Fresh Water - PAMS-Doyle
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Transcript Fresh Water - PAMS-Doyle
Fresh Water
Fresh Water
• Most of the Earth’s fresh
water is found in moving
water and in standing water.
• Rivers, streams, and springs
are moving water, ponds,
lakes, and swamps are
standing water.
Water Cycle
Where is the rest of the
water?
• Groundwater – the water that remains in the
ground. Eventually flows into the ocean. Some
of this returns to the earth from springs
• Frozen water
– Glaciers
• A. Valley glaciers – long, narrow glaciers that
move downhill between mountain valleys.
• B. Continental glaciers – thick sheets of ice that
covers millions of square km of the earth’s
surface, moves slowly in all directions.
• C. Icebergs – Some are as large as Rhode Island
Valley and Continental
Glacier
Running Water
Pore space
• Surface runoff – the water that enters a
river or stream after a heavy rain or
spring thaw.
• Pore space – the space between
particles of soil. More pore space =
more water it can hold.
• Watershed – a land area in which
surface runoff drains into a river or a
system of rivers and streams.
Standing Water
• Lakes – usually deep depressions in
the earth’s crust filled with fresh
water. Usually where glaciers once
were.
• Ponds – shallow depressions with
fresh water, plants usually
throughout.
• Reservoirs – the most frequently
used source of fresh water. Built by
damming a stream or river and is
protected from polluting by laws.
Lakes, Ponds, and
Reservoirs
POND
RESERVOIR
LAKE
Groundwater
• Present because the types of precipitation
does not stop traveling when it hits the
ground, it moves downward through the
permeable areas
• Permeable: material in which the water can
move quickly, sandstone has a high
permeability rate
• Impermeable: water does not flow through
the ground easily, clay is impermeable
Underground Zones
• When groundwater reaches a layer of
impermeable rock it fills up the pore spaces
above forming a zone of saturation
• Above the water filled zone is an area that is
mostly dry, this drier region where the pores
are filled with air is called the zone of aeration
• The area between these two zones marks the
boundary where the ground is saturated and is
called the water table
Water Table
• When you dig in the soil and reach a point
where the hole fills with water you have
located the water table
• Hills and mountains the water table is deep,
valleys, marshes and swamps the water
table is closer to the surface
• Deserts have a deep water table, while wet
climates have it near the surface
• Water table can change depth when there
are times of drought or heavy rains/snow
fall or if wells are being overused
Wells
• Holes drilled or dug into the water table
• Aquifer: Layer of rock that allows water to pass
freely and moves sideways. Usually layers of
sandstone, gravel, sand or cracked limestone
• Found when a permeable layer gets trapped in
between two impermeable layers
• Is a source of groundwater for wells
• Since the water moves underground over very
large distance it is vulnerable to pollution which
can contaminate the whole aquifer quickly
• Artesian Well: A well from which water flows on
its own without pumping
• Aquicludes: Barriers to groundwater flow
Groundwater Systems
• Springs: water discharges at the surface
where aquifers and aquicludes meet
• Temperature varies from cool to hot, is
generally the average annual temperature
of the region
• Hot Springs: water from deep in earth has
risen
• Geysers: explosive hot springs that erupt
at regular intervals
Groundwater
Composition
• Water can contain compounds that are
not hazardous such as iron (red) or
sulfur (egg smell) compounds.
• Hard Water: Water contains high
concentrations of calcium, magnesium
or iron, common in limestone regions.
It can clog your pipes
• Soft Water: makes soap more slippery,
very little minerals present
Solubility
• Solvent – the substance that does
the dissolving. Water is the
universal solvent.
• Solute: the substance that gets
dissolved
• Solution – contains two or more
substances mixed on the molecular
level, one thing must be dissolved.
• Soluble – can be dissolved.
• Insoluble – cannot be dissolved.
Wetlands
• Wetland: land area covered with water for most of
the year, serves as a filtering system that traps
pollutants, sediments and bacteria, houses birds
and other wildlife
1. Bog: get their water from precipitation only, very acidic soil, grows
unusual plants such as peat moss and the Venus Fly Trap
2. Marsh: form in areas with deltas, grows shallow rooted marsh grasses
which aid in the deposition of silt and sand
3. Swamp: located near streams, contains shrubs and tree’s, after
millions of years the decayed plant material forms coal
Watersheds
• The simple
definition
It's the area of land
that catches rain
and snow and
drains or seeps into
a marsh, stream,
river, lake or
groundwater.
• You're sitting in a watershed now
Homes, farms, ranches, forests, small
towns, big cities and more can make up
watersheds.
Some cross county, state, and even
international borders. Watersheds come in
all shapes and sizes.
Some are millions of square miles, others
are just a few acres. Just as creeks drain
into rivers, watersheds are nearly always
part of a larger watershed
Virginia’s Main
Watersheds
• The three main
watersheds of Virginia
are:
• Chesapeake Bay
• Albemarle Sound of North
Carolina
• Atlantic Ocean via
Mississippi River
I know that you can’t get
much more excited!!!