Sediment (un)balance budget in a high-gradient stream on flysch bedrock: A case study using dendrogeomorphic methods and bedload transport simulation

CATENA ◽  
2015 ◽  
Vol 124 ◽  
pp. 18-27 ◽  
Author(s):  
Karel Šilhán ◽  
Tomáš Galia
Keyword(s):  
Bedload Transport ◽  
Balance Budget ◽  
High Gradient ◽  
Transport Simulation

How reliable is the K-Ar glauconite chronometer? A case study of Eocene sediments from the Isle of Wight

Clay Minerals ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 167-176 ◽  
Author(s):  
N. Clauer ◽  
J. M. Huggett ◽  
S. Hillier
Keyword(s):  
Magnetic Separation ◽  
Isotopic Age ◽  
High Gradient Magnetic Separation ◽  
Isle Of Wight ◽  
High Gradient ◽  
Final Selection ◽  
Age Determinations ◽  
Highly Evolved

AbstractK-Ar ages of Eocene glauconite pellets from the Isle of Wight are related to quantified amounts of older glauconite pellets and to occurrences of detrital mica/illite particles that might have been added to synsedimentary pellets during reworking processes. Addition of older glauconite did not significantly bias the K-Ar dates, as the results most often provide the expected stratigraphic reference ages or even significantly lower ages. Alternatively, K-Ar dates significantly greater than those suggested by the stratigraphy appear to result from non-glauconized detrital mica in the pellets which is not always removable, even by high-gradient magnetic separation.Unexpected ‘old’ K-Ar glauconite ages do not result from misapplication of the method, but from inability to systematically identify and remove the `contaminant' particles from glauconite splits. Analysis of highly evolved glauconite separates is definitely appropriate for reliable isotopic age determinations, but it might not be enough for the final selection, as long-lasting diagenesis might have taken over the synsedimentary process. Much if not all depends on the separation and characterization of the separates, but also on the completion of the glauconitization process which effects cannot always be anticipated.

scholarly journals Bedload transport in two creeks at the ice-free area of the Baranowski Glacier, King George Island, West Antarctica

2017 ◽  
Vol 38 (1) ◽  
pp. 21-39 ◽  
Author(s):  
Joanna Sziło ◽  
Robert J. Bialik
Keyword(s):  
Water Discharge ◽  
Weather Conditions ◽  
Arithmetic Mean ◽  
Bedload Transport ◽  
Water Levels ◽  
West Antarctica ◽  
Weighted Arithmetic ◽  
Granulometric Analysis ◽  
First Time

Abstract This paper presents a unique case study and methodology for measurements of the bedload transport in the two, newly created troughs at the forefield of the Baranowski Glacier: Fosa and Siodło creeks. The weather conditions and the granulometric analysis are presented and discussed briefly. Rating curves for the Fosa and Siodło creeks are presented for the first time for this region. Changes of the bedload transport as well as water discharge and water velocity at both creeks are investigated. The hysteresis for the relationships between rate of bedload transport and water discharges were identified showing that for both creeks for the higher water levels a figure of eight loop may be easily recognized. Moreover, a new method for the calculation of bedload transport rate, based on the weighted arithmetic mean instead of the arithmetic mean, is proposed.

Hybrid Multimodal and Intermodal Transport Simulation: Case Study on Large-Scale Evacuation Planning

2016 ◽  
Vol 2561 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Gregor Lämmel ◽  
Mohcine Chraibi ◽  
Armel Ulrich Kemloh Wagoum ◽  
Bernhard Steffen
Keyword(s):  
Large Scale ◽  
Evacuation Planning ◽  
Intermodal Transport ◽  
Transport Simulation

scholarly journals The January 2014 Flashflood in the Ambato River (Catamarca, Argentina)- A Case Study of Megaboulders Fluvial Transport

2021 ◽  
Vol 2 (2) ◽  
pp. 3150-3166
Author(s):  
Moshe Inbar ◽  
Julio A. Costello ◽  
Jorge Eremchuk
Keyword(s):  
Urban Areas ◽  
Field Studies ◽  
Urban Environments ◽  
Bedload Transport ◽  
Alluvial Fan ◽  
Economic Losses ◽  
Arid Environments ◽  
Stream Power ◽  
The Village

