Land and Water
JoAnn Lawall Grade 4
Goodnoe Elementary School
3/15/11

Overview video
 Model – how
scientists represent
complex events to
help understand them
better

Fresh water – about
2.8% of the world’s
water
The Water Cycle – it’s a continuous
process (Lesson 1 & 2)
Precipitation
Evaporation
Condensation
 Water
cycle.html
The Water Cycle

Precipitation


Clouds gather excess
water
Water falls back to earth
•
•
•
•

Hail
Rain
Snow
Sleet
Drought – long periods
without precipitation
The Water Cycle

Condensation





Water vapor rises
Cold air forms in the
atmosphere
Water vapor clings to
particles of dust
Cold air turns droplets
to particles
Droplets combine to
form clouds
The Water Cycle

Evaporation



The sun heats the
earth
Water changes to gas
(water vapor)
Minerals are left
behind
Other related concepts…
Transpiration – plants
“sweat” or lose water
into the atmosphere
 Hydrologist –
scientists who study
water on the earth
and in the
atmosphere
 Geologist – scientists
who study landforms

Watershed
Modeling Rain

Precipitation – it goes
several places




surface waters
(streams, lakes,
oceans, etc.)
the ground
evaporates into water
vapor
Runoff of impervious
surfaces and saturated
land
Examining Earth Materials
(Lesson 5)
 Two
types of matter
 Inorganic – weathered rock
fragments; never alive
 Organic – living and decaying plant
and animal materials
Four Soil Components

Gravel




Inorganic
Heaviest, biggest
particles
Colored - tan, white,
brown, gray
Sinks in water
Four soil components continued…..
 Sand






Inorganic
Lighter than gravel
Grainy texture
Colored – white, gray,
tan
Clumps in water
Floats
Four soil components continued…
 Clay





Inorganic
Lightest soil
Powdery
Orange-brown
Suspends in water
Four soil components
continued…….
 Humus






(top soil)
Organic
Loose texture
Large and small
pieces
Holds a lot of water
Clumps
Floats, then sinks
Where Does Water Go?
(Lesson 6)

Water seeps into
ground between soil
particles or pore
space under the force
of gravity
 Pore space – space
between soil particles
 Gravity – force that
pulls matter to earth
Where Does Water Go?
 Impervious
– layers of rock, water flows off
or around it
 Runoff – water that flows over land
 Compaction – the degree to which soil
packs together
Water Table

Underground
boundary between
zone of saturation
(land filled with water)
and the zone of
aeration (land filled
with air and soil.)
Investigating Streams

Origin of streams
 Flowing water or precipitation
 Melting snow and ice
 Underground springs
• Water that flows out of cavities or caves
(aquifers)
• Groundwater discharge
Investigating Streams continued….
 Different




forms of streams…..
Rivulets – tiny channels that form gullies
Gullies – deeper channels
Tributaries – small stream branches
Rivers – joined streams and tributaries
Investigating Streams continued….
 Parts





of a stream channel (trunk)
Head – top of stream
Delta – triangular –shaped landform created
by deposited sediment
Mouth – where the bottom meets larger body
of water
Floodplain – land left behind after flood waters
drain (often covered after heavy rain flows)
Tributary – branches of stream
Erosion & Deposition
(Lesson 7 & 8)
Aerial drawing –
“bird’s eye view” ;
view of stream model
from above
 Velocity – the speed
of water flow

Erosion & Deposition continued….


Weathering - the process
by which rocks break
down into various earth
materials including soil
Erosion – the wearing
away of land




Wind
Waves
Flowing water or
precipitation
Glaciers
Erosion & Deposition continued….




Deposition – the soil
which is moved by water
Sediment – another way
to describe deposition
Suspension – when fine
particles float in water
and do not dissolve
Load – large amount of
sediment

Causes an overflow of
water
Glaciers

Moving rivers of ice
 Usually only moves a
few inches a day
Modeling Tributaries (Lesson 9)

Stream trunk and its
tributaries act as a
system for draining
land
 Watershed – all of
surrounding area
drained by stream
channel and
tributaries
Hills and Rocks: How Nature Changes the
Direction and Flow of Water? (Lesson 11)
 What
Is An Oxbow Lake? An oxbow is a
crescent-shaped lake lying alongside a
winding river. The oxbow lake is created
over time as erosion and deposits of soil
change the river's course. You can see
how an oxbow lake takes shape below:
Oxbow Lake
Dams: How Humans Change the
Direction and Flow of Water
(Lesson 12)
dams – a barrier that
controls the direction and flow of water
 Flood-control

Main purpose is to hold excess water from a
storm
 Reservoir
is an artificial lake created for
excessive runoff
 Hydroelectric power – stored water
generates electricity
“Dams” continued
– caused by a severe storm which
can cause a stream to overflow its banks
 Flash flood - sudden increase in runoff due
to heavy flood of water
 Levee – high ridges along banks that
prevents or minimize flooding
 Flood
“Dams” continued
– environment in which plants
and animals live and interact
 Irrigation – brings water to farmland
through drainage channels that provides
water for growing crops
 Ecosystem