Abstract
Alluvial river channels adjust readily to formative discharges of moderate magnitude and frequency. Bedrock river channels present various thresholds to effective channel adjustment, such that only relatively rare, highmagnitude flood discharges contribute to shaping their morphologies. Very high values of power per unit area of bed, exceeding 102 Wm-2, result in high-energy erosional processes, including cavitation and macroturbulent plucking. Although these processes are best exemplified in the Channeled Scabland and other late Pleistocene cataclysmic flood channels, they also can be achieved in modem bedrock gorges where very resistant rocks are acted upon by unusually large floods. Examples include the Katherine Gorge, northern Australia, and various gorges of the Narmada and Tapi Rivers in central India. Distinctive scabland-like morphologies occur, including wide, shallow bedrock surfaces with inner channels and narrow, deep gorges. As in alluvial rivers, there may be an adjustment to energy expenditure, but at a much higher level of energy associated with rare floods.
| Original language | English (US) |
|---|---|
| Title of host publication | Rivers Over Rock |
| Subtitle of host publication | Fluvial Processes in Bedrock Channels, 1998 |
| Publisher | Blackwell Publishing Ltd |
| Pages | 153-165 |
| Number of pages | 13 |
| Volume | 107 |
| ISBN (Electronic) | 9781118664292 |
| ISBN (Print) | 9780875900902 |
| DOIs | |
| State | Published - Jan 1 1998 |
Publication series
| Name | Geophysical Monograph Series |
|---|---|
| Volume | 107 |
| ISSN (Print) | 0065-8448 |
| ISSN (Electronic) | 2328-8779 |
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ASJC Scopus subject areas
- Geophysics
Cite this
The role of extreme floods in shaping bedrock channels. / Baker, Victor; Kale, Vishwas S.
Rivers Over Rock: Fluvial Processes in Bedrock Channels, 1998. Vol. 107 Blackwell Publishing Ltd, 1998. p. 153-165 (Geophysical Monograph Series; Vol. 107).Research output: Chapter in Book/Report/Conference proceeding › Chapter
}
TY - CHAP
T1 - The role of extreme floods in shaping bedrock channels
AU - Baker, Victor
AU - Kale, Vishwas S.
PY - 1998/1/1
Y1 - 1998/1/1
N2 - Alluvial river channels adjust readily to formative discharges of moderate magnitude and frequency. Bedrock river channels present various thresholds to effective channel adjustment, such that only relatively rare, highmagnitude flood discharges contribute to shaping their morphologies. Very high values of power per unit area of bed, exceeding 102 Wm-2, result in high-energy erosional processes, including cavitation and macroturbulent plucking. Although these processes are best exemplified in the Channeled Scabland and other late Pleistocene cataclysmic flood channels, they also can be achieved in modem bedrock gorges where very resistant rocks are acted upon by unusually large floods. Examples include the Katherine Gorge, northern Australia, and various gorges of the Narmada and Tapi Rivers in central India. Distinctive scabland-like morphologies occur, including wide, shallow bedrock surfaces with inner channels and narrow, deep gorges. As in alluvial rivers, there may be an adjustment to energy expenditure, but at a much higher level of energy associated with rare floods.
AB - Alluvial river channels adjust readily to formative discharges of moderate magnitude and frequency. Bedrock river channels present various thresholds to effective channel adjustment, such that only relatively rare, highmagnitude flood discharges contribute to shaping their morphologies. Very high values of power per unit area of bed, exceeding 102 Wm-2, result in high-energy erosional processes, including cavitation and macroturbulent plucking. Although these processes are best exemplified in the Channeled Scabland and other late Pleistocene cataclysmic flood channels, they also can be achieved in modem bedrock gorges where very resistant rocks are acted upon by unusually large floods. Examples include the Katherine Gorge, northern Australia, and various gorges of the Narmada and Tapi Rivers in central India. Distinctive scabland-like morphologies occur, including wide, shallow bedrock surfaces with inner channels and narrow, deep gorges. As in alluvial rivers, there may be an adjustment to energy expenditure, but at a much higher level of energy associated with rare floods.
UR - http://www.scopus.com/inward/record.url?scp=84923650144&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84923650144&partnerID=8YFLogxK
U2 - 10.1029/GM107p0153
DO - 10.1029/GM107p0153
M3 - Chapter
SN - 9780875900902
VL - 107
T3 - Geophysical Monograph Series
SP - 153
EP - 165
BT - Rivers Over Rock
PB - Blackwell Publishing Ltd
ER -