Chapter 9 Flashcards
HYDROSPHERE
-aqueous envelope of the Earth
-Includes bodies of waters(oceans, freshwater lakes,rivers) & aqueous vapor in the atmosphere
-is the total amount of water on the planet
-Home for many quantic life
-Essential to life (animals & plants)
H2O is __ of our bodies
-H2O covers __ of earth surface
-in__
60%
70%
oceans, lakes, rivers, glacier, etc
If earth were flat, H2O would cover it up
to 3000 m deep
Fortunately, H2O is concentrated in
depressions(deep areas like trenchs) all over earth surface.
Units of Measurement for water consist of?
How many gallons is Once acre foot ?
- Various units e.g., gallons, acre-feet, etc
Once acre-foot = water required to cover one acre of land, one foot deep
-1 Acre-foot = 325,851 gallons
The Hydrologic Cycle:(watch a video on this)
-Describes circulation of H2O falling as rain, flowing to oceans, infiltrating to
groundwater, evaporating back to the atmosphere, condenses & falling back
as rain:
Ocean has __ of H2O on earth, But..?
Remaining__ is fresh H2O
75 % of the 3 % in __?
97 %, salty & not useful to plants & animals
3 %
glaciers ice and snow
Processes (and Rainfall):Evaporation 1
Liquid to vapor below BOILING POINT
(watch video)
Processes (and Rainfall):Sublimation 2
Solid H2O (ice) to vapor directly, mainly on bright, windy days ( snow -> vapor)
(watch video)
Processes (and Rainfall):Humidity 3
Amount of H2O vapor in air (Warm air is more than cold air.)
Processes (and Rainfall):Saturation Point 4
Air is at saturation point when it contains as much H2O as it can hold at that
temperature (T)
Processes (and Rainfall):Relative Humidity 5
-Actual amount of H2O in air relative to saturation point at that temp (T).
Satuartion point:the stage at which no more of a substance can be absorbed into a vapor
saturation temp at which a liquid boils into its vapor phase.
Processes (and Rainfall):Condensation 6
-H2O molecules aggregate(form a group/cluster) about saturation point => called CONDENSATION
Processes (and Rainfall):Dew Point 7
-Temperature at which condensation begins.
Processes (and Rainfall): Rainfall 8
With enough condensation, rainfall occurs!!! (main source of H2O supply)
Condesation can either be cluster on a water bottle or something or alot of water in the clouds
Rainfall is unevenly distributed due to what?
effects of winds & topography (hills & valleys)
-Rainfall is more at the tropics and on windward side of mountains.
(watch five minutes of crash course vid)
Compartments :River is an important geologic agent for:
(1)Water Supply(fresh water)
(2) shaping the landscape by eroding and depositing materials on ground
surface
(3) flooding
To evaluate these effects of a river, we need to know..?
some factors of the river,
e.g., DISCHARGE and GRADIENT
Discharge:
*Amount of water flowing past a point in the river channel for a given period of time.
*Discharge evaluated through the Discharge Equation:
Q = V X A
(Discharge (Q) = Velocity (V) X Cross-sectional area (A))
-Q = Discharge of river in cubic feet of water per second (cfs)
-V = Velocity of water in feet per second (ft/sec)
-A = Area of channel in square feet (ft2)
- Q = 18 cfs, A = 1 sq. yd. (yd2)
V = ?
18?
- Q = 20 cfs, V = 5 ft/min
A = ?
4
In general, the greater the discharge, the better the…?
water supply and more erosion.
1.Velocity - discharge relation
2. Depth - discharge relation
3. Width - discharge relation
How is discharge relation established?
is established by making frequent measurements of the stage and of the corresponding discharge in the river
Gradient:
-Longitudinal profile or side view of a river:
-Gradient = Vertical drop (rise) = 10 /Horizontal distance (run) 100
(look at image)
The smaller the gradient, the…?
less the level of erosion
Features of stream:Erosional
Meander: S-shaped features along river
-Oxbow lake: Erosion and deposition produce tight meanders and eventually
oxbow lakes form
Features of stream:Depositional
-Alluvium: Sediments deposited by streams
-Deltas: Triangular shaped sediments found where water runs into standing bodies
of H2O
*Usually good as reservoirs for H2O (aquifers) and oil
Features of stream: Various shapes
1.Stream - dominated
2. Wave - dominated
3.Tide - domintated
FLOOD PLAINS:Gradient of a stream ___ in its lower reaches.
decreases in its lower reaches
Flood Plains: High precipitation may provide what?
large volumes of H2O to cause flooding in
these reaches(watch video)
What are flood plains
The FLAT AREAS flanking the valley, on which sediments are deposited
during flooding are the flood plains.
(watch video)(basically the flat areas right next to a valley at which water flows, there are seidments deposited on those areas making them flood plains
Flood Plains:Flooding: Read up more about it
From May through September of 1993, major and/or record flooding occurred across North Dakota, South Dakota, Nebraska, Kansas, Minnesota, Iowa, Missouri, Wisconsin, and Illinois. Fifty flood deaths occurred, and damages approached $15 billion. Hundreds of levees failed along the Mississippi and Missouri Rivers