Megaboulders mantle the steep channels of mountainous rivers, and moderate incision rates by increasing channel roughness. Direct measurement of the transport of boulders in natural rivers is difficult, therefore there are few field studies on the subject. The transportation of megaboulders downslope in catastrophic floods in urban environments releases a destructive power. This study analyses the Ambato river flood that occurred in Argentina in January 2014 with an assumed recurrence interval of 1:100 years. The flood was caused by concentrated rainfall in the upper basin, at an elevation of 4000 m. The Ambato river forms a boulder alluvial fan drained by episodic floods. The 2014 flood caused casualties and economic losses in the village of El Rodeo in the province of Catamarca. Several houses and a bridge were destroyed and vehicles were swept away. All bedload sizes- including megaboulders with 2000 mm b-axis- were transported during the flood. The empirical equation for stream power value and the unit bedload transport rate of megaboulders were validated. An assessment of boulder mobility is necessary to mitigate flow hazards in mountainous urban areas. The effects of climate change in semi-arid environments would be greater if they involved increased precipitation or more extreme rainstorms due to events such as El Niṅo.

Frequency of fast geomorphological processes in high-gradient streams: case study from the Moravskoslezské Beskydy Mts (Czech Republic) using dendrogeomorphic methods

2012 ◽  
Vol 39 (2) ◽  
pp. 122-132 ◽  
Author(s):  
Karel Šilhán
Keyword(s):  
Debris Flows ◽  
Alluvial Fan ◽  
High Mountains ◽  
Snow Melting ◽  
Short Term ◽  
Dynamic Activity ◽  
High Gradient ◽  
Growth Disturbances ◽  
Geomorphological Processes

Abstract High-gradient streams are localities with the most dynamic activity of geomorphological processes in medium-high mountains. This study of the frequency of floods and debris flows in a selected high-gradient stream in the Moravskoslezské Beskydy Mts was based on a dendrogeomorphic approach. It makes use of the most accurate methods applied in the dating of historic geomorphological processes. Individual events were reconstructed on the basis of the dating of various growth disturbances displayed in 99 samples taken from 56 predominantly broad-leaved trees. As for the studied area, 26 years out of the last 113 years have been identified as years of rapid geomorphological processes. The frequency of the processes has been high above average since the 1970s. A majority of the events can be considered as flash floods. Debris flows, which can only be observed sporadically, originate due to the reactivation of old accumulation material that subsequently ends up re-accumulated on the alluvial fan at the mouth of a stream. A large number of events occur in connection with extreme short-term precipitation in summer months. In addition, they are affected by fast snow melting in spring, which has also been proved by intra-seasonal dating of selected events.

scholarly journals Beach Gravels as a Potential Lithostatistical Indicator of Marine Coastal Dynamics: The Pogorzelica–Dziwnów (Western Pomerania, Baltic Sea, Poland) Case Study

Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 367 ◽  
Author(s):  
Cyprian Seul ◽  
Roman Bednarek ◽  
Tomasz Kozłowski ◽  
Łukasz Maciąg
Keyword(s):  
Baltic Sea ◽  
Chemical Weathering ◽  
Grain Shape ◽  
Crystalline Rock ◽  
Bedload Transport ◽  
Mechanical Destruction ◽  
Petrographic Composition ◽  
Individual Variations ◽  
Glacial Tills

The petrographic composition and grain shape variability of beach gravels in the Pogorzelica–Dziwnów coast section (363.0 to 391.4 km of coastline), southern Baltic Sea, Poland were analyzed herein to characterize the lithodynamics and trends of seashore development. Gravels were sampled at 0.25 km intervals, in the midpart of the berm, following an early-autumn wave storm and before beach nourishment. Individual variations in petrographic groups along the shore were investigated. Gravel data were compared and related to coastal morpholithodynamics, seashore infrastructure, and geology of the study area. The contribution of crystalline rock gravels (igneous and metamorphic) was observed to increase along all coast sections, whereas the amount of less resistant components (limestones, sandstones, and shales) usually declined. This effect is explained by the greater wave crushing resistance of igneous and metamorphic components, compared with sedimentary components. Similarly, the gravel grain shape (mainly elongation or flattening) was observed to change, depending on resistance to mechanical destruction, or due to the increased chemical weathering in mainly the limestones, marbles, and sandstones. Observed increase in contribution of discoid and ellipsoid grains is a potential indicator of depositional trends along the coast sections investigated. On the other hand, increased contents of spheroidal and spindle-shaped grains may be related to erosional trends, where intensive redeposition and mechanical reworking of gravels occurs. However, due to the great number of coastal embankments, the petrographic composition and shape parameters of beach gravels do not always clearly indicate the dominant direction of longshore bedload transport. Increased amount of eroded limestone located east of Pogorzelica indicate increased erosion of glacial tills. These sediments are deposited, building the shallow foreshore, with additional redeposition of morainic material towards the shore.

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