Sex that moves mountains: The influence of spawning fish on river profiles over geologic timescales

Geomorphology ◽  
2018 ◽  
Vol 305 ◽  
pp. 163-172 ◽  
Author(s):  
Alexander K. Fremier ◽  
Brian J. Yanites ◽  
Elowyn M. Yager
Keyword(s):  
River Profiles

New constraints on sediment-flux–dependent river incision: Implications for extracting tectonic signals from river profiles

Geology ◽  
2008 ◽  
Vol 36 (7) ◽  
pp. 535 ◽  
Author(s):  
Patience A. Cowie ◽  
Alexander C. Whittaker ◽  
Mikaël Attal ◽  
Gerald Roberts ◽  
Greg E. Tucker ◽  
...  
Keyword(s):  
Sediment Flux ◽  
River Incision ◽  
River Profiles

scholarly journals Experimental migration of knickpoints: influence of style of base-level fall and bed lithology

2016 ◽  
Vol 4 (1) ◽  
pp. 11-23 ◽  
Author(s):  
J.-L. Grimaud ◽  
C. Paola ◽  
V. Voller
Keyword(s):  
Fall Rate ◽  
Pool Depth ◽  
Similar Shape ◽  
Base Level ◽  
Self Organized ◽  
Plunge Pool ◽  
Source To Sink ◽  
Constant Rate ◽  
Geomorphic Features ◽  
River Profiles

Abstract. Knickpoints are fascinating and common geomorphic features whose dynamics influence the development of landscapes and source-to-sink systems – in particular the upstream propagation of erosion. Here, we study river profiles and associated knickpoints experimentally in a microflume filled with a cohesive substrate made of silica, water and kaolinite. We focus on the effect on knickpoint dynamics of varying the distribution of base-level fall (rate, increment, and period) and substrate strength, i.e., kaolinite content. Such simple cases are directly comparable to both bedrock and alluvial river systems. Under a constant rate of base-level fall, knickpoints of similar shape are periodically generated, highlighting self-organized dynamics in which steady forcing leads to multiple knickpoint events. Temporary shielding of the bed by alluvium controls the spacing between these unit knickpoints. Shielding is, however, not effective when base-level drops exceed alluvium thickness. While the base-level fall rate controls the overall slope of experiments, it is not instrumental in dictating the major characteristics of unit knickpoints. Instead the velocity, face slope and associated plunge pool depth of these knickpoints are all strongly influenced by lithology. The period between knickpoints is set by both alluvium thickness and base-level fall rate, allowing use of knickpoint spacing along rivers as an indicator of base-level fall rate.

Geomorphological evolution of longitudinal river profiles in the Carpathians

Geomorphology ◽  
2003 ◽  
Vol 50 (4) ◽  
pp. 293-306 ◽  
Author(s):  
Maria Rãdoane ◽  
Nicolae Rãdoane ◽  
Dan Dumitriu
Keyword(s):  
The Carpathians ◽  
River Profiles ◽  
Geomorphological Evolution

scholarly journals Temporal and spatial evolution of dynamic support from river profiles: A framework for Madagascar

2012 ◽  
Vol 13 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Gareth G. Roberts ◽  
Jonathan D. Paul ◽  
Nicky White ◽  
Jeffrey Winterbourne
Keyword(s):  
Spatial Evolution ◽  
Temporal And Spatial Evolution ◽  
Dynamic Support ◽  
Temporal And Spatial ◽  
River Profiles

scholarly journals The Generation and Scaling of Longitudinal River Profiles

2019 ◽  
Vol 124 (1) ◽  
pp. 137-153 ◽  
Author(s):  
Gareth G. Roberts ◽  
Nicky White ◽  
Bhavik Harish Lodhia
Keyword(s):  
River Profiles

Divide mobility controls knickpoint migration on the Roan Plateau

2020 ◽  
Author(s):  
Wolfgang Schwanghart ◽  
Dirk Scherler
Keyword(s):  
Colorado River ◽  
Drainage Area ◽  
Lagrangian Model ◽  
Drainage Network ◽  
Migration Rates ◽  
Tectonic History ◽  
Area Loss ◽  
Temporal Aspects ◽  
History Of ◽  
River Profiles

<p>Knickpoints in longitudinal river profiles provide proxies for the climatic and tectonic history of active mountains. The analysis of river profiles commonly relies on the assumption that drainage network configurations are stable. Here we show that this assumption must made cautiously if changes in contributing area are fast relative to knickpoint migration rates. We study the Parachute Creek basin in the Roan Plateau, Colorado, United States. Low spatial variations in climate and erosional efficiency permit us to reveal and quantify drainage-area loss that occurred in one of the subbasins where observed knickpoint locations are farther upstream than predicted by a model that takes present-day drainage areas into account. We developed a Lagrangian model of knickpoint migration which enables us to study the kinematic links between drainage area loss and knickpoint migration and that provides us with constraints on the temporal aspects of area loss. Modelled onset and amount of area loss are consistent with cliff retreat rates along the margin of the Roan Plateau inferred from the incisional history of the upper Colorado River.</p>

River profiles from digital elevation models – limitations and new ideas

2020 ◽  
Author(s):  
Stefan Hergarten ◽  
Jörg Robl
Keyword(s):  
Tectonic Geomorphology ◽  
Limiting Factor ◽  
Mesh Width ◽  
Tectonic History ◽  
Digital Elevation ◽  
New Ideas ◽  
Channel Slope ◽  
River Profiles ◽  
Made In

<p>Longitudinal river profiles have been a central if not even the most important subject in tectonic geomorphology since the 1950s. During the last decades, considerable progress has been made in unraveling the tectonic history from river profiles. Going along with the rapidly increasing availability of DEMs, however, scientists try to derive more and more information from the topography. So the quality of the DEM is still a limiting factor in many studies. In particular, local channel slopes are strongly affected by the DEM. Several approaches have been proposed in order to reduce the errors and to distinguish specific features such as knickpoints from noise of the DEM.</p><p>In this study we use DEMs with a mesh width of 1 m obtained from airborne laser scans and reduce their resolution artificially in order to analyze the effect of the mesh width on the accuracy of river profiles systematically. Based on the results, we present an idea how the errors in channel slope could be reduced with focus on narrow valleys. Going beyond the majority of the previously published approaches, our idea does not only take into account the elevation along the river profile, but also the curvature of the topography in direction normal to the valley floor.</p><p> </p>

Sign in / Sign up

Export Citation Format

Share Document