10: Landforms Made by Running Water Flashcards
flowing waters
fluvial systems
most dominant and effective agent of erosion and deposition
moving water
land-sculpting agent
- moves sediments and shapes landforms
running water
one of the four active agents of denudation
erode, transport, deposit sediments
water
four active agents of denudation
- water
- wind
- waves
- glacial ice
applied to the processes and landforms associated with the action of running water
fluvial
can erode and transport soil particles from slopes and uplands causing soil erosion
Fluvial processes
Rates of and soil formation are in equilibrium on the slopes of most natural landscapes.
geologic norm
Disturbance of this
equilibrium (geologic norm) by human activity or natural catastrophes
accelerated
erosion
difference of alluvium and colluvium
colluvium - eroded soil particles are deposited immediately at the base of slopes
alluvium - enter streams and are carried downstream before being deposited along valley floors
Soft materials can be
effectively eroded by __, while hard bedrock materials can only be eroded by __
hydraulic action, abrasion
3 ways stream load or sediment carried by a stream is transported
which is the largest?
dissolved load, suspended load (largest), and bedload
Stream capacity to carry solid sediment is dependent
on ___, which, in turn, is dependent on channel gradient.
stream flow velocity
Streams tend to a ___ over time such that the channel gradient and stream capacity are adjusted to move the average amount of water and sediment
supplied by slopes.
graded condition
2 Indicators of a graded condition
development of a floodplain and a smooth stream profile
Grade is maintained as landscapes are eroded toward base level
and, in tectonically stable areas, erosion can eventually lead to the formation of a __
peneplain
involves lateral channel shifting by bank erosion on the outside of channel bends and deposition of alluvium in point bars on the inside of channel bends
results in valley widening and the development of alluvial meanders
Floodplain development
large rivers with low gradients and wide floodplains
alluvial rivers
Meandering or lateral shifting of alluvial rivers produces ___
cutoff meanders, oxbow lakes
Tectonic and environmental changes can cause __ and __ in alluvial rivers and lead to the formation of __ and alluvial terraces and entrenched meanders
aggradation and degradation
alluvial terraces and entrenched meanders
very effective in shaping desert landforms because of the sparse vegetation cover
Fluvial processes
3 distinctive fluvial landforms of arid regions
alluvial fans, pediments, and playas
