scholarly journals Sediment Budget and Sediment Trap efficiency of Baglihar Hydroelectric project Reservoir – a calibrated model for prediction of longevity of the Dam

2021 ◽  
Vol 38 (1) ◽  
pp. 65-74
Author(s):  
Romesh Kumar ◽  
AHSAN UL HAQ ◽  
G M Bhat ◽  
Yudhbir Singh ◽  
Javid Ahmed Dar
Keyword(s):  
Sediment Trap ◽  
Empirical Relationship ◽  
Field Investigation ◽  
Sediment Budget ◽  
Hydropower Project ◽  
Trap Efficiency ◽  
Hydroelectric Project ◽  
Reservoir Volume ◽  
Total Sediment

 The field investigation of the reservoir area of Baglihar Hydropower project shows that the sediment budget to the reservoir is controlled by fragile rock type like shales, sandstones, phyllites and slates, soil characteristics, steep hill slopes, rainfall and landslides. The rocks are highly weathered, fissile and micaceous in nature and very sensitive to water absorption.  The analysed sediments are characterised by dominance of sands, silts and clays with lower values of plasticity (14.3PL), liquidity (23.5 LL), cohesion (118) and shear strength (202 Kpa). The slope wash deposits are highly susceptible to landslides and slope failures and directly contribute to the sediment budget in the reservoir. In addition tributaries of Chenab River also bring sediments in the reservoir from the catchment area. The empirical relationship for estimating the long-term reservoir trap efficiency for large storage based on correlation between the relative reservoir size and trap efficiency was simulated in 3D model which shows that the annual sediment trap efficiency of the Baglihar reservoir is of 0.39%. The extrapolation of the calculated values shows that the total sediment load shall increase by 11% in the next 30 years and 20% in the next 50 years and correspondingly 40% in the next 100 years that shall induce corresponding decrease in the reservoir volume over the time.  By applying flushing schemes, life span of the reservoir can be extended. It is estimated that after 100 years the reservoir shall lose ~35.6% storage volume. On further extrapolation, the trap efficiency will decrease from 25.5% after 30 years to 23% after 100 years. The estimated trap efficiency of Baglihar reservoir is 60%, which is greater than that based on numerical results, showing a significant overestimation.

Modelling the long-term sediment trap efficiency of small ponds

2001 ◽  
Vol 15 (14) ◽  
pp. 2797-2819 ◽  
Author(s):  
Gert Verstraeten ◽  
Jean Poesen
Keyword(s):  
Sediment Trap ◽  
Trap Efficiency

Influence of ground ice and permafrost on coastal evolution, Richards Island, Beaufort Sea coast, N.W.T.

1996 ◽  
Vol 33 (5) ◽  
pp. 664-675 ◽  
Author(s):  
Scott R. Dallimore ◽  
Stephen A. Wolfe ◽  
Steven M. Solomon
Keyword(s):  
Coastal Erosion ◽  
Sediment Budget ◽  
Storm Event ◽  
Ground Ice ◽  
Coastal Evolution ◽  
Thermal Erosion ◽  
Ice Wedge ◽  
Mechanical Erosion ◽  
Sea Coast

A long-term sediment budget (1947−1985) for northern Richards Island shows that, when ground ice and offshore erosion are accounted for, there is a near balance between headland erosion and coastal deposition. Excess ice constitutes about 20% of the total volume of eroded material from the headlands, with massive ground ice contributing nearly 9% and segregated ice lenses and ice wedges making up the remainder. Coastal response to major storms in 1987 and 1993 suggests that erosion is episodic, with short periods of intense disruption followed by readjustment of cliff profiles. Processes characteristic of this environment include mechanical erosion of ice-bonded sediments creating unstable erosional niches, mechanical failure of niches along ice-wedge planes, and longer term thermal erosion of ice-bonded sediments. Where ice contents are high, localized thaw slumps initiated by coastal erosion may retreat at rates substantially higher than those observed at other sections of the coast. Cliff-top retreat rates may be out of phase with storm-event chronology.

scholarly journals Is the Water Temperature of the Danube River at Bratislava, Slovakia, Rising?

2008 ◽  
Vol 9 (5) ◽  
pp. 1115-1122 ◽  
Author(s):  
Pavla Pekarova ◽  
Dana Halmova ◽  
Pavol Miklanek ◽  
Milan Onderka ◽  
Jan Pekar ◽  
...  
Keyword(s):  
Time Series ◽  
Water Temperature ◽  
Heat Load ◽  
Empirical Relationship ◽  
Danube River ◽  
Average Heat ◽  
The Danube River ◽  
Average Temperature ◽  
Monthly Discharge

