physio graphs of water Flashcards
u6
rivers are made due to gravity and thermodynamics. how?
precipitation of water from sky hits mountain = gravity causes water to flow down the hill = water accumulates in low areas = erosion forms channels = forms rivers
rivers are ____% of total freshwater
0.006
longest river
nile
largest discharge
amazon
largest drainage
amazon
drainage area definition
land area drained by all tributary systems above a chosen point on a main channel
(where water is being drained from upstream)
what is a watershed
outer boundary of drainage area
what is discharge
volume of water passing through a channel through unit of time
T/F a first order stream is typically larger than a third order stream
false the third one is typically larger
hydrograph plots
discharge vs time
how amount of water changes over time
shape of hydrograph depends on ____ and ___.
hydrographs are also ____ specific
soil and rain event
biome specific
3 ways rainwater reaches streams
overland flow
subsurface flow
groundwater
perennial flow def
flow at all times except during severe drought and receive groundwater at all times
intermittent flow def
flow some of the times, and sometimes receives ground water (seasonal)
ephemeral flow def
flow rarely (only when storms) and never receive groundwater
T/F: humans putting a dam in the middle of a river will cause more variability of river flow
false: dam = less variability of flow = more stable/constant flow
why do meanders (S shaped pattern of rivers form)
alternate areas of erosion and deposition due to different speed of water flowing in different areas
pool riffle features of rivers
regular pattern of shallow, fast areas, alternating with deep, slow areas
braided rivers occur with ____ slopes and ______ sediments
high
non cohesive
confined rivers are ____ channels made by ______ sediments
narrow
unerodable (erode very slowly)
the floodplain is what
the level area near the channel that is flooded during moderate flowt
the floodplain is most common in _____ rivers
lowland/meandering
____ and _____ resist erosion
vegetation and soil cohesion
most bank erosion during ___ flows
high
the composition of the river bed determines
if a river can erode and move sediment
T/F. it’s easier to erode sand compared to clay and gravel
no, clay is smaller = easier to move = faster erosion
gravel is larger but once it’s moving it’s easier to erode
what comprises the “wash load”
the dissolved load and suspended load
(those particles move in/though the water)
why is the material of the bed load, NOT part of the wash load
because those particles move along the bed
T/F: highest concentration of heavy particles at top of water column/river
False
heavy shit like sand and pebbles stay near bottom of river. the lighter materials like clay are easier to move around and are eaqually dispersed through river
T/F a river will always move small particles in the wash load region
false, if there’s not enough flow strength to move the smaller particles in the wash load, they could always move along the bed load
river channel form/shape determined by…
discharge and sediment
