streams environmental science section 3 flashcards unfinished

flowing surface water contained within a channel

rivers

larger streams

headwaters

upper portion of a river or stream where it originates.

mouth

lower part of stream where it flows into another body of water.

tribituaries

smaller streams or rivers that flow into a larger river

gradient

change in elevation/distance

velocity

speed and direction of moving water (m/s)

cross sectional area

area of stream channel occupied if the channel was sliced in half (width x avg depth)

discharge

volume of water passing a particular location within a designated time

does discharge increase or decrease downstream

increase due to tribituaries combining into the stream

physical weathering

breaks rocks without altering composition

chemical weathering

alters composition, water is important due to polarity

erosion

removes and transports sediment

deposition

when sediment settles in a new location

sediment load

material transported by a river/stream

competence

largest particle size a stream can transport

capacity

total amount of sediment a stream can transport

Do larger particles deposit first or smaller ones?

larger particles first due to energy

meander

bend or curve in river channel

cut bank

occurs on the outside of the meander (erosion)

point bar

occurs on inside of meander (deposition)

oxbow lake

sediment cuts off bend from main channel

floodplain

flat land adjacent to river that periodically floods

floods can…

redistribute minerals

widening/ narrowing stream channels

impact velocity

streams are narrow, steep, with coarse sediment

headwaters/ top of stream

downstream the channel becomes

wider, smaller sediment, near mouth

near mouth of stream there is

high discharge, low gradient, deposition

delta

when sediment accumulates faster than waves/ tides/ currents remove it, the sediment builds outwards into a fan shaped deposition called a delta