Abstract This paper aims to reveal the annual regime, time series, and long-term water temperature trends of the Danube River at Bratislava, Slovakia, between the years 1926 and 2005. First, the main factors affecting the river’s water temperature were identified. Using multiple regression techniques, an empirical relationship is derived between monthly water temperatures and monthly atmospheric temperatures at Vienna (Hohe Warte), Austria, monthly discharge of the Danube, and some other factors as well. In the second part of the study, the long-term trends in the annual time series of water temperature were identified. The following series were evaluated: 1) The average annual water temperature (To) (determined as an arithmetic average of daily temperatures in the Danube at Bratislava), 2) the weighted annual average temperature values (Toυ) (determined from the daily temperatures weighted by the daily discharge rates at Bratislava), and 3) the average heat load (Zt) at the Bratislava station. In the long run, the To series is rising; however, the trend of the weighted long-term average temperature values, Toυ, is near zero. This result indicates that the average heat load of the Danube water did not change during the selected period of 80 yr. What did change is the interannual distribution of the average monthly discharge. Over the past 25 yr, an elevated runoff of “cold” water (increase of the December–April runoff) and a lower runoff of “warm” water (decrease of the river runoff during the summer months of June–August) were observed.

Paleomagnetic Analysis Of A Long-Term Sediment Trap, Kooken Cave, Huntingdon County, Pennsylvania, USA

2007 ◽  
pp. 71-81 ◽  
Author(s):  
Ira. D. Sasowsky ◽  
Rebecca A. Clotts ◽  
Bryan Crowell ◽  
Selena M. Walko ◽  
Edward J. LaRock ◽  
...  
Keyword(s):  
Sediment Trap

scholarly journals Erosion assessment in the middle Kali Gandaki (Nepal): A sediment budget approach

2013 ◽  
Vol 46 ◽  
Author(s):  
Monique Fort ◽  
Etienne Cossart
Keyword(s):  
Drainage Basin ◽  
Sediment Budget ◽  
Mountain Range ◽  
Primary Concern ◽  
Stream Power ◽  
Sediment Budgets ◽  
Relative Chronology ◽  
Wide Range ◽  
History Of

Active mountains supply the largest sediment fluxes experienced on earth. At mountain range scale, remote sensing approaches, sediments provenance or stream power law analyses, collectively provide rough long-term estimates of total erosion. Erosion is indeed controlled by rock uplift and climate, hence by a wide range of processes (detachment, transport and deposition), all operating within drainage basin units, yet with time and spatial patterns that are quite complex at local scale. We focus on the Kali Gandaki valley, along the gorge section across the Higher Himalaya (e.g. from Kagbeni down to Tatopani). Along this reach, we identify sediment sources, stores and sinks, and consider hillslope int eractions with valley floor, in particular valley damming at short and longer time scales, and their impact on sediment budgets and fluxes. A detailed sediment budget is presented, constrained by available dates and/or relative chronology, ranging from several 10 kyr to a few decades. Obtained results span over two orders of magnitude that can best be explained by the type and magnitude of erosional processes involved. We show that if large landslides contribute significantly to the denudation history of active mountain range, more frequent medium to small scales landslides are in fact of primary concern for Himalayan population.

Comprehensive Evaluation of Rutting of Warm-Mix Asphalt Utilizing Long-Term Pavement Performance Specific Pavement Studies

2020 ◽  
Vol 2674 (7) ◽  
pp. 272-283 ◽  
Author(s):  
Biswajit K. Bairgi ◽  
A.S.M. Asifur Rahman ◽  
Rafiqul A. Tarefder ◽  
Matias M. Mendez Larrain
Keyword(s):  
Comprehensive Evaluation ◽  
Field Investigation ◽  
Warm Mix Asphalt ◽  
Pavement Performance ◽  
Laboratory Evaluation ◽  
Production Temperature ◽  
Wheel Tracking Test ◽  
Modified Binder ◽  
Wheel Tracking

Warm-mix asphalt (WMA) technologies allow binder softening for compaction benefits. Lower production temperature also causes reduced short-term aging in WMA. Considering the long-term implication of the reduced aging and binder softening, WMA is being questioned about its rutting characteristics. As such, this study evaluates different WMA technologies for rutting characteristics in comparison to traditional hot-mix asphalt (HMA) through laboratory and field investigation. The study utilized the long-term pavement performance (LTPP) project in the state of New Mexico called Specific Pavement Study-10 (SPS-10), which was designed to evaluate the WMA performances. The LTPP SPS-10 section includes: (i) control HMA, (ii) foaming, (iii) Evotherm, (iv) Cecabase 1, and (v) Cecabase 2 mixtures. Cecabase 2 mixture consists of a polymer-modified binder (PG 70-28+), whereas other mixtures consist of PG 70-28 binder. The aggregate type, properties, and gradations are the same in all the sections. Laboratory evaluation of rutting was conducted through the Hamburg wheel tracking test. Long-term field rutting was evaluated through Mandli’s pavement profile scanner, a laser-based distress evaluation technology. The study found that WMA with foaming, Evotherm, or Cecabase shows slightly higher rutting compared with the control HMA; however, all the sections satisfied laboratory and field rutting criteria. The use of a polymer-modified binder in WMA significantly improves the rutting characteristics.

