Rivers and Floods Flashcards
Steeper gradient (slope) (Upstream or Downstream?)
Upstream
Gentler gradient (slope) (Upstream or Downstream?)
Downstream
Higher velocity
Upstream or Downstream?
Upstream
Lower velocity
Upstream or Downstream?
Downstream
Small discharge (how much water is flowing) (Upstream or Downstream?)
Upstream
Huge Discharge (how much water is flowing) (Upstream or Downstream?)
Downstream
Rocks and gravel
Upstream or Downstream?
Upstream
Sand and Mud
Upstream or Downstream?
Downstream
Rivers dump out sediment when they hit a lake or the ocean, forming a muddy bulge or…..
Delta
Two extreme shapes of deltas
Classic Delta
Birdsfoot Delta
Have very narrow valleys
Fairly straight channels
Young Rivers
Extreme young rivers
Slot canyons
Normal young rivers
V-shaped valley
Rain gets trapped in a narrow valley.
Water level rises and falls quickly.
Flash Floods
Moderate valleys
Gently curved channels
Mature Rivers
Floodplains can be ____ or _____
Narrow or wide
Rivers can get dammed by ice
Water level rises and falls slowly
(Mature Rivers)
Ice-Jam Floods
Very wide flat floodplain
Sinuous (S shaped) or meandering channels
Old River
S shaped
Meandering
Build over time and hold back the river until they suddenly break
Natural levees
Flood risk in Old Rivers
Levee-Burst Floods
Water level rises quickly but takes a very long time to drain away
Levee-Burst Floods
When old rivers get uplifted, they keep their shape and they cut down
Rejuvenated Rivers
Rivers are trapped in crooked narrow canyons
Entrenched meanders
