EESA01 Lecture5-2011-compressed - EESA01
Lecture
5


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Unformatted text preview: EESA01
Lecture
5
 Energy,
Hydrology
and
Freshwater
 Resources
 October
17,
2011
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 1
 Mid‐Term
 •  •  •  •  •  •  •  •  •  Monday,
October
24
at
5‐7
pm
in
the
following
rooms:
AC223,
 AA112,
and
HW216.
 Surname
begins
with
A‐L:
AC223
 Surname
begins
with
M‐T:
AA112
 Surname
begins
with
U‐Z:
HW216
 Mid‐term
is
ALL
mulQple
choice.

 About
60
quesQons
(not
yet
complete).
 Worth
25%
of
your
final
grade.

 Anything
including
up
to
what
I
get
through
today
(and
its
 associated
readings)
is
fair
game
for
the
mid‐term.

Also,
material
 from
tutorials/assignments
1
AND
2
are
also
fair
game.
 Reminder:
There
are
NO
make‐ups
for
the
mid‐term.

If
you
miss
 it,
you
will
get
ZERO
unless
you
have
an
extremely
valid
excuse.


 Lecture
5
–
Water
Science
and
Freshwater
Resources
 2
 Some
Reprieve
 •  All
students
are
allowed
to
bring
ONE
8
½
 x
11”
sheet
of
paper
with
equaQons
on
 ONE
SIDE
as
a
“crib
sheet”.

 •  The
sheet
can
ONLY
have
equaQons
on
it
 and
you
can
also
write
what
each
 component
in
the
equaQon
is.

 •  If
you
include
anything
else,
your
crib
 sheet
will
be
taken
from
you
during
the
 mid‐term.
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 3
 Example:
Easy
QuesQon
 The
human
populaQon
is
approximately:

 a)  1.5
million
 b)  6.5
million
 c)  1.5
billion
 d)  6.9
billion
 e)  10
billion
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 4
 Example:
Slightly
harder
 Rocks,
wind,
temperature,
and
insolaQon
are
 all
examples
of:
 a)  Renewable
resources
 b)  Biodegradeable
materials
 c)  Non‐renewable
resources
 d)  AbioQc
environmental
factors
 e)  BioQc
environmental
factors
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 5
 Example:
Just
a
bit
harder
 If
a
populaQon
roughly
doubles
over
50
 years,
its
growth
rate
would
be
close
to:
 a)  1.5%
 b)  5%
 c)  10%
 d)  20%
 e)  25%
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 6
 Example:
Quite
a
bit
more
 applied
 (d) (c) (a) (b) In
the
above
figure,
(a)
is
Earth
during:

 a)  December
 b)  The
winter
 c)  The
summer
 d)  A
Qme
of
intense
insolaQon
 e)  A
Qme
of
changing
Qdal
forces
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 7
 Example:
CalculaQon
Problem
 A
surface,
which
is
32°C
is
emiing
energy
at
a
 rate
of
390
W
m‐2.

Given
that
the
Stefan‐ Boltzmann
constant
is
5.67
x
10‐8
W
m‐2
K‐4,
 what
is
the
emissivity
of
the
surface?
 a)  1.3
 b)  0.79
 c)  6600
 d)  23
 e)  0.23
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 8
 Example:
Follow‐up
QuesQons
 Is
this
surface
a
“black
body”?
 a)  Yes
 b)  No
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 9
 Energy
Flux
 •  The
rate
(amount
per
Qme)
of
energy
 (Joules)
received
at
a
surface
is
called
Power
 (J
s‐1).

This
is
a
Wan
(W).
 •  Power
per
surface
area
is
an
Energy
Flux
 and
is
measured
in
W
m‐2.

 •  The
rate
of
energy
emined
by
a
substance
is
 governed
by
the
Stefan‐Boltzmann
Law.

