GRS IR 701 Lecture Notes - Lecture 8: Alluvial Fan
9 Nov 2017
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Document Summary
Precipitation falls, it runs off, infiltrates into the ground, and it gets into the river. It evaporates from river into the clouds and the cycle continues. Issues: superfloods circa 200 year cycle, levee breaks point source of 1000 miles of flood waters, beaches and barrier islands disappearing, why: due to dams and channeling of rivers (for shipping to deep waters, they are barriers against hurricanes. Downstream changes: longitudinal profile, high on profile: erosion >> deposition, low on profile: erosion = deposition, except during floods, changes downstream: width (>), depth (>), velocity all multiplied called discharge. Stream cross section: meanders and erodes on the outer layer. V-shaped valleys (youthful stream): erosion: tributary cut into. Between stages of flooding, they get cut off. An alluvial fan: looks like a delta but deposited at the edge of the mountain but has dried. Dams prevent fish from going upstream, sediment from going into bodies of water.
