scholarly journals Fluvial suspended sediment transfer and lacustrine sedimentation of recent flood turbidites in proglacial Eklutna Lake, western Chugach Mountains, Alaska

2021 ◽  
Vol 35 (10) ◽  
Author(s):  
Erik Schiefer ◽  
Jason Geck ◽  
Johnse S. Ostman ◽  
Nicholas P. McKay ◽  
Nore Praet ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Lacustrine Sedimentation ◽  
Sediment Transfer

scholarly journals Streamflow and Suspended Sediment Transfer to Lake Sophia, Cornwallis Island, Nunavut, Canada

2000 ◽  
Vol 32 (4) ◽  
pp. 456-465 ◽  
Author(s):  
Carsten Braun ◽  
Douglas R. Hardy ◽  
Raymond S. Bradley ◽  
Michael J. Retelle
Keyword(s):  
Suspended Sediment ◽  
Sediment Transfer ◽  
Cornwallis Island

scholarly journals Reduced fine sediment flux in response to the managed diversion of an upland river channel

2015 ◽  
Vol 3 (4) ◽  
pp. 1179-1220
Author(s):  
M. T. Perks ◽  
J. Warburton
Keyword(s):  
Suspended Sediment ◽  
Fine Sediment ◽  
Sediment Flux ◽  
Analysis Of Covariance ◽  
Before And After ◽  
Suspended Sediment Concentrations ◽  
Sediment Transfer ◽  
The Uk ◽  
The Impact ◽  
B Coefficients

Abstract. This paper describes the implementation of a novel mitigation approach and subsequent adaptive management, designed to reduce the transfer of fine sediment in Glaisdale Beck; a small upland catchment in the UK. Hydro-meteorological and suspended sediment datasets are collected over a two year period spanning pre- and post-diversion periods in order to assess the impact of the channel reconfiguration scheme on the fluvial suspended sediment dynamics. Analysis of the river response demonstrates that the fluvial sediment system has become more restrictive with reduced fine sediment transfer. This is characterised by reductions in flow-weighted mean suspended sediment concentrations from 77.93 mg L−1 prior to mitigation, to 74.36 mg L−1 following the diversion. A Mann–Whitney U test found statistically significant differences (p < 0.001) between the pre- and post-monitoring median SSCs. Whilst application of one-way analysis of covariance (ANCOVA) on the coefficients of sediment rating curves developed before and after the diversion found statistically significant differences (p < 0.001), with both Log a and b coefficients becoming smaller following the diversion. Non-parametric analysis indicates a reduction in residuals through time (p < 0.001), with the developed LOWESS model over-predicting sediment concentrations as the channel stabilises. However, the channel is continuing to adjust to the reconfigured morphology, with evidence of a headward propagating knickpoint which has migrated 120 m at an exponentially decreasing rate over the last 7 years since diversion. The study demonstrates that channel reconfiguration can be effective in mitigating fine sediment flux in upland streams but the full value of this may take many years to achieve whilst the fluvial system, slowly readjusts.

scholarly journals Fluvial Suspended Sediment Transfer and Lacustrine Sedimentation of Recent Flood Turbidites in Proglacial Eklutna Lake, Western Chugach Mountains, Alaska

2021 ◽  
Author(s):  
Erik Schiefer ◽  
Jason Geck ◽  
Johnse Ostman ◽  
Nicholas McKay ◽  
Nore Praet ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Sediment Cores ◽  
Late Summer ◽  
Spatial Modelling ◽  
Current Strength ◽  
Sediment Delivery ◽  
Annual Variations ◽  
South Central ◽  
Wide Range ◽  
Sediment Transfer

Suspended sediment delivery and deposition in proglacial lakes is generally sensitive to a wide range of hydrometeorologic and geomorphic controls. High discharge conditions are of particular importance in many glaciolacustrine records, with individual floods potentially recorded as distinctive turbidites. We used an extensive network of surface sediment cores and hydroclimatic monitoring data to analyze recent flood turbidites and associated sediment transfer controls over instrumental periods at Eklutna Lake, western Chugach Mountains, Alaska. Close to a decade of fluvial data from primary catchment tributaries show a dominating influence of discharge on sediment delivery, with various interconnections with other related hydroclimatic controls. Multivariate fluvial models highlight and help quantify some complexities in sediment transfer, including intra-annual variations, meteorological controls, and the influence of subcatchment glacierization. Sediments deposited in Eklutna Lake during the last half century are discontinuously varved and contain multiple distinctive turbidites. Over a 30-year period of stratigraphic calibration, we correlate the four thickest flood turbidites (1989, 1995, 2006, 2012) to specific regional storms. The studied turbidites correlate with late-summer and early-autumn rainstorms with a magnitude of relatively instantaneous sedimentation 3 to 15 times greater than annual background accumulation. Our network of sediment core data captured the broad extent and sediment variability among the study turbidites and background sediment yield. Within-lake spatial modelling of deposition quantifies variable rates of downlake thinning and sediment focusing effects, and highlights especially large differences between the thickest flood turbidites and background sedimentation. This we primarily relate to strongly contrasting dispersion processes controlled by inflow current strength and turbidity. Sediment delivery is of interest for this catchment because of reservoir and water supply operations. Furthermore, although smaller floods may not be consistently represented, the lake likely contains a valuable proxy record of regional flooding proximal to major population centers of south-central Alaska including Anchorage.

scholarly journals Streamflow and Suspended Sediment Transfer to Lake Sophia, Cornwallis Island, Nunavut, Canada

2000 ◽  
Vol 32 (4) ◽  
pp. 456 ◽  
Author(s):  
Carsten Braun ◽  
Douglas R. Hardy ◽  
Raymond S. Bradley ◽  
Michael J. Retelle
Keyword(s):  
Suspended Sediment ◽  
Sediment Transfer ◽  
Cornwallis Island

Challenges to the representation of suspended sediment transfer using a depth-averaged flux

2016 ◽  
Vol 41 (10) ◽  
pp. 1337-1357 ◽  
Author(s):  
Chen Cheng ◽  
Huiming Huang ◽  
Chengyan Liu ◽  
Weimin Jiang
Keyword(s):  
Suspended Sediment ◽  
Sediment Transfer

scholarly journals Balance sedimentario del embalse de Ribarroja

2021 ◽  
Author(s):  
A. Tena ◽  
D. Vericat ◽  
R.J. Batalla
Keyword(s):  
Suspended Sediment ◽  
Sediment Load ◽  
Land Use Changes ◽  
Suspended Sediment Transport ◽  
Suspended Sediment Load ◽  
Lower Reach ◽  
Iberian Range ◽  
Intermittent Rivers ◽  
Sediment Transfer

The aim of this study was to build up a sediment budget of the Ribarroja Reservoir, which is located in the lower reach of the River Ebro. For this purpose, we analysed continuous discharge and suspended sediment transport data at several river sections entering the reservoir and at the dam outlet, for the period 2008-2011. The sediment load estimated upstream of the Mequinenza reservoir was 0.66×106 t a-1, whereas the estimated output was 0.04×106 t a-1. The sediment input coming from the large but highly regulated Pyrenean tributaries (Segre and Cinca) was 0.16×106 t a-1, whereas intermittent rivers naturally flowing from the Iberian Range (Matarraña and Algars) supplied an average load of 760 t a-1. The suspended sediment load trapped in the Mequinenza and Ribarroja reservoirs for the study period was estimated at 0.78×106 t a-1, which implies a reduction of ca. 95% of the sediment load of the river. The results illustrate the role of reservoirs in interrupting the sediment transfer in the lower reach of the Ebro, within a context of structural sediment deficit, following widespread land use changes (afforestation) that took place in the catchment after the 1940s.

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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