 QR = εσT 4 σ = 5.67 x 10-8 W m-2 K-4 Lecture
5
–
Water
Science
and
Freshwater
Resources
 10
 Solar
Constant
 •  DefiniQon:
the
rate
at
which
insolaQon
is
received
 at
the
outer
atmosphere
of
Earth.
 •  Solar
constant
=
1367
W
m‐2
 •  Energy
hiing
Earth
averages
342
W
m‐2.
Why?
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 11
 LaQtude
Controls
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 Figure 13.4 12
 Earth’s
Energy
Balance
 •  The
Sun
emits
shortwave
radiaQon
(K),
 whereas
the
Earth
emits
longwave
radiaQon
 (L).
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 13
 Albedo
and
Available
Energy
 •  Earth
reflects
about
30%
of
the
insolaQon
it
 receives
and
another
20%
or
so
is
absorbed
in
the
 atmosphere.

 •  This
reflecQvity
is
termed
albedo.

 •  0
≤
α
≤
1
 •  Albedo
is
related
to
a
substance’s
properQes
:
 snow
has
high
albedo
(0.8‐0.95)
whereas
asphalt
 has
low
albedo
(0.05‐0.1).
 •  The
50%
of
available
energy
that
Earth
absorbs
 goes
toward
important
processes
like
 photosynthesis
and
driving
our
climate
(i.e.,
 through
evaporaQon,
winds).

 Lecture
5
–
Water
Science
and
Freshwater
Resources
 14
 What
Takes
More
Energy?
 1.  Raising
the
temperature
of
a
glass
of
 water
by
1°C.

 2.  Raising
the
temperature
of
a
glass
of
 water
by
50°C.

 3.  Changing
ice
at
0°C
into
water
at
0°C.

 4.  Changing
water
at
100°C
into
water
 vapour
at
100°C.
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 15
 What
Happens
to
the
Energy
 •  3
main
uses
of
the
70%
of
insolaQon
that
 is
absorbed
by
Earth
and
its
atmosphere:

 1.  HeaQng
the
ground
(ground
heat
flux)
 2.  Providing
warmth
(sensible
heat
flux)
 3.  Changing
phases
of
water
(latent
heat
flux)
 •  Sensible
and
ground
heat
can
be
 measured
by
a
thermometer
whereas
 latent
heat
cannot;
it
is
“hidden”
energy.
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 16
 Desert/Oasis
Example
of
Energy
 ParQQoning
 Oasis Desert Lecture
5
–
Water
Science
and
Freshwater
Resources
 17
 The
parQQoning
of
energy,
 especially
toward
latent
energy,
 is
fundamental
to
global
 HYDROLOGY
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 18
 What
is
Hydrology?
 •  DefiniDon:
The
science
of
water,
its
global
 circulaQon,
distribuQon,
and
properQes,
 specifically
water
at,
near,
or
below
Earth’s
 surface.

 •  Hydrologic
Cycle:
A
simplified
model
of
 the
flow
of
water,
ice,
and
water
vapour
 from
place
to
place.
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 19
 Key
Processes
in
the
Hydrologic
 Cycle
 1.  PrecipitaDon:
The
condensaQon
of
water
vapour
in
 the
atmosphere
resulQng
in
its
return
to
Earth’s
 surface.
 2.  EvapotranspiraDon:
The
release
of
water
into
the
 atmosphere
through
a
combinaQon
of
phase
change
 from
open
surfaces
and
release
of
water
vapour
by
 plants.
 3.  InfiltraDon:
PenetraQon
of
water
through
the
soil
 surface.
 4.  Runoff:
The
flow
of
water
across
or
under
Earth’s
 surface
under
the
force
of
gravity.
 5.  Groundwater
Flow:
The
movement
of
water
beneath
 the
water
table.
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 20
 The
Hydrologic
Cycle
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 21
 Key
Points:
Global
Hydrologic
 Cycle
 1.  More
water
evaporates
from
the
ocean
 than
is
returned
by
precipitaQon.

