the outlet stream will likely be more subdued later in the season.

Fitzroy River Basin, Queensland, Australia. IV. Identification of flood sediment sources in the Fitzroy River

2008 ◽  
Vol 5 (3) ◽  
pp. 243 ◽  
Author(s):  
G. B. Douglas ◽  
P. W. Ford ◽  
M. R. Palmer ◽  
R. M. Noble ◽  
R. J. Packett ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Isotope Geochemistry ◽  
Temporal Trends ◽  
Flood Event ◽  
Sediment Sources ◽  
Sediment Fraction ◽  
Flood Hydrograph ◽  
Basaltic Soils ◽  
First Time ◽  
Fitzroy River

Environmental context. During flood events, the Fitzroy River is a major contributor to the loads of suspended sediment and nutrients to the southern Great Barrier Reef. The present geochemical and modelling study provides for the first time a quantitative estimate of the temporal variation in sediment sources over an entire flood hydrograph. Basaltic soils are substantially enriched in this flood event relative to their catchment abundance. Abstract. Suspended sediment collected over a complete flood hydrograph in the Fitzroy River provided an insight into the origin and transport of sediment in this system. Strong temporal trends are evident in the proportions of catchment soil types estimated using a Bayesian mixing model in the fine (<10 μm) fraction of the suspended sediment. These temporal trends were also manifested in changes in mineralogy, major and trace element and Nd–Sr and C–N isotope geochemistry. Tertiary Basaltic soils were the most abundant catchment soil type transported in the flood event studied here, constituting 39% of the <10-μm sediment fraction, but varied between an estimated 20 and 50% of the suspended solids over the course of the flood event. The techniques used here allow quantification and comparison between flow and suspended sediment sources and are widely applicable to other river systems.

scholarly journals Nonstationary Analysis for Bivariate Distribution of Flood Variables in the Ganjiang River Using Time-Varying Copula

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 746
Author(s):  
Tianfu Wen ◽  
Cong Jiang ◽  
Xinfa Xu
Keyword(s):  
Suspended Sediment ◽  
Flood Event ◽  
Dependence Structure ◽  
Copula Model ◽  
Time Varying ◽  
Bivariate Distributions ◽  
Marginal Distributions ◽  
The Mean ◽  
Water Stage ◽  
Dependence Structures

Nonstationarity of univariate flood series has been widely studied, while nonstationarity of some multivariate flood series, such as discharge, water stage, and suspended sediment concentrations, has been studied rarely. This paper presents a procedure for using the time-varying copula model to describe the nonstationary dependence structures of two correlated flood variables from the same flood event. In this study, we focus on multivariate flood event consisting of peak discharge (Q), peak water stage (Z) and suspended sediment load (S) during the period of 1964–2013 observed at the Waizhou station in the Ganjiang River, China. The time-varying copula model is employed to analyze bivariate distributions of two flood pairs of (Z-Q) and (Z-S). The main channel elevation (MCE) and the forest coverage rate (FCR) of the basin are introduced as the candidate explanatory variables for modelling the nonstationarities of both marginal distributions and dependence structure of copula. It is found that the marginal distributions for both Z and S are nonstationary, whereas the marginal distribution for Q is stationary. In particular, the mean of Z is related to MCE, and the mean and variance of S are related to FCR. Then, time-varying Frank copula with MCE as the covariate has the best performance in fitting the dependence structures of both Z-Q and Z-S. It is indicated that the dependence relationships are strengthen over time associated with the riverbed down-cutting. Finally, the joint and conditional probabilities of both Z-Q and Z-S obtained from the best fitted bivariate copula indicate that there are obvious nonstationarity of their bivariate distributions. This work is helpful to understand how human activities affect the bivariate flood distribution, and therefore provides supporting information for hydraulic structure designs under the changing environments.

Observed Suspended Sediment Profiles under the Effect of Single and Double Peaked Wave Spectra

2006 ◽  
Author(s):  
M. R. Delgado Blanco ◽  
M. Olabarrieta Lizaso ◽  
A. Giardino ◽  
R. Banasiak ◽  
R. Verhoeven ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Wave Spectra ◽  
Sediment Profiles
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