Flow-Field Investigation of Two Gas-Sampling Probes

2006 ◽  
Author(s):  
Leiyong Jiang ◽  
Shaji Manipurath ◽  
Gilles Bourque ◽  
Michel Houde
Keyword(s):  
Cooling Water ◽  
Elevated Pressure ◽  
Field Investigation ◽  
Complex Conjugate ◽  
Probe Design ◽  
Wall Region ◽  
Original Design ◽  
Gas Sampling ◽  
Heat Transfers

The flow fields in and around two versions of a water-cooled gas-sampling probe, situated downstream of a gas turbine combustor, were numerically studied in an elevated pressure and temperature environment. The probes are of triple-walled stainless steel assembly, where the gas sample is transported through a centre tube, while preheated and pressurized cooling water flows through two surrounding annuli. Complex conjugate heat transfers amongst the exhaust mixture, cooling water and probe walls were modelled at a selected operating condition. The numerical results indicate over-heating and possible vaporization of water or cavitation in the upstream tip region of the probe with the original design. This is consistent with the evidence of damage observed in these probes from prolonged testing under similar conditions. For the modified probe, the effectiveness of cooling water is much improved, which is confirmed by long-term combustor rig testing. From this investigation, some recommendations for probe design and operation are provided. Moreover, the present study has proved that the numerical simulation is a valuable tool for probe design and trouble-shooting, and to accurately predict conjugate heat transfers in such flows, the laminar sub-layer in the near-wall region should be adequately resolved.

West Sole Pipeline Stabilisation

2005 ◽  
Author(s):  
Z. Chen ◽  
Eamon Sheehan
Keyword(s):  
Negative Impact ◽  
Optimal Solution ◽  
Sediment Budget ◽  
Gas Field ◽  
Critical Position ◽  
Coastal Evolution ◽  
Sea Bed ◽  
Pipeline Failure ◽  
The Uk

The BP West Sole gas field is located in Block 48/6 in the UK sector of the southern North Sea, about 70 km off the Holderness coast. Production from the gas field is exported to a shore terminal at Easington by two pipelines. Both pipelines were trenched at installation. Pipeline surveys over the last few years show that both pipelines are substantially exposed at the shore approach and inshore sections. This has occurred in part due to the retreat of the cliffs in Easington and subsequent lowering of the sea bed level and also the migration of sand from around the pipelines leaving them largely unburied and sitting on the local clay abrasion platform. It has been concluded that both pipelines require stabilisation sooner rather than later to reduce the risk of pipeline failure. Pipeline stabilisation options need to take account of the environment in which they have been placed. Easington is at a critical position along the Holderness coast. All net sediment transport from the Holderness coastline passes through this section. Any interruption to this movement could result in a change to the adjacent coast. Maintenance of the sediment budget is important to a wider area of the East coast of England. Stabilisation options must not reduce the net amount of sediment moving southwards past Dimlington and must not result in any long term negative impact on the coastal evolution. This paper outlines consultancy required and problems process regarding the geomorphological issues in getting acceptance from government and non-government bodies. A methodology has been developed that allows quantification of impacts of different options on the sediment budget and on the long-term coastal evolution (see also Chen et al 1998, 2001 and 2002). Application of this method aimed at providing understanding and information which is considered to be important in the process of selecting an optimal solution for the pipeline stabilisation in such an environmental sensitive coast.

scholarly journals Estimation of Background Erosion Rate at Janghang Beach due to the Construction of Geum Estuary Tidal Barrier in Korea

2020 ◽  
Vol 8 (8) ◽  
pp. 551
Author(s):  
Sahong Lee ◽  
Jung Lyul Lee
Keyword(s):  
Coastal Erosion ◽  
Sediment Budget ◽  
Coastal Development ◽  
Coastal Sediment ◽  
Littoral Cell ◽  
Watershed Development ◽  
Open Sea ◽  
Sediment Loss ◽  
The Future

In this study, a reduction in sediment budget due to the development of a river watershed, resulting in coastal erosion, was reviewed, and the rate of background erosion was calculated through an examination of the loss of coastal sediment into the open sea. The west coast of the Korean peninsula is severely impacted by the intercept of inflowing sediments from rivers, owing to the watershed development. However, the effects have not fully propagated into the entire coastal area, and thus, the long-term coastal erosion remains insignificant. However, a serious and irrevocable disaster may occur once the coastal erosion begins. Therefore, an analysis of the coastal erosion resulting from changes in the sediment budget, due to the development of the watershed, was conducted on Janghang Songrim Beach. A littoral cell of the Geum River was selected for a quantitative analysis of the decrease in the sediment budget from the watershed development. The rate of coastal sediment loss offshore, which reflects the characteristics of the Janghang Songrim Beach, and the future rate of coastal erosion were calculated. Then, the results were verified by employing geometrically corrected satellite photographs from previous years. This will enable us to predict the time of coastal erosion in the future due to a reduction in the sediment budget and watershed development, and prepare for future disasters resulting from the coastal erosion. Based on research into the components constituting the coastal development, the present study presents theoretical formulae allowing the prediction of the sediment budget and providing a practical contribution to the prevention of coastal erosion, for which additional reliable studies need to be conducted.

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