 2.  More
water
is
returned
to
the
surface
of
 conQnents
by
precipitaQon
than
is
lost
via
 evapotranspiraQon.

 3.  The
imbalance
in
points
#1
and
#2
above
 are
resolved
by
runoff
of
water
from
 conQnents
to
the
ocean.
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 22
 What
is
needed
for
it
to
rain?
 1.  Air
needs
to
cool
enough
such
that
water
 will
condense
(needs
to
reach
dew
point).

 –  Dew
point:
the
temperature
at
which
a
given
 parcel
of
air
becomes
saturated
 2.  ParQcles
must
be
present
in
the
atmosphere
 onto
which
water
can
condense
 (condensa0on
nuclei).

 3.  Water
droplets
must
grow
to
a
sufficient
size
 such
that
they
do
not
evaporate
enQrely
 before
reaching
the
ground.

 Lecture
5
–
Water
Science
and
Freshwater
Resources
 23
 The
Key
Point
is
Cooling
Air
 Vapour pressure: the partial pressure of water in the atmosphere. Lecture
5
–
Water
Science
and
Freshwater
Resources
 24
 Air
Cools
by
Lixing
 1.  ConvecDve
liRing:
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 25
 Air
Cools
by
Lixing
 2.

Orographic
liRing:
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 26
 Air
Cools
by
Lixing
 3.

Frontal
liRing:
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 27
 Where
are
most
of
the
Earth’s
 Deserts?

 1.  2.  3.  4.  Around
the
equator.
 Around
the
sub‐tropics.

 Around
the
temperate
zone.

 Near
the
poles?
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 28
 Global
PrecipitaQon
Panerns
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 29
 EvapotranspiraQon
 Key
Controls:
 1.  Energy
 2.  Gradient
in
 vapour
pressure
 3.  Wind
 4.  Resistance
from
 plants
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 30
 Runoff
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 31
 The
Water
Balance
 Inputs
–
Outputs
=
Change
in
Storage
 OR
 I
–
O
=
ΔS
 Inputs:
PrecipitaQon
(rain
AND
snow)
 Output:
EvapotranspiraQon,
Runoff
 (streamflow)
 Storage:
Groundwater,
soil
moisture,
lakes
 and
reservoirs,
rivers
and
streams.
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 32
 A
Catchy
Tune?
 To
help
you
remember
the
water
cycle:
 hnp://www.youtube.com/watch? v=T05djitkEFI&feature=related
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 33
 What
is
there
more
of?
 1.  2.  3.  4.  Fresh
water
in
lakes.
 Fresh
water
in
rivers.
 Fresh
water
belowground?
 Fresh
water
frozen
in
glaciers
and
ice
 caps?
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 34
 Fresh
Water
is
VERY
Limited
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 35
 Rivers
 •  Watershed
 •  Drainage
Divide
 •  Tributaries
 •  Stream
Order
 Lecture
5
–
Water
Science
and
Freshwater
Resources
 36
 Wetlands
 •  •  •  •  •  •  •  Lecture
5
–
Water
Science
and
Freshwater
Resources
 Marshes
 Swamps
 Peatlands
 Prairie
Potholes
 Habitat
 Drainage
 Ramsar
ConvenQon
 37
 Lakes
and
Ponds
 Linoral
zone
 Benthic
zone
 LimneQc
zone
 Profundal
zone
 Oligotrophic
vs
 eutrophic
 •  Hypolimnion
 •  Turnover
 •  •  •  •  •  Lecture
5
–
Water
Science
and
Freshwater
Resources
 38
 Groundwater
 •  Aquifer
 •  Water
Table
 •  Confined
vs.
 Unconfined
Aquifer
 •  Recharge
vs.
 Discharge
Zones
 •  Artesian
Well
 Figure 11.5 Lecture
5
–
Water
Science
and
Freshwater
Resources
 39
 ...
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This note was uploaded on 02/29/2012 for the course ENVIRONMEN eesa01 taught by Professor Mitchel during the Fall '11 term at University of Toronto- Toronto.

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