WaterCycleReview.ppt Civil Engineering Notes

Water Civil Engineering Notes for Diploma students

1. Water Cycle
Bell Work:
Where does the water
cycle get its energy
from?

2. What is the water cycle?
•The water cycle describes the
existence and movement of
water on, in, and above the
Earth.
•Water is always in motion
•Water is always changing states
–Liquid
–Solid
–gas

3. Hydrologic Cycle
•The water cycle can also be called the Hydrologic Cycle…
WHY?
•Since the water cycle is truly a "cycle," there is no beginning
or end.
•Water can change states among liquid, vapor, and ice at
various places in the water cycle
•These processes have been happening over millions of years.
•The water in the apple you ate yesterday may have fallen as
rain half-way around the world last year or could have been
used 100 million years ago by Mama Dinosaur to give her
baby a bath.

4. Components of the Water Cycle
•Water storage in oceans
•Evaporation
•Sublimation
•Evaporation
•Water in the atmosphere
•Condensation
•Precipitation
•Water storage in ice and snow
•Snowmelt runoff to streams
•Surface runoff
•Stream flow
•Freshwater storage
•Infiltration
•Ground-water storage
•Ground-water discharge
•Springs

5. Water storage
•96.5% of the water on
earth is in the oceans
•3.5% of the water on earth
is fresh
•90% of the evaporated
water contained in the water
cycle came from the ocean
•Ice caps and glaciers

7. Evaporation
•Evaporation is when the sun heats up water
in rivers or lakes or the ocean and turns it into
vapor or steam.
 
•The water vapor, or steam, leaves the river,
lake or ocean and goes into the air.
•90% comes from oceans, seas, lakes and rivers
•10% comes from plants: transpiration
•Humidity
•Evaporation removes heat from the
environment: HOW??
•Once evaporated, a water molecule spend
about 10 days in the air.

10. Sublimation
•Sublimation: The change of snow
or ice to water vapor without melting
•Solid  gas
•High amounts of energy is
needed….Where would this energy
come from???
•South side of Mt. Everest:
–Low temperatures
–Strong winds
–Intense sunlight
–Low air pressure

11. Transpiration
•Transpiration is the process by which plants lose
water out of their leaves.
 
•Transpiration gives evaporation a bit of a hand in
getting the water vapor back up into the air
•Moisture is carried through plants from roots to
small pores on the underside of the leaves, where it
changes to vapor and is released to the atmosphere.
•A large oak tree can transpire 40,000 gallons of
water a year.
•Factors that effect Transpiration:
–Temperature
–Relative humidity
–Wind and air movement
–Soil-moisture availability
–Types of plants

13. Water in the atmosphere
•The atmosphere always
contains water
•Tiny water particles are too
small to see UNLESS….
•Clouds
•Superhighway used to
move water around the
globe

14. Condensation
•Condensation: Water vapor in the air gets cold
and changes back into liquid, forming clouds.
 
•Responsible for the formation of CLOUDS
•Vapor  liquid
•Condensation is the opposite of evaporation
•Fog
•Moisture on your windows or drink
–Water vapor in the warm air, turns back
into liquid when it touches the cold glass

17. Precipitation
•Precipitation:
  Occurs when so
much water has condensed that
the air cannot hold it anymore.
 
•The clouds get heavy and water
falls back to the earth in the
form of rain, hail, sleet or snow
•Millions of cloud droplets are
required to make a single
raindrop

18. Precipitation Rates Vary by location

19. Surface Runoff
•Surface Runoff: Occurs as precipitation travels
over the soil surface to the nearest stream channel.
•Run over the soil and collect in the oceans, lakes
or rivers where the cycle starts
•Ground saturation
•Flash flood
•Deposition can happen during this time….What
was that??
•Dangerous time for pollution to occur

21. A
watershed is
an area of
land where
all of the
water that
falls in it and
drains off of
it goes into
the same
place.

22. Groundwater
•A portion of the water that falls as precipitation
can infiltrate (seeps into) the subsurface soil and
rock.
•Used by plants and burrowing animals
•Keeps soil cool during the summer

23. Groundwater
Permeable
Layers
Impermeable
Layer
Unsaturated
Zone
Water Table
Solid Rock
Unconnected
Pores
Air
Water
Saturated Zone

24. Water Table
•The top of the surface where ground water occurs is
called the water table

25. Aquifer
•An underground layer of water-bearing porous
stone, earth, or gravel

26. Groundwater
Artesian Well
Aquifer
Impermeable
Rock
Well
Dry
Well
Aquifer
Water
Table
Aquifer
Spring