lecture 2: big rivers: geologic setting, hydrology and...
TRANSCRIPT
Lecture 2: Big Rivers: Geologic setting, hydrology and sediment yields
•What is the geologic setting of the Worlds big rivers? •What controls their hydrology? – the amount and delivery of runoff •What are the sediment yields and their variability – and why?
from Potter and Hamblin, 2006
• Tectonics – sets relief
• Climate – e.g. glaciations
• Base level
• Volcanism
from Potter and Szatmari, 2009
Longitudinal Foreland Basin
Longitudinal Foreland Basin
Transverse Systems: Amazon
Transverse Systems: Mississippi
Intrabasinal Setting: Brahmaputra
Intrabasinal Setting: Mekong
Tectonics, climate and sea-level
Big River Hydrology and Q: •Diverse – due to large drainage areas •Peak ‘unit’ discharge lower than smaller rivers •Baroclinic (high-latitude) and barotropic (equatorial) •BUT nowadays modified extensively by human intervention
El Niño-Southern Oscillation
After Wohl (2007): Equatorial Drylands Mid-latitudes Rivers draining south from Himalayas Rivers of South and SE Asia High latitude
March 5 2003
August 6 2003
Magdalena, Brahmaputra, Sông Hóng (Red), and Irrawaddy
Ganges, Godavari, Mekong, Yangtze, and Pearl
Amazon, Orinoco, Sao Francisco, and Salween
Chapter 2: pages 7-17 Geology of Large River Systems Sampat Tandon and Rajiv Sinha Chapter 3 Hydology and discharge Ellen Wohl
Big Rivers: Consideration of river management and ecology. River channel and
floodplain interactions. Disasters, flooding, bank erosion, impoundment, damming and